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crandles

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Re: "Stupid" Questions :o
« Reply #1600 on: September 08, 2018, 12:15:09 AM »
1. AIUI Top melt becomes dominant late in the season but earlier in the season bottom melt is more important.

Here is data from a buoy:

https://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=327.0;attach=49351;image

For this buoy data, in total, it looks like bottom melt is slightly greater, which is what I would expect.

Different buoys react differently depending on their location. Note that bottom melt is a combination of both upward heat flux as you mentioned but also sideways: Open water absorbs far more heat due to its lower albedo and currents and wind can drive that under the ice. Thus near the edge of an ice flow you might get more bottom melt. Buoys may well be placed in thickest strongest looking ice so may be further from edges of floes than average. So bottom melt might be a little more important than data from buoys suggest.

2. Yes, the temperature does matter. The greater the temperature differential the faster the rate of heat flow. Heat lost less any upward heat flow to water beneath the ice is a good measure of the quantity of ice that forms.

3. Clouds slow the rate of heat loss from atmosphere to space and from surface to space. You may have noticed that cloudless nights are a lot colder than cloudy nights. See answer to 2. above regarding effect this has.

Hope this helps.



magnamentis

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Re: "Stupid" Questions :o
« Reply #1601 on: September 08, 2018, 01:20:13 AM »
Hi, I have two rather simple question I unfortunately don't know the answer to. Please also correct me if something I wrote is wrong, I love to learn new stuff.

I ask this because of the very high winter temperature anomalies in the arctic where temperatures sometimes spike up a lot but still stay under 0°C by a significant amount.


everything that crandles said plus water does only freeze at around zero degrees if it's fresh water. salty water will freeze at lower temps, something between 1.5-1.8C i think is what applies to the kind of water in the arctic while due to mixing with waters from below it can take temps around -10C to really freeze in earnest, meaning open water in over large areas.

on the other hand if the waters are full of ice floes it can take less and i could imagine that if the cold drops in quickly, let's say a day after there was still melt that would produce a fresh water layer, it can freeze very fast, which IMO can be observed each fall in the CAB.

perhaps someone can add even more details or make corrections but something along this line it should be.

Tor Bejnar

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Re: "Stupid" Questions :o
« Reply #1602 on: September 08, 2018, 05:18:04 AM »
In addition, Phil, ice is translucent (as is snow less than about 10 cm IIRC), so light penetrating through ice heats water (and plankton) towards the top of the water column.

Of course, such nuances can continue!
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Phil42

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Re: "Stupid" Questions :o
« Reply #1603 on: September 08, 2018, 11:48:57 AM »
Thanks a lot for the informative answers!

Chuck Yokota

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Re: "Stupid" Questions :o
« Reply #1604 on: September 09, 2018, 05:28:56 AM »
Thanks for your answers to my question from a few days ago. I can see that winter is warming increasingly quickly. I was asking about a graph for the decadal average for the daily dmi 80+ to see if finer grained trends could be observed; e.g. if some months have been changing faster than others.

gerontocrat

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Re: "Stupid" Questions :o
« Reply #1605 on: September 12, 2018, 07:28:18 PM »
Hullo everybody,

I cannot find a simple table giving the area of each Arctic sea as used by NSIDC in their spreadsheets. No problem for enclosed seas that have 100% ice extent in winter, but what about Bering, Greenland etc. I have emailed NSIDC (see below) but no reply yet.

In a quandary,

Gerontocrat.  :(  (My very first emoji)
_______________________________________________________________________
Quote
I am currently working on a new measure of changes in Arctic sea ice. The idea is to track the decline in sea ice area over time for each Arctic sea that is changing the seas from what are basically ice deserts to open water maritime seas. The calculation is simple, for each day and each sea my spreadsheets calculate the percentage of that sea that is open water, and from that get annual annual and seasonal changes.

BUT for that I need the area of each of the 14 seas used in your spreadsheets. For enclosed seas and those 100% ice-covered in winter (e.g. Hudson Bay, Central Arctic) the data can be derived from maximum winter sea ice extent in the NSIDC spreadsheets. But others are bounded by open water e.g.Greenland, Okhotsk, Bering). I have googled but cannot find those figures.

Can you send me the figures that NSIDC has defined as the area for each of these seas so I can plug them as the parameter into my analyses.

Hoping for your assistance,
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Dharma Rupa

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Re: "Stupid" Questions :o
« Reply #1606 on: October 13, 2018, 09:12:53 PM »
Conditions over weeks is the weather.  Conditions over several years is the climate.   Is there a term for conditions over about a year?

