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Messages - A-Team

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Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: September 10, 2020, 06:40:57 PM »
I think it's real. Noaa-20
Oh, there isn't any doubt.

It really confirms what A-Team and others have been saying about the ice this season.

It also highlights the disconnect between actual conditions an the models we are relying on.  It illustrates that fundamental changes have taken place in the Arctic as a system, and similar fundamental assumptions made by the models - in particular volume - need to be reevaluated.  In previous years, certainly pre-2012, possibly as late as 2016, a modest cyclonic feature - not even a storm - like that would not have shattered the main pack across such a wide area.

We desperately need more and different data.

Consequences / Re: COVID-19
« on: March 10, 2020, 08:17:36 PM »
Bernard wrote: "Indeed. And name me a single country where things are better today."

Almost all European countries I think. In our hospitals in the Netherlands there are no beds with patients in the corridors.
Was your question serious?

So do you think you had peak infections in the netherlands ?

Consequences / Re: COVID-19
« on: March 05, 2020, 08:21:15 PM »
The article tells that the government admids that it escaped ? Than what is that Iranian government telling, probably the country is imploding.

Consequences / Re: COVID-19
« on: March 05, 2020, 07:56:50 PM »
China is 9,6 million square km in size. In these 9,6 million square km there is one lab, at a few hundred meters of the foodmarket.  Does this makes me a conspiracy theorist ? Or is it suspicious.

Consequences / Re: COVID-19
« on: March 03, 2020, 07:36:19 PM »
I think Europe will become one big Wuhan, with Belgium as the epicenter

Arctic sea ice / Re: MOSAiC news
« on: February 26, 2020, 01:34:03 PM »
Drifted quickly past the 45deg line yesterday. Here showing the 3 buoys from oct4-feb26
P207, 2020-02-26T03:00:25,88.4991,40.4124
Deployment line at start
edit: For Tor below, Graticule lines are Lat=0.5deg, Lon=5deg. (otherwise there are too many lines at that resolution. Too lazy to annotate it. Still waiting for someone to post a PS temperature chart.)

Arctic sea ice / Re: MOSAiC news
« on: February 22, 2020, 11:17:33 AM »
Verifying those large low concentration leads north of Greenland., feb21-22, Kaleschke sic leads inset. ctr

drift update. Below 45E they start drifting away from the pole. At the recent rate of ~3degrees/day that's maybe 5-6days away. KD might just make it.

Arctic sea ice / Re: MOSAiC news
« on: February 13, 2020, 11:36:31 PM »
Now, where to put that airstrip?
Here showing most Mosaic IABP buoys that report on the hour. Some report only on the half hour. Inset is nullschool wind isobaric at 1000hpa. Frames are repeated twice to match the hourly buoys. Projection is done using PlotSvalbard in R. Delaunay triangulation in Octave.

Arctic sea ice / Re: MOSAiC news
« on: December 12, 2019, 03:05:54 PM »
drift update, ~12 days in 50 frames

Arctic sea ice / Re: MOSAiC news
« on: December 06, 2019, 01:48:34 PM »
To me it looks like the MOSAIC project has had some windy times but not a real humdinger. So I did a google to see if they should expect one.

Perhaps they should, especially in this month.
Winter storms accelerate the demise of sea ice in the Atlantic sector of the Arctic Ocean

The strongest storms in the Arctic Ocean typically occur during winter and originate from the North Atlantic Ocean1,2 (Fig. 1). The number and intensity of Arctic winter storms has increased over the period 1979–2016. These storms often generate strong southerly winds that transport heat and moisture into the Arctic from the mid-latitudes, contributing to record breaking winter temperatures.
Extreme cyclone events in the Arctic: Wintertime variability and trends

Typically 20–40 extreme cyclone events (sometimes called 'weather bombs') occur in the Arctic North Atlantic per winter season, with an increasing trend of 6 events/decade over 1979–2015, according to 6 hourly station data from Ny-Ålesund. This increased frequency of extreme cyclones is consistent with observed significant winter warming, indicating that the meridional heat and moisture transport they bring is a factor in rising temperatures in the region. The winter trend in extreme cyclones is dominated by a positive monthly trend of about 3–4 events/decade in November–December, due mainly to an increasing persistence of extreme cyclone events. A negative trend in January opposes this, while there is no significant trend in February.

Arctic sea ice / Re: MOSAiC news
« on: November 23, 2019, 01:16:16 PM »
update on close buoys, nov19-23. The diagonal to the legend is 120E with 2deg intervals, the line top right is 85.5N, with 0.1deg intervals. No labels. Testing semi transparent buoy markers.
Westerly buoys get two northerly lurches, the easterlies only one.

