Please support this Forum and Neven's Blog

Author Topic: Siberian Arctic coast  (Read 36192 times)

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #50 on: March 05, 2016, 07:48:31 PM »
That made me look up temperatures for Tiksi (next door to the Lena delta).
Monthly plots are May and June last year (later melt than 2014). As one would expect high temps correlate with southerly winds, cold with north and easterly winds blowing over the ice. The air is warmed by dark land surfaces where a thin surface layer (with permafrost below) warms quickly. My point is that thicker snow delays warming by lowering albedo for longer. Of course weather conditions can overwhelm that effect.
If inflows of warmer and moister air this winter increased snowcover, then this could have a negative feedback effect which may  reduce the effect of lessened ice growth.
There are physical reasons why ice doesn't disappear as easily as is often predicted. That doesn't mean nothing is changing.

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #51 on: March 21, 2016, 12:28:25 PM »
the cracking ice between Wrangel island and the coast made me look up some weather data for the region e.g. http://www.wunderground.com/history/wmo/25051/2016/1/21/MonthlyHistory.html?req_city=Pevek&req_statename=Russia&reqdb.zip=00000&reqdb.magic=1&reqdb.wmo=25051
interesting to see the breaking ice correlating coinciding with strong wind. The strong wind also brings higher temps but still below freezing, I think this shows in the satellite images where open water is freezing over.

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #52 on: March 21, 2016, 12:49:27 PM »
I also looked at comparisons with recent years, this kind of cracking is no unusual, maybe closer to the coast this year.
The recent discussion of the effect of snow made me look for data http://www.weatheronline.co.uk/weather/maps/city and I found snow depth for wrangel island surprising given the arctic wide charts shown on another thread by seaicesailor http://forum.arctic-sea-ice.net/index.php/topic,1493.msg71604.html#msg71604
his could be because this single location is not representative of the wider area? but nevertheless I'll put it here to see if it helps to interpret what happens later in the melting season.
« Last Edit: March 21, 2016, 12:56:16 PM by Andreas T »

meddoc

  • ASIF Citizen
  • Posts: 150
    • View Profile
Re: Siberian Arctic coast
« Reply #53 on: March 21, 2016, 09:30:33 PM »
My guess is it's not only surface & jetstream winds that are causing those higher temps...

http://postimg.org/gallery/18pthc6zo/04132433/


 :(

seaicesailor

  • Guest
Re: Siberian Arctic coast
« Reply #54 on: March 21, 2016, 09:34:53 PM »
I also looked at comparisons with recent years, this kind of cracking is no unusual, maybe closer to the coast this year.
The recent discussion of the effect of snow made me look for data http://www.weatheronline.co.uk/weather/maps/city and I found snow depth for wrangel island surprising given the arctic wide charts shown on another thread by seaicesailor http://forum.arctic-sea-ice.net/index.php/topic,1493.msg71604.html#msg71604
his could be because this single location is not representative of the wider area? but nevertheless I'll put it here to see if it helps to interpret what happens later in the melting season.


It is a single point, but observations nonetheless!. Models of snow depth have very bad reputation. Thank you Andreas for so many data.

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #55 on: March 22, 2016, 12:56:42 AM »
I should have looked this up earlier, the same data is available for Pevek on Chunskaya bay, which has a very different pattern from Wrangel island

and Tiksi further west along the coast near the lena delta

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #56 on: March 22, 2016, 01:40:15 AM »
comparing 2014 and 2015 on worldview july3 and 4 (last years abbreviated links no longer work)https://worldview.earthdata.nasa.gov/?p=arctic&l=MODIS_Terra_CorrectedReflectance_TrueColor,Graticule,Coastlines&t=2015-07-03&v=-1569373.1042577664,1708828.9817932022,-928349.1042577664,2018076.9817932022
fits the pattern of snowdepth well:
chaunskaya bay broke up earlier in 2015 than 2014
landfast ice east of tiksi broke up earlier in 2014 than in 2015

