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Messages - kassy

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Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 25, 2020, 01:56:51 PM »
Winter is finally here, Kotolny Island is really cold!
No it isn't. The quite moderate 10 day forecast is attached below. The icons indicate extent of cloud cover which affect radiative balance. The weather station reports 2m temperatures but those are relative to its elevation of 8m above sea level. congelation land-fast ice

While ECMWF and GFS assimilate this station in their regional forecasts (and CR in turn), it's not at all clear which hPa over the Laptev (925?) is most relevant to the cold experienced by open water (near-surface air is somewhat clamped to surface water temperature).

GFS is currently reporting air temperatures of -4.5, -4.7, -15.9 at the surface, 1000 hPa, 850 hPa respectively at UTC noon today. These bear no immediate relationship to highs or lows at Kotolny (-12. -7).
Can buoys in Laptev validate or improve on SST measurement
That 204672 buoy is in a good location but it does not currently appear in IADP's table!

However 204761 and 204762 do: these are global drifters of type SVP-B, placed by AARI-USIABP (Russian Arctic and Antarctic Research Institute joint US Interagency Arctic Buoy Program). The former is at 75.23 114.88 on 10/25/2020 measuring water temperature at the bottom of the buoy at 0.96ºC. The latter is at 76.78 118.34 showing 1.68ºC.

It seems like 204763 and 204764 are also worthy of consideration. These are at 76.70 111.48 showing -1.68ºC and 79.90 121.38 seeing -0.80ºC. Uniq has picked these up in #538 below.

"These SVP (surface velocity drifters) were standardized in 1991 with small spherical hull, floats and large Holey-Sock drogues 15m below the surface. In 1993, drifters with barometer ports, called SVPB drifters measure sea surface currents, sea surface temperature baryometric pressure and lat/lon."

The hourly data is in .dat format which opens as tab-ready row & column in any text editor. It uses day number instead of dates: 299 is today Oct 25th. The most recent 557 readings from 204761 average 1.36ºC with a range of 0.58 to 4.08 ºC and stdev of 0.97, that is, the buoy has not seen any temperatures below zero and has mostly been around 1.4±1.0 ºC during its drift.
Do direct buoy measurements provide an independent check on the daily SST product from GHRSST?
More likely, the buoy data is assimilated into the product but that's unconfirmed.
Can radiative heat loss be determined from Worldview?
No. Clear weather allows that dramatic definition of heat loss leads via band 15 of Suomi VIIRS along the upper CAA. Note this is calculated from top-of-atmosphere in kelvin and is not suitable for determining overall blackbody heat loss:

"It does not provide an accurate temperature of either clouds nor the land surface, but it does show relative temperature differences which can be used to distinguish features both in clouds and in sea ice and open water over the polar regions during winter (in cloudless areas).... The sensor resolution is 375m, the imagery resolution is 250m, and the temporal resolution is daily."
How unusual is the current pattern of open water?
The image below calculates the frequency of open water at each position on Nov 1st for the seven years 2013-19 (this date in 2012 is not available from AMSR2_UHH). This gives the lightest gray for open water in all seven years, a slightly darker gray for open water in six of seven years and so on. The progression is fairly orderly Chukchi; the Laptev has mostly been frozen over. The pink shows areas that have never before been open on Nov 1st.

The base image is Smos-Smap ice thinness for Oct 23rd. It has an interesting green fringe of presumably nascent ice in the 2-3 cm thinness range. The interior ice thicker than 0.5m has been replaced with OsiSaf ice motion for the same date; the exterior open water has been removed to reveal the historical open water probabilities.

An email to  the nice Dr. Zhang is needed (I have been too busy to write one).
Dr Zhang has confirmed that  the figure on the website is incorrect and our calculated value of 4162 Km^3 is correct.  (the website has not yet  been updated).

"I double checked. Your calculation is correct. We had an error at our end in calculating September mean.
Thanks for the note,

The website has now been updated to 4200, PIOMAS apparently only reports the monthly figure to the nearest 100K.

Policy and solutions / Re: Energy Efficiency: The “First Fuel”
« on: October 23, 2020, 11:00:33 PM »
Here's a story about a town in Kansas (USA) that rebuilt using sustainable methods after being destroyed by a tornado in 2007.

The town that built back green
After a tornado demolished Greensburg, Kan., it rebuilt without carbon emissions. Can its lessons help communities and economies rebound from fires, hurricanes and covid-19?

 By Annie Gowen
October 23, 2020

GREENSBURG, Kan. — After powerful tornadoes swept through Nashville earlier this year, killing 25 and leaving a trail of destruction for miles, one of the first calls officials made was to tiny Greensburg, population 900.

A wind-swept farming community in southwestern Kansas, Greensburg rebuilt “green” after an EF5 tornado — the most violent — barreled through at more than 200 miles per hour and nearly wiped it off the map in 2007.

A decade later, Greensburg draws 100 percent of its electricity from a wind farm, making it one of a handful of cities in the United States to be powered solely by renewable energy. It now has an energy-efficient school, a medical center, city hall, library and commons, museum and other buildings that save more than $200,000 a year in fuel and electricity costs, according to one federal estimate. The city saves thousands of gallons of water with low-flow toilets and drought-resistance landscaping and, in the evening, its streets glow from LED lighting.

Greensburg is no liberal bastion. It sits in Kiowa County, where Trump handily beat Hillary Clinton in 2016, carrying 83 percent of the vote.

But leaders there now are routinely consulted by communities around the world grappling with devastating weather events from wildfires, tsunami, earthquakes and floods — in Australia, China, Japan and Joplin, Mo. In March, the city council member in Nashville wanted to ask what kind of building codes or regulations could make its buildings more tornado-resistant going forward.

Greensburg’s efforts have gained new currency in recent months as climate catastrophes have continued to worsen and Americans struggle with a deadly pandemic that has shut down much of the economy — and begin to rethink what life might look like after a vaccine.

They held meetings in a temporary red-striped tent set up downtown, where townspeople commented on the rebuilding plan. And they stressed the practical savings of installing energy-efficient windows and insulation in new homes. According to a recent NREL estimate, energy costs for a 2,000-square-foot home with standard construction in Greensburg are about $1,820 annually. Adding more insulation, an energy-efficient furnace, LED lighting and a small solar panel system would save 70 percent of the energy use and reduce energy costs to $1,260 in the first year, which includes the additional mortgage costs for the upgrades.

More than a decade later, the town has about 400 modest, newly rebuilt homes — many of them with white-pillared front porches — centered in a small downtown where the key buildings are clustered among a few walkable blocks. There’s the city hall, hospital, courthouse, a commons building with a media center and library and school, all built with green construction features like angled windows that make the most of winter sun, cisterns to collect rainwater for irrigation and geothermal heating and cooling systems.

The green areas on the map above show where wind energy is commercially viable.

The city was able to halve its carbon footprint by shifting to 100 percent wind energy from a 10-turbine wind farm south of town that is owned and operated by Exelon Corp. The turbines, which began operating in 2010, are capable of producing 12.5 megawatts of electricity, enough to power about 4,000 homes, according to Exelon.

Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 23, 2020, 06:57:23 PM »
Have you seen the snow extent growth over Siberia and Western Canada? Anything to comment or you only rejoice on the bad feedbacks?
apart from this, the weather is about to become propitious for a quick rebound of sea ice next week.

This seems like an emotional type response, especially as a reply to such an informative post which did not actually feature any rejoicing...

The previous posts were an actual attempt at figuring out some of the extent of the damage done.

A quick rebound next week would already be late but both recent comments in this thread and in the SIA&E thread hint that the it might not be quick.

You are thinking too much about the area/extent (so 2D) while ignoring the 3D problems like the stall in TPD.

In other words, 2021 and 2022 could be rebound years as probable as big melt years. I don’t see the doom scenario here (more in line with the scientific consensus of 2040+)

In case you missed it we are discussing what we see. Oh and i think that scientific consensus might have shifted a bit...
Yes Kassy it’s an emotional response because I get the feeling people choose to not talk about that, there may be other mechanisms that kick in and explain why the Arctic didn’t completely tank 8 years ago.

Rebound years (08/09, 13/14, 17/18) are surrounded by certain mystery or silence.

Ok I’ll try to open that discussion in another thread.
In any case the posts here lately are excellent, I don’t deny people are well informed, much better than me in any case.

Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 23, 2020, 08:41:20 AM »
What I am trying to bring up is that extent by itself is only an indication of when ice thickening can possibly begin, and with the current extreme delay in the Asian sea ice extent, the ice growth in thickness is being delayed. While historically some areas of the Asian seas have had slow growth in extent, 2020 is the first year on record (as far as I know) that will likely still have an ice free NE passage on Nov 1. (And not just dodging ice, but wide a open sea lane.) The fear is that if this continues much longer even with eventual universal 100% extent on the Asian side, that first year ice will not have a chance for a 'normal' gain in thickness. Instead of >1M ice, much of the Asian sea ice could end the freezing season in a very fragile state leading to much earlier breakup and melt in 2021. Already basically the whole of the Asian side has lost a month of thickness growth, where in previous years a fairly large percentage of those seas had already started that growth.

