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Messages - BornFromTheVoid

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1
Arctic sea ice / Re: The 2020 melting season
« on: Today at 10:32:13 PM »
An animation of the simple projections so far this melt season.

2
Arctic sea ice / Re: The 2020 melting season
« on: Today at 10:25:16 AM »
That's a bit pedantic, Paul.

Okay it might be more consistent to stick with the one model, however scrollling through both ECMWF and GFS 2m anomalies over next few days both show very little +ve anomalies in the area BFTV has circled.  (If anything I would say GFS is more often the warmer at the 2m level over the Arctic basin).

But this is distracting from the main point of my post - not to confuse 850hPa with 2m temps.

850hPa temps are of course very useful for other reasons. So I cannot be sure exactly what BFTV's intention was. It could be said for example that the high 850hPa's are indicative of the presence of high pressure over the area of thickest ice.

Remember that over the ice the surface temperature will be pegged close to 0C due to the latent heat of fusion of ice, much like the 80N temps are. So you will not see strong +ve surface temperature values until the ice has melted, no matter how much heat is actually in the air.
As such, using 850hPa level (or 925hPa if available) in these situations works better for assessing ice thaw than surface level values.

3
Arctic sea ice / Re: The 2020 melting season
« on: August 06, 2020, 09:36:00 PM »
Almost impressive how focused the positive temperature anomalies are forecast to be for the next 5 days, right over the remaining thick ice.

4
Arctic sea ice / Re: The 2020 melting season
« on: August 06, 2020, 04:58:11 PM »
Latest projection now requires a recording breaking extent reduction to beat 2012. The average of the last 10 years produces the 5th lowest minimum, 4.16 million km2

5
Arctic sea ice / Re: The 2020 melting season
« on: August 06, 2020, 11:05:36 AM »
Animation of the Beaufort sea over the last 12 days.

6
Arctic sea ice / Re: The 2020 melting season
« on: August 06, 2020, 10:07:25 AM »
Detailed look at 7 days of ice movement and change on the north coast of Greenland.

(Larger file version here: https://twitter.com/Icy_Samuel/status/1291283817366421506)

7
Arctic sea ice / Re: The 2020 melting season
« on: August 05, 2020, 10:09:34 AM »
North of Greenland over the last 6 days.

Higher-res version on twitter here: https://twitter.com/Icy_Samuel/status/1290921823769632768

8
Arctic sea ice / Re: Latest PIOMAS update (August 2020)
« on: August 04, 2020, 11:27:40 AM »
A focus on July and the larger picture.

Gap to lowest on record down to just 150 km3

9
Arctic sea ice / Re: The 2020 melting season
« on: August 04, 2020, 10:59:51 AM »
Change in the north of Greenland for the last 2 days

10
Arctic sea ice / Re: The 2020 melting season
« on: August 03, 2020, 03:30:09 PM »
North of Greenland, change from July 24th to August 2nd.
Higher-res version on here: https://twitter.com/Icy_Samuel/status/1290278384564465667

11
Arctic sea ice / Re: The 2020 melting season
« on: August 02, 2020, 12:21:24 PM »
Here's the difference between the concentration from the 31st of July and the 1st of August. Only the areas with change outside of -10% to +10% are coloured.

12
Arctic sea ice / Re: The 2020 melting season
« on: August 01, 2020, 09:51:08 PM »
Here's the video (gif was waaaay too big) of the concentration and MODIS data side by side for July. Let me know if there's any suggestions on improving it.

(Edit: Removed the video - didn't realise it was autoplaying. Here's a link instead:https://twitter.com/Icy_Samuel/status/1289672698361257984)

13
Arctic sea ice / Re: The 2020 melting season
« on: August 01, 2020, 12:37:51 PM »
Here's the final version of the comparison between the MODIS imagery and the concentration data. As usual, there's a higher-res version on the twitter page too: https://twitter.com/Icy_Samuel/status/1289510103733817344

I'll try put together a version, from a broader perspective, for the whole of July later on.