Arctic sea ice / Re: MOSAiC news
« on: November 17, 2019, 07:03:53 PM »
update on drift speed of the meereis Pbuoys from nov14-16 ~11:30

see below

Arctic sea ice / Re: The 2019/2020 freezing season
« on: November 09, 2019, 05:31:34 PM »
Could holes (polinios sp?) in the ice over winter cause extra circulation to draw up warmer water... <snippage>
With air temperatures of -25C the leads (fractures) won't be open water for very long, though the thinner ice does show up warmer using worldview brightness temperature.

The animation below shows uni-hamburg amsr2-uhh ice concentration overlaid onto mercator (model) 0m sea temperature. (amsr2 0% concentration, normally dark blue, has been set to transparent)
oct1-nov8. It looks like a wind driven retreat in the ESS.

edit: Polarview Sentinel 1A of wave action on thin ice near the Chukchi coast today.

Arctic sea ice / Re: MOSAiC news
« on: November 08, 2019, 06:17:46 PM »
One of this morning's sentinel images with mosaic Pbuoy overlay.
This time using the final frame of a very large 2 frame macid animation and using further scaling and rotation to match the sentinel jpg graticule. click to run.

Arctic sea ice / Re: MOSAiC news
« on: November 04, 2019, 09:20:04 PM »
A closer look at whoi itp102
ITP102 was deployed on a 0.7 m thick ice floe in the Transpolar Drift on October 10, 2019 at 85° 7.9 N, 135° 34.1 E in collaboration with the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition from the Russian Research Vessel Federov. On the same icefloe, a Naval Postgraduate School Arctic Ocean Flux Buoy (AOFB) and Seasonal ice mass balance buoy were also installed. The ITP includes a second generation prototype MAVS current sensor operating on a pattern profiling schedule including 2 one-way profiles between 7 and 760 m depth each day and SBE-37 microcat fixed at 6 m depth.
The profile contours show small changes down to 50m since the start and the microcat highlights temperature and salinity changes at 6m depth since day300. Here we are also using macid's 3d R analysis to focus on temperature down to 50m showing a small rise of up to 0.16C at ~30m.

A rise in temperature and drop in salinity  at shallow depth could imply some bottom melt but no doubt there are other reasons for these conditions in this area.

Arctic sea ice / Re: MOSAiC news
« on: October 24, 2019, 10:34:54 PM »
Deformation test suggesting there is still significant movement up to 7am this morning. A few buoys reported till 10am but not really enough to run a separate subset. There are 32 in this animation.
The iabp page updates a few times a day(not sure of the exact times yet), the mosaic buoy data less often.

Arctic sea ice / Re: The 2018 melting season
« on: August 21, 2018, 03:50:51 AM »
The TSI, which has been substandard for 12+(more?) years.
I  think you put too much repeated emphasis on the TSI, especially as I don't think this 12-years claim is even true.
I suggest to back it up with some data and historical charts, in an appropriate thread (not here).

Arctic sea ice / Re: The 2018 melting season
« on: August 19, 2018, 08:56:50 PM »

The big event coincided with some remarkable weather, a high of 13.4ºC (56ºF) on August 3rd and strong winds of 42 km/h to the west, very close to the date of the remarkable ice lift-off and surge westward. Open water reached its northernmost extent on Aug 13th at 84.5º, some 105 km north of the nearest land but still 610 km short of the pole.

Given excellent 2m hourly observational data from CMJ, Alert, Nord etc weather stations, it makes no sense to use GFS at nullschool other than for an atmosphere overview. GFS does not incorporate Greenland data as tie points and often gets wind and weather at the level of ice pack completely wrong. Nullschool did ok on the wind on Aug 3rd but missed the peaks and never saw the temperature surge.

I wonder what was the official maximum temperature at Cape Morris Jesup (pictured) on August 3rd ?

At 19UTC the temperature was as high as 13.4 C. There was some big fluctuations that day coupled with changes in wind direction. Biggest change of all occurred between the hours of 12 and 13 UTC with a rise in temp from 4.7 C to 17.0 C ! 

Either this figure is erroneous or possibly the change in wind direction to SSW indicates a downslope fohn type wind coming down form the mountainous interior creating a rapid rise in temperature ?   