It is a rough estimate, but if you use the correlation of Freezing Degrees Day (FDD) with ice thickness, you need ~5500 FDD to go to 2m first year ice, and ~3500 FDD to go to 1.5 meters. October is usually worth ~300 to ~400 FDD in the Arctic, so it can make a significant dent into the ice growth.
To give some more numbers, for Ostrov kotel'nyj for example. Mean temperature from 1st of October to 30th of April over the last 10 years (2010-2019) was -20.8°C, which is about 4400 - 4500 FDD. If you count from the 1st of November, this leads to 4100 - 4200 FDD. And if you ignore November and start the ice thickening the 1st of December, it makes only 3800 - 3900 FDD. This is ignoring the risk that oceanic heat flux could be strong enough this winter to weaken this correlation. If ice growth does not start in a hurry on the Siberian side, the winter would probably not be able to fully erase the memory of this melting season. Which is a great peril, as up to the last years, winter was always cold and long enough to at least bring Arctic back to some kind of a "2m FYI" state, helping to stabilize the system.

Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 22, 2020, 09:16:22 PM »
runaway feedbacK? much of Siberian side sea ice could end the freezing season in a very fragile state leading to earlier breakup and melt in 2021. A few days weeks late then catch-up with really fast refreeze (even though graphs of past years don't show this behavior)?
The SST will be nowhere near freezing by the end of the month; indeed air temperatures at -3 aren't cold enough to even move the needle. It takes much deeper longer cold to lower water temperature from +1ºC enough to set the stage at -1.8º for a flash freeze especially if the upper 10m of water is in play (not talking here about a micron at the surface).

The weather system over the next 120 hrs will be bringing in a fair amount of TCW (total cloud water). This again is not conducive to radiative cooling.

I'm wondering if the TransPolar Drift will set up late or perhaps hardly at all. This amount and location of open water heat may feed back on the atmospheric pressure pattern to some extent, undercutting what is needed for persistent TPD winds. If so, export out the Fram would be diminished, mostly to what ice is in the intake funnel now.

Alternatively, since Fram export stopped back in mid-May along with no garlic press and only a quarter turn Beaufort Gyre, something at a much larger atmospheric scale has changed, with late open water only having a secondary effect.

Where is nullschool getting its SST and TCW values from or rather, are there other sources that might be better or at least independent? Hard to say: multiple sources are listed for SST; none for TCW! The latter may be derived from Band 7 (2.1 μm) on Modis where it is called Cloud Water Path at WorldView

Policy and solutions / Re: Nuclear Power
« on: October 22, 2020, 07:33:10 PM »
Instead of spending tens of billions on nuclear plants, spend far less on wind (and solar), put in an extra amount for grid batteries, and spend some change on keeping your coal plants mothballed rather than dismantle them. Then when the dreaded calm cloudy period comes AND WW3 is upon us so the interconnects stop working, use those coal plants for a week.
Achieving this solution will be much cheaper, much quicker, and will emit less CO2 overall.

Consequences / Re: Places becoming more livable
« on: October 22, 2020, 12:26:18 AM »
Farmers across Africa have been regreening the Sahel and reversing desertification for decades.  Crop yields are much higher now than they were in the '80s.

The Age of Humans
The “Great Green Wall” Didn’t Stop Desertification, but it Evolved Into Something That Might
The multibillion-dollar effort to plant a 4,000-mile-long wall of trees hit some snags along the way, but there’s still hope

By Jim Morrison
August 23, 2016

It was a simple plan to combat a complex problem. The plan: plant a Great Green Wall of trees 10 miles wide and 4,350 miles long, bisecting a dozen countries from Senegal in the west to Djibouti in the east. The problem: the creeping desertification across Africa.

Planting trees across the Sahel, the arid savanna on the south border of the Sahara Desert, had no chance to succeed. There was little funding. There was no science suggesting it would work. Moreover, the desert was not actually moving south; instead, overuse was denuding the land. Large chunks of the proposed "wall" were uninhabited, meaning no one would be there to care for the saplings.

Reij, Garrity and other scientists working on the ground knew what Wade and other political leaders did not: that farmers in Niger and Burkina Faso, in particular, had discovered a cheap, effective way to regreen the Sahel. They did so by using simple water harvesting techniques and protecting trees that emerged naturally on their farms.

Slowly, the idea of a Great Green Wall has changed into a program centered around indigenous land use techniques, not planting a forest on the edge of a desert. The African Union and the United Nation's Food and Agriculture Organization now refer to it as "Africa’s flagship initiative to combat land degradation, desertification and drought." Incredibly, the Great Green Wall—or some form of it—appears to be working.

"We moved the vision of the Great Green Wall from one that was impractical to one that was practical," says Mohamed Bakarr, the lead environmental specialist for Global Environment Facility, the organization that examines the environmental benefit of World Bank projects. "It is not necessarily a physical wall, but rather a mosaic of land use practices that ultimately will meet the expectations of a wall. It has been transformed into a metaphorical thing."

Reij, now based in Amsterdam, began working in the Sahel when the soil literally was blowing away during dust storms. After years away, Reij returned to Niger and Burkina Faso in the summer of 2004. He was stunned by what he saw, green where there had been nothing but tan, denuded land. He quickly secured funding for the first of several studies looking at farming in villages throughout Burkina Faso and Niger.

Over two years traveling through Burkina Faso and Niger, they uncovered a remarkable metamorphosis. Hundreds of thousands of farmers had embraced ingenious modifications of traditional agriculture practices, transforming large swaths into productive land, improving food and fuel production for about 3 million people.

Garrity recalls walking through farms in Niger, fields of grains like millet and sorghum stretching to the sun planted around trees, anywhere from a handful to 80 per acre. “In most cases, the trees are in random locations because they sprouted and the farmer protected them and let them grow,” he says. The trees can be cut for fuel, freeing women who once spent two and a half hours a day collecting wood to do other tasks. They can be pruned for livestock fodder. Their leaves and fruit are nutritious.

From 2004 on, they published a series of research papers and reports sounding the call about the transformation. Reij says that by 2011, there were more than 12 million acres restored in Niger alone. More than 1.2 million were restored in Mali, but no one knew until 2010 because no one looked.

The key, Reij says, is scaling up the effort in the drylands countries by building up grassroots efforts, addressing the legal issues (like tree ownership), and creating markets for the products of agroforestry. "We've never seen anything near this size and impact on the environment anywhere in west Africa," Tappan adds. "In our mind Niger already has its great green wall. It's only a matter of scaling it up."

Reij says the World Bank—which has committed $1.2 billion to the effort—the Global Environment Facility and others are convinced natural regeneration is an important way forward, but the approaches are up to each country. At the African Union, Elvis Paul Tangem, coordinator of the Great Green Wall for the Sahara and Sahel Initiative, says that 21 countries now have projects within the framework of the initiative.

Thanks gero.

I've just re-read the first chapter of "The Unnatural History of the Sea" by Callum Roberts and it sketches the living nature that Europeans found in North-America when they first got there.

The descriptions from sailors at that time show a living nature so mind-bogglingly rich as to be hardly believable. Those Europeans couldn't believe their eyes, literally. Already the native american 'indians' lived there for thousands of years of course and living nature was not in any way visibly disturbed.
The Europeans/Settlers destroyed all the riches in about 200 years by taking as much as they could, and then some.

The 'Garden of Eden'.

Gone. Everywhere. Even under water. Wetiko's total destruction.
Such an immense grief comes over me.

 :'( :'( :'( :'( :'( :'( :'( :'( :'( :'( :'( :'( :'( :'( :'(

Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 20, 2020, 10:04:12 PM »
Too much heat stored. May, July, August were the warmest on record north of 70 latitude, June was the 2nd warmest, September the 3d warmest.
Plus too much summer sunshine on low albedo open water in addition to longer term trend marine preconditioning.

Coastal landfast ice ... forget it. It was a big deal 30-40 years ago. It will not grow out significantly and certainly not meet up with the main ice pack. Ice grows primarily all around the periphery of the main ice pack. There's a reason for that: it's colder next to a lateral wall of ice (Fig.1). The ice pack will grow up towards the ESS, eventually separating the Laptev waters from the Chukchi (which will be the very last to freeze, early January).

The second figure adds the ice pack to uniq's Laptev active temperature sensors and deletes the non-reporting devices leaving 6 instruments (plus a few weather stations) reporting on millions of sq km of open water. Too bad the Polarstern had to go in. The Arctic basin is currently 39.8% open water by pixel count.

Revisiting @zlabe's Laptev records, at this point 2020 does not resemble previous record years at all so a new record date is likely, perhaps 2-3 weeks beyond the previous latest freeze-up (Nov 6th).

Looking now at the last 18 days of thickening of new ice at the pack edge with SMOS-SMAP (which can only measure 0.0 to 0.5 m thickness), it's not all that clear how rapidly thickness is progressing to the cutoff (tan color) because cycling winds are moving features around on a daily basis per OsiSaf. Click to animate.

Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: October 20, 2020, 11:47:21 AM »
JAXA ARCTIC SEA ICE EXTENT:  5,066,151 KM2 as at 19-Oct-2020

- Extent gain on this day 66k, 74 k less than the average gain on this day (of the last 10 years) of 140k,
- Extent gain from minimum on this date is 1,511 k, which is 883 k, 37% less than the 10 year average of 2,394 k.
- Extent is at position #1 in the satellite record
- Extent is  434 k LESS than 2019,
- Extent is  939 k LESS than 2016,
- Extent is  1,064 k LESS than 2012
- Extent is  925 k LESS than 2007
- Extent is  1,577 k LESS than the 2010's Average
On average 24.0% of extent gains  from minimum to maximum done, and 143 days to maximum

Projections. (Table JAXA-Arc1)

Average remaining extent gain (of the last 10 years) would produce a maximum in March 2021 of 12.64 million km2, 1.24 million km2 below the March 2017 record low maximum of 13.88 million km2.
Modest upticks in daily extent gain in the last 2 days.
Since 2007,every year's remaining freeze would lead to a record low maximum -except 2019-20.

