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Messages - Tealight

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1
Antarctica / Re: Sea Ice Extent around Antarctica
« on: May 12, 2019, 06:03:23 PM »
Hi Rich, the current low sea ice extent is caused mostly by the Weddel Sea (see picture below). The Ross Sea is around average. I would say the cause is the current weather pattern. The circumpolar winds are very weak and plenty of mid latitude warmth reaches further south. Somewhere I read that the Antarctic Circumpolar Current is gradually moving south over the last few years, but I can't remember the source.

2
Arctic sea ice / Re: Albedo-Warming Potential
« on: May 05, 2019, 11:18:23 PM »
Thanks everyone. I can confirm it feels good to beat major international organisations like NASA, MetOffice and ecmwf.

Tealight, you derive AWP using sea ice area and then use this as a basis to calculate the energy available to reduce sea ice thickness ? How do you translate reduced thickness into resulting sea ice area and extent? A sea might have remaining ice piled up in one area  or spread out giving a higher extent value due to varying winds and currents?

Technically I keep track of two sea ice concentration values. One to calculate the melt (using SIC from previous years) and another calculated from thickness. The second one is the final model output. The additional thickness step makes the model more robust against flashes of low SIC like short term melt ponds.

For the Antarctic I used the following formula to get the best results:
SIC(%) = (Thickness(m)^1.3) / 0.0155

Thickness(m)   SIC value (%)
1.4   100
1.25   86
1   65
0.75   44
0.5   26
0.25   11
0   0

anything over 1.4m stays at 100% SIC.

3
Arctic sea ice / Re: Albedo-Warming Potential
« on: May 05, 2019, 08:27:26 PM »
Very popular here are the sea ice minimum and maximum polls guessing the correct sea ice extent in millions of square kilometer. A more scientific oriented version of it is the Sea Ice Prediction Network: https://www.arcus.org/sipn
This year was the second time they made a trial run to forecast the Antarctic summer minimum and I participated (as Nico Sun) with a forecast model derived from this Albedo-Warming Potential model. The underlying physics are the same. The major difference is that instead of accumulating an energy value in a grid cell, this energy is used to calculate the sea ice thickness loss. Additionally I added an outgoing infrared radiation variable to get an actual energy balance.

With the post season report released I can proudly claim victory not only in overall area values, but also on a regional scale with the lowest error over the entire 3 month forecasting period. This is in part thanks to the real world usefulness of the AWP model and in part due to the submission deadline of 1st December. Some other team's can only run their models at the beginning of every month and had to use October data for their model initialization. I attached the two most relevant figures, but recommend to read the whole report.

Full 2018-2019 post season report
http://www.climate.be/users/fmasson/SIPN-South_2018-2019_postseason.pdf

General SIPN south website
http://acecrc.org.au/sipn-south/


Sea Ice Loss Formula of the forecast model:

Ed = MJ_inlat,day x (1 - SIC) - MJ_out
z = Ed / Efusion

Ed = Melt energy per day
MJ_in = incoming solar radiation per m2
MJ_out = outgoing infrared emmision per m2
SIC = sea ice concentration
z = thickness loss in m
Efusion = Enthalpy of fusion per m3

4
Antarctica / Re: What's new in Antarctica ?
« on: May 04, 2019, 06:29:14 PM »
I made some Glacier size comparison charts featuring Greenland & Antarctic Glaciers. I hope it better visualizes how much ice is exposed to ocean water than a Bedrock map. The charts shows the dimensions of the glacier front. Where the x-axis is the glacier width and the y-axis is the glacier height.

https://cryospherecomputing.tk/Glacier-size

(same post as what's new in Greenland)

5
Greenland and Arctic Circle / Re: What's new in Greenland?
« on: May 04, 2019, 06:28:40 PM »
I made some glacier size comparison charts featuring Greenland & Antarctic Glaciers. I hope it better visualizes how much ice is exposed to ocean water than a Bedrock map. The charts shows the dimensions of the glacier front. Where the x-axis is the glacier width and the y-axis is the glacier height.

https://cryospherecomputing.tk/Glacier-size

6
Arctic sea ice / Re: AMSR2 Snow & Ice Volume/Thickness
« on: May 03, 2019, 11:29:48 AM »
Another month of low overall gain, but above average thickness.

