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Messages - dosibl

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1
Arctic sea ice / Re: The 2019 melting season
« on: June 17, 2019, 08:42:27 PM »
We're not going to see major anomalies on the DMI 80n chart during summer until a nontrivial part of 80n is open water, so a lack of continuing anomaly there doesn't necessarily mean things are better or worse.

2
Arctic sea ice / Re: Albedo-Warming Potential
« on: June 10, 2019, 08:16:23 PM »
The Beaufort seems to have exceeded the Y axis on the daily anomaly graphs, not sure if that value can be easily changed or if this would be problematic for older graphs which have the current Y axis maximum.

3
Arctic sea ice / Re: The 2019 melting season
« on: May 10, 2019, 02:49:22 PM »
Snow cover graphs/maps have also been added at cryospherecomputing.tk, I've really been digging the new site.

4
Arctic sea ice / Re: Albedo-Warming Potential
« on: May 02, 2019, 04:54:43 PM »
No surprise that we're tracking to get a similar anomaly in the Bering as last year, iirc last years ~250 mj/m2 was basically double any prior year.

Tealight, my understanding of the 'potential' part of AWP is that the calculation doesn't account for weather, correct? A cloudy season and a sunny season with similar extent would produce similar AWP numbers but would experience different actual warming?

5
Arctic sea ice / Re: The 2019 melting season
« on: April 19, 2019, 03:43:39 PM »
I'm sure this is a line of research somewhere that I'm just not familiar with, but I would think that the early melt in the Okhotsk could impact the inner seas by partially participating in the large scale weather patterns we'll encounter over the summer. The effect might be positive, negative, or mostly a wash, but all things being equal I think I'd prefer more ice.

6
Arctic sea ice / Re: Latest PIOMAS update (April 2019)
« on: April 16, 2019, 09:17:22 PM »
We should be mindful that stickied threads in particular have a lot of readers who don't actively participate, so churning unrelated discussion in them is a lot of noise for people who specifically just want to see PIOMAS numbers for example.

7
Arctic sea ice / Re: The 2018 melting season
« on: June 21, 2018, 07:53:13 PM »
magnamentis, is there any product for measuring cloud cover? I'm loathe to try and eyeball worldview pictures and draw any conclusions.

8
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: June 13, 2018, 10:03:34 PM »
I believe extent data is measured and not modeled (I wouldn't count any light post-processing of measurements as modeling), so I'm inclined to decently trust these numbers. With dispersion I'd expect to see a moderate loss of area with neutral or rising extent, which would mean lower compaction. Compaction has indeed been going down over the past several days, so dispersion seems like a reasonable conclusion.

https://sites.google.com/site/cryospherecomputing/daily-data

9
Arctic sea ice / Re: The 2018 melting season
« on: June 13, 2018, 04:14:50 PM »
My understanding of 15% for extent is that it was picked for navigation vs being indicative of the ice  in general, its continued use is because extent data is our oldest dataset so it affords us better historical comparison.

11
Arctic sea ice / Re: The 2018 melting season
« on: May 07, 2018, 04:19:36 PM »
Is there a product or model people would recommend for tracking cloud cover? CCI reanalyzer has a precipitation/cloud cover display but its hard to judge clouds on ice.

12
Arctic sea ice / Re: The 2018 melting season
« on: April 24, 2018, 08:48:48 PM »
Jdallen (or others), with that in mind what are the key weather metrics we can keep an eye on over the next two months? Up-thread Neven and others have been noting the persistent high that is trying to set up shop, my recollection from last melting season is that a high pressure system can potentially lead to less clouds and more insolation, is that the main concern?

I know the various GACs (may not be the best term for them) from the past few years can really churn up the ice, but my understanding was that storms generally compact the ice and didn