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Messages - Tealight

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1
I'm 95% certain that the lake already drains beneath the ice on the southern side. With under 810m it's the only side which doesn't significantly rise above the lake level of 795m.

The elevation data is from "ALOS Global Digital Surface Model DSM" (30m resolution)

2
Some time ago I posted regional snow extents, but the topic is kind of lost in the depth of the forum. After some minor improvements and adding two new regions in Asia I created a seperate webpage for the data. It makes it easier to analyse than several different forum posts.

On the snow-cover webpage, featuring snow maps I added the long term NOAA data since 1967. The low 200km resolution looks terrible compared to the new 24km, but the longer timespan is better to judge changes over time.

https://cryospherecomputing.tk/Snow-Cover
https://cryospherecomputing.tk/snow-regional

3
Arctic sea ice / Ice Melt AWP
« on: July 17, 2020, 04:00:23 AM »
A few people follow my NRT AWP site and use it as a predictor for future melt. The model though only calculates how much energy went into a grid cell and thus is only good to predict re-freeze. It does not give a good indication about the amount of ice that has melted. Ice-free regions can appear because the ice has melted, or the ice was transported away by winds and currents. If it gets compacted on the other side of the Arctic, it is harder to melt. A smaller area taken up by the ice means less sunlight is available to melt it. This phenomenon is already known in the compaction ratio (area/extent). During the summer, a low ratio will result in more melt.

The new Ice-melt AWP model better visualises this phenomenon by only accumulating AWP if the sea ice concentration (SIC) is above 25%. In case of an ice-free region driven by wind, the new model will remain at zero while the regular AWP model will accumulate huge amounts due to the low ocean albedo. In the Eastern Greenland Sea, the sea ice is continuously replenished and melting throughout the summer. On average this region melts the most ice.

Initially I intended to run this model just as described, but while the maps looked good the values for graphs were not helpful for determining strong melting seasons. Due to its size the central Arctic had by far the most accumulated AWP even though there is still little melt. Instead of an upwards trend in melting over the decades there was a significant downwards trend. This was not a model error. In the past there was simply more ice present to absorb more sunlight. Additionally, less greenhouse gases meant more of the absorbed energy was lost to space instead of melting ice.

To address these two issues, I decided to test the model with a “heat loss to space” component from my Sea Ice Forecast Model for the Sea Ice Prediction Network. The heat loss is 4-6 MJ/m2/day depending on a mean temperature and CO2 level. This level of heat loss is just a third of the measured outgoing longwave radiation for the Arctic.  Its purpose was to improve the forecast model, which is only a local energy model without any heat transfer from lower latitudes. Since the Ice Melt AWP model does not include any heat transfer either it seemed appropriate to use the same level of intensity.

The heat loss adjustment per CO2 level is necessary to avoid over prediction of ice loss in the 1980s and under prediction of ice loss in the 2000s and 2010s. In the model the late 2010s at around 410ppm CO2 have an 11% reduced heat loss compared to the early 1980s at 340ppm.
With these model additions the central Arctic now has the lowest ice melt AWP of all regions and the melting energy has a clear upwards trend over the decades. All years with the lowest sea ice extent/area (2007,2012,2016,2019) are also the ones with the highest Ice Melt values. Apart from comparison to other years I would not put any other use case into the presented values. Especially relating negative values with freezing conditions. It is still not even close to a volume model. For sea ice volume we already have PIOMAS, Cryosat2 and my AMSR2 Snow & Ice Volume.

Maps & Graphs:
https://cryospherecomputing.tk/melt-awp
Datasheets:
https://github.com/NicoSun/ScienceData/tree/master/Ice_Melt_AWP

NRT charts will follow soon

4
Arctic sea ice / Re: The 2020 melting season
« on: July 15, 2020, 03:12:07 PM »
.... TJ is almost nothing for the Arctic. Even 1000 TJ is almost nothing. 1 W/m2 * 5M km2 * 1 day = 432000 TJ.

You are right the unit is actually Exajoule (EJ). Damn km2 to SI unit conversion.

Quote
However, the statement that " Ice-free regions don't contribute any energy towards melting ice." must refer just to the model, no?