Full size images and April animation at:
https://cryospherecomputing.tk/SIT

7
Arctic sea ice / Re: Albedo-Warming Potential
« on: May 01, 2019, 01:05:08 AM »
Just in time before the May melt ponds start I created the regional anomaly charts. Just like last year almost all of the early accumulated AWP anomaly comes from the Bering Sea, but this year none of the regions is in the negative.

https://cryospherecomputing.tk/NRTawp

8
Arctic sea ice / Re: Albedo-Warming Potential
« on: April 27, 2019, 07:04:48 PM »
Before working on all region graphs I created another section for the High Arctic. This one should be more useful for determining the record low in September. It only includes the following regions: Kara Sea, Laptev Sea, East Siberian Sea, Chukchi Sea, Beaufort Sea, Canadian Archipelago, Central Arctic.

For the high Arctic 2012 still holds the record high followed by 2016 in second and 2007/2011 tied in third. The far higher average ice cover also significantly increases the gap to a completly ice-free state. On one hand the 2010s just reach 40% of the ice-free conditions compared to 61% for the whole Arctic. But on the other hand the 2010s absorb 32% more than the 1980s. For the whole Arctic it's just 15% more. So the last ten years really impacted the high latitudes more than the lower ones.

https://cryospherecomputing.tk/awp

Note: Before doing this recalculation I increased the ice albedo from 80% to 85% relative to ocean albedo. This is more in line with the values I measured from satellite images. The result is slighly lower absolute values, but hardly any change to anomaly values. The near-real time data will be updated tomorrow.

9
Antarctica / Re: What's new in Antarctica ?
« on: April 23, 2019, 01:49:47 AM »
The Antarctic Bedrock data was over 10 times harder to align than Greenland. There are hardly any landmarks, just plain white and with fast ice or ice shelfs you don't even know where the land begins. I had to use huge area images to align islands and then cut it down to individual glaciers. The bedrock resolution is just 1km/px as opposed to 0.15km/px for Greenland data.

https://cryospherecomputing.tk/Bedrock-Antarctica

10
Greenland and Arctic Circle / Re: What's new in Greenland?
« on: April 22, 2019, 12:08:53 PM »
Did anybody say their favorite glacier isn't featured? No? Well here is all of Greenland Bedrock anyway.

https://cryospherecomputing.tk/Bedrock

11
Arctic sea ice / Re: Albedo-Warming Potential
« on: April 20, 2019, 05:33:12 PM »
Two images to show the current massive regional differences. First a Peak Watt map showing maximum solar intensity at noon. It might be important to get the initial punch to turn snow into a melt pond. The high Arctic never receives this intensity and relies entirely on imported warmth.

For daily averaged energy values the Sea of Okhotsk, closely followed by Bering Sea currently absorbs over ten times more energy than the central Arctic.

Arctic mean: 6.1 MJ/m2

Sea of Okhotsk   18.711
Bering Sea   16.264
Hudson Bay   4.977
Baffin Bay   9.695
East Greenland Sea   8.159
Barents Sea   8.567
Kara Sea   2.753
Laptev Sea   2.387
East Siberian Sea   2.462
Chukchi Sea   3.255
Beaufort Sea   2.598
Canadian Archipelago   2.75
Central Arctic   1.601

12
Greenland and Arctic Circle / Re: What's new in Greenland?
« on: April 20, 2019, 11:37:05 AM »
New Bedrock overlay page for all of Greenlands major glaciers.

https://cryospherecomputing.tk/Bedrock

13
Greenland and Arctic Circle / Re: Bedrock overlay poll
« on: April 20, 2019, 11:34:33 AM »
Thanks everyone for voting. As I suspected both options have a use case. The problem with combining them was that the template for the image overlay slider and the template for the range slider both had "slider" in the name and interferred with another. I solved it by setting the opacity with a number input field and a button.