Sea ice extent is 1.577 million km2 less than the 2010's average. - that is the area of France+Germany+Poland+UK, or more than twice the area of Texas.
That is an awful lot of ice gone missing.
N.B. Click on image to enlarge

Science / Re: 2020 Mauna Loa CO2 levels
« on: October 17, 2020, 10:45:23 PM »
I just added a poll to this thread, because 420 ppm is exactly 50% above pre-industrial and we are approaching this limit in the not too distant future. When exactly - this is up to you to guess.
One option per voter, which cannot be changed.

Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: October 17, 2020, 06:00:03 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

October 16th, 2020:
     4,928,965 km2, a drop of -9,602 km2:o
     2020 is the lowest on record on this date.
     Highlighted the 5 years with a daily lowest min in September. In million km2:
     [ 1) 2012: 3.18,  2) 2020: 3.55,  3) 2019: 3.96,  4) 2016: 4.02  &  5) 2007: 4.07 ].
     In the graph are today's 10 lowest years.

Arctic sea ice / Re: What the Buoys are telling
« on: October 15, 2020, 10:48:20 PM »
A closer look at the Atlantic side temperatures at 80m depth. Max temp has been capped at -0.8C to show detail along the transpolar drift line. This means that some data is not shown fully at the Yermak plateau. I plan to look at that in more detail later.

Antarctica / Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE
« on: October 15, 2020, 09:05:57 PM »
In the linked article, Hansen & Sato discuss how in the past five years, GMSTA has accelerated from the trend line from the past half century:

Title: "Accelerated Global Warming"

Extract: "In the past five years global temperature has jumped well above the trend which has been stable at about 0.18°C per decade for the past half century (see figure above). This deviation is too large to be explained by unforced climate variability."

Consequences / Re: Water wars
« on: October 15, 2020, 07:34:37 PM »
Kitroeff at nytimes on US-Mexico water disputes: this is a war

"The Mexican government was sending water — their water — to Texas, leaving them next to nothing for their thirsty crops, the farmers said. So they took over the dam and have refused to allow any of the water to flow to the United States for more than a month."

"water rights are governed by a decades-old treaty that compels the United States and Mexico to share the flows of the Colorado and Rio Grande rivers, with each side sending water to the other. Mexico has fallen far behind on its obligations to the United States and is now facing a deadline to deliver the water this month."

"this has been one of the driest years in the last three decades for Chihuahua, the Mexican border state responsible for sending the bulk of the water Mexico owes. Its farmers have rebelled, worried that losing any more water will rob them of a chance for a healthy harvest next year."

"activists in Chihuahua have burned government buildings, destroyed cars and briefly held a group of politicians hostage. For weeks, they’ve blocked a major railroad used to ferry industrial goods between Mexico and the United States."

"he never saw himself as the type of person who would lead hundreds over a hill to overwhelm a group of soldiers protecting a cache of automatic weapons. "

“What happened at the Boquilla dam was impressive, because we took off our farmer clothes and put on the uniform of guerrilla fighters.”

" Mexico has fallen far behind on its water shipments to the United States. It now has to send more than 50 percent of its average annual water payment in a matter of weeks. The Mexican government insists it will still comply, despite the takeover of the dam"

"the United States sends Mexico about four times as much water as it receives from its neighbor."

"Mexico’s need for water has grown since the signing of the North American Free Trade Agreement in the 1990s, as more people settled in the country’s dry border region and agricultural production ramped up to satisfy American consumers."

"The National Guard shot Ms. Silva several times in the back "


Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 15, 2020, 05:41:55 PM »
I think it is worth remembering we are living on Earth not Mars... We have a layer of gas above ours heads which is not transparent to IR. Even in the old, dark, dry Arctic of the past it was impossible to radiate an infinite amount of heat to space. There is always an upper limit. A temperature inversion in the low layer, even in Siberia in the 1880s could not have been greater to ~ -25°C. At some point, even in an absolutely dark and dry Arctic a point of equilibrium will be reached. And on top of that amount of heat lost to space is not primarily a function of the temperature at surface, it is not the case, definitively. The temperature at surface is not totally decorrelated from the heat lost to space of course. But there is an atmosphere above surface, in the end. It is Earth here, not Mars... Heat has to go trough the atmosphere before, and there is on the road CO2, CH4, H2O in every states possible, etc... And now that Arctic is providing a lot of heat and moisture, we are seeing a new state where there is a layer of clouds and moisture in the low layers which is isolating the surface, with temperature between 0 and -5°C at 2 meters versus -20°C to -30°C at 2 meters in the case there is no clouds.
Holy mother of Einstein, it is Earth here, not Mars !
The picture which follows is the forecast for Saturday for a given model. It is the minimum for the temperature of brilliance in infrared (10.8 microns) for the all day. Scale is from blue for the warmest (~0°C) to white (~ -40°C) going trough the brown / beige / I don't know which color (-10°C to -20°C). There is also the isolign for the surface temperature of -2°C to roughly approximate the edge of sea ice (more or less, we all see what the shape of sea ice currently). Over Beaufort, yes we are radiating at 0°C (blue color) and we are losing heat to space. But over Chukchi, ESS, Laptev, Kara, Barents, we have a layer of clouds as thick as the troposphere. And the temperature of brilliance is -20°C to -40°C. The temperature of brilliance is more directly correlated to heat lost to space than surface temperature. This really means, this really means, that during the storm, we are not going to radiate heat toward space at ~0°C from the ocean. We are going to radiate heat at -20°C or -30°C or -40°C. And there is a factor 1.5 to 2 between the radiation from a black body at 0°C and a black body at -30°C or something. The heat stirred by the storm is heat at ~0°C, the heat lost to space is heat at -30°C, and there is a ratio of 1.5 to 2 between the two... I made the same map but with the mean of the IR temperature from Friday to Thurday. The ice sheet is high and dry, radiating at -30°C and isolating the ocean at 0°C below. The Beaufort is, yes, a good heat sink fully radiating toward space. But for the siberian side, the clouds are here as the ice sheet, isolating the surface below. Even with a mean over 5 days, almost all the siberian side is forecasted to be isolated.

Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 14, 2020, 12:59:44 AM »
the ice edge is a baroclinic zone --> clouds --> heat retained
Right. Here's a very nice display of historic October extent on the Siberian side that really brings out the unprecedented situation of the current season. The trend is to open earlier, open more, freeze later in this region of the Arctic Ocean.

Yet another fabulous graphic from @zlabe ... such an effective color scheme! Needs an inset map that defines 'Siberian Arctic' though. See above for closely related nice graphic from Geronto.)

Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 13, 2020, 10:58:55 PM »
No idea, I’d say it’s too cold
I would say it's far too warm between the ice pack and the entire Siberian side to even be considering refreezing inroads by Nov 1st. The southern limit of ice has hardly budged since Oct 1st (magenta line) so still has 1200 km to go. The sea surface temperature anomalies are remarkable today and even out nine days to Oct 22nd, per Mercator Ocean.

An immense volume of warm water is still several degrees above the freezing point of salt water from the surface to a depth of 30+m, again out to Oct 22nd, making for some 90,000 cubic km of sea water needing to be cooled (if vertically mixed) by air having only a thousandth the specific heat capacity.

A delayed freeze has significant consequences in terms of thinner, brine pockety ice by spring like it did last year in the wake of the extreme TransPolar Drift

The Chukchi is even slated to get warmer towards the end of the month from incoming advection of yet warmer waters from the Bering Sea. At this rate, the southern Chukchi will remain open water into early or even mid January.

Weakening of Cold Halocline Layer Exposes Sea Ice to Oceanic Heat in the Eastern Arctic Ocean
IV Polyakov, T Rippeth et al
J. Climate (2020) 33 (18): 8107–8123. free full

"The upward release of AW heat is regulated by the stability of the overlying halocline, which we show has weakened substantially in recent years. Shoaling of the AW has also contributed, with observations in winter 2017–18 showing AW at only 80 m depth, just below the wintertime surface mixed layer, the shallowest in our mooring records. The weakening of the halocline for several months at this time implies that AW heat was linked to winter convection associated with brine rejection during sea ice formation. This resulted in a substantial increase of upward oceanic heat flux during the winter season, from an average of 3–4 W m−2 in 2007–08 to >10 W m−2 in 2016–18. This seasonal AW heat loss in the eastern EB is equivalent to a more than a twofold reduction of winter ice growth. These changes imply a positive feedback as reduced sea ice cover permits increased mixing, augmenting the summer-dominated ice-albedo feedback."

Greater role for Atlantic inflows on sea-ice loss in the Eurasian Basin of the Arctic Ocean
IV Polyakov et al
Science  21 Apr 2017  free full

Arctic sea ice is being increasingly melted from below by warming Atlantic water
Tom Rippeth  Prof Physical Oceanography, Bangor ME
September 18, 2020  popularization by co-author of two papers above

"What’s causing this decline in minimum sea ice extent? The short answer is our changing climate. But the more specific answer is that Arctic sea ice is increasingly being thinned not just by warm air from above but by ever-warmer waters from below.