Yes, just in the current model. But on the maps you will see which Regions have continuously strong melt due to winds/currents pushing ice into warm waters. The Laptev Sea is not one of them.

For the central Arctic the daylight intensity drops in August to below melting conditions for a solid ice pack. Extensive meltponds can delay this point somewhat, but generally not as much as a very dispersed icepack as we have seen in 2012 and 2016. Currently the ice is just compacted against Canada/Greenland as a solid icepack. I wouldn't count on a strong melt in August.

By including heatloss to space the model returns the concept of negative Ice Melt Energy, also known colloquial as freezing.

5
Arctic sea ice / Re: The 2020 melting season
« on: July 15, 2020, 12:57:57 PM »
I have two teaser images to share for a new NRT product coming soon to CryosphereComputing.tk

It shows why my SIPN forecast model doesn't expect a record melt like 2012. 2020 just keeps up with 2016 and 2019, though maybe not for long.

Unlike the AWP model this new Ice-Melt-Energy model only considers ice covered regions. Ice-free regions don't contribute any energy towards melting ice. A full explanation of the new model will soon follow in an extra topic.

6
Arctic sea ice / Re: Albedo-Warming Potential
« on: July 09, 2020, 01:44:36 AM »
Hi AWP interested people,

The Albedo Warming Potential was never intended to be used as a melting forecast indicator. It's purpose was first to rank years differently from the September minimum. Only later it turned out be be a good indifcator for the re-freeze season. Maybe I should include this on the website. It's been four years now since the original ungridded version and new people stumbling on it don't find my old posts.

Quote
First...thanks for the wonderful contribution. Love your site.

Thank you :)

Quote
I'm wondering if you would considering some kind of tool to validate your model in terms of its ability to predict sea ice volumes.

No. I have a sea ice forecast model which uses the same major albedo physics, but includes a few other "melt mechanisims". You could describe them as curve fitting variables. The albedo model on it's own is not good to predict actual sea ice loss.

Current extra factors in my 2020 model
Heat loss to space: otherwise it would never re-freeze
bottom melting: for stronger late august to early september melt than possible from albedo
fake cooling/heating layer: to replicate icedrift. Mostly Fram export, northern Beafort Sea and into Canadian Achipelago
CO2 levels: to correct heat loss to space over time. If I use a fixed value my model overpredicts iceloss in the 1980s and underpredicts ice loss in the 2010s. (This correction is 2-3 times as strong as the percentage increase in CO2 levels.)

https://www.arcus.org/sipn/sea-ice-outlook/2020/june

I investigated an Ice-Melt AWP model, which doesn't consider ice-free areas. It certainly gives interesting results and maps which look completly different, but I'm not sure it's any good as a melting indicator. I can share it in 1-2 days.


Quote
However we are currently in a situation where the CAB is made up of gray ice full of extensive melt ponds and hardly any snow, with an albedo which is probably 50%-60% and certainly not 85%. So in a typical July day it is probably receiving double your number at about 200 W/m2.

Are these albedo values just guessed? If you actually measure gray ice in paint you get 200/255 RGB values or equivalent to 78% albedo. I have a program to calculate the albedo of an image and even the melt pond areas are in the 70% range. I feel in general people tend to overestimate albedo drop from snowfree areas and meltponds. See my attched images for measurements.


Quote
he is assuming an albedo of 80% for ice and snow, and 85% for ice and snow in the High Arctic. For open water he is assuming 0% albedo

Close but not quite. My energy values already include water albedo. This is one reason why my high arctic energy values during summer solitice are below lower latitude ones. My early anamoly only model had an 80% value, but since I calculate absolute numbers (1-2 years ago) and not only anomaly values it changed.


0% SIC results in 100% absorption of my water albedo corrected energy values.
100% SIC results in 15% absorption of my water albedo corrected energy values.

Formula:
AWPdaily = ((1-SIC) * MJ) + 0.15 * MJ * SIC

Example:
MJ = 20
SIC = 75%
AWP = (1-0.75)*20 + 0.15 * 20* 0.75
AWP = 5 + 2.25
AWP = 7.75

7
Greenland and Arctic Circle / Re: What's new in Greenland?
« on: June 02, 2020, 09:11:54 PM »
After being empty for over a year I finally had an idea what to put on my IceSheet main page.