The test pages are now removed and the overlays have an offical page:
https://cryospherecomputing.tk/Bedrock

14
Greenland and Arctic Circle / Bedrock overlay poll
« on: April 14, 2019, 03:40:48 AM »
I've often seen users asking about a glaciers bedrock elevation to estimate future retreat. Then some veteran users post a bedrock map, but it's still difficult to compare it to current satellite images. Therefore I want to build a bedrock overlay webpage for all major glaciers. However I'm not sure which of the two presentation styles is better.

You can vote for both options if you have no major preference.

Horizontal overlay
https://cryospherecomputing.tk/Test1

Full image Opacity
https://cryospherecomputing.tk/Test2

15
Arctic sea ice / Re: Albedo-Warming Potential
« on: April 11, 2019, 12:11:44 AM »
Some feedback - not sure if you are aware but images don’t seem to load on mobile. When I hold down on the empty space and ask to open image though, it does show up on the next tab.

I still have to upload daily updated images to google drive and insert a shared link into the website. (I don't know yet how put them on the github server)

Oren had the exact same problems and it had something to do with his googleaccount. Can you try opening the webpage in incognito mode?

16
Arctic sea ice / Re: "Stupid" Questions :o
« on: April 10, 2019, 02:25:57 AM »
With the high (relative) levels of melting in the Arctic recently, the flooding that occurred in the NE USA, and the jet stream in that area..... I was wondering whether the water in the clouds came from the melting in the Arctic region, traveled South, then dropped it on the US?

It seems plausible in my head, but is that what happened?

The water generally comes from the warm & wet south, especially in spring. However without cold air from the Arctic the moisture wouldn't come down as heavily and cause flooding. The cold & dense air causes the warm & less dense air to rise, kind of like a mountain. As the warm air rises it cools, can't hold the moisture anymore and develops thick clouds & rain. On earth.nullschool.net I have often seen constant weather front change in the north eastern USA and south eastern Canada. A few days of warm & wet Atlantic air followed by cold air from the Arctic.

Good overview on wikipedia:
https://en.wikipedia.org/wiki/Cold_front

17
Arctic sea ice / Re: Albedo-Warming Potential
« on: April 07, 2019, 10:37:28 PM »
Thanks for the patience and support everybody.

Here is the AWP NRT link:
https://cryospherecomputing.tk/NRTawp

By the way I added a website icon which should be displayed next to the page name in the tab. Right now it's some melting sea ice in Beaufort Sea (2016) at super low resolution. Maybe I make a logo in the future.

18
Arctic sea ice / Re: Albedo-Warming Potential
« on: April 07, 2019, 12:11:26 AM »
The new near-real-time Albedo-Warming Potential script is programmed. If it updates tomorrow as intended I post the website link. The regional data has to wait until I structure the regional data from the previous 40 years.

19
Arctic sea ice / Re: Latest PIOMAS update (April 2019)
« on: April 04, 2019, 01:21:33 AM »
question to the specialists, theoretically i can calculate but there may be hidden traps for a layman, hence i thought to ask:

how much thicker must the ice be to keep the same volume while loosing > 1'000'000km2 in the 2 other dimensions. i assume extent and area won't produce the same result and since i'm not privy with the calculations, i ask that question.

trigger for the question is that each time after a month of steep losses i wonder how it can be that volume could keep level or even increase, is it realistic that the reminder at the same time would grow that much in thickness ?

after all the real area of thickness increase is relatively small, since i think that if the ice is melting at the periphery, there must be some significant range in the midle between the pole and the periphery where ice is melting, just not to zero, keeping thickness and another part where thickness is growing only a little, hence there is not much area left where ice would grow so much to compensate for all the losses.

so much my logics which may be wrong (apparently) and i want to know why i'm apparently erring.

In simple terms the ice that melts at the edge must be replaced by new ice in the centre. The major problem here is that everyone is only publishing average thickness values for the entire Arctic. The ice that was in Bering Sea and Guld of St Lawrence was probably just 10-20cm thick. So 20cm*1million km2 divided by 10 million km2 for the central Arctic gives you a thickness increase of only 2cm.