14
Arctic sea ice / Re: The 2020 melting season
« on: July 31, 2020, 08:12:30 AM »
An update on the side by side comparison. Those apparent concentration drops are looking more real than not.
Slightly higher res version on twitter, for those without data limits: https://twitter.com/Icy_Samuel/status/1289080922617372672

(Large file, click to play)

15
Arctic sea ice / Re: The 2020 melting season
« on: July 30, 2020, 05:54:12 PM »
Some of the concentration reductions are very real, some aren't. How much is real won't be apparent until we get more clear views.
Por ejemplo...

16
Arctic sea ice / Re: The 2020 melting season
« on: July 30, 2020, 01:07:41 PM »
As it appears (to my non-expert eyes) that clouds cause artifacts in the concentration products, the big question in my mind is whether they cause high-concentration streaks, or whether they cause low concentration streaks... Can some kind soul superimpose (and synchronize) the cyclone and the concentration images and prove it one way or the other?
p.s. Of course it's also possible the storm causes actual concentration changes that appear to be in its shape. Would love an expert opinion.

Another version, to add to uniquorns great work.

(Large file warning!)

17
Arctic sea ice / Re: The 2020 melting season
« on: July 30, 2020, 07:34:45 AM »
An update on the storm and concentration comparison. Higher res version on twitter.
https://twitter.com/Icy_Samuel/status/1288708042951929857

(click to play)

18
Arctic sea ice / Re: The 2020 melting season
« on: July 29, 2020, 10:30:48 PM »
Looks like a long lasting -ve dipole coming up. The pack will get spread out towards the Pacific and Siberian side. We will probably see extent continue fall at a slower than average rate for the next week, all while area continues to fall at a steady pace. June cliff 2.0?

5 day mean SLP with concentration overlayed below.


19
Arctic sea ice / Re: The 2020 melting season
« on: July 29, 2020, 06:44:20 PM »
Just 2 of the last 20 melt seasons now produce 2012-beating minimum.
16/20 would put 2020 at 2nd lowest on record.

20
Arctic sea ice / Re: The 2020 melting season
« on: July 29, 2020, 10:51:38 AM »
A side by side animation of the Arctic storm from MODIS worldview (mosaic for the 29th) with sea ice concentration. No concentration data yet for today, hence the blank right panel at the end.

I posted a higher res version on twitter too: https://twitter.com/Icy_Samuel/status/1288395604805267456

(Large file still, click to play)


21
Arctic sea ice / Re: The 2020 melting season
« on: July 28, 2020, 04:16:06 PM »
Now just 4 of the previous 20 melt seasons beat the 2012 minimum. However, all but 2 get 2020 down to 2nd lowest on record.

22
Arctic sea ice / Re: The 2020 melting season
« on: July 28, 2020, 02:03:42 PM »
Here's a composite of the different worldview images sources today, with the bottom part (Greenland and CAA) filled in with yesterdays data.

23
Arctic sea ice / Re: The 2020 melting season
« on: July 28, 2020, 12:53:47 PM »

There is a mistake with the left image. It's labeled 2012.

Nice catch, fixed!

24
Arctic sea ice / Re: The 2020 melting season
« on: July 28, 2020, 11:49:26 AM »
Concentration for the 26th, 27th and both combined.

25
Arctic sea ice / Re: The 2020 melting season
« on: July 27, 2020, 03:43:53 PM »
Side by side of July 26th in 2012 and 2020.

26
Arctic sea ice / Re: The 2020 melting season
« on: July 27, 2020, 03:07:26 PM »
In 2012, the storm took a little time to build in strength, and spread out the pack in the process causing a slight pause before the flash melt occurred. The ice around the Chukchi and ESS was much more sparse and broken compared to the Beaufort and Chukchi this year, so I don't think the slight pauses arise from the same process.

27
Arctic sea ice / Re: The 2020 melting season
« on: July 27, 2020, 11:41:19 AM »
Seems like the developing storm is pulling is the smoke/ash clouds from the Siberian wildfires. A risk of this getting deposited across the Beaufort and Chukchi ice.
https://twitter.com/Icy_Samuel/status/1287683902912503815

28
Arctic sea ice / Re: The 2020 melting season
« on: July 27, 2020, 09:23:07 AM »
Here's a comparison of the concentration averaged over the 23rd to the 25th, vs the concentration from the 26th.

