2014 Arctic Snow Cover Melting Season

[icefest]

Seeing as Sea Ice has it's own thread and I'm feeling bad about crossposting whenever I mention land snow cover I've started this thread for the discussion thereof.

I've take the liberty of making an updated animation of arctic snow cover. If people are interested, I'm happy to make these more often.

Click for animation.

[prometheus]

This may be a dumb question, but why is the GIS showing regions of ~80% snow cover? I would expect Greenland, outside of regions near the coast, to be a uniform 100%...

[Neven]

Icefest, I've slightly altered your topic title to prevent confusion with the other 2014 melting season thread. Hope that's okay with you.

How does snow cover loss this year so far compare to 2012? In a week or so the Rutgers bar graph for April will be updated, which will give us more of a clue. And there's this new website by the NSIDC as well.

My hunch is it isn't looking too different from 2012 at this stage.

[icefest]

prometheus,
I think the algorithms that remove cloud cover do not work so well above the GIS. I wouldn't rely on this data. I suspect it is because the satellites are optical and do not have the radar penetration; and because the infrared used to detect cloud top temps might be getting interfered with by the cold ice surface.

Neven,
Thanks for changing it.

I'm not tech savy enough to work with the HDF files so I can't compare to 2012. - yet
Once we get into May I'll be able to get png images off earthdata and with some transforming (NASA changed their projections) I should be able to get a 3 year comparison animation.

[Rubikscube]

As requested by F.Tnioli elsewhere I've made another snow cover comparison using the Cryosphere Today images, though, for some reason all pictures between 27. April and 13. May 2012 seem to have fallen out of the CT Archive, thus I only provide a comparison with 2013 this time. (One should keep in mind that the way CT present their data makes snow cover extent in southern latitudes look smaller compared to an equally large extent lokated further North, as opposed to Rutgers maps which slightly overestimates extent far south).



It is clear that the differences in snow cover are much smaller this time than two weeks ago, which is perhaps no big surprise taken in consideration how fast things startet to move on the russian side during early May last year. Though, temps in far eastern russia are currently very high, with temperatures in Yakutsk crossing 20 C during the peak of the day, so further considerable melting should be expected during the coming week.

[Neven]

Rutgers has updated their April graph:

[Rubikscube]

I provide you with another round of my home brew snow cover comparisons in the hope that someone will find these pictures of interest or amusement (preferably both ).
 
2014


2014 vs 2011


2014 vs 2012


2014 vs 2013

(I didn't notice until afterwards that this picture is from the 13th, as it turn out that the CT archives have the 13. May 2013 file stored under both the 13th and 14th, not big difference though)

I remind you that blues represent an increase snow cover, while reds represent a decrease from the year of comparison.

[Shared Humanity]

The impact of an anomalously warm winter and spring in Alaska is certainly visible.

[Rubikscube]

The impact of an anomalously warm winter and spring in Alaska is certainly visible.

It is indeed, and what is also interesting to note is that according to the Rutgers departure map the deficits in eastern Siberia is approximately the size of the ones in Alaska, despite snow cover is this area apparently being much larger than in the three previous years. So it seems like this setup is rather different from both 2012 and especially 2013, even though the total deficits are close to those of previous years.

I'm a little bit surprised that we suddenly have so much more snow in Russia compared to the latest melt seasons, but it seems the high temperetures in these regions were confined to the areas where the snow had allready melted. Either way I still expect to see some serious melting in the coming week, especially in these furthermost eastern regions of Russia.

[Rubikscube]

A weekly update on snow cover.

2014


2014 vs 2011


2014 vs 2012


2014 vs 2013

(Once again the CT archives refuses to display the requested date for 2013, thus forcing me to compare with May 20th, though, this time the comparison is at least made with the same date of 2014. Fortunately all three dates seems to be availible for next week)

There are still substantial deficits in Alaska and substantial surpluses of snow in Eastern Siberia compared to the  last three years, however, the overall differences appear to have declined despite 2014 still lagging behind all years of comparison. It currently looks as though NH snow cover extent this May is going to be the highest since 2009.