PIOMAS is really bad at getting the ice edge right, most of all soutwest Greenland which is pretty much never frozen. It's one of the reason why I developed the high resolution "AMSR2 Snow & Ice Volume". It's not as good for the very thick central Arctic, but much better for thin ice and defining an ice edge.

https://cryospherecomputing.tk/SIT

20
Arctic sea ice / Re: Albedo-Warming Potential
« on: April 03, 2019, 01:45:58 AM »
Stumbled on to it while looking at your AMSR2 tab and I have to say it is absolutely beautiful in its presentation.

Please keep up the amazing work and cannot wait for the near real time data additions!

Thanks Viggy, it really means a lot to me. The presentation takes up about 75% of the time, but is also the most important part.

21
Arctic sea ice / Re: Albedo-Warming Potential
« on: April 03, 2019, 01:19:03 AM »
BAM! Two years have gone by without an update.

I finally have the processsing power and coding skills to take the AWP model to where I intended it to be. Instead of only calculating the anomaly of potentially absorbed solar radiation. I now calculate the raw accumulated values, the anomaly and a percentage of the current year to the maximum possible (complete Ice-free conditions). From the 1980s to 2010s this percentage has gone up from roughly 52% to 62%. Generally from August onwards the Arctic is 75% icefree and from September onwards the Arctic is 90% icefree.

Everything is now much better presented with interactive graphs and sliders to compare individual years. The regional data is already calculated, but needs even more work for proper presentation. Near-real time data for 2019 is in the works too.

Fancy new webpage:
https://cryospherecomputing.tk/awp

Still too short documentation of AWP model:
https://cryospherecomputing.tk/doc.


22
Arctic sea ice / Re: AMSR2 Snow & Ice Volume/Thickness
« on: April 02, 2019, 11:16:09 AM »
Only a moderate thickness increase and a complete volume stall in the second half of March, probably caused by the Bering Sea and Gulf of St Lawrence melt out.

Full size images and March animation at:
https://cryospherecomputing.tk/SIT

23
Arctic sea ice / Re: What's new in the Arctic ?
« on: March 28, 2019, 02:17:41 PM »
New Sea Ice comparison tool showing the number of Ice Free Days in a year and the anomaly compared to the long term baseline of 1979-2018.

https://cryospherecomputing.tk/IceFreeDays

24
All hail HTML, CSS, Javascript and the W3.CSS template creators.

I managed to combine a beautiful slider with an image slideshow. Now I have the tools to easily compare years against each other. The images are updated in the same place to a new year for easy comparison instead of putting all images into a huge grid like on my old website.

These news are posted here due to the first content using this are the Snow Covered Days maps.

https://cryospherecomputing.tk/Snow-Cover

25
Arctic sea ice / Re: The 2019 melting season
« on: March 12, 2019, 02:37:40 AM »
A short off topic announcement & question. (It will help you following sea ice melt in the future)

I'm trying to get off googlesites to get more presentation freedom and created a webpage with github pages and a proper address saluting to the glorios pacific atoll of Tokelau.  :D

https://cryospherecomputing.tk/

Currently it's just a generic template with links to the images on googledrive thrown into. None of the buttons should do anything. Does anybody have problems accessing the website or seeing any of the images?

Attached is an image of all Tokelau islands (stuck next to each other) and how the website should look like on a 1080p monitor.

26
Greenland and Arctic Circle / Re: What's new in Greenland?
« on: March 10, 2019, 06:47:44 PM »
As many of you know the DMI moved all their Greenland data products to the Polar Portal website (http://polarportal.dk/en/greenland/surface-conditions/)

I emailed them about the missing accumulated SMB map and their reply was that it isn't as popular as the anomaly map and therefore unlikely to make it over to PolarPortal. I find it dissapointing, but to brighten up my day I found their monthly raw data is freely available for research purposes. (currently Jan 1980 to Aug 2017)

So I think I produce the accumulated SMB maps myself all the way back to 1980 and create some long term SMB graphs (whole year Sep-Aug) and only the melt season (Jun-Aug). Is there anything you would like to see that's possible to create with monthly surface mass balance data?