Sebastian Jones

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Re: "Stupid" Questions :o
« Reply #1607 on: October 14, 2018, 05:03:28 AM »
Gerontocrat: Wikipedia tells me that Okhotsk is 1,583,000 km2, Bering is 2,000,000 (which seems suspiciously "round" and the Greenland Sea is 1,205,000.
I don't know if this is precise enough for your project.

gerontocrat

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Re: "Stupid" Questions :o
« Reply #1608 on: October 14, 2018, 11:45:53 AM »
Gerontocrat: Wikipedia tells me that Okhotsk is 1,583,000 km2, Bering is 2,000,000 (which seems suspiciously "round" and the Greenland Sea is 1,205,000.
I don't know if this is precise enough for your project.
Thanks, Sebastian. The trouble is that the areas included in the NSIDC system are not necessarily consistent with the definitions used in Wikipedia. The NSIDC data for the Okhotsk includes (I think) a bit of the Japan Sea, while the NSIDC data for the Bering excludes (I think) that part that has never had ice.

So what I did was take the highest daily maximum sea ice extent from the NSIDC satellite data for those seas that have open ocean boundaries. After all, the object of the exercise was to look at each sea to graph the transition over time from ice to open water. (Examples attached re "The Atlantic Front").
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tomatothief

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Re: "Stupid" Questions :o
« Reply #1609 on: October 18, 2018, 09:14:30 PM »
I'm aware that this is an incredibly basic question, no pressure to answer. Does anyone have any resources for understanding the content posted on this forum, please?

I've started lurking and I'm finding it really difficult to understand and keep up. I'm working my way through a first year undergraduate physical geography textbook and greatly enjoying it, and any other recommendations of resources (I don't mind things that are dense, or take time to digest) would be very much appreciated. Or is it a case of googling each term you're using and I'll pick it up along the way?

Neven

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Re: "Stupid" Questions :o
« Reply #1610 on: October 18, 2018, 09:54:13 PM »
Are you referring to a specific thread? The freezing season thread usually devolves to more complex discussions (salinity, currents, atmospheric shifts) when the day-to-day excitement of the end of the melting season is dialled back. That's hard to follow for anyone. But usually, the melting season isn't all that complex ('look there, it's melting faster now than any time on record').
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oren

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Re: "Stupid" Questions :o
« Reply #1611 on: October 18, 2018, 09:57:09 PM »
Hi Tomatothief, first of all don't despair. The stuff here takes ages to digest. I recommend to keep on reading, at some point the immersion will bring better understanding. There is a glossary to help you with the terms and acronyms:
Glossary ... for newbies and others
In addition, I am told that there are other sites that present the more basic information in a more organized way, I am sure folks here will gladly point you in these directions as well.

Tor Bejnar

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Re: "Stupid" Questions :o
« Reply #1612 on: October 19, 2018, 03:07:35 AM »
Skeptical Science generally does a great job of explaining AGW (woops, not in main glossary  :) ) - Anthropogenic Global Warming - and ACC - Anthropogenic Climate Change - details.

Neven (creator of this forum and the related blog) has some resources listed on the right side of his ASIB (Arctic Sea Ice Blog).  See link at the top of this page.

And welcome! (I hope we don't have any fruit to lure you into your trade.)
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FishOutofWater

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Re: "Stupid" Questions :o
« Reply #1613 on: October 19, 2018, 04:46:16 AM »
You are starting in the right place. There's quite a bit of geography to learn before you can make sense of where things are happening. As Neven has noted the science of the freezing season and what's happening under the ice is complicated so don't expect to understand it quickly. Neven has quite a good compilation of web resources for Arctic sea ice that you can link to from his blog.

And the link is also on the top right of the front page of the forum.

https://sites.google.com/site/arcticseaicegraphs/

gerontocrat

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Re: "Stupid" Questions :o
« Reply #1614 on: October 19, 2018, 11:42:27 AM »
You are starting in the right place. There's quite a bit of geography to learn before you can make sense of where things are happening.

Looking at maps - just browsing, helps to give you a sense of place. There is a section on Arctic Maps on ASIF - https://forum.arctic-sea-ice.net/index.php/topic,417.0.html.  Physical geography, bathymetry, land-use etc.

As an amateur I've been looking at geography and geology for over 50 years, and the cryosphere for over 15 years. Most days I learn something new. Be careful you don't get infected - you may become incurable.
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kassy

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Re: "Stupid" Questions :o
« Reply #1615 on: October 20, 2018, 01:39:41 PM »
Conditions over weeks is the weather.  Conditions over several years is the climate.   Is there a term for conditions over about a year?