In fact, in a recently published scientific study my colleagues and I looked at why sea ice was melting in the eastern Arctic Ocean and showed that the influence of heat from the interior of the ocean has now overtaken the influence of the atmosphere.

While atmospheric heat is the dominant reason for melting in the summer, it has little influence during the cold dark polar winter. However, the ocean warms the ice from below year-round. Our new research shows that this influence has more than doubled over the past decade or so and is now equivalent to the melting of nearly a meter thickness of sea ice each year.

Further to the east, this warm water has been isolated from the sea surface and so sea ice by a layer of colder, fresher water. However, as the heat blob is getting warmer and moving closer to the surface its influence is now spreading eastwards through the Arctic.

In a second scientific paper we showed that currents in the upper Arctic ocean were increasing, which when combined with declining sea ice and the weakening of the boundaries between layers of warm and cold water, was potentially stirring more warm water from the heat blob towards the surface. The combined impact is a new back and forth relationship between sea ice and ocean heat which could lead to a new ocean climate state in the eastern Arctic Ocean."

Consequences / Re: Drought 2020
« on: October 13, 2020, 03:17:24 AM »
Drought Depletes Paraguay River, a Country's Lifeline

The Paraguay River has reached its lowest level in half a century after months of extreme drought in the region, exposing the vulnerability of a landlocked economy.

Some 85 percent percent of Paraguay’s foreign trade is conducted via the river, which has been depleted because of a lack of rainfall in the Pantanal area of Mato Grosso state in Brazil. The river flows from that area and also runs through Bolivia and Argentina.

The fall in the water level has slowed down cargo vessel traffic on the Paraguay River, causing significant cost overruns for the transport of fuel, fertilizer, food and other imported goods. The crisis has also exposed the precariousness of Paraguay's access to drinking water.

Esteban dos Santos, president of the Paraguayan Shipowners’ Centre, said losses in Paraguay’s river transport sector have already reached US$250 million.

“What worries us the most is that the river is going down at a rate of three or four centimetres (1.2 to 1.6 inches) per day. The navigation situation is critical. In a week, no boat will be able to reach Asunción,” dos Santos said.

Paraguay could face bigger price increases and fuel and other shortages if the situation continues to deteriorate. Wildfires have also broken out in parts of the country because of the dry conditions

Consequences / Re: COVID-19
« on: October 12, 2020, 10:31:02 PM »

Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 10, 2020, 08:56:50 AM »
I guess we are veering way off topic here but here is a quote from a standard textbook on the basic science of global warming, David Archers "Global Warming. Understanding the forecast".

In chapter 7, p 73 f he writes:
A feedback is a loop of cause and effect (Figure 7-1). At the center of a feedback is a state
variable. The state variable in many of the climate feedback loops in this book is the average
temperature of the Earth. To see a feedback in action, drive the temperature a bit by changing
some external factor, like the intensity of the sun. A positive feedback makes the temperature
change larger than it would have been without the feedback, amplifying the temperature change.
A negative feedback counteracts some of the external forcing, tending to stabilize the state
variable. ... A negative feedback is a stabilizer. The drain in the kitchen sink analogy has a
negative feedback to the water level. ... A positive feedback is an amplifier.

He also names a few examples, explained in the attached figure 7-1

An the NASA writes
Climate feedbacks: processes that can either amplify or diminish the effects of climate forcings. A feedback that increases an initial warming is called a "positive feedback." A feedback that reduces an initial warming is a "negative feedback."

What I find strange is - I am with aslan here - that some people are calling well known atmospheric effects "less clear and of more conjectural nature". The greenhouse effect would be totally different without the influence of clouds, water vapor, lapse rate, moist convection ... imho they are not conjectural but basic (basic text-book stuff actually).

Just one example, again  from David Archer (p 62 and fig 6-5):
Even when averaging out the seasonal cycle, the radiative energy budget of a single spot on the surface of the Earth is still probably way out of balance, because heat energy is redistributed around the Earth’s surface by wind and water currents (Figure 6-5). There is a net influx of heat in the tropics as sunlight brings in energy faster than the outgoing IR. It does not get hot enough in the tropics for outgoing IR to balance the incoming sunlight locally. Heat is carried into the cooler high latitudes by warm winds and ocean currents. In high latitudes, the Earth vents the excess tropical heat as excess radiative heat loss to space.

Did I say I think I am going off-topic?  :-[

Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 10, 2020, 03:12:19 AM »
FWIW, the "open water heading into the arctic night = GOOD" argument has always struck me as a violation of Occam's Razor: Less ice, more open water, later and later into the fall just does not seem "good" to me.
It’s not that it is good. It is that there are physical reasons (Stefan-Boltzmann Law) to expect that the more energy you make available now, the more energy will radiate out to space during the NH night.

The net effect is energy loss and therefore another factor to moderate, rather than precipitate, the decline of sea ice in the years to come.

A-Team is conflating this negative feedback effect that he, as scientist, knows well, with other atmospheric effects which are less clear and of more conjectural nature, to produce an overtly alarming picture.
I'll disagree mildly with the last and bolded, and to a lesser degree with how you characterize A-Team's method.

I really can't remember in 7 years where he's seriously overstated an effect or mechanism.

Or even modestly for that matter.

Frankly, I think it is hard to understate the likely impact of warming of the Laptev, ESS, Barents and Kara in particular that took place during the melting season.

I think it's hard to understate the impact of the breakdown of stratification in the peripheral seas on the Atlantic side, along with the enormous influx of heat that's being pulled along by "Atlantification".

Other posters have correctly pointed out that outgoing black body radiation will not be able to dump the heat that's been accumulated, and is *still* being imported by southerlies pulling storms, heat and moisture into the basin from further south.

I think it bears serious watching, as my "hunch" at this point is we will see an extremely anemic refreeze, with a significant reduction in end of refreeze volume, even if those peripheral seas appear to refreeze robustly.  I think the portents for next year are very serious indeed.

Edit:  What we need, desperately, this winter:

- A strong polar vortex
- Crystal clear skies
- Minimal snow on the pack

I'm pessimistic about the probability of any of them.

Policy and solutions / Re: Nuclear Power
« on: October 09, 2020, 08:06:51 PM »
I'm not sure where NeilT's chart comes from or what it's trying to show.  Electricity generation for the UK is measured in the terawatt hours (TWh), his chart shows gigawatts (GW).

Here is an article about the UK's changing electrical generation mix.

Britain’s electricity since 2010: wind surges to second place, coal collapses and fossil fuel use nearly halves
January 6, 2020

In 2010, Great Britain generated 75% of its electricity from coal and natural gas. But by the end of the decade*, these fossil fuels accounted for just 40%, with coal generation collapsing from the decade’s peak of 41% in 2012 to under 2% in 2019.

The near disappearance of coal power – the second most prevalent source in 2010 – underpinned a remarkable transformation of Britain’s electricity generation over the last decade, meaning Britain now has the cleanest electrical supply it has ever had. Second place now belongs to wind power, which supplied almost 21% of the country’s electrical demand in 2019, up from 3% in 2010. As at the start of the decade, natural gas provided the largest share of Britain’s electricity in 2019 at 38%, compared with 47% in 2010.

Besides the reduction in carbon emissions, there was another remarkable shift in Britain’s electrical system during the 2010s. The amount of electricity consumed fell by nearly 15% between 2010 and 2019, with the economy using 50 terawatt hours (TWh) less electricity in 2019 than it did in 2010. That’s enough electricity to power half of Britain’s cars and taxis, if they were all electric vehicles.

Since August 2018, renewables have produced more electricity than nuclear power for 17 months straight. Nuclear fell to less than a fifth of electricity generation in 2019, its lowest level since 2008 due to extended maintenance periods at six nuclear power stations. This helped the annual output of wind energy to surpass nuclear for the first time in 2019.

Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 09, 2020, 01:16:19 AM »
Would really like to see that math
It won't be forthcoming because in addition to imperative cloud considerations, it would also have to explain why the Barents no longer freezes over in winter despite reaching 80ºN where it's also rather cold. Ice may blow in from the Kara or across the FJL-SV line but apparently no longer forms significant sea ice on its own.

Like the Yermak, Barents too receives a branch of Atlantic Water inflows and has largely lost its stratification (previously maintained by fresh water from ice melt); in terms of wind mixing, over a third of the Arctic Ocean (mostly on the Siberian side) has shallower water than the ~300m deep Barents.

The Bering Sea too no longer freezes over in winter despite large water exchanges with the Chukchi -- which still has open water on Jan 1st in recent years. The Chukchi is well over a thousand km south of the Barents and only partly above the Arctic Circle.

There are no instances over the last 7 years of Jan 1st open water in the ESS or Laptev. This year bears watching however for open water persisting after mid-November because of the cumulative impact of double diffusion of Atlantic Waters over the years and the massive solar heat input this July to early low albedo open waters of the Laptev.

The AW brings in enough heat each year to melt all the ice, the question has always been how much of that heat it leaves behind -- more and more per Mercator Ocean and Laptev moorings (Polyakov 2019).

It should not be assumed that all the open water in the Arctic Basin will magically refreeze in winter. As time goes on, more and more open water will persist later and later into the depths of winter. A lot of blackbody radiation (Planck effect) comes right back down so it doesn't have the cooling effect that one might imagine.