27
Arctic sea ice / Re: Guess the date of the max
« on: February 21, 2019, 11:49:06 PM »
Anyway I am going for the 15th March as recommended by my ouija board. After all, this is a science-oriented forum.

The 11th - 15th March category is almost completly empty in your graph. The average is just there because other years are earlier and later.

I voted 1-5th of March, but I feel it might be even earlier. Currently we have very high extent in the southern most regions of Sea of Okhotsk and around Newfoundland which melt early. The only region with significant growth potential is the Bering Sea.

28
Arctic sea ice / Re: PIOMAS vs CryoSat
« on: February 12, 2019, 10:58:59 AM »
Well this region has been very cold this winter, but we can only guess if this has translated into extra thickness. From Lebedev ice growth formula we know that sea ice over 2m grows very slowly no matter how cold the air is.

All I know for sure is that my AMSR2 thickness is high as well, but it is definitely affected by snow.

29
Antarctica / Re: Thwaites Glacier Discussion
« on: February 01, 2019, 09:14:44 PM »
New melting and breaking off at Thwaites Glacier. Today I analysed the outer ice field which continues Thwaites Ice tongue to the northwest. I compared the EOSDIS data from Jan 12 and Jan 30, 2019. I marked lost fast sea ice positions in pale magenta and newly formed cracks in orange. I wonder whether this outer ice field, which now has almost completely lost its connection to the Thwaites Ice tongue, will survive this fading austral summer.
See attached picture.

What you have marked as "Thwaites Ice tongue" has been named iceberg B22A for several years., since it is not connected to the main glacier anymore.

Looking through past years i noticed there has been a swathe of grounded icebergs in the past which seemed to follow the same line as some of the present sea ice.
To have a better comparison I have overlayed an image of 21 feb 2008 in a purple tint over 22 jan 2019
This shows that the stranded icebergs were mostly further west than the curved piece of sea ice. In the same location there are still icebergs which don't move when other bits of ice move around them.
We will probably see soon how much the mobility of the large chunk of sea ice is constrained by frozen in icebergs.

So, my hunch was a bit off, but I thought it might be worth sharing because it tells us something about water depth in that area.

The water depth is known relatively well and available on the bedmap2 from the British Antarctic Survey.

https://www.bas.ac.uk/project/bedmap-2/#data

The whole ice field is over a roughly 300-400m deep part.This is about half the depth of the surrounding areas. I attached an image of the bedrock overlayed with a coastline mask. The mask is maybe from 2012 when the bedmap2 was created and doesn't have the newest glacier front positions.




30
Permafrost / Re: Snow Cover changes on regional scale
« on: January 29, 2019, 03:40:48 AM »
Question for you, Tealight. Would you be able to reproduce the US graphs with two curves for each 10-year period? (i.e., 1999-2008, and 2009-2018?). Or 11-years, whatever the split is. Curious to see how the curves shift when we compare longer averages vs. individual years and I would think that would be most informative re: ongoing trends.

Sure I can show 10 year averages, but you have to be careful in not selcting a very specific range which happended to be very high or low. We only have 21 years of data so I chose the middle period (2004-2013) as a control period.

2004-2013 compared to 1999-2008 and 2009-2018
Rockies: pretty consistently between the other two averages
Mid-West: mostly between other two except early December significantly higher
North-east: same as the other two averages
South: similar noise to other two averages

31
Slow and steady growth of the side crack continued, now growing directly towards the centre crack and about halfway there. I'd bet they connect by the start of summer.

32
Antarctica / Re: Rift in Larsen C
« on: January 21, 2019, 09:51:18 PM »
A nice view of A-68A today showing the rifts in a lot more detail than usual. A small part even broke off since the last picture posted here in December.

33
Antarctica / Re: What's new in Antarctica ?
« on: January 18, 2019, 07:58:39 PM »
I'm failing in finding an article that tells me how this is happening. I would like to know the physics behind this because in freezing temperatures at a high albedo (fresh)water should not just melt, right?

Melting snow and ice below freezing is nothing extraordinary at molecular level.