[Neven]

Very nice, RC, but if I may ask: how trustworthy is CT for snow cover? What's the resolution, etc? And doesn't Rutgers have anything similar/better?

[Rubikscube]

Very nice, RC, but if I may ask: how trustworthy is CT for snow cover? What's the resolution, etc? And doesn't Rutgers have anything similar/better?

I must admit that I, unlike some other people on this forum, do not posses intimate knowledge about the kind of processing algorithms used to get hold of snow cover extent or SIE/SIA. It appears to me though, that extent wise CT and Rutgers show more or less the same, but that CT in addition has higher resolution, an extra shade, and a generally much cooler look. Whether or not these additional effects are excluded by Rutgers because they are not reliable or not deemed to be of significance, I do not know.

Rutgers do have superior products, their monthly summaries are excelent and their daily maps are very informative, though as far as I know Rutgers do not have the same tools for visual year to year comparisons such as they have for comparisons with the long term average. Neither do I know of anyone who publishes similar maps. Of course there might be good reasons for that, but I still find it rather interesting to make an accurate comparison between this year with the most recent ones.

[diablobanquisa]

Hi Rubikscube, I like your CT comparisons, very nice.

But you can get the Rutgers daily maps (daily snow and daily departure) with the browsing arrows: http://climate.rutgers.edu/snowcover/chart_daily.php?ui_year=2014&ui_day=141&ui_set=0

May 21, 2014





May 21, 2013





May 21, 2012





May 21, 2011





May 21, 2010




May 21, 2009

[Neven]

Very nice, RC, but if I may ask: how trustworthy is CT for snow cover? What's the resolution, etc? And doesn't Rutgers have anything similar/better?

I must admit that I, unlike some other people on this forum, do not posses intimate knowledge about the kind of processing algorithms used to get hold of snow cover extent or SIE/SIA. It appears to me though, that extent wise CT and Rutgers show more or less the same, but that CT in addition has higher resolution, an extra shade, and a generally much cooler look. Whether or not these additional effects are excluded by Rutgers because they are not reliable or not deemed to be of significance, I do not know.

Rutgers do have superior products, their monthly summaries are excelent and their daily maps are very informative, though as far as I know Rutgers do not have the same tools for visual year to year comparisons such as they have for comparisons with the long term average. Neither do I know of anyone who publishes similar maps. Of course there might be good reasons for that, but I still find it rather interesting to make an accurate comparison between this year with the most recent ones.

The reason I asked, is because I really like what you've done with the CT maps, and might use them at some point. But I have to know about accuracy first, of course. I prefer other sea ice concentration maps over CT's for instance.

Thanks for the extra maps, DB. This year Alaska really stands out, but 2010 (the massive volume loss year) was worst of all of them, says the eye ball.

[Rubikscube]

The reason I asked, is because I really like what you've done with the CT maps, and might use them at some point. But I have to know about accuracy first, of course. I prefer other sea ice concentration maps over CT's for instance.

I feel very complemented, but as I vaguely suggested, I cannot give any proper guarantees for their accuracy. I assume that the CT is doing a reasonably professional job, and I have never found clear contradictions with Rutgers, then I try to be as accurate as I can with the false colors. In the end my pictures are perhaps more artistic than scientific, at least in the sense that I do not feel I can guarantee for any the "scientific accuracy".

[Rubikscube]

Another week has passed, thus the time should have come for some snow sover comparisons

2014


2014 vs 2011


2014 vs 2012


2014 vs 2013


I appears as though there hasn't been any further melt in Alaska, but that a lack of melt in this region has been compensated with substantial losses west of the Hudson Bay. This is also a region which is bound to see more great losses during the week to come if weather remains as it is.