For climate we use averages over multiple years so the conditions over a year are just weather for year X looking at the hard data.

To complicate the matters you can actually refer to the weather as expected over the year as a climate as used in the Köppen climate classification. For example i live in the Netherlands. Nice maritime climate where the summers are not too hot and the winters not too cold. But that is our climate because our weather is like that every year.



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Klondike Kat

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Re: "Stupid" Questions :o
« Reply #1616 on: October 20, 2018, 05:44:35 PM »
Conditions over weeks is the weather.  Conditions over several years is the climate.   Is there a term for conditions over about a year?

For climate we use averages over multiple years so the conditions over a year are just weather for year X looking at the hard data.

To complicate the matters you can actually refer to the weather as expected over the year as a climate as used in the Köppen climate classification. For example i live in the Netherlands. Nice maritime climate where the summers are not too hot and the winters not too cold. But that is our climate because our weather is like that every year.

Agreed.  When someone refers to it as a warm or cold year, they are comparing the past years weather against the longer term climate.  Even the term climate change does not mean a change of climate;  the Netherlands will still have a maritime climate.  Rather, the average temperature and precipitation has increased within that climate.

Dharma Rupa

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Re: "Stupid" Questions :o
« Reply #1617 on: October 20, 2018, 08:58:29 PM »
Even the term climate change does not mean a change of climate;  the Netherlands will still have a maritime climate.  Rather, the average temperature and precipitation has increased within that climate.

Interesting point, but it kind of describes my dilemma.   If next year the SST in the North-Eastern Atlantic were to be 27 degrees the Nederlands would still have a Maritime Climate.  How does one name a year which is radically different than past climate, but within which each day is inside climate normals?

kassy

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Re: "Stupid" Questions :o
« Reply #1618 on: October 22, 2018, 12:42:43 AM »
I kind of doubt that a radically different year can co-exist with a year with no extremes. 

27 C seems like tropical SST so in the long term the climate would go that way. The difference in the two climates is mainly in temperatures which are higher and a lot more rainfall and similar seasons with no neat winter, spring, summer and autumn like we used to have (basically this pattern is broken already).

So the first year that happened (in an imaginary scenario where this happens overnight) you could probably point out that the temps across the year are usually record highs and so consistent that if they repeat year over year we would be in a different climate type. Then you add that the increased precipitation also points in that direction and some other bits in the data like the seasons smoothing out. You include caveats because you are still discussing 1 years data so essentially weather.

In the real world SSTs would creep up slowly so all these patterns are already establish especially if other datasets tell you the SSTs won´t drop for centuries.

The only recent flip is the Barentz Sea going atlantic. This differs a bit from land climates but they basically had a couple of important data points. It hardly froze anymore and the salinity profile changed and also the types of animals in the catch. It is not exactly the same but if you get the correct long link (which is probably somewhere on this forum) it shows how they construct the case for a change.



 
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Dharma Rupa

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Re: "Stupid" Questions :o
« Reply #1619 on: October 22, 2018, 01:06:48 AM »
I kind of doubt that a radically different year can co-exist with a year with no extremes. 

Try a year where almost every day is one degree less than the record.

Or in the case of the Arctic, a year where the Summer is consistently slightly colder than normal and the Winter is consistently quite a bit warmer than normal.

kassy

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Re: "Stupid" Questions :o
« Reply #1620 on: October 22, 2018, 01:40:13 AM »
To be fair for radically different i meant proposed SST changes (basically double their current values). Or something far less then that but way out of line with current climates.

The Arctic is different. The ice cools until its gone but there are many threads to discuss various aspects of that here.   
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Phil.

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Re: "Stupid" Questions :o
« Reply #1621 on: October 22, 2018, 03:51:18 AM »
I kind of doubt that a radically different year can co-exist with a year with no extremes. 

27 C seems like tropical SST so in the long term the climate would go that way. The difference in the two climates is mainly in temperatures which are higher and a lot more rainfall and similar seasons with no neat winter, spring, summer and autumn like we used to have (basically this pattern is broken already).

So the first year that happened (in an imaginary scenario where this happens overnight) you could probably point out that the temps across the year are usually record highs and so consistent that if they repeat year over year we would be in a different climate type. Then you add that the increased precipitation also points in that direction and some other bits in the data like the seasons smoothing out. You include caveats because you are still discussing 1 years data so essentially weather.

In the real world SSTs would creep up slowly so all these patterns are already establish especially if other datasets tell you the SSTs won´t drop for centuries.