Melting snow and ice is all about breaking bonds between water molecules. At 0°C and standard atmospheric pressure the individual molecules move or vibrate so much around that existing bonds break and not enough new bonds can form. Temperature is just a description of the average movement of the molecules. Some move faster and some move slower than the average. During noon the slopes of the Amery ice shelf get to around -5°C so not very far off from 0°C. Depending on the slope angle the surface also get's blasted with 700-1000W/m2 (during noon)  of electromagnetic radiation from the sun which further increases the movement of molecules.

Albedo is just an average of reflected vs absorbed energy for all molecules in an area. A single molecule doesn't have an albedo value. Either it get's hit and absorbs the photon's energy (followed by a quick re-release of the energy with a lower energy photon) or the photon misses the molecule.

On a macro level snow can get down to an albedo of 50%, meaning it absorbs 300-500W/m2 while only losing maybe 100-200W/m2 to the below freezing air.


34
Antarctica / Re: Antarctic Icebergs
« on: January 17, 2019, 11:46:51 AM »
Looking at    http://www.arctic.io/explorer/   top right drop down  Antarctica-true color

B22 broke clear from Thwaites between 2002.02.13 and 2002.03.13 and joined the ice peninsular (which often formed) by about 2012.03.20.
Another major calving from the Thwaites tongue occurred in the dark before 2012.09.01 and headed north east of B22 towards the open sea. It drifted westwards, then back towards the coast, onwards towards the northern Ross Sea, where it was breaking up on 2018.03.14 (long153.9, lat 67.8 )
This shows that Thwaites is fairly free to calve even if B22A does not move (and the ice tongue that B22A joined at the base is more often present than not.) but some of the other 'bergs are trapped to the west of Thwaites.

If you only look at ice edge glacier definitions it is true that Thwaites could calve freely the last few years. Especially the sub-region of Thwaites Ice Tongue where several other icebergs came from. I meant more the whole Thwaites area. Haynes Glacier is really just a sub glacier of Thwaites. Even the Crosson ice shelf is connected to Thwaites over Pope/Smith glacier.

35
Permafrost / Re: Snow Cover changes on regional scale
« on: January 12, 2019, 03:06:32 PM »
We finish the Arctic regions with the mean extent over the whole year to see when each region starts to melt and at what rate. For example Alaska melt starts early at the end of April, but takes until the end of June. In contrast Eastern Siberia doesn't start until mid May, but also finishes at the end of June.

The 2000s and 2010s mean snow extents of Alaska and Eastern Canada show the magnitude of low spring snow cover or high autumn snow cover compared to the whole year.

36
Permafrost / Re: Snow Cover changes on regional scale
« on: January 11, 2019, 02:32:41 AM »
West Siberia varies more noticably from year, but has again an early summer low point around 2010-2012. October shows the typical long-term autumn increase in snow cover which we have observed in other regions. November only has a very small increase due to the large year to year variability.

37
Permafrost / Re: Snow Cover changes on regional scale
« on: January 11, 2019, 02:31:58 AM »
Today we continue with the Arctic region with Siberia. This post is about the Eastern and Central Siberia. The next one is exclusive to western Siberia. Check the region map in the first post for the exact boundaries.

Like the Arctic in Northern America early summer snow cover was lowest in the 2010-2012 region and increases for earlier years and later years. For eastern Siberia this is most pronounced in June and for Central Siberia in May.

Autumn Snow Cover shows no significant trend for eastern Siberia, possibly due to almost complete coverage by the end of October. Central Siberia experiences a slight increase in October and November snow cover.

38
Permafrost / Re: Snow Cover changes on regional scale
« on: January 09, 2019, 11:40:55 PM »
Eastern Canada doesn't have a downwards trend during Spring. Instead it's positive like in the autumn. The theory here is that eastern Canada receives so much more snowfall that it offsets any increased snow melt during spring. See the Northern Hemisphere snow cover thread for discussion, maps & graphs (around post 200).

snow cover trend per month
April: slight increase
May: clear increase
June: neutral
July: slight increase
Aug: None
Sep: clear increase (although at very low level)
Oct: clear increase
Nov: clear increase

39
Permafrost / Re: Snow Cover changes on regional scale
« on: January 09, 2019, 11:21:42 PM »
Today we continue with Canada. This post is about the Canadian Rockies and Central Canada. The next one is exclusive to eastern Canada. Check the region map in the first post for the exact boundaries.