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #57 on: April 18, 2016, 09:10:32 PM »
SAR image north of Lena delta 15.4.  http://www.polarview.aq/images/106_S1jpgsmall/201604/S1A_EW_GRDM_1SDH_20160415T223508_2B38_N_1.jpg
I'm posting this to see later whether any of the features are recognizable

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #58 on: May 17, 2016, 03:22:56 PM »
The loss of snow cover is surprisingly quick. Having earlier pointed out higher snow level at Pevek than last year, I didn't expect Chaunskaya bay to darken so quickly. Further west we are also seeing the ice exposed (darker because it is more transparent than snow) after a short period of high temperatures. the reason I think we are seeing the ice itself are the different types of ice, formed under different condition which are showing.
This would indicate the snow was thin before. I do not think the bluish hues others have seen are more than the variations you get with light angle in MODIS tracks.
Pity we do not have better information from the groundlevel

werther

  • ASIF Middle Class
  • Posts: 705
    • View Profile
Re: Siberian Arctic coast
« Reply #59 on: May 17, 2016, 10:27:08 PM »
Andreas, you’re welcome to not see those blue hues as variations in light angle as picked up by the MODIS sensor.
But as I’ve come to see these blue hues in spring, they’re true proxy for wet snow, water on ice and surface melt.
The Kolyma delta today:



That blue is not a trick of light. It is a river breaking through and wide spread water on ice. Cherskiji, a town 90 km upstream, had +17 dC yesterday!

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #60 on: May 17, 2016, 10:54:58 PM »
Sorry if I expressed myself badly I don't dispute this kind of blue as indication of melting. The hues I doubt are less clearly located in a geographical area. One side of a modis swath is usually brownish in hue the other blueish, despite the name "true colour" in worldview I think it can be best to not take this always literally.

werther

  • ASIF Middle Class
  • Posts: 705
    • View Profile
Re: Siberian Arctic coast
« Reply #61 on: May 17, 2016, 11:41:25 PM »
Accepted, Andreas.
I agree it is not easy to interpret all information that can be deriven from MODIS.

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #62 on: May 18, 2016, 10:10:30 PM »
when I looked at this graph for snow depth at pevek I am greatly surprised that the snow mostly disappeared in March! Can this be corroborated?

edit: just found temp and wind speed for March on wunderground https://www.wunderground.com/history/wmo/25051/2016/3/18/MonthlyHistory.html?req_city=Pevek&req_state=&req_statename=Russia&reqdb.zip=00000&reqdb.magic=1&reqdb.wmo=25051
no melt likely but strong wind from the south seems to have blown it out over the sea ice (and sublimated some) which fits the shape of the dark patch in chaunskaya bay.
Another observation near the Kolyma delta: an IR image from the end of January shows that the lighter lines are younger ice formed where cracks opened in the middle of winter
 http://go.nasa.gov/1Tp5W2h colour scale squashed 230 - 280K to fit the low temps of that time of the year.
identically framed (edit: almost) image from today for comparison
« Last Edit: May 18, 2016, 10:27:50 PM by Andreas T »

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #63 on: May 28, 2016, 02:01:45 PM »
As a response to a post by S Pansa http://forum.arctic-sea-ice.net/index.php/topic,119.msg78292.html#msg78292on another thread I have looked at deformation of ice in the western Chukchi sea where PIOMAS and cryosat are showing surprisingly thick ice.
The images are AMSR-2 brightness temperature on worldview http://go.nasa.gov/1XXcE1b
Although I don't think I can relate the colours shown to thickness or other clearly identifiable parameters of the ice, they do show up persistent features which help tracking movement over long periods and through clouds. Unfortunately there are no AMSR-2 images in worldview before 12 Jan 2016.
I have marked some features which show a reduction in area between these features and therefore an increase in thickness, because at that time of the year volume does not decrease.
I expect that to happen through formation of ridges so that the average thickness includes first year ice with thickness below 2m together with overriding and tilted floe edges which form  the much thicker ridges.
dates are shown in file names: 4 Feb, 20 Feb, 5 Mar, 21 Mar
« Last Edit: May 28, 2016, 02:26:54 PM by Andreas T »