It's all about clouds and moisture intrusions from mid-latitude:

Following moist intrusions into the Arctic using SHEBA observations in a Lagrangian perspective
S. Mubashshir Ali  Felix Pithan  19 June 2020

"Warm and moist air masses are transported into the Arctic from lower latitudes throughout the year. Especially in winter, such moist intrusions (MIs) can trigger cloud formation and surface warming. While a typical cloudy state of the Arctic winter boundary layer has been linked to the advection of moist air masses, direct observations of the transformation from moist midlatitude to dry Arctic air are lacking.

"The Surface Heat Budget of the Arctic (SHEBA) and the Norwegian Young Sea Ice (N‐ICE2015) expeditions have shown that the wintertime Arctic boundary layer is characterized by a bi‐modal distribution between a radiatively clear and an opaquely cloudy state. This bi‐modality is also observed in the time series from the ARM site at Utqiaġvik for the boreal winter (F Pithan 2014, fig 10). The two states have different net surface long‐wave radiation (NetLW) as the clear state is characterised by strong long‐wave cooling (NetLW ∼ − 40 W·m−2) under clear skies or ice clouds and the cloudy state with little to no surface cooling (NetLW ∼ 0 W·m−2) under low‐level mixed‐phase clouds."

Cloud Radiative Forcing of the Arctic Surface: The Influence of Cloud Properties, Surface Albedo, and Solar Zenith Angle
Matthew D. Shupe; Janet M. Intrieri
J. Climate (2004) 17 (3): 616–628.  classic paper on subject from co-leader of Mosaic

"An annual cycle of cloud and radiation measurements made as part of the Surface Heat Budget of the Arctic (SHEBA) program are utilized to determine which properties of Arctic clouds control the surface radiation balance. Surface cloud radiative forcing (CF), defined as the difference between the all-sky and clear-sky net surface radiative fluxes, was calculated from ground-based measurements of broadband fluxes and results from a clear-sky model. Longwave cloud forcing (CFLW) is shown to be a function of cloud temperature, height, and emissivity (i.e., microphysics). Shortwave cloud forcing (CFSW) is a function of cloud transmittance, surface albedo, and the solar zenith angle. The annual cycle of Arctic CF reveals cloud-induced surface warming through most of the year and a short period of surface cooling in the middle of summer, when cloud shading effects overwhelm cloud greenhouse effects."

Arctic amplification is caused by sea-ice loss under increasing CO2
Aiguo Dai, Dehai Luo, Mirong Song & Jiping Liu   10 January 2019

"Increased outgoing longwave radiation and heat fluxes from the newly opened waters cause Arctic Amplification, whereas all other processes can only indirectly contribute to it by melting sea-ice. Seasonal sea-ice melting from May to September opens a large portion of the Arctic Ocean, allowing it to absorb sunlight during the warm season. Most of this energy is released to the atmosphere through longwave (LW) radiation, and latent and sensible heat fluxes during the cold season from October to April when the Arctic Ocean becomes a heat source to the atmosphere10 (Supplementary Figure 1)"

Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 08, 2020, 02:25:37 PM »
This article pretty much ignore clouds or overall atmospheric circulation, or anything else, and is just saying that if you remove sea ice, a lot, lot, lot of energy will be radiated to space in winter. Yes of course, nothing new. But it is likely that things will not proceed as linearly. Studies and measures are showing that it seems likely that open water during fall and winter is going to destabilize the PBL. Implying more clouds and moisture, which is going to limit the amount of heat lost to space. And atmospheric circulation, and oceanic circulation, and etc... are also going to respond to an ice free Arctic and establish a new equilibrium which is definitively not going to be the same that "all else equal excepted for sea ice".

Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: October 08, 2020, 11:39:07 AM »
JAXA ARCTIC SEA ICE EXTENT:  4,359,627 KM2 as at 07-Oct-2020

- Extent gain on this day 37k, 53 k less than the average gain on this day (of the last 10 years) of 90k,
- Extent gain from minimum on this date is 805 k, which is 235 k, 23% less than the 10 year average of 1,040 k.
- Extent is at position #2 in the satellite record
- Extent is  291 k LESS than 2019,
- Extent is  820 k LESS than 2016,
- Extent is  136 k MORE than 2012
- Extent is  489 k LESS than 2007
On average 10.5% of extent gains  from minimum to maximum done, and 155 days to maximum

Projections. (Table JAXA-Arc1)

Average remaining extent gain (of the last 10 years) would produce a maximum in March 2021 of 13.25 million km2, 0.63 million km2 below the March 2017 record low maximum of 13.88 million km2.

The chances of daily extent being at a record low for the day by the end of the weekend have increased significantly
N.B. Click  on image to enlarge

The forum / Re: Arctic Sea Ice Forum Humor
« on: October 08, 2020, 05:23:45 AM »
Whatever happened to Covid jokes?

Looks like they are only getting started


Florifulgurator is enrapt...

Antarctica / Re: Pine Island Glacier (PIG) Calving and Discussion
« on: October 07, 2020, 11:26:05 PM »
I take advantage of the fact that the Sentinel2 image of 21/09, which partially covers SWT, was clear to present some considerations on the DZ of SWT:

In the good old days, the PIG forced the SWT to rotate 120° around an Ice Rise and its left part was pushed against this Ice Rise. Sometimes, after the PIG (and the SWT) calving’s, the pressure was temporarily lacking and it could open locally some gaps between the SWT and the Ice Rise, but these openings were without tomorrow and the SWT then approached again to the Ice Rise => no DZ

Now no more PIG, the right side of the SWT has retreated a lot and now its movement is towards the North and tends to straighten up later on by powering up the SIS. In conclusion the left part is completely free, its movement is no longer parallel to the Ice Rise and the SWT is moving away from the Ice Rise => Opening a DZ
And already the Ice Rise it takes advantage of it to expand...

Since the speed with which the SWT moves away from the Ice Rise is maximum upstream, the DZ has started to open upstream to then extend downstream and soon it will be open to the sea. In this case the emptying will be slowed down by the fact that there is an Ice Rumple under the final part of the SWT (for this reason here the icebergs, once calved, wait a long time before moving away definitively), but the complete separation between the SWT and the eastern part of the Ice Rise can be considered as definitive.  In the same way it seems to me that the loss of the pinning point provided by the Ice Rumple with a front, for the SWT, further upstream is inevitable.
I find that we are witnessing a complete dismantling of the PIIS and that it proceeds quickly, too quickly...

You will find three animations:
The first one, very large to give an idea of the whole, contains the images spread out between the 21/10/2016 and the 21/09/2020 an image approximately every 6 months.
The other two limited to the period between 02/03/2019 and 21/09/2020 present two zooms on the DZ: one for the upstream part and the other for the downstream part.

Large images, click to animate

Added: SWT image with notations

Science / Re: Trends in atmospheric CH4
« on: October 06, 2020, 08:35:52 PM »
Here is the latest monthly average of Mauna Loa CH4 concentration:

June 2020:     1872.2 ppb
June 2019:     1858.8 ppb
Last updated: October 05, 2020

This is an annual increase of 13.4 ppb. This is the highest annual increase since February 2015!

I set an index = 100 for the 1980 average [1601.2 ppb]. June 2020 is at 116.9 compared to that index.

Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 06, 2020, 12:41:40 PM »
To illustrate, a set of graph for the period August - Septemeber. Record for Gmo Im. E. K. Federova, breaking its record by 2.2°C (cap Tcheliouskine),or 3.5 sigma above the most recent 30 years mean... And there is ~ 1500 km between Heiss (Polargmo or wmo 20046) and Hatanga (20891), which squared is ~ 2 millions km²

Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 05, 2020, 01:52:13 PM »
Today's images and animation

Consequences / Re: COVID-19
« on: October 04, 2020, 12:06:22 AM »
Hitoshi at japanpolicyforum trsanslated from Gaiko(Diplomacy): see the forest

"The difference was the strategy to suppress the transmission. In short, Japan’s strategy was “to see the forest to understand the whole”. Western countries, including New York City, focused more on seeing the trees instead."

"The core of Japan’s strategy was not to overlook large sources of transmission. By accurately identifying what we call “clusters”, which are sources that have a potential to become a major outbreak, we were able to take measures for the surroundings of the clusters. By tolerating some degree of small transmissions, we avoided overexertion and nipped the bud of large transmissions. Behind this strategy is the fact that, for this specific virus, most people do not infect others, so even if we tolerate some cases go undetected, as long as we can prevent clusters where one infects many, most chains of transmissions will be dying out."

"From Western perspective, it may be unforgivable and unbearable to be in a limbo where you may have been infected but cannot be tested immediately ... Those who criticize this course of action do not see the forest for the trees."

"this is putting into question the ways of Western societies, that have led the world until today, as well as the ways how the entire world should be."

"Western response was to identify cases and completely eliminate the virus. There is a notion of “completely annihilating the evil”. One way that is apparent is that not only politicians but even many academic experts have used war metaphors to talk about COVID-19."

" Japan and other Asian societies have developed a relationship with infectious diseases that contains a sort of resignation, as we had accepted living together with microbes."

"If that question is, “will Japan completely rid of COVID-19?”, then the answer is no ... over the next year or several years, this virus will take root in our society"

"n the short term, we, including Japan, cannot go back to the world before COVID-19. If we relax restrictions a little bit whenever transmissions decrease like the western countries are doing, it would increase transmissions again, and we would be fighting a war of attrition. Repeating that would destroy the economy and society."

"So we need to change the way society works. We need to leverage telework more and need to rethink whether everyone needs to travel to Tokyo for work. Even if we change our behavior adapting to “a new lifestyle”, we need to be prepared for even the worst-case scenario in the long run."