Arctic sea ice / Re: The 2018 melting season
« on: August 18, 2018, 11:54:54 AM »
I've identified four floes north of the Ryder Glacier fjord (don't know if it has a proper name), the animation shows the 13th and the 17th, both with fairly clear skies, and I've attempted to indicate both movement and rotation of the floes.

Movement is less than 20 km between the images, but it's clear that they all rotate, the yellow one by more than 90 degrees counter-clockwise, and except for the double-red piece floating out from land, the all rotate in the same direction.

Whether this is due to wind or currents I've no idea!

Arctic sea ice / Re: The 2018 melting season
« on: August 14, 2018, 03:48:53 PM »
Mercator 0m salinity, jul12-aug12. (if you need the to read the scale)
edit:image name dates were incorrect

Arctic sea ice / Re: The 2018 melting season
« on: August 07, 2018, 06:51:57 PM »
Doing a 'reality check', I'm zooming in on an area of thick ice.

Arctic ice thickness (CICE), via yesterday's Navy website [I ignore certificate issues.] shows lots of 2 to 4 meter ice in the Lincoln Sea.  (Color scale pasted into image).  WorldView shows the Lincoln Sea to be filled with a loose mélange with some larger floes that I presume are thick (probably 3 meters or more thick). [Scale moved to be within view.] An arrow points to a floe that, in the Sentinel Hub image (note 3 km scale),  is in the lower right corner.  This shows much of the mélange to be floes, some 5 km across or more, but many on the order of 50-500 meters across.  (Arrow points to corner of floe that is in the lower left corner of 200m scaled enlargement.)  These are plenty big enough to be 2 or more meters thick. [Sentinel-hub doesn't go north of this location.]  See the melt ponds on the enlargement.

Even if it is mostly thick floes, there are a lot of floe edges that can chip away (wind-induced bumper-car style destruction) or melt (wave assisted).

Arctic sea ice / Re: The 2018 melting season
« on: June 21, 2018, 10:08:43 PM »
magnamentis, is there any product for measuring cloud cover? I'm loathe to try and eyeball worldview pictures and draw any conclusions.

perhaps a few of the "Pros" know better sources but what i mean, beside the fact that
it applies today as well as each time i was looking in the past 2 weeks, are the ones
linked below.

i hope the link takes you directly to the right page and zoom level,66.089,-1.846,3

as neven said recently somewhere else, it's all about the weather and clouds to my limited understanding are part of that weather.
The situation with clouds and inbound/outbound energy fluxes is far more complicated than what you can tell by eyeballing visible spectrum. I learnt a lot from working with prof emeritus Steven Salter on his cloud brightening proposal back in 13/14 on this matter, and frankly when frivolous goes crowing about no chance of a record year because he sees cloud across most of the basin on worldview he is talking through the proverbial hole that ain't his mouth.  There is only a narrow range of very small liquid water droplet cloud at that has a beneficial effect on radiation fluxes and it must be at least a kilometer up to not be subject to wind waves that are rolling it down on the ice surface. Ice crystal cloud is always bad as it let's in most of the high energy part of the spectrum but blocks outgoing long wave. It may feel cooler to you under ice crystal cloud than a clear sky but you will sunburn just as fast. And bottom melting is likely to be enhanced. Low-level large water droplet cloud like fog or anything even a little gray, also blocks outgoing long wave, and very efficiently absorbs all incoming solar spectra but for a few narrow bands of visible spectrum. If there is any air movement then the droplets and worse liberated vapour transfer the energy to the ice. And the absorbed spectra are reradiated as long wave that half of get down to the surface anyway. So if it is below freezing at 850hpa you can pretty much guarantee there is no cloud beneficial to ice. And any significant air movement near surface ditto. If you compare total atmospheric column total cloud water numbers with total precipital water you will realise that there is far more water as vapour than cloud these days over the Arctic. This is very bad as its latent heat when it condenses and/ or crystallises is enormous. Whether its directly on the ice at altitude where the long wave can deeply penetrate the ice this is very bad. You may not feel the heat of being cooked by microwaves but you are. And you may feel cold in humid or foggy conditions when the air temp is low but above freezing but you are warmer, the ice is colder, so it feels warm.
Regarding Neil repeatedly bringing up solar minimum as beneficial for ice retention. My understanding is that the large number of sunspots and solar storms during minimum with the high flux of very high energy particles striking the upper atmosphere cause it both to down radiate more long wave, and expand increasing its insulation properties, trapping more heat in the lower atmosphere. So not good for ice, but I believe the magnitude of this effect is small less than one percent over a year. But it could be much higher for shorter periods during and after solar events.