29
Arctic sea ice / Re: The 2020 melting season
« on: July 26, 2020, 04:41:09 PM »
With the latest update, now just 5 of the previous 20 years would beat 2012, while the 10 year average would hit a low of 3.59 million km2.

Also, I've added a little video of the ice loss between June 30th and July 22nd below, but you can see it on my twitter account here also: https://twitter.com/Icy_Samuel/status/1287386145714839552

30
Arctic sea ice / Re: The 2020 melting season
« on: July 26, 2020, 11:16:55 AM »
Tuesday's storm potentially below 970hPa now, not quite GAC2012 but seemingly strengthening as we get closer.

31
Arctic sea ice / Re: The 2020 melting season
« on: July 25, 2020, 08:48:26 PM »
I put together a little animation using the GFS ensembles probability of 50km/h winds and the latest concentration map. (click to play)

32
Arctic sea ice / Re: The 2020 melting season
« on: July 25, 2020, 06:46:34 PM »
While extent has flat-lined over the last 2 days, the concentration continues to drop, especially in the Beaufort sea. It will be interesting to see how it deals with the low pressure early next week.
https://twitter.com/Icy_Samuel/status/1287065182452187136

33
Arctic sea ice / Re: The 2020 melting season
« on: July 25, 2020, 04:19:01 PM »
With little change in the last 2 days, the NSIDC extent is now lowest on record by 481,000km2, and less than 1 million km2 below the 2010s average again.

The simple projection only produces a new September low for 6 of the last 20 years. The 10 year average melt will reach a low of 3.6 million km2, or 2nd lowest on record.
https://twitter.com/Icy_Samuel/status/1287026915765780480
https://twitter.com/Icy_Samuel/status/1287027525630275586

34
Arctic sea ice / Re: The 2020 melting season
« on: July 23, 2020, 03:55:52 PM »
NSIDC extent now lowest on record by 655k, and over a million km2 below the average of the last 10 years. We're 1.06 million km2 below the 2010s average, 1.98 million below 00s, 2.78 million below 90s and 3.31 million below the 80s.
https://twitter.com/Icy_Samuel/status/1286293031981912073

9 of the last 20 melt seasons will produce a minimum below 2012, and the 10 year average gets us down to 3.45 million km2. Slowest melt, 2001, will produce the 5th lowest minimum, at 4.21 million km2.
https://twitter.com/Icy_Samuel/status/1286294094910816258

35
Arctic sea ice / Re: The 2020 melting season
« on: July 23, 2020, 12:11:56 PM »
0z ECM and GFS in broad agreement on the weather to day 4/5, a variable mix of high and low pressure and a broad pattern favouring dispersion.
After that, ECM allows a deep low to take hold with some potentially stormy conditions, while the GFS produces a reverse dipole with a strong Atlantic to Pacific air flow.

06z GFS coming out now, so interesting to see where that goes

https://twitter.com/Icy_Samuel/status/1286225443776081920

36
Arctic sea ice / Re: The 2020 melting season
« on: July 22, 2020, 03:56:03 PM »
8 of the last 20 melt seasons will produce a minimum below 2012 now, and the 10 year average gets us down to 3.52 million km2. Slowest melt, 2001, will produce the 6th lowest minimum, at 4.347 million km2.


37
Here's a Landsat 8 RGB composite of Petermann Glacier, from July 17th.
https://twitter.com/Icy_Samuel/status/1285656073517531138


38
Arctic sea ice / Re: The 2020 melting season
« on: July 21, 2020, 08:22:19 PM »

I have a quibble with these sorts of projections: They don't take into account the patterns of melt. Virtually every season rather closely follows a few overall patterns, and virtually every melt season has the specific pattern that the slope of the line in the first half of July continues into mid- or late August. Just tagging on the melt from this point on onto the end of 2020 is not likely to capture the actual potential outcome.