"I think that the next threat will be an influenza pandemic. "

" a globalized world, in other words, an efficient world that prioritizes economic efficiency, is extremely vulnerable to infectious diseases. We are now being challenged whether we want to return to such a vulnerable world even after COVID-19."

"we need to be questioning the old vertical structure where the rich help the poor – where the Western countries create guidelines that get implemented by lower-income countries. "

"it is suggestive that western countries, which have culture of trying to thoroughly eliminate threats of infectious diseases, all trapped themselves into dangerous situations, while Asian and African countries, which have adopted more of a “coexistence” approach, have been able to hold on up to this point. In addition, countries like Japan, China, South Korea, Taiwan, and Vietnam have all been successful with varying approaches. This indicates that the conventional vertical relationship and “one-size fits all” approach no longer make sense. "


Arctic sea ice / Re: MOSAiC news
« on: October 03, 2020, 02:42:58 PM »
And thx to Uniquorn for getting this forum off the ground and contributing so much to buoy and other visualizations!

The wartime secrecy surrounding mundane data such as ship location, ice thickness, experimental layout, timestamps on photos, weather balloons etc etc was astonishing -- who was the enemy?

Not our melt and freeze forums. The enemy was the rest of the scientific community who might, most implausibly, steal data and publish first or worse, publish better. Wars always bring civilian casualties -- here the collateral damage was to public understanding of climate change.

They missed a great opportunity at the north pole, dropping memorializing trash and passing out souvenir water instead of doing scientific work, then rushing on for a short stay at a meaningless secondary floe. This year's ice mobility and melt ponds were especially auspicious for reaching the public, that didn't happen.

The public paid for the entirety of this expedition (includes $25 million from US public). If these scientists wish to do private science, let them pay for it out of their own pocket. In terms of ducking responsibility for public understanding of climate change (stale papers published in 2023 have zero impact), silence from scientists simply does not work.

Mosaic floated the preposterous notion that policy makers will read these 2023 papers and make the needed inferences about climate change abatement. Mosaic is an extreme version of controversy avoidance and seeking the least drama -- the scientists involved are fully aware it's already too late for the Arctic.

AWI is not an educational institution; even though everyone on staff lists themselves as professor, there are no students. Outreach was self-promotional and mis-directed, not overseen by anyone with a scientific background and often wrong.

Anything that went amiss -- and inevitably a lot did given the unexpected drift and floe shifts -- was strictly sanitized to present an unrelenting smiley face to the world. Information did emerge but was scattered all over Twitter and institutional blogs with no central directory.

I've attached their final weather summary. Like all graphics to date, it's done ineptly (eg scaling, wind rose, summary stats). The data going into is attached as a text file if someone wants to work on it. The source web page could disappear with the end of the expedition; the data will be retained but as a deep dive into archival petabytes.

Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 02, 2020, 12:57:06 PM »
Todays update

Reminded me of one of my favorite jokes:

A man inherited a parrot. At first he thought this was a good thing. But the parrot would do nothing but swear. It's language could have offended hardened sailors.

On the first day the man played the parrot soothing music and put its condition down to the stress of moving.

On the second day he tried witty put downs, but the parrots language continued to get worse.

On the third day he ignored it. Nothing worked, the parrot still let forth a torrent of blue words.

On the fourth day he snapped after a particularly creative insult involving his mother, a goat and the local vicar, the man grabbed the parrot and thrust him into the freezer.

For a few minutes the parrot continued unabated. Then everything went quiet. The man, worried that he had killed the parrot, took a peek into the freezer. The parrot hopped out onto his arm and was strangely silent for a minute, and then said:

"I am most terribly sorry, old chap, if I in any way offended you earlier with my choice language, it will never happen again"

The man was speechless, and looked at the bird in disbelief from its change in attitude,

The bird continued:

"By the way....could I just ask......what did the chicken do?"

Antarctica / Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE
« on: September 30, 2020, 03:41:38 AM »
While I disagree with the timeframes cited in the linked reference, I provide the following information for those who are interested:

Garbe, J., Albrecht, T., Levermann, A. et al. The hysteresis of the Antarctic Ice Sheet. Nature 585, 538–544 (2020).

Abstract: "More than half of Earth’s freshwater resources are held by the Antarctic Ice Sheet, which thus represents by far the largest potential source for global sea-level rise under future warming conditions1. Its long-term stability determines the fate of our coastal cities and cultural heritage. Feedbacks between ice, atmosphere, ocean, and the solid Earth give rise to potential nonlinearities in its response to temperature changes. So far, we are lacking a comprehensive stability analysis of the Antarctic Ice Sheet for different amounts of global warming. Here we show that the Antarctic Ice Sheet exhibits a multitude of temperature thresholds beyond which ice loss is irreversible. Consistent with palaeodata2 we find, using the Parallel Ice Sheet Model3,4,5, that at global warming levels around 2 degrees Celsius above pre-industrial levels, West Antarctica is committed to long-term partial collapse owing to the marine ice-sheet instability. Between 6 and 9 degrees of warming above pre-industrial levels, the loss of more than 70 per cent of the present-day ice volume is triggered, mainly caused by the surface elevation feedback. At more than 10 degrees of warming above pre-industrial levels, Antarctica is committed to become virtually ice-free. The ice sheet’s temperature sensitivity is 1.3 metres of sea-level equivalent per degree of warming up to 2 degrees above pre-industrial levels, almost doubling to 2.4 metres per degree of warming between 2 and 6 degrees and increasing to about 10 metres per degree of warming between 6 and 9 degrees. Each of these thresholds gives rise to hysteresis behaviour: that is, the currently observed ice-sheet configuration is not regained even if temperatures are reversed to present-day levels. In particular, the West Antarctic Ice Sheet does not regrow to its modern extent until temperatures are at least one degree Celsius lower than pre-industrial levels. Our results show that if the Paris Agreement is not met, Antarctica’s long-term sea-level contribution will dramatically increase and exceed that of all other sources."

Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: September 29, 2020, 09:17:35 PM »
Forums focus so much on measuring ice area that it's easy to forget sea ice loss is open sea gain. Open water has drastically lower albedo than all the variants of ice (Perovich 2011: snow, rain-on-snow, melt ponds, age etc) so in terms of oceanic heat gain from solar insolation, this gain is highly significant to the extent it matches the insolation season.

The flip side is less solar reflected back out to space, a previous service provided by Arctic Ocean  ice that moderated climate. (Old-timers recall when the Barents, Bering, Greenland and Baffin seas had late season reflective ice too, not just the inner basin.)

This year, open water took up 55% of the surface area of the Arctic Ocean basin by mid-September (based on pixel counts of 0% sea ice concentration on AMSR2_UHH adjusted for conformal projection). That percentage would be higher classifying pixels in the 0-20% range as open water but not by much (~2%). The one million sq km version of BOE has ~85% open water at end season. BOEs can only be understood in their whole-season context, below.

Historically, the match has been very poor so decay of the 'planetary refrigerator' reflectance out to space was somewhat a non-issue. There was not that much open sea area and it formed late in the melt season long after sunshine had peaked. Under incipient BOE however, the lag and mismatch will be dissipating.

The double graph below shows open sea areas on days spaced over the 2020 melt season overlain on the (fixed) surface solar radiation budget (neglecting clouds) restricted to the Arctic Ocean basin. (These years, there's a surprising amount of open water even before the summer solstice. Peak open water in mid-Sept is still quite distant from peak insolation and lingering persistence into October would have no effect on total solar heat seasonal adsorption.)

However solar insolation at 75ºN continues a long ways into the modern melt season at the lower latitudes that matter -- those with the most and earliest open water. Below, the weekly area of open sea can be weighted by its week of solar input on out to the right (ie relevant area under the curve) to see the overall affect which is to disproportionately lift up the left end of the open water graph.

For example, a parcel of open water in back in late May may be small in area but it will be taking in some 16 weeks of insolation at 90+% efficiency including the peak solstice and so exceed a much larger parcel only opening up in mid-August. Sunlight converted to heat will be redistributed in various ways but once converted that incident sunlight cannot be reflected back out to space the way it once was (from higher albedo ice).

Pistone 2019 and Guarino 2020 fast-forward the quantitation (clouds included) to a full-on ever-earlier BOE with catastrophic impacts on climate change amelioration efforts.

Reposting another version of the albedo graphical calculator that has components for ice at various stages in albedo evolution and also for permafrost land. These use 1º latitude bands restricted to surface type; in the limit, band width could go to zero for an integral. The satellite data comes in polar stereographic EPSG 3413 (ofter without netCDF) which only has equal area pixels at 70º.

However pixel counts can be converted to accurate areas by a small latitude-dependent adjustment reaching only 6% at the pole. Thus the first terms of the taylor series expansion of the trig function suffice given the errors elsewhere. For a proper treatment of grid choices, see:

 A Comparison Study of Three Polar Grids
TC Chen et al

The most commonly used reanalyses generated by global data assimilation systems of various operational centers [eg ERA-40) are archived on the rectangular latitude–longitude (EL) grid with a 2.5° latitude  2.5° longitude resolution. Because the radius of latitude circles is proportional to the cosine of the latitude, the circumference of latitude circles reduces toward the Poles. For example, from 47° to 70°N, the circumference of a latitude circle is almost halved.

Meteorological data are often presented using an EL grid on a polar stereographic projection such as EPSG 3413. The analysis quality of some meteorological fields on this grid, such as wind vectors, may be degraded by the convergence of analysis points near the Poles. The closer analysis points allow smaller scales to be resolved, but there is no corresponding increase in constraining observations, so that the added smaller scales may not be weather/climate signals.