Arctic sea ice / Re: The 2018 melting season
« on: June 11, 2018, 10:49:52 PM »
I went through the ascat data and made notes on the earliest days when weather artifacts appeared and when significant features in the Beaufort sea were lost. It is a subjective analysis so others may differ on the day numbers. I'm afraid I haven't yet attempted to cross reference all the events with nullschool back to 2014, though that might be informative.

2018: day 152 significant weather artifacts, features lost
2017: day 143 significant weather artifacts, no strong beaufort features
2016: day 132 weather artifacts, day 157 features lost
2015: day 135 significant weather artifacts, features lost
2014: day 123 significant weather artifacts, day 176 features lost
2013: day 138 weather artifacts, day 160 significant weather artifacts
2012: day 140 significant weather artifacts, features lost
2011: day 126 significant weather artifacts, features lost

So it looks like data has been good for longer than usual this year(with one blip). Thanks to all at NOAA who continue to provide us with such a useful resource.

and Yaay! amsr2-uhh is back up again:)

Arctic sea ice / Re: The 2018 melting season
« on: June 10, 2018, 10:13:09 PM »
Early June actually saw two unusually disruptive storms. The first swept down from eastern Siberia past Banks Island, leaving a broad swath of melting temperatures (and likely rain) that obliterated long-standing Ascat roughness features beginning on June 2nd (frame 36 vs 37; 12 hour AB resolution).

A similar event appears to have happened in 2016. Ascat day126-160.
May5-Jun8 2016

edit: I checked 2012 day132-160, and 2015 (neither are shown) which also show a similar feature loss. (I haven't checked all years)

Arctic sea ice / Re: The 2018 melting season
« on: June 09, 2018, 09:20:13 AM »
What's next for the Beaufort and Chukchi ?

[1] According to Navis HYCOM/CICE model - big cracking to the first & big melting to the latter.

[2] In accordance with what Friv and others have said: The RASM-ESRL predicts - Laptev & ESS will get smoked (2nd image, ice melt in the bottom left corner).

[3] The Laptev is already feeling the heat [needs a cklick to animate - not anymore]

But methinks: This might not show up immediately in the extent numbers

Arctic sea ice / Re: The 2018 melting season
« on: June 09, 2018, 08:03:09 AM »
In terms of potential Regional major melt the GFS is definitely showing potentially unprecedented ice melt over the Laptev and parts of the ESS heading into late June.

The most important points:

1.  Land based Warm Air Advection connection.  The models essentially park a modulating ridge over North Eastern Siberia that will extend out over the ESS, Chuchki, and Laptev through the next 10 days.

With an area of lower pressure essentially over the Kara region.

These features will help funnel warm air from the Russian continent continuously.

This will not only bring extra heating cause of the warm land mass but continue to widen the already large area of ice free open water.

This pool of water could easily reach 10C by next week.


3.  Shallow waters... The heat will easily warm all the way to the sea bed..allowing a constant flow of heat bombarding the ice from the sides.

This says it all. It's over an area that was going to melt out anyways.  But this could be something historic in how fast it does.

Arctic sea ice / Re: The 2018 melting season
« on: June 05, 2018, 11:39:46 PM »
I've been looking for a quick way to validate temperatures from models across the Arctic. VIIRS Brightness Temperature (Band I5, Day) and Night overlays seem to work pretty well.

Nice. I edited the palette a bit to show a bigger range of temperatures and stop band15 overlapping the visible ice (just a shame about the clouds)
Temperatures range from ~-1C (light blue) to ~11C(yellow)
It shows Kotzebue Sound warming up very well over the last week.

edit:Not sure that 9C in Kotzebue Sound is that realistic, this might need some more work.
edit2: could be ok, slightly over max average water temperatures for june.

Worldview link
I only edited Band15, Day and left Night as it was for comparison

Arctic sea ice / Re: The 2018 melting season
« on: May 24, 2018, 10:12:38 AM »
Wafer Thin refreeze ice north of the Lena delta in the Laptev can't hold out long against current heat influx.. I also made a little gif showing the boundary of the fast ice against a bathymetry map (from the Laptev wiki page) I roughly stretched to match projections

Arctic sea ice / Re: The 2018 melting season
« on: May 22, 2018, 04:21:34 PM »
Thursday's ecmwf wam(wave) forecast from windy certainly won't help.
edit: Looks pretty rough near the Kane Basin arch too

Quite a few red areas on the pacific side using Worldview terra/modis bands 3,6,7. I'm no expert at spotting melt ponds though.

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