The only recent flip is the Barentz Sea going atlantic. This differs a bit from land climates but they basically had a couple of important data points. It hardly froze anymore and the salinity profile changed and also the types of animals in the catch. It is not exactly the same but if you get the correct long link (which is probably somewhere on this forum) it shows how they construct the case for a change.

The same thing has happened in the Bering, the 'cold pool' ceased this year and the distribution of cod and pollock has changed as a result, it'll be interesting to see if that persists over this winter.
http://www.nomenugget.com/news/noaa-survey-shows-shocking-lack-thermal-barrier-between-northern-and-southern-bering-sea
« Last Edit: October 22, 2018, 04:40:54 PM by Phil. »


sark

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Re: "Stupid" Questions :o
« Reply #1623 on: November 01, 2018, 09:50:26 PM »
What are the predictions for the US winter ?

https://electroverse.net/another-vortex-winter-would-be-catastrophic-says-bank-of-america-merrill-lynch-sending-natural-gas-to-5

"Another vortex would be catastrophic" well, if that's the case, buckle up.  The average for polar vortex displacement / split occurrence is above 1 per winter.

NOAA put out a winter outlook a couple of days ago: https://earthsky.org/earth/winter-2018-2018-weather-outlook-for-us

Figure is from a master's thesis:

Fortin, Ashley, "The Impact of a Changing Climate on the Frequency of Sudden Stratospheric Warming Events" (2017). Master's Theses. 4797.
http://scholarworks.sjsu.edu/etd_theses/4797
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AmbiValent

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Re: "Stupid" Questions :o
« Reply #1624 on: November 05, 2018, 03:26:23 PM »
Is there a name for the process in which a tropical cyclone becomes an extratropical one and later a polar one?

And is this connected to heat transport towards the North Pole, or is that rather caused by a specific arrangement of a number of pressure systems, and is there a name for such an arrangement?
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magnamentis

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Re: "Stupid" Questions :o
« Reply #1625 on: November 05, 2018, 04:10:15 PM »
Is there a name for the process in which a tropical cyclone becomes an extratropical one and later a polar one?

And is this connected to heat transport towards the North Pole, or is that rather caused by a specific arrangement of a number of pressure systems, and is there a name for such an arrangement?

the weather pro's here will tell us but it would make sense if a storm north or south of the tropics of caprricorn / cancer would be extra tropical and a cyclone that would be north or south of the respective polar circle would be called polar, arctic or antarctic cyclone. i'm also interested to read what our weathermen have to say  ;) good question

gerontocrat

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Re: "Stupid" Questions :o
« Reply #1626 on: November 05, 2018, 07:16:32 PM »
Is there a name for the process in which a tropical cyclone becomes an extratropical one and later a polar one?

And is this connected to heat transport towards the North Pole, or is that rather caused by a specific arrangement of a number of pressure systems, and is there a name for such an arrangement?

the weather pro's here will tell us but it would make sense if a storm north or south of the tropics of caprricorn / cancer would be extra tropical and a cyclone that would be north or south of the respective polar circle would be called polar, arctic or antarctic cyclone. i'm also interested to read what our weathermen have to say  ;) good question
The little I know is -

A tropical storm requires heat - from an ocean at above 26 degrees celsius surface temperature. When it passes over cooler water or land that energy supply disappears, and so its internal structure collapses. If caught by mid-latitude winds (e.g. Atlantic westerlies) it can morph into a standard low pressure system (e.g. Hurricane Oscar that was still intact when it brushed the UK and Iceland as a strong low pressure system).
 
What that change is called and how it works I don't know.

Yes, a very good question.
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Sam

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Re: "Stupid" Questions :o
« Reply #1627 on: November 05, 2018, 07:45:38 PM »
Quote
A tropical storm requires heat - from an ocean at above 26 degrees celsius surface temperature. When it passes over cooler water or land that energy supply disappears, and so its internal structure collapses. If caught by mid-latitude winds (e.g. Atlantic westerlies) it can morph into a standard low pressure system (e.g. Hurricane Oscar that was still intact when it brushed the UK and Iceland as a strong low pressure system).
 
What that change is called and how it works I don't know.

Yes, a very good question.

I too am not an expert in the definition of storms. What I believe I have learned is this:

Hurricanes and Typhoons (differing in name only because of the region in which they formed) have warm cores with uprising air. These occur when sea surface temperatures exceed some critical threshold, often taken as being 26 degrees C. Much more is involved though to drive their formation and destruction.  High altitude shear plays a strongly limiting role.