For the Rockies May, June and October seem to have a consistent downward tend in snow cover over the last 20 years. The other months are very close to either the maximum extent or to the minimum extent. Only November has a very slightly positive trend in snow cover.

In Spring/Autum snow cover in Central Canada is highly variable from year to year. However October and November show a very clear upwards tend. So the data is confirming the theory that the higher atmospheric moisture from an increasingly ice free Arctic causes more snow cover in the autumn.

40
Permafrost / Re: Snow Cover changes on regional scale
« on: January 08, 2019, 02:37:53 PM »
The data is now available as a formatted Excel sheet through the Link in the first post. I try to post 2-3 regions every day until we covered all of them.

Today we continue the northern regions with northern Canada and Alaska. They feature a pattern I've seen in several northern regions. Early summer snow cover was lowest in the 2010-2012 region and increases moderately for earlier years and slightly later years.

41
Permafrost / Snow Cover changes on regional scale
« on: January 07, 2019, 01:25:37 AM »
I finished calculating regional snow extent data and will post my analysis here. The main snow cover thread doesn't quite fit for this detailed long term analysis. At the moment all data is still in one long list, but after formatting we can graph things like snow extent for region x in month y. I attached a map showing all regions and an example for Greenlands snow extent.

Eventually regional graphs should also get daily updates on my main snow cover webpage
https://sites.google.com/site/cryospherecomputing/snow-cover

Data Download (csv & formatted ExcelSheet)
https://github.com/NicoSun/CryosphereComputing/tree/master/ScienceData/Snow_Cover_Regional


42
Arctic sea ice / AMSR2 Snow & Ice Volume/Thickness
« on: January 03, 2019, 09:01:01 PM »
AMSR2 thickness and volume ties with 2013 and 2014 for the highest values.

Full size images + gif +netcdf at:
https://cryospherecomputing.tk/SIT

43
Antarctica / Re: Sea Ice Extent around Antarctica
« on: December 18, 2018, 10:50:05 PM »
Antarctic Sea Ice Area is now at record low, 60,000 km2 below 2016 and 2.72 SD below the mean. This is even slightly below the low estimate of my SIPN_south forecast which is already far lower than any other forecast. With compaction staying at record low too, I don't expect this year to slow down in area losses like 2016 which turned to above average compaction at this point.

more Area data and sea ice map on:
https://sites.google.com/site/cryospherecomputing/daily-data-antarctic


44
Permafrost / Re: Northern Hemisphere Winter 2018-2019 Snowcover / Misc Obs
« on: December 17, 2018, 01:22:59 AM »
I will try and boldly go where only Tealight has gone before.
...............
I think Tealight has got his timing for getting his project on the street just about right.

Thanks for helping out  :)   I would say its a year too late. Not only did we have major arguments here about albedo, but I also need to take a long break from Climate Science research. It's not so much of a time issue, but I need all my concentration and analysis power for my day job.

Anyway, the Near-Real-Time AWP page (soon daily updated) is coming along, but I'm not sure on the main graph. It's supposed to compare major Regions of the world. Canada and the USA are each large enough to put them into the same category as Europe, but the southern USA has almost never snow cover (see atached map) and is more similar in latitude to northern Africa. So for now I have excluded the two southern US regions. Apart from high altitude Tibet all other regions extent to around 35 degrees south.

I think I make at least 4 regional graphs. One for European subregions, one for Asia and one or two for North America. 8 regions might be a little too cluttered. Then it will be one graph for Canada + Alaska and one graph for US Pacific, US Rockies, US Mid-West and US North East

https://sites.google.com/site/cryospherecomputing/awp/awp-northern-hemisphere


45
Permafrost / Re: Northern Hemisphere Winter 2018-2019 Snowcover / Misc Obs
« on: December 16, 2018, 12:56:06 AM »
The time has come  :)

After a few hours of coding and 1.5h of calculation the AWP and AWP_anomaly data for the Northern Hemisphere is ready to be explored. For eastern Canada, the most discussed Region here I already made two charts of the mean anomaly for April and May.