seaicesailor

  • Guest
Re: Siberian Arctic coast
« Reply #64 on: May 28, 2016, 02:20:34 PM »
Wow Andreas that is cool. Somebody been sweeping over the Actic.
So your images show these compression regions are really confined, should be thick enough to make for the increased effective thickness even when surrounding ice is 2m. Chris Reynolds shows gice plots the statistical tail of many meters thick ice increase a lot indeed.

http://dosbat.blogspot.com.es/2016/05/piomas-april-2016.html?m=1

Laurent

  • ASIF Governor
  • Posts: 2524
    • View Profile
Re: Siberian Arctic coast
« Reply #65 on: May 28, 2016, 03:18:11 PM »
Oups west of Wrangel Island, west of Wrangel islands Laurent!
Does look even worse... Nothing to quantify but should we at this point, it is all wrecked, broken into pieces. Just a little band one or two kilometres wide remain !
« Last Edit: May 28, 2016, 03:59:54 PM by Laurent »

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #66 on: May 28, 2016, 03:38:44 PM »
The gif does not play when I click on it :(

edit: now it does , thank you!
but now I realize that you are showing east of Wrangel and I am talking mainly about west :-[
still not completely off topic I think

This ice has been broken several times during the winter, that it breaks again is not a sign that all of it is thin. What we are concerned about is ice melting not that it doesn't stay in one piece.
Of course that may have an effect on warming of water later, but it is worth keeping the distinction in mind.
Have a look at previous years, it was broken up in 2014 at this time but still around in July http://go.nasa.gov/22rV7Pi
« Last Edit: May 28, 2016, 03:44:35 PM by Andreas T »

Laurent

  • ASIF Governor
  • Posts: 2524
    • View Profile
Re: Siberian Arctic coast
« Reply #67 on: May 28, 2016, 03:58:17 PM »
Yes, damned me, East of Wrangel Island. I think that is what S.Pansa was pointing at ?

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #68 on: May 29, 2016, 06:11:15 PM »
http://forum.arctic-sea-ice.net/index.php/topic,119.msg69488.html#msg69488
http://forum.arctic-sea-ice.net/index.php/topic,119.msg71526.html#msg71526
These are the monthly animations Wipneus has posted for January and Febuary which shows when (according to PIOMAS) this ice has grown so thick. The Febuary burst in thickening fits with the movement shown in the AMSR-2 images in my earlier comment. Another good place to follow (large scale) movement if one doesn't want to rely on models is the NIPR ADS site (also using AMSR-2 brightness but animating quicker than worldview)

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #69 on: May 30, 2016, 01:13:04 PM »
squashing the colour scale to 268 - 282K on daytime aqua produces this image for the Chukchi and siberian coast to Wrangel.
http://go.nasa.gov/1TSdXwK
I think it picks out thicker, colder floes but I am not sure how much brightness temperature at that sort of fine detail is actually showing surface temperature with such accuracy. Emissivity effects possibly start to play a role and are there contributions from the atmosphere?

I still think it indicates warming water in the Chukchi sea and that some floes will resist melting longer than others, we will see and hopefully lern more about interpreting these images in the process.


jdallen

  • ASIF Upper Class
  • Posts: 2432
    • View Profile
Re: Siberian Arctic coast
« Reply #71 on: June 02, 2016, 03:55:43 AM »
BTW - OT aside - I want to give a shout out to Andreas T for getting this thread started.  It's nice to have a landing spot for this discussion and images going forward.  I hope it becomes a useful record.
This space for Rent.