Maps of the bedrock or surface elevation show exactly where it is high/low, but it's still hard to estimate how much area overall is at a particular elevation level. So I created a Histogram for Greenland Ice thickness, surface elevation and bedrock elevation.

https://cryospherecomputing.tk/IceSheets

Data abstraced from:
NSIDC BedMachine v3 Greenland


 


8
Arctic sea ice / Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« on: October 17, 2019, 11:43:31 AM »
you can clearly see the effect of refraction  in the photo.
The sun should be a round disk in that photo it is an oblong shape suggesting light bending from refraction.

I agree the photo shows just a refraction. If the sun would be above the horizon the ice would also be very bright, but it is dark. You must keep in mind that at 87N you are only surrounded by extremly flat and highly reflective sea ice. No mountains, trees or buildings to block sunlight. If direct sunshine hits the ice at 82N at an angle of 1-2 degrees it gets reflected and travels a few hundred kilometer further through the atmosphere. Clouds can then reflect this reflection back again towards the surface.

I so happen to have webcam footage from McMurdo Station in Antarctica from the 9th August when the sun was equally 4 degrees below the horizon and the phenomena looks the same to me.

9
The southern portion calved today.

10
Arctic sea ice / Re: AMSR2 Snow & Ice Volume/Thickness
« on: September 02, 2019, 06:54:43 PM »
Volume and thickness are the same league as 2012 and 2016, but the minimum might have already happened.

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

11
Glaciers / Re: Barnes Ice Cap / Penney Ice Cap
« on: August 25, 2019, 01:19:07 AM »
Here is a high resolution Sentinel 2 animation of the retreat in the northern part. From Aug 2016 to Aug 2019 retreat ranges from about 50m on land to 130m in the lake. Or 16.6m/yr and 43.3m/yr.

Assuming a 33m/yr melt rate for the widest part it would take 750 years for the ice cap to melt away.

12
Arctic sea ice / Re: AMSR2 Snow & Ice Volume/Thickness
« on: August 02, 2019, 10:03:48 AM »
Volume and thickness were record low until the second half of the month and then lost slightly out to 2012 and 2016.

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

13
Arctic sea ice / Re: AMSR2 Snow & Ice Volume/Thickness
« on: July 02, 2019, 08:41:19 PM »
Volume and thickness crashed to lowest during the second half of June. In the first half melt was apparently below average. The gif shows the Beaufort gyre in action transporting ice into the melt zone.

One should keep in mind that the product doesn't try to calculate actual ice thickness, but average thickness per ice covered gridcell. If you have an even 50/50 split of water and ice than the gridcell thickness is just 50% of the ice floes.

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

14
Arctic sea ice / Re: Albedo-Warming Potential
« on: June 17, 2019, 06:26:31 PM »
Did you submit to the SIPN? The site seems abandoned, no way to know the participants of course...

I did submit my forecast. The June Report is scheduled to be released on the 21 June 2019. It seems like the whole ARCUS (Arctic Research Consortium of the United States) website was taken offline, not just SIPN.

15
Two years ago I spotted quite big icebergs in the lake, but just like you didn't find a name.

old thread:
https://forum.arctic-sea-ice.net/index.php/topic,2149.0.html

16
Tealight, bear in mind that in some years in August the sea ice disappears from the inner bay, and all the icebergs are swept away. I think this happens every couple of years, but haven't done the stats. This is discussed somewhere upthread. My pet theory was that the massive iceberg jam stuck in sea ice could delay calving processes and even possibly slow the glacier down slightly. Never tested it though.

Oren, you are talking about recently calved icebergs. I was talking about icebergs that have already been swept away from the glacier. About 100km further south the icebergs are piling up like Tetris blocks. They just don't magically vanish  once a latitude line is full. There is still around 1800km2 (30*60) of space for new icebergs, but maybe 600km2 has already been tightly piling up.

17
Arctic sea ice / Re: Albedo-Warming Potential
« on: June 08, 2019, 01:07:52 AM »
The recent warm temperatures over the central Arctic did not result in a significant albedo drop. I suspect the peak sunshine intensity this far north is just too low to force widespread meltponding. Without imported heat from the south it just stays an iceblock. It's like trying to melt some metal in a common household oven. You can heat it for a few days, but you never melt the surface unlike a few minutes in a furnace.