Extratropical storms form in the northern and southern oceans where the sea surface temperatures are lower. These systems have cold down flowing cores making them different from their tropical cousins. Visually, they comprise alternating white cloud and dark (open air) bands wrapped around a central area, as contrasting from tropical systems that are solid white clouds in bands wrapped around the core. They are typically much larger in area than their trivial cousins. And though their wind speeds tend to be lower and their central pressures higher than their tropical cousins, they can rival them in each of these areas. Tropical systems have a true eye. Extratropical systems may have a loose eye, but generally do not.

Hurricanes and Tropical storms that form and move poleward often either convert from warm core to cold core systems once the sea surface temperature drops below some critical threshold. They also quite often merge with extratropical lows creating even larger and more powerful systems in the process. In much rarer cases, systems can and have apparently moved toward the equator and converted from extratropical nature to hurricane or typhoon nature.

I suspect, but do not know, that there may be a difference in the atmospheric driving forces as well. Coriolis forces seem to play a large role with tropical systems. High altitude circulation appears to play a large role with extratropical systems; both in their creation and in their destruction.

If these are true, the three band atmospheric circulation no doubt plays several roles in driving storms, and in forcing the conversion of tropical systems into extratropical ones. With the failure the three band circulation, this may change allowing tropical systems to range further from the equator.


Peter Ellis

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Re: "Stupid" Questions :o
« Reply #1629 on: November 07, 2018, 10:46:21 AM »
Why is the Amazon rainforest a carbon sink? During its lifetime a tree absorbs carbon as it grows, but then it eventually dies and the carbon is all released back into the atmosphere as it decomposes. Therefore a tree is carbon-neutral when looked at over its entire existence. So where does the carbon that is absorbed by the sink go to?

binntho

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Re: "Stupid" Questions :o
« Reply #1630 on: November 07, 2018, 10:57:26 AM »
Why is the Amazon rainforest a carbon sink? During its lifetime a tree absorbs carbon as it grows, but then it eventually dies and the carbon is all released back into the atmosphere as it decomposes. Therefore a tree is carbon-neutral when looked at over its entire existence. So where does the carbon that is absorbed by the sink go to?
Not all the carbon is released back to the atmosphere - as with all vegetation, some of the plant residue collects in the soil. However, a tropical rainforest is probably a very minimal carbon sink in this sense.

Taken collectively, a forest contains a lot of carbon that would be elsewhere (e.g. in the atmosphere) if the forest didn't exist. So cutting down a forest releases carbon, and when a forest regrows it sequesters carbon. Increased amounts of carbon dioxide in the atmosphere probably leads to increased forest growth, which in that sens acts as a sink for part of the increased carbon dioxide.

So even if all the carbon were to be released over the lifecycle of a single tree, the total mass of the forest probably increases with increased carbon dioxide, and in that sense it acts as a carbon sink.

But recent research has shown (as far as I am aware) that increased temperatures can work against the uptake of carbon dioxide, so that the forest will be less and less able to act as a carbon sink as temperatures increase.
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Pmt111500

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Re: "Stupid" Questions :o
« Reply #1631 on: November 07, 2018, 01:22:58 PM »
Count in all the organic debris floating out in the Amazon, and sinking wherever off the continental shelf.
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gerontocrat

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Re: "Stupid" Questions :o
« Reply #1632 on: November 07, 2018, 07:39:23 PM »
Why is the Amazon rainforest a carbon sink? During its lifetime a tree absorbs carbon as it grows, but then it eventually dies and the carbon is all released back into the atmosphere as it decomposes. Therefore a tree is carbon-neutral when looked at over its entire existence. So where does the carbon that is absorbed by the sink go to?
Not all the carbon is released back to the atmosphere - as with all vegetation, some of the plant residue collects in the soil. However, a tropical rainforest is probably a very minimal carbon sink in this sense.

That depends - in many places forest soils are very thin, i.e. not much organic matter is stored long-term. In other places (e.g. Congo, parts of Indonesia) conditions are such that vast deposits have built up into peat. I believe that some of the forest fires that started in the last big drought in Indonesia are still slowly chewing away at the peat underground and may smoulder for perhaps decades. These are significant sinks.

Mind you at the moment the climate models assume that CO2 emissions from deforestation are somewhat less than that from CO2 capture due to increased growth* as CO2 concentrations increase. (Though this apparently has its limits).