Adam Ash

  • ASIF Citizen
  • Posts: 246
    • View Profile
    • The 100 metre line
Re: Siberian Arctic coast
« Reply #72 on: June 02, 2016, 11:11:37 AM »
Interesting to compare 2016 with same date 2015

http://www.arctic.io/explorer/8-8/2016-06-01;2015-06-01/6-N70.92097-E174.56061

..and to step on for a few days from 1 June in 2015 to see the trashing of ice between Wrangle and Bering Straight.
« Last Edit: June 02, 2016, 11:17:33 AM by Adam Ash »

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #73 on: June 02, 2016, 08:20:03 PM »
what stands out for me in these images is how much less snow cover there is in 2016. Temperatures are forecast to rise from 12oC to 24oC on Monday at Pevek. When snow is gone the ground (surface) warms up quickly
Wrangel has a forcast of 13oC on Sunday
http://www.weatheronline.co.uk/RussianFeder/WrangelIsland.htm
this site also gives a temperature curve for Wrangel island for the last 200 weeks, but sadly not for Pevek.

Timothy Astin

  • ASIF Lurker
  • Posts: 50
    • View Profile
Re: Siberian Arctic coast
« Reply #74 on: June 03, 2016, 01:47:28 PM »
As Werther noted in the 2016 melting thread, the Lena Delta is seen clear and beautiful in MODIS today.

Lets compare the Lena River and the Mackenzie River to get some idea of the Lena River and delta potential for sea ice melting.

During the peak month (May) of river discharge, the Mackenzie River averages about 15,000 m3/s discharge. During its peak month (June), The Lena River averages about 80,000 m3/s (https://epic.awi.de/37164/1/Fedorova_et_al_2015_BG.pdf Fig.2), so about 5 times as much potential heat input as the Mackenzie.  Again by comparison with the timing of water appearing at the delta edge on the two deltas, peak discharge at the Lena delta coastline is sometime in the next couple of weeks.

The Lena delta has a much wider area of landfast ice for the discharge water to flow under before it reaches the widening dark ocean. And the Lena delta is almost at a rightangle to the regional Laptev "ice/coast line".  But I think we can infer a significant Lena river boost to ice melting in the Laptev Sea during June.  (From the discussions of the Mackenzie River input in the 2016 thread, I estimate that at its peak, the Mackenzie River contributed equivalent of about 25% of insolation heat input into the expanding Beaufort polynya. The size of the Lena River implies an even more significant contribution.)

No doubt others can improve these estimates.


Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #76 on: June 04, 2016, 07:20:54 PM »
Jay W, I don't understand why you don't use worldview http://go.nasa.gov/22FavIe please explain if I am just being dense. ???
To get a sigtly different angle I have looked up air temperatures reported at Tiksi in June and July 2014 and 2015.
http://www.weatheronline.co.uk/weather/maps/city Combining this with visible images is giving an idea what needs to happen to make the ice disappear in that part of the siberian coast.
melting out was around 9. July   in both years

JayW

  • ASIF Citizen
  • Posts: 350
    • View Profile
Re: Siberian Arctic coast
« Reply #77 on: June 04, 2016, 09:14:59 PM »
Hi Andreas,

  I just prefer to watch the animations available made with multiple images per day, to get a good handle on ice movements from the Colorado state site.  And I also prefer the VIIRS imagery, as each image covers a much wider field of view than the MODIS images.  Also, the images available from the university of Alaska fairbanks are of very high resolution, again, an advantage in my mind.

"To defy the laws of tradition, is a crusade only of the brave" - Les Claypool

oren

  • ASIF Upper Class
  • Posts: 1547
    • View Profile
Re: Siberian Arctic coast
« Reply #78 on: June 04, 2016, 10:25:19 PM »
To get a sigtly different angle I have looked up air temperatures reported at Tiksi in June and July 2014 and 2015.
Combining this with visible images is giving an idea what needs to happen to make the ice disappear in that part of the siberian coast.
melting out was around 9. July   in both years
Temperatures seem to be one week ahead this year.