We have:
21 years * 365 days * 24 Regions * 2 variables = 367,920 values

That will take some time to get through and find all interesting parts. I hope some forum members can explore it too. The data is available as usual on Google Drive and now also on Github.

Google Drive:
https://drive.google.com/drive/u/1/folders/1MiBVuMjoG-TRBsJhwPiChJYF5lKlaaxC
Github:
https://github.com/NicoSun/CryosphereComputing/tree/master/ScienceData/Northern_Hemisphere_AWP

46
Permafrost / Re: Northern Hemisphere Winter 2018-2019 Snowcover / Misc Obs
« on: December 14, 2018, 01:49:08 PM »
I'm almost finished with my Northern Hemisphere AWP model, hopefully done this weekend. The most important part left is coding the calculations for each individual region and then the daily updates can start.

A proper documentation, long term graphs and other visulization will follow soon after.

In the regional breakdown it's impossible to create exact regions for each individuals preferences. So I chose my regions by considering geographic regions and international borders. (apart from mid latitude Asia, no one there is interested in it anyway)


47
Antarctica / Re: Sea Ice Extent around Antarctica
« on: December 12, 2018, 08:34:19 PM »
In any case, the graphs posted by Tealight (though they do not show very many years) suggest that the rate of melt we're now seeing is at least unusual if not unprecedented. I still haven't seen anyone give an answer to gerontocrat's question about whether we're witnessing a bigger change in the last few years, to bring cause this decline in Antarctic sea ice extent, or whether this is just an anomaly. The rate of melt occurring now may seems like an important piece of evidence to be considered.

Generally Antarctic sea ice is more variable from year to year, but doesn't have a clear trend like the Arctic. As far as I know it is more sensitive to weather patterns as the Arctic because it isn't constraint by continents on all sides, only one in the middle. In the last two years we got weather favoring low sea ice and with the addition of greenhouse gases it looks like an extreme warming. My cumulative albedo warming maps look completely different from year to year and I don't see a clear trend. This year will most likely end up in second place so the top 3 years in accumulated solar energy are the last 3 years.

https://sites.google.com/site/cryospherecomputing/awp/Antarctic-Overview

On my compaction graphs I only show record high and record low years (apart from recent years). The middle contains over 30 years zig-zagging around the mean. For this time of the year sea ice compaction is unprecedented. The second lowest compaction value for 11th December is 60.7% in 2010. Is the graph with two standard deviations any better?


48
Arctic sea ice / Re: Latest PIOMAS update (November mid-monthly update)
« on: December 03, 2018, 02:12:10 AM »
The November coldness seems have had an impact on the ice. Both thickness and volume increased way above previous years.

Full size images + gif +November netcdf at:
https://sites.google.com/site/cryospherecomputing/amsr2-sea-ice-volume

49
Permafrost / Re: Northern Hemisphere Winter 2018-2019 Snowcover / Misc Obs
« on: November 29, 2018, 08:19:01 PM »
I also think the actual average map is of interest, as it can show which specific points and areas tend to be more or less snow-covered.

Ok here is a map of the 2000-2017 mean snow coverage. Do you like the colorbar better with inconsistent ticks of 90 days & last one of 95 instead of the three 100 day ticks?

Full size at:
https://drive.google.com/drive/u/1/folders/19b4bnBcnv7Ho3nbmjubMnwVJy2tkP1F7

50
Permafrost / Re: Northern Hemisphere Winter 2018-2019 Snowcover / Misc Obs
« on: November 28, 2018, 12:59:06 AM »
I calculated how long in each year (2000-2017) a gridcell is covered by snow or ice. The presentation is quite bad with google sites so I recommend viewing the images in the google drive folder or even better download the netcdf file and choose the visualization yourself.

NetCDF & Images:
https://drive.google.com/drive/u/1/folders/1QCM9lVx6tg0QGQXgK8NBZmKkYHLQN940

Website:
https://sites.google.com/site/cryospherecomputing/analysis/snow-covered-days

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