*That increased growth is just about everywhere, including the tundra. But that change in the tundra vegetation could assist the release the CO2 and methane held in the enormous highly organic peaty deposits held there.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

uniquorn

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Re: "Stupid" Questions :o
« Reply #1633 on: November 22, 2018, 01:41:45 PM »
It seems a paradox to be getting warmer while the freeze is so fast.

So is the Mpemba effect.

There is no end of study into how mixing affects melt and upwelling of warm water.  I doubt that there has been very large amount of study into the re-freeze in the same way, but I could be wrong.

One of the studies to try and understand the Mpemba effect shows that suddenly stirring very cold water can cause flash freezing.  We know that the pack protects the water from the worst effects of storms.  What we don't know is how weather is affecting water sitting at -1.8c and giving up its heat before freezing.

I'm sure this will be studied in time but, today, we're in fairly uncharted territory.

Does anyone have any ideas on whether it is possible to have large scale 'flash freezing' before overturning is complete?


Does warm water tend to freeze faster than cold in the right conditions?

No.  Spraying hot water into cold air will result in instant freezing due to a combination of severely cold and dry air.  The heat loss due to evaporation will make a difference.  Not so in a water medium.

Maybe this, on a huge scale, only with cold, stormy water.
« Last Edit: November 22, 2018, 05:21:32 PM by uniquorn »

Red

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Re: "Stupid" Questions :o
« Reply #1634 on: November 30, 2018, 11:54:26 AM »
Where’s the science to backup this 1.5c/2c bs. All the science I can find on 400+ppm CO2 in the atmosphere before present says the global average temp was 4-6c higher than today. We’re told now that if we follow some path we can hold the rise to 2c or below. Several million years back approximately 400 ppm+/- meant 4-6c more and yet that does not apply anymore. Why not? Did the physics change? If we stop adding CO2 to the atmosphere now, is the 130ppm extra going to fall out in short order? Our sinks have been crippled to within a centimetre or so of functioning at all, but somehow if we stop adding now we will reach equilibrium at 1.5c-2c. What kind of logic is this!? 400ppm = 4-6c full stop. What changed or more likely what am I missing?

gerontocrat

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Re: "Stupid" Questions :o
« Reply #1635 on: November 30, 2018, 12:12:12 PM »
What changed or more likely what am I missing?

Most / many ? IPCC scenarios envisage going over the +1.5 to +2 limit but then the miraculous (as yet non-existent) low-cost technology will exist to  directly capture many billion of tonnes of CO2 from the air which will gradually bring down the temperature increase to "reasonable" levels.

Some might say that this is cloud-cuckoo land but I am sure that those who presume to advise and govern us know what they are doing. (Looks for emoji for heavy sigh")
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

oren

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Re: "Stupid" Questions :o
« Reply #1636 on: November 30, 2018, 12:32:29 PM »
What he said. They imagine removing the extra CO2. A world that cannot pull itself together enough to install solar panels and wind turbines that have an immediate and high return on investment for the installer, will unite and pull itself together to perform a much costlier action with no immediate return on investment, all for the common good. That is not delusion, that is negligence with criminal intent.

Red

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Re: "Stupid" Questions :o
« Reply #1637 on: November 30, 2018, 12:44:30 PM »
Hmph. Missed only the fact that these future casts rely entirely on wishful thinking. So collapse it is then. Thanks for the replies much appreciated, just confirms what most paying attention already know, I guess. Has anyone seen the following: Hugh Montgomery

kassy

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Re: "Stupid" Questions :o
« Reply #1638 on: November 30, 2018, 01:57:20 PM »
Haven´t watched it yet.

At least viruses become less virulent over time because a dead host is hard to hi-jack...we are not doing that (yet).

I guess i don´t like the analogy because there is only 1 earth. This is very different from the viral lifecycle.

Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

Tor Bejnar

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Re: "Stupid" Questions :o
« Reply #1639 on: November 30, 2018, 02:58:02 PM »
Where’s the science to backup this 1.5c/2c bs. ... What changed or more likely what am I missing?
I am not a climate scientist, but I pretend to be one with my friends...

I am aware of approximately three things that may have changed since '400 ppm CO2 = 4-6C warmer'.
How these affect, or how much they affect, what would be a stable temperature for any given greenhouse gas concentration, I'm not certain.
Arctic ice is healthy for children and other living things.

SteveMDFP

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Re: "Stupid" Questions :o
« Reply #1640 on: November 30, 2018, 04:08:09 PM »
Where’s the science to backup this 1.5c/2c bs. ... What changed or more likely what am I missing?
I am not a climate scientist, but I pretend to be one with my friends...