JayW

  • ASIF Citizen
  • Posts: 350
    • View Profile
Re: Siberian Arctic coast
« Reply #79 on: June 08, 2016, 12:03:05 PM »
To get a sigtly different angle I have looked up air temperatures reported at Tiksi in June and July 2014 and 2015.
Combining this with visible images is giving an idea what needs to happen to make the ice disappear in that part of the siberian coast.
melting out was around 9. July   in both years
Temperatures seem to be one week ahead this year.

Looking at Wipneus' images, the ESS area numbers in particular, it appears the a sudden drop followed by recovery may be common, and the important first step towards "real melt".  Not just surface melting.  The "V" this year was slightly ahead of others, except maybe 2014.

2nd attachment is a close-up

https://sites.google.com/site/arcticseaicegraphs/regional
"To defy the laws of tradition, is a crusade only of the brave" - Les Claypool

NW Passenger

  • ASIF Lurker
  • Posts: 3
    • View Profile
Re: Siberian Arctic coast
« Reply #80 on: June 10, 2016, 06:19:28 AM »
Fast ice in the ESS is showing cracks in today's MODIS imagery.  With all the melt ponding, I can't help but think that the rest of the ESS and Laptev can't be too far behind.  That should help get the drops in sea ice extent and area going again over the next couple weeks. 

« Last Edit: June 10, 2016, 06:47:41 AM by NW Passenger »

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #81 on: June 12, 2016, 10:34:51 AM »
....

Looking at Wipneus' images, the ESS area numbers in particular, it appears the a sudden drop followed by recovery may be common, and the important first step towards "real melt".  Not just surface melting.  The "V" this year was slightly ahead of others, except maybe 2014.

...

This is an interesting observation, fitting with the visual pattern. In 2014 though the sudden drop in May was due to the sea ice pack moving away from the landfast ice and opening water that way see worldview around 20th Mayhttp://go.nasa.gov/1tkbWPP. This was the year of the early Laptev bite. This year the movement has been more along the coast and has exposed less water. This can change quite quickly I think when a push from southerly winds appears, the pack is starting to look quite "loose" now with gaps appearing between floes.

JayW

  • ASIF Citizen
  • Posts: 350
    • View Profile
Re: Siberian Arctic coast
« Reply #82 on: June 14, 2016, 12:47:57 PM »
2 days over Wrangel island.  Day 1 the storm moves through and puts down a small amount if snow on the east side of Wrangel, but then melts as the sun returns.

It's interesting how vastly different this ice looks than the Beaufort.  Much smaller pieces.  The west to east motion of the ice along the shore isn't terribly noticeable on my animation, but it's there.  Then the ice takes an abrupt left turn after getting by Wrangel, where it joins the dark swirls of the Chukchi.

There's an unavoidable gap between about 0z-12z.  The satellite just doesn't catch those areas at those times.

Images courtesy of the university of Alaska at fairbanks
http://feeder.gina.alaska.edu/search?commit=Search&search%5Bend%5D=&search%5Bfeeds%5D%5B1%5D=1&search%5Bfeeds%5D%5B10%5D=1&search%5Bfeeds%5D%5B11%5D=1&search%5Bfeeds%5D%5B12%5D=1&search%5Bfeeds%5D%5B13%5D=1&search%5Bfeeds%5D%5B14%5D=1&search%5Bfeeds%5D%5B15%5D=1&search%5Bfeeds%5D%5B16%5D=1&search%5Bfeeds%5D%5B17%5D=1&search%5Bfeeds%5D%5B18%5D=1&search%5Bfeeds%5D%5B3%5D=1&search%5Bfeeds%5D%5B5%5D=1&search%5Bfeeds%5D%5B6%5D=1&search%5Bfeeds%5D%5B8%5D=1&search%5Bfeeds%5D%5B9%5D=1&search%5Bsensors%5D%5B3%5D=1&search%5Bstart%5D=&utf8=
"To defy the laws of tradition, is a crusade only of the brave" - Les Claypool

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #83 on: June 15, 2016, 12:14:10 AM »
Chaunskaya bay is breaking up, earlier than the last 3 years. The ice didn't look as thin (as much as one can tell from a satellite photo) to me than at previous breakups.