The absence of importet heat means 2016 won the battle for first place and in a few days begins the dominance of 2012 until the end of the melting season.

18
Arctic sea ice / Re: Updating the ASIG
« on: June 04, 2019, 01:13:32 AM »
There also seems to be a problem with DMI no longer updating the Greenland maps and graphs they had on their website. Polarportal has the same images, but their addresses are dynamic (ie each date has its own file name) and so I can't hotlink to them. I wish I knew how to write scripts...

I haven't used googlesites in a while, but I know how to write html image references with a variable url. The following solution works with a generic html file (copy everything into a text file, rename ending to html and open in a browser)
You can try putting it into an HTML box in google sites and maybe it will work.

Code: [Select]
<html>
<img id="Greenland">

<script>
var today = new Date();
yesterday = new Date(today - 68400000); //set off time in milliseconds
var dd = String(yesterday.getUTCDate()).padStart(2, '0');
var mm = String(yesterday.getUTCMonth() + 1).padStart(2, '0'); //January is 0!
var yyyy = yesterday.getFullYear();

yesterdaystring = yyyy+mm+dd;

var imageid = "http://polarportal.dk/fileadmin/polarportal/surface/SMB_map_LA_day_EN_"+yesterdaystring+".png";
document.getElementById("Greenland").src = imageid;
</script>

</html>

Edit: changed getDate() to getUTCDate() for same execution worldwide

19
Arctic sea ice / Re: AMSR2 Snow & Ice Volume/Thickness
« on: June 02, 2019, 01:01:30 AM »
Volume continued below the mean, but thickness went up at the end of the month. It looks like the Beaufort gyre compacted sea ice against eastern Siberia and Hudson Bay ice was compacted against the southern coast.

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

20
Arctic sea ice / Re: What's new in the Arctic ?
« on: May 31, 2019, 12:33:55 AM »
I made a quick and lightweight sea ice comparison page for the entire NSIDC data set. At the moment it's just for the 1st of the month, but soon I add the 15th of the month as well.

https://cryospherecomputing.tk/PastSIC

21
Antarctica / Re: Antarctic Icebergs
« on: May 28, 2019, 10:11:01 PM »
A68A rotation continues in the same spot. Animation beween 3rd May and 28th May.

22
Greenland and Arctic Circle / Re: Greenland 2019 Melt Season
« on: May 22, 2019, 11:43:21 PM »
Even if we have slightly more melt than precipitation right now. Most losses are happening in June and July. On the attached gif I compared the 10th July 2012 with today. It almost looks like we have no melt right now.

23
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.

24
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.

25
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

26
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)

27
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

28
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

29
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

30
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.

31
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

32
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

33
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

34
Greenland and Arctic Circle / Re: What's new in Greenland?
« on: April 20, 2019, 02:50:03 PM »
Just awesome Tealight!

May i suggest using a bigger font and a visual separation (thin line perhaps) between the glaciers and centring of the pics. Would make it even more beautiful imho.

Technically all pictures are centered (if you span the browser over two monitors) The Petermann Glacier has a different aspect ratio and the image overlay code needs a point zero which is set for the widest images. So all image overlays have to begin at the same position.

I try to add a visual separation, but the font is already quite big imo. After loading the webpage from the web and not locally I noticed it has a loading time. With 20MB it's already a decent size. Thus I probably create a separate page for Antarctic Glaciers.

Tealight...you should get an award for this work.

For this? It's just using some web templates, downloading other peoples work and aligning two images in a paint program. All in all two afternoons of work.

35
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

36
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

37
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

38
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?

39
Arctic sea ice / Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« 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

40
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.

41
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.

42
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

43
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.

44
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.


45
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

46
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

47
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

48
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.

49
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?

50
Arctic sea ice / Re: AMSR2 Snow & Ice Volume/Thickness
« on: March 07, 2019, 02:12:18 PM »
Only moderate increases in the AMSR2 Snow & Ice Volume. The St. Lawrence and Sea of Okhotsk ice
is too thin affect the overal numbers much.

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

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