I largely agree. The projections I post are simple and naive, not meant in terms of any genuine scientific pursuit. Every melt season is different - every year the ice is configured differently in terms of thickness, coverage, age, formation history. The weather is different each year too. In fact, everything is different every year. Even where slopes line up, they can be lining up for completely different reasons. No method so far is capable of capturing the eventual outcome, mine is certainly no different.

We are in uncharted territory here, but there's no harm is playing with the data a bit!

39
Arctic sea ice / Re: The 2020 melting season
« on: July 21, 2020, 04:18:58 PM »
Latest simple projection has 7 of the last 20 melt seasons causing a record low, and the 10 year average melt gives a low of 3.53 million km2. Slowest melt (2001) gives a low of 4.39 million km2.

40
Arctic sea ice / Re: Arctic Image of the Day
« on: July 21, 2020, 01:23:21 AM »
Something I put together earlier from the New Siberian Island.

Slightly higher res version on my twitter:
https://twitter.com/Icy_Samuel/status/1285324472724213761

41
Arctic sea ice / Re: The 2020 melting season
« on: July 21, 2020, 12:30:43 AM »
ECM want to send some heat over the remaining thick ice at the end of the week. 2020 is relentless.

42
Arctic sea ice / Re: The 2020 melting season
« on: July 19, 2020, 09:43:52 PM »
What numbers do we get if we use the most konservative numbers from now and onward?

Based on the last 20 years, the slowest melt was, by far, 2001. That would produce a minimum of 4.41 million km2, 7th lowest on record.
Next slowest is 2006, which would give a minimum of 4.16 million km2, 5th lowest.

43
Arctic sea ice / Re: The 2020 melting season
« on: July 19, 2020, 05:42:05 PM »
Latest projection has 7 of the last 20 years beating 2012, and the 10 year average melt reaching a low of 3.56 million km2

44
Despite remaining in roughly 4th lowest position since the last update, the gap to the lowest volume continues to shrink.




45
Arctic sea ice / Re: The 2020 melting season
« on: July 18, 2020, 01:52:34 PM »
The ensemble probability maps (animated below for 120 to 192 hours out) are now showing a high risk of strong winds (>50km/h) around the Arctic from 5 days out. These kinds of maps can be more informative than looking at individual model runs when assessing the probability of storms and such.

46
Arctic sea ice / Re: The 2020 melting season
« on: July 17, 2020, 04:45:14 PM »
After the latest NSIDC extent update, we're now below the minima of 4 additional years, '82, '86, '92 and '96.

All but 2 of the last 20 melt seasons would put the 2020 minimum at least 2nd lowest on record.

The average extent loss of the last 10 years would produce a minimum of 3.64 million km2


47
Arctic sea ice / Re: The 2020 melting season
« on: July 17, 2020, 11:30:58 AM »
With the NSIDC data updated, we've seen a drop of 2.257 million km2 since June 30th, this is a record for that time period, with the next lowest being 2007 with 1.951 million. It's also a record in terms of the % dropped, 23.9% , much higher than the next largest, 20.2% in 2011. Incredible changes.

Will PIOMAS join in on the dramatics, I wonder?

48
Arctic sea ice / Re: The 2020 melting season
« on: July 16, 2020, 11:11:43 PM »
Attached is a gif (quite big ~9.7mb), showing the projections of the 2020 NSIDC extent using the extent losses of the last 20 years, and starting in March. Unfortunately, the NSIDC data hasn't updated since the 12th, so I'm fascinated to see how it looks now!

49
Arctic sea ice / Re: The 2020 melting season
« on: July 16, 2020, 11:08:10 AM »
An animation of the ADS concentration values at 5 days increments, from June 30th to July 15th.
(click to play)

50
Arctic sea ice / Re: The 2020 melting season
« on: July 11, 2020, 04:41:53 PM »
Latest NSDIC daily extent shows a big drop again, 176k. That's 2 mega melt weeks in a row, 2.015 million km2 lost in 2 weeks.

Below is the latest projection up to the end of September, and an animation of how that has changed over the last 4 days below that.




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