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #84 on: June 15, 2016, 05:32:54 PM »
The ice in the ulf of Ob is not just breaking but disintegrating. It also looks thin to me because it is transparent, a stream of sediment rich water can be seen entering under the ice from the Taz estuary.
A comparison with the next bay to the east where much less riverwater is entering may illustrate the role freshwater from further inland can play. The ice surface did not show signs of surface melting as elsewhere, yet bottom melt seems to have reduced the ice to a very weak state in a shorter time .

JayW

  • ASIF Citizen
  • Posts: 350
    • View Profile
Re: Siberian Arctic coast
« Reply #85 on: June 17, 2016, 12:53:27 PM »
First animation Siberian coast from May 20-June 17

I used the "day-night" band, which I hope really shows is utility in the winter months.  :)

Sure looks like the most recent frames show a large swath of ice shattering into tiny pieces and being swept north. (Edit: more like northeast.)

Second attachment is the Chukchi over the same period, I know the Chukchi hasn't seen great losses as of late, but the ice looks very sparse.  It also looks like a fair amount has been brought into the area, only to melt.   Open water moving steadily towards Wrangel island.

VIIRS imagery courtesy of Colorado state university.

http://rammb.cira.colostate.edu/ramsdis/online/archive_with_thumbnails_hi_res.asp?data_folder=npp_viirs_arctic/alaska_overview_day_night_band_solar_ref&width=800&height=800
« Last Edit: June 17, 2016, 01:01:07 PM by JayW »
"To defy the laws of tradition, is a crusade only of the brave" - Les Claypool

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #86 on: June 20, 2016, 11:16:05 PM »
A week of sunshine on ice thinned by the river inflow (Ob)http://go.nasa.gov/28Kxrnh and this is the result:

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #87 on: June 25, 2016, 02:50:21 PM »
Chaunskaya bay is breaking up, earlier than the last 3 years. The ice didn't look as thin (as much as one can tell from a satellite photo) to me than at previous breakups.

click on quote to see image from 14th.
In previous years ice has disappeared quickly after breakup, this year the early breakup has not meant early melt. Compare with 2015 in worldview.
http://go.nasa.gov/293W0d6

further west breakup is progressing east of Lena delta
http://go.nasa.gov/293WqjV
« Last Edit: June 25, 2016, 02:56:38 PM by Andreas T »

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #88 on: June 26, 2016, 02:37:15 PM »
another fairly clear view of the Gulf of Ob allows comparison with the image of the 15th. Only small remnants of ice remain in the gulf whereas the next bay to the east (sorry for not looking up the name, maybe somebody else can help out) which does not have much river input is still largely ice covered.

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #89 on: June 26, 2016, 02:57:46 PM »
« Last Edit: June 26, 2016, 07:48:42 PM by Andreas T »

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #90 on: July 03, 2016, 07:35:04 AM »
an update on Chaunskaya bay (near Pevek):
The ice is in the last stages of melting out. 2015 was in a similar state at this time and all gone on the 6th after 4 days of sunshine. http://go.nasa.gov/29q1vmO

Tor Bejnar

  • ASIF Upper Class
  • Posts: 1486
    • View Profile
Re: Siberian Arctic coast
« Reply #91 on: July 07, 2016, 12:07:10 AM »
Neven, on the ASIB, wrote
... Who knows, maybe a lot of that thicker ice on the Siberian side of the Arctic will be preserved and the Northern Sea Route won't open up completely for the first time in a decade. But somehow I doubt it.
  I also had that first thought ... and the doubt.  :)
Arctic ice is healthy for children and other living things.

seaicesailor

  • Guest
Re: Siberian Arctic coast
« Reply #92 on: July 07, 2016, 12:42:32 AM »
Neven, on the ASIB, wrote
... Who knows, maybe a lot of that thicker ice on the Siberian side of the Arctic will be preserved and the Northern Sea Route won't open up completely for the first time in a decade. But somehow I doubt it.
  I also had that first thought ... and the doubt.  :)
The storm will also be pulling ice against the warm open water and the warmed lands, apart from the usual mess around. Bring cold, too but not good so close to the coast. But then again, after many of us predicting open coasts from Canada to Siberia by the 1st of June... I have my doubts too