Arctic sea ice / Re: The 2020 melting season
« on: September 29, 2020, 12:15:08 PM »
It's a fair question but for me also it is too early to come to a conclusion. Too much movement and not enough data. Next analysis will be yearly paths with 50m temperature to see what that shows. It's likely to be warm pacific incoming from the Chukchi plateau as there is no rough topography at ~78N-140. Maybe the buoys will show us how 'wide' the warmer area is. Mercator at 34m and 92m depth misses the peak. Maybe Aslan can help with that.

OTG has plenty of suggestions ;)

edit: latest data from itp121 is a bit cooler at 50m

%ITP 121, profile 18: year day longitude(E+) latitude(N+) ndepths
2020  273.25141  -138.1066  77.2762  375
2020  273.25303   44   -0.0354   30.0949
2020  273.25311   46    0.3879   30.2224
2020  273.25319   48    0.4206   30.3668
2020  273.25328   50    0.4183   30.5225
2020  273.25336   52    0.2941   30.6820
2020  273.25345   54    0.5035   30.8875
2020  273.25353   56    0.5986   31.0057
2020  273.25361   58    0.5534   31.1116
2020  273.25369   60    0.6788   31.2080
2020  273.25377   62    0.7504   31.2909
2020  273.25385   64    0.9152   31.3495
2020  273.25394   66    0.8092   31.3845
2020  273.25403   68    0.6351   31.4414
2020  273.25411   70    0.3613   31.5064
2020  273.25419   72    0.2022   31.5450
2020  273.25427   74    0.0279   31.5973
2020  273.25435   76   -0.0417   31.6361

Consequences / Re: COVID-19
« on: September 28, 2020, 10:27:29 PM »
kassy, it's a reflection of the evolution of a persons thought process over the past 6 months

Why question something as innocuous as that, one day, while allowing ad hominem screeds and harrassments to go unchallenged for the past 2 days? There's got to be a balance somewhere in between I think.

That was what struck me. There were other comments I made that dismissed what I considered to be over the top concerns. I didn't get it. Didn't understand what was heading our way.

Science / Re: Where are we now in CO2e , which pathway are we on?
« on: September 28, 2020, 08:47:29 PM »
I found the data for the RCP scenario assumptions on the IPCC website.

At that webpage, click on the top link, "Climate System Scenario Tables (Annex II of IPCC 5th Assessment Report, WG1 -- as Excel workbook"

This will open a large Excel spreadsheet with many tabs.  The tabs showing greenhouse gas concentrations by year are 4-1 (CO2), 4-2 (CH4), etc...

Here is the table for CO2:
Table AII.4.1 | CO2 abundance (ppm)                                 
Year   Observed   RCP2.6   RCP4.5   RCP6.0   RCP8.5   A2   B1   IS92a   Min   RCP8.5&   Max
PI   278 ± 2   278   278   278   278   278   278   278         
2011 obs   390.5 ± 0.3                              
2000      368.9   368.9   368.9   368.9   368   368   368         
2005      378.8   378.8   378.8   378.8               378.8   
2010      389.3   389.1   389.1   389.3   388   387   388   366   394   413
2020      412.1   411.1   409.4   415.8   416   411   414   386   425   449
2030      430.8   435.0   428.9   448.8   448   434   442   412   461   496
2040      440.2   460.8   450.7   489.4   486   460   472   443   504   555
2050      442.7   486.5   477.7   540.5   527   485   504   482   559   627
2060      441.7   508.9   510.6   603.5   574   506   538   530   625   713
2070      437.5   524.3   549.8   677.1   628   522   575   588   703   810
2080      431.6   531.1   594.3   758.2   690   534   615   651   790   914
2090      426.0   533.7   635.6   844.8   762   542   662   722   885   1026
2100      420.9   538.4   669.7   935.9   846   544   713   794   985 ± 97   1142

Here is the table for CH4:

Table AII.4.2 | CH4 abundance (ppb)                                                         
Year   RCP2.6   RCP4.5   RCP6.0   RCP8.5   A2   B1   IS92a      RCP2.6&         RCP4.5&         RCP6.0&         RCP8.5&   
PI   720   720   720   720            722   ±   25   722   ±   25   722   ±   25   722   ±   25
2011 obs                        1803   ±   4   1803   ±   4   1803   ±   4   1803   ±   4
2000   1751   1751   1751   1751   1760   1760   1760                                    
2010   1773   1767   1769   1779   1861   1827   1855   1795   ±   18   1795   ±   18   1795   ±   18   1795   ±   18
2020   1731   1801   1786   1924   1997   1891   1979   1716   ±   23   1847   ±   21   1811   ±   22   1915   ±   25
2030   1600   1830   1796   2132   2163   1927   2129   1562   ±   38   1886   ±   28   1827   ±   28   2121   ±   44
2040   1527   1842   1841   2399   2357   1919   2306   1463   ±   50   1903   ±   37   1880   ±   36   2412   ±   74
2050   1452   1833   1895   2740   2562   1881   2497   1353   ±   60   1899   ±   47   1941   ±   48   2784   ±   116
2060   1365   1801   1939   3076   2779   1836   2663   1230   ±   71   1872   ±   59   1994   ±   61   3152   ±   163
2070   1311   1745   1962   3322   3011   1797   2791   1153   ±   78   1824   ±   72   2035   ±   77   3428   ±   208
2080   1285   1672   1940   3490   3252   1741   2905   1137   ±   88   1756   ±   87   2033   ±   94   3624   ±   250
2090   1268   1614   1819   3639   3493   1663   3019   1135   ±   98   1690   ±   100   1908   ±   111   3805   ±   293
2100   1254   1576   1649   3751   3731   1574   3136   1127   ±   106   1633   ±   110   1734   ±   124   3938   ±   334

Arctic sea ice / Re: What's new in the Arctic ?
« on: September 28, 2020, 03:54:14 PM »
Phytoplankton found to begin growing in Baffin Bay as early as February

Annual cycles of phytoplankton biomass

A small international team of researchers has found that phytoplankton resumes growing in Baffin Bay as early as February.

For many years there has been a consensus among marine biologists: phytoplankton ceases growing during the early winter in the Arctic Ocean when ice forms and does not resume growing until the ice melts in the spring. Then when the ice does finally melt, the phytoplankton are thought to explode with growth. In this new effort, the researchers have found that such thinking has been wrong. Phytoplankton can start growing even before the ice above it begins to melt.

... This observation suggests that the explosive growth seen when the ice finally melts is not as explosive as has been thought—the phytoplankton has already been growing for months. The group describes the results in their paper published in the journal Science Advances.

Environmental constraints of Arctic phytoplankton throughout the year.

Achim Randelhoff et al. Arctic mid-winter phytoplankton growth revealed by autonomous profilers, Science Advances (2020)

Policy and solutions / Re: Renewable Energy Transition and Consumption
« on: September 27, 2020, 02:21:10 PM »
EROI was used to compare the energy return on extracting crude from different environments.
Then it was used to compare returns from different fossil fuels. If you want to include it in comparisons with renewable energy I believe you have to widen the discussion to look at what the energy is used for.

Generation of electricity -
Generation from fossil fuels is inefficient. This reduces the effective EROI of fossil fuels.
Wind, and especially solar, is extremely efficient.

Transportation - vehicles
The energy is there to turn the wheels (+ a bit for AC & lights).
A fossil fuel engine is very inefficient. The effective EROI of the fuel is reduced accordingly.
Energy loss from the electricity grid (or rooftop solar) to battery to wheels is low.

How efficient is the oil furnace or gas boiler in an average dwelling?
Industrial use - e.g. gas ovens for ceramics, can be very efficient.
This may be the hardest final nut to crack in full transition to renewable energy.

EROI is only one component of the Asset Life Cycle analysis methodology when applied to energy measurement instead of simply cost. This requires widening the scope. An obvious example is to include the energy wasted from gas flaring during crude extraction. Then you have to add energy from methane leakage from the tens of thousands of abandoned wells, coal mines and coal tips.You can start looking at the energy costs of CO2 emissions - increasing use of AC as AGW takes hold.

Vehicles and power plants are machines. They wear out and will need replacing. It is surely better to replace them with renewable energy based machines than fossil fuel based machines. It is probably only an interim solution as humanity has to come to terms with the other human activities (e.g. the 6th mass extinction) that are also current and / or future existential threats to humanity.
ps: It is far cheaper, quicker and far more efficient to get electricity to the many millions without it by wind and especially solar.

Arctic sea ice / Re: The 2020/2021 freezing season
« on: September 27, 2020, 12:01:10 PM »
  BTV - Could do a version of the bar chart to show change from Sept Minimum to Minimum? 
That would visualize the stats posted by Oren showing what an absolute beast 2007 was.

I think this is what you're after.

Science / Re: Ocean temperatures
« on: September 25, 2020, 06:51:24 PM »
Major Wind-Driven Ocean Currents Are Shifting Toward the Poles

"Satellite observational sea surface temperature anomaly during the last five years (2015-2019), reference to the first five years (1982-1986)". Credit: Alfred-Wegener-Institut/Gerrit Lohmann

The severe droughts in the USA and Australia are the first sign that the tropics, and their warm temperatures, are apparently expanding in the wake of climate change. But until now, scientists have been unable to conclusively explain the reasons for this, because they were mostly focusing on atmospheric processes. Now, experts at the AWI have solved the puzzle: the alarming expansion of the tropics is not caused by processes in the atmosphere, but quite simply by warming subtropical ocean.