I am aware of approximately three things that may have changed since '400 ppm CO2 = 4-6C warmer'.
How these affect, or how much they affect, what would be a stable temperature for any given greenhouse gas concentration, I'm not certain.

I can't say that any of these things should have much impact on the total global energy budget (solar energy in, heat radiating out). 
The earth gradually moving away from the sun *might*, except that it's only 15 cm/yr.
That edging away is almost certainly overwhelmed by an influence in the opposite direction. The sun is getting hotter and more luminous over time, about 6% every billion years.
https://usm.maine.edu/planet/sun-getting-hotter-if-so-why-will-earth-eventually-become-too-hot-life

Calculating the relative impact of these two factors is slightly beyond my time/confidence to calculate today.  But the radiation of the sun goes up with the 4th power of temperature, while radiation intensity goes down with the 2nd power of distance.  So there.

I suspect the immense heat capacity of the oceans is simply dampening the time to equilibrium effects of the 50% increase in CO2 concentration from pre-industrial.  Give it a millenium or so.

Dharma Rupa

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Re: "Stupid" Questions :o
« Reply #1641 on: November 30, 2018, 04:34:19 PM »
I suspect the immense heat capacity of the oceans is simply dampening the time to equilibrium effects of the 50% increase in CO2 concentration from pre-industrial.  Give it a millenium or so.

The sudden swings in sea level tend to add doubt about that millennium estimate.

SteveMDFP

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Re: "Stupid" Questions :o
« Reply #1642 on: November 30, 2018, 04:41:30 PM »
I suspect the immense heat capacity of the oceans is simply dampening the time to equilibrium effects of the 50% increase in CO2 concentration from pre-industrial.  Give it a millenium or so.

The sudden swings in sea level tend to add doubt about that millennium estimate.

How so?  Sea level depends mostly on melting of ice on land masses.
If the mean temperature of the lower atmosphere goes up by 2 degrees C, how long does it take for the mass of the oceans to rise in temperature by a corresponding amount?

The accumulating heat of the earth at present won't be fully reflected in surface temperatures until heat stops going into the oceans and raising their heat content.  We know that total heat content of the oceans is increasing, so we know surface temperature increases don't fully reflect the current planetary radiation imbalance.

Steven

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Re: "Stupid" Questions :o
« Reply #1643 on: November 30, 2018, 04:48:18 PM »
All the science I can find on 400+ppm CO2 in the atmosphere before present says the global average temp was 4-6c higher than today.

I'm not sure where that is coming from.

According to the IPCC fifth assessment report, Chapter 5:

Quote
During the mid-Pliocene (3.3 to 3.0 million years ago), atmospheric
CO2 concentrations between 350 ppm and 450 ppm (medium confidence)
occurred when global mean surface temperatures were 1.9°C
to 3.6°C (medium confidence) higher than for pre-industrial climate.

Klondike Kat

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Re: "Stupid" Questions :o
« Reply #1644 on: November 30, 2018, 04:57:12 PM »
Where’s the science to backup this 1.5c/2c bs. All the science I can find on 400+ppm CO2 in the atmosphere before present says the global average temp was 4-6c higher than today. We’re told now that if we follow some path we can hold the rise to 2c or below. Several million years back approximately 400 ppm+/- meant 4-6c more and yet that does not apply anymore. Why not? Did the physics change? If we stop adding CO2 to the atmosphere now, is the 130ppm extra going to fall out in short order? Our sinks have been crippled to within a centimetre or so of functioning at all, but somehow if we stop adding now we will reach equilibrium at 1.5c-2c. What kind of logic is this!? 400ppm = 4-6c full stop. What changed or more likely what am I missing?

Even if we assume that temperature and CO2 should correlate this well throughout our planet's history, your numbers do not match the records.  Here are the CO2 estimates from the last 500 million years:

https://static.secure.website/wscfus/9167827/4542986/co2-400-m-years-400-ppm-20-m.png

CO2 was at 400 ppm during several eras; most recently at 15 million years ago and 60 MYA.

The temperatures at those times were ~+2C higher, +3C higher. 

https://muchadoaboutclimate.wordpress.com/2013/08/03/4-5-billion-years-of-the-earths-temperature/

The temperature reached 4-6C higher, when CO2 levels neared 1000 ppm, some 40-50 MYA.  Can we even say that the planet is in the same regime as 15 MYA?