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #93 on: May 21, 2017, 12:16:32 AM »
I looked at the open water off Chaunskaya bay and there are the first signs of melting. Snow cover is disappearing on land but also on the landfast ice. Floating ice is disintegrating as well as darkening.
The brief animation shows recent cloud free days: 16th,19th 20th as well as the age of the melting ice: disintegrating ice formed at the end of March, the ice loosing snow cover formed end of February, so had less cover than ice from the autumn.

Shared Humanity

  • ASIF Upper Class
  • Posts: 2069
    • View Profile
Re: Siberian Arctic coast
« Reply #94 on: May 21, 2017, 04:36:58 PM »
A lot of clouds forming over the open water. Is this due to high humidity and what impact on the melt?

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #95 on: May 21, 2017, 05:19:18 PM »
Yes humidity which is above the dewpoint at temperature above the ocean which is colder than land which is wet from melting snow. (sorry about the mangled sentence but I hope you get my meaning)
The cloud is quite thin, we can see the dark waters below, so quite some sunlight is reaching down and is absorbed but albedo is increased compared to clear sky, less energy coming in. But also less energy going out (cloud top cooler than surface). Quantifying this is beyond me, it clearly would require knowing exactly how thick / warm the cloud is. The condensing humidity releases additional energy (picked up when water evaporated on land), since cloud tops are no warmer than surface below, this energy must be radiated to the ground I reckon.
worldview link https://go.nasa.gov/2qIb1v5 (should have done this in the earlier post)
temperature scale squashed to 255K - 280K

JayW

  • ASIF Citizen
  • Posts: 350
    • View Profile
Re: Siberian Arctic coast
« Reply #96 on: May 22, 2017, 12:44:04 PM »
First attachment is a 100 hour loop.  "Landcover" band helps separate the clouds from the snow and ice.

Second attachment shows a plane contrail I noticed while making the gif, and it's shadow.  The lower sun angle shots can draw out features that often get lost.  Comparing it to the very "short shadows" of the low clouds/fog/sea smoke, we can see that these are quite thin and close to the surface.

All images courtesy of the University of Alaska at Fairbanks.
http://feeder.gina.alaska.edu/npp-gina-alaska-landcover-images?page=4&search%5Bfeeds%5D%5B6%5D=1&search%5Bsensors%5D%5B3%5D=1
"To defy the laws of tradition, is a crusade only of the brave" - Les Claypool

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #97 on: May 25, 2017, 06:44:56 PM »
Looking at your animation reminds me to look more carefully at wind directions, I don't think my claim of moisture forming those clouds coming from adjoining land stacks up looking more carefully. The way low cloud formation follows the coast does relate it to the lower temperatures of the sea surface (both ice covered and open ) compared to land.

Keeping an eye out for effects of rising water temperature, I spotted this floe which is stuck, probably on the shallow sea floor. A smaller part of it has been stuck since February, more ice has stuck to it since. It must have some pretty substantial ridge I guess.
Another noticeable feature in this image are the swirls of less clear water, sediment? algae?

seaicesailor

  • Guest
Re: Siberian Arctic coast
« Reply #98 on: May 25, 2017, 07:06:23 PM »
Intrusions of water from further East mixing with coast sediments?

Andreas T

  • ASIF Upper Class
  • Posts: 1076
    • View Profile
Re: Siberian Arctic coast
« Reply #99 on: May 26, 2017, 12:39:30 AM »
I found this http://s3.nprb.org/projects/40093f37-6464-439e-a836-c84a2998ecec/FinalReport1225.pdf with sea floor charts. these are low resolution versions but it looks like there is a very shallow spot just where that floe is stuck. Water depth seems to be less than 10m.