To date, experts assumed that processes in the atmosphere played a major role—for instance a change in the ozone concentration or the aerosols. It was also thought possible that the natural climate fluctuations that occur every few decades were responsible for the expansion of the tropics. For many years researchers had been looking in the wrong place, so to speak.

"Our simulations show that an enhanced warming over the subtropical ocean in both the Northern and Southern Hemispheres are the main drivers," says Hu Yang, the study's lead author. These subtropical warming patterns are generated by the dynamic of subtropical ocean gyres, measuring several hundreds of kilometers in diameter, which rotate slowly. These currents are especially well-known in the Pacific, because the majority of floating marine litter is concentrated in them. "Because the currents in the region bring together the surface warming water masses particularly intensely, it's easier for the subtropical ocean surface to accumulate warmth than in other regions—and the same applies to plastic," says Lohmann. As a result of this warming of the subtropical ocean, the tropical warm ocean regions are expanding. According to his calculations, this phenomenon is the catalyst for the tropics expanding to the north and south. "Previous researchers had been taking an overly complicated approach to the problem, and assumed it was due to complex changes in the atmosphere. In reality, it's due to a relatively simple mechanism involving ocean currents."

What led the experts to explore this avenue: data on ocean gyres that they happened to come across five years ago—data on ocean temperatures and satellite-based data, freely available on databases. Both sources indicated that the gyres were becoming warmer and more powerful. "That's what led us to believe that they might be a decisive factor in the expansion of the tropics," explains Hu Yang.

The AWI experts were right: their findings perfectly correspond to actual observations and the latest field data on tropical expansion. Just like in reality, their climate model shows that the tropics are now stretching farther to the north and south alike. In the Southern Hemisphere, the effect is even more pronounced, because the ocean takes up more of the overall area there than in the Northern Hemisphere.

Hu Yang et al, Tropical Expansion Driven by Poleward Advancing Midlatitude Meridional Temperature Gradients, Journal of Geophysical Research: Atmospheres (2020)

Arctic sea ice / Re: The 2020/2021 freezing season
« on: September 25, 2020, 09:26:00 AM »
Well. With Mosaic basically proving that the best piece of ice in the best position on the Atlantic side of the Lomonosov ridge LOST thickness on its entire transit from October to may, from 7m to 5m, through constant bottom melt, and never froze it's soggy core. And now that they can cruise at open water efficiency, from laptev to Fram north of 86 latitude, and never register any fresh freezable layer...
 There appears to be no such thing as a Arctic sea ice freezing season anymore in this half of the Arctic basin.
Therefore I suggest a poll to rename this forum the SiAlCa sea ice forum. Hopefully there will be a few years while those elements hydrated minerals can still stay cold enough to remain solid on those sectors polar seas. Unlike Venus.
Wry and somewhat twisted that this bad half joke may sound.

On the Atlantic side, it is looking like that the halocline has taken a serious hit. And the weather is totaly nuts on the russian islands. As of the 24th, the record of the most crazy anomaly is probably for Ostrov Golomnjannyj. The current mean temperature, 4.7°C, is 4° (!) above the old record of 2012, and even 2°C above the warmest month ever recorded, August 1932. Every day have broken their daily record, 15 days had a Tx above the old monthly record, and even one Tn was above the monthly record of Tx... And all of this with 71 mm of rain (and I mean, really rain, liquid water at 5°C), wich is more than three time the normal monthly precipitation amount. From Ostrov Heiss to Ostrov Kotel'Nyj, crossing Khatanga and Ostrov Vize, mean monthly temperature are going to be 2 to 4°C above previous record, and going to be more than 3 sigma above normal. Seing such and anomaly over such an area (we are speaking of something like more than 2 millions of km² or 0.5% of Earth surface) for a monthly mean is unprecedent.

2020 SMB + Melt from June to Sept 22


click to play, or you can download it by clicking on the filename below the image and then run it offline on an app of your choice.

Policy and solutions / Re: Renewable Energy Transition and Consumption
« on: September 22, 2020, 06:27:00 PM »
 I used EROEI in trying to calculate how much energy was used to create electric gardening tools and the solar / battery necessary to power them verses how many food calories could be produced with those tools before they wear out and need replacing. And since I am lazy all I learned is it takes a lot of food calories to equal even the small amount of power needed to manufacture batteries, metal, and solar cells for one small electric tiller.  Several seasons of food calories worth so you need your equipment to last several seasons more to come out ahead. I think doing the same calculations for calorie payback of large items like tractors would result in manufacturing energy that never gets repaid in food calories. That is the 10 calories of fossil fuel energy used to manufacture and operate equipment never yields 10 calories of food.
 Maybe I am wrong but if we are going to live without fossil fuels we have to figure out how to feed ourselves with equipment that was manufactured with solar, wind, hydro energy. So we aren’t worried about this problem enough to even calculate the numbers let alone design a way out of it.
 But we are star struck by Tesla making cars with fossil fuel energy just because they use less energy than a car that runs and is manufactured with fossil fuel. Because we are addicted to driving around in big metal boxes we rationalize using less energy as good enough and we believe that the manufacturing can someday also be converted to solar/ wind sources. Maybe so maybe not but I would like someone with some solid numbers, or something like the science Oren expects out of Ralfy to spell it out for me.
 Maybe I am a simpleton but if the energy it takes to smelt shovel and hoe blades never repays itself with food calories then nothing else is going to ever pay back. Again maybe I am a simpleton but if we can’t prove a very simple food system ever repays it’s energy debt then how do we think we can rationalize Tesla sized fossil fuel manufacturing that never produces any calorie returns at all. 
 We got here because some farmer figured out how to grow more calories than he needed and civilizations were developed on the excess. Now run that calculation back to where those first farmers succeeded. Slaves and beasts of burden were our power sources. The smelting of metal allowed plows to improve but the energy in extra food calories produced still was net positive I suppose. Somewhere when we went steam and coal the numbers went upside down and building bigger and bigger machines with more and more fossil fuel energy has resulted in more and more food but a very upside down EROEI. 
 To deconstruct we would start over but instead we are trying to repower the monster. If the top ten percent had to grow their own food without using any fossil fuel , slaves or beasts of burden our problem would be much smaller and it would only last a decade or two till they all died of starvation.
But we prefer the war machine that civilization created with more borrowed energy. And we will die together.

Antarctica / Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE
« on: September 21, 2020, 06:48:07 PM »
The linked reference indicates that the climate forcing from global aviation is higher than previously assumed by consensus climate science:

Lee, D. S. et al. (2020) The contribution of global aviation to anthropogenic climate forcing for 2000 to 2018, Atmospheric Environment, doi:10.1016/j.atmosenv.2020.117834

Global aviation operations contribute to anthropogenic climate change via a complex set of processes that lead to a net surface warming. Of importance are aviation emissions of carbon dioxide (CO2), nitrogen oxides (NOx), water vapor, soot and sulfate aerosols, and increased cloudiness due to contrail formation. Aviation grew strongly over the past decades (1960–2018) in terms of activity, with revenue passenger kilometers increasing from 109 to 8269 billion km yr−1, and in terms of climate change impacts, with CO2 emissions increasing by a factor of 6.8–1034 Tg CO2 yr−1. Over the period 2013–2018, the growth rates in both terms show a marked increase. Here, we present a new comprehensive and quantitative approach for evaluating aviation climate forcing terms. Both radiative forcing (RF) and effective radiative forcing (ERF) terms and their sums are calculated for the years 2000–2018. Contrail cirrus, consisting of linear contrails and the cirrus cloudiness arising from them, yields the largest positive net (warming) ERF term followed by CO2 and NOx emissions. The formation and emission of sulfate aerosol yields a negative (cooling) term. The mean contrail cirrus ERF/RF ratio of 0.42 indicates that contrail cirrus is less effective in surface warming than other terms. For 2018 the net aviation ERF is +100.9 mW (mW) m−2 (5–95% likelihood range of (55, 145)) with major contributions from contrail cirrus (57.4 mW m−2), CO2 (34.3 mW m−2), and NOx (17.5 mW m−2). Non-CO2 terms sum to yield a net positive (warming) ERF that accounts for more than half (66%) of the aviation net ERF in 2018. Using normalization to aviation fuel use, the contribution of global aviation in 2011 was calculated to be 3.5 (4.0, 3.4) % of the net anthropogenic ERF of 2290 (1130, 3330) mW m−2. Uncertainty distributions (5%, 95%) show that non-CO2 forcing terms contribute about 8 times more than CO2 to the uncertainty in the aviation net ERF in 2018. The best estimates of the ERFs from aviation aerosol-cloud interactions for soot and sulfate remain undetermined. CO2-warming-equivalent emissions based on global warming potentials (GWP* method) indicate that aviation emissions are currently warming the climate at approximately three times the rate of that associated with aviation CO2 emissions alone. CO2 and NOx aviation emissions and cloud effects remain a continued focus of anthropogenic climate change research and policy discussions.

Consequences / Re: The Climatic Effects of a Blue Ocean Event
« on: September 18, 2020, 12:33:37 PM »
Is Central Arctic a combination of the blue seas or a separate entry?
I'm pretty sure it's only the Central Arctic Sea - as in the NSIDC definition of 3.2 million km2 which is MAISIE Area 11.

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