Stephan

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Re: "Stupid" Questions :o
« Reply #1645 on: November 30, 2018, 05:02:12 PM »
Where’s the science to backup this 1.5c/2c bs. All the science I can find on 400+ppm CO2 in the atmosphere before present says the global average temp was 4-6c higher than today. We’re told now that if we follow some path we can hold the rise to 2c or below. Several million years back approximately 400 ppm+/- meant 4-6c more and yet that does not apply anymore. Why not? Did the physics change? If we stop adding CO2 to the atmosphere now, is the 130ppm extra going to fall out in short order? Our sinks have been crippled to within a centimetre or so of functioning at all, but somehow if we stop adding now we will reach equilibrium at 1.5c-2c. What kind of logic is this!? 400ppm = 4-6c full stop. What changed or more likely what am I missing?
Another answer may be the time frame until the temperature is reached. Scientists agree that the time needed for a new temperature equilibrium after a (sudden) change of CO2 is measured in many centuries or millenia. Many of the publications in radio or TV look at the time until the year 2100. If you think about the energy needed to melt ice this time lag is easily explainable. Responsible scientists always say that - if nothing is done about a reduction of GHG emissions and no geoengeneeric means are taken to put the CO2 out of the atmosphere, global temperatures will continue to rise beyond 2100 until 2-3°C above preindustrial with a CO2 content of 410 ppm.
It is too late just to be concerned about Climate Change

Red

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Re: "Stupid" Questions :o
« Reply #1646 on: November 30, 2018, 05:19:39 PM »
Wow!! guys thanks for all the responses on my stupid question. I love this blog. Great debates here that are both informative and stimulating. Thanks again and blog on!

Pmt111500

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Re: "Stupid" Questions :o
« Reply #1647 on: November 30, 2018, 06:08:48 PM »
Isthmus of Panama closing caused Tropical Atlantic to cool somewhat as the Pacific is the warmest ocean... I think. If there was a channel, The El Nino waters might enter the Atlantic giving a boost to Hurricanes and likely also warm up the North Atlantic Gyre. This would probably lead to warmer temperatures than what is currently projected. Though it might be economically nice to have a sea level channel in the place of the Panama Canal, the economy might get a hit if the hotter Atlantic would be +6°C all the time round Greenland and super-typhoon type storms hit the North American eastern shores every year like in Philippines.

Much guesswork here but at least somewhat based on reality.
« Last Edit: November 30, 2018, 07:26:54 PM by Pmt111500 »
Cooling the outside by heat pump.

RoxTheGeologist

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Re: "Stupid" Questions :o
« Reply #1648 on: November 30, 2018, 07:18:49 PM »
What changed or more likely what am I missing?

Most / many ? IPCC scenarios envisage going over the +1.5 to +2 limit but then the miraculous (as yet non-existent) low-cost technology will exist to  directly capture many billion of tonnes of CO2 from the air which will gradually bring down the temperature increase to "reasonable" levels.

Some might say that this is cloud-cuckoo land but I am sure that those who presume to advise and govern us know what they are doing. (Looks for emoji for heavy sigh")


This one is a strange one: Shoot me, but I have started thinking the best way to get improve our carbon sink is to pellet woody material, combine it with rock dust from quarries and harden it with resin then dump it into the deep ocean trenches. In that way we increase the capture of carbon of forests by trapping it in sediments, preventing aerobic, anaerobic and methanogenic digestion.

Living in California this might not be a bad option. Basically we take woody biomass left over from forest use and instead of burning it we put it back into the ground.

SteveMDFP

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Re: "Stupid" Questions :o
« Reply #1649 on: November 30, 2018, 07:30:46 PM »
What he said. They imagine removing the extra CO2. A world that cannot pull itself together enough to install solar panels and wind turbines that have an immediate and high return on investment for the installer, will unite and pull itself together to perform a much costlier action with no immediate return on investment, all for the common good. That is not delusion, that is negligence with criminal intent.

Completely agree.  It seems every few weeks I see a gee-whiz science article about a new technology to make atmospheric CO2 extraction more feasible, efficient, or economical.  Invariably, these gee-whiz articles omit basic thermodynamic/economic facts.

To reduce CO2 to usable/storable organic carbon requires approximately as much energy as was released when the fossil carbon was burned.  That's an inescapable fact.  (Among the few alternatives that don't require such thermodynamic energy is to react CO2 with alkaline rock, which requires eons of time, or pulverization of unimaginable amounts of rock, also energy-intensive.)

The energy posited by these articles is otherwise useful energy, which is never free.  There are always alternative uses, even if the source is sunlight.  There are costs to such energy, steep costs.  Absent some political mechanism to arrange financing of almost unimaginable amounts of zero-carbon energy production, these are all pipe dreams.