On the Russian side things are still moving quite slowly, and again I'm a little bit surprised that the gap between this year and previous years isn't colsing. For the week to come I would expect the melt on the Eurasian side to be slowest in westernmost Russia/Kara area, while I also this week am expecting some action in the Russian far east as well as Scandinavia.

Note by the way the red spot south of Disko Bay, Greenland. Is it a bug or a sign of below normal snow fall during winter months?

[Steven]

Northern Hemisphere snow cover for May 2014 (from Rutgers University Global Snow Lab) was 6th lowest on record, behind 2010-2013 and 1968.

http://climate.rutgers.edu/snowcover/chart_anom.php?ui_set=1&ui_region=nhland&ui_month=5



Monthly Snow - May 2014:

[diablobanquisa]

Northern Hemisphere snow cover for June 2014 (from Rutgers University):



Sixth lowest.

[diablobanquisa]

July (sixth lowest):

[Neven]

July (sixth lowest):

I checked the graph yesterday and thought it wasn't updated because it says 1967-2013, but it looks like someone forgot to change to 2014.

[diablobanquisa]

August:



http://climate.rutgers.edu/snowcover/

[BornFromTheVoid]

3rd largest snow cover extent on record for September



http://climate.rutgers.edu/snowcover/table_rankings.php?ui_set=1

[wili]

So does that bode well for a further recovery of sea ice mass this winter?

[ChrisReynolds]

BFTV,

You might find this of interest:
http://web.mit.edu/jlcohen/www/Cohen_NOAA_fcst.pdf

Cohen relies on October snow advance in Eurasia. The correlation between snow advance in September and October doesn't seem great. But the snow advance over Eurasia in September has been the greatest recorded by a large margin. EDIT - made a mistake, it's the total NH snow cover that has been the largest due to N America, Eurasia is one of the highest but not the highest.

Could this mean we're in for another Warm Arctic - Cold Continents pattern winter? If we are then the process involves wave breaking driven by the snow advance. Might be worth looking for Sudden Stratospheric Warming over the pole.

I've been in touch with Dr Cohen in the past, I may email him again.

[BornFromTheVoid]

BFTV,

You might find this of interest:
http://web.mit.edu/jlcohen/www/Cohen_NOAA_fcst.pdf

Cohen relies on October snow advance in Eurasia. The correlation between snow advance in September and October doesn't seem great. But the snow advance over Eurasia in September has been the greatest recorded by a large margin.

Could this mean we're in for another Warm Arctic - Cold Continents pattern winter? If we are then the process involves wave breaking driven by the snow advance. Might be worth looking for Sudden Stratospheric Warming over the pole.

I've been in touch with Dr Cohen in the past, I may email him again.

Hi Chris,
I'm familiar with Cohen's work, though I believe the SAI is mainly based on the rate of snow cover build up south of 60N. The big thing at the moment is the October Pattern Index (OPI), which claims a 0.91 correlation with the winter AO between 1976 and 2012. It seems to be based off several 500hPa height anomaly fields and the orientation of the polar vortex during October.



There doesn't appear to be much in English that explains it well, so you might need to use google translate!
http://www.centrometeotoscana.it/forum/index.php?topic=7364.msg

It's currently very negative, so it will be interesting to see how things pan out through the rest of the month.
http://app.til.it/opi/

[ChrisReynolds]

Thanks BFTV,

I can't read that OPI page - lots of text cut out because I am not a member. But I found your comment at NetWeather.
https://forum.netweather.tv/topic/81494-october-pattern-index-opi-monitoring-winter-season-2014-2015/page-6

I'll dig into this when NCEP/NCAR is back on line.

Is this something you havve found or is it in the literature?

BTW Cohen & Jones 2011 "A new index for more accurate winter predictions" do state:

The snow advance index (SAI) is the regression coefficient of the least square fit of the daily Eurasian SCE equatorward of 60°N calculated for the month of October.

I had just wondered if September might be a good set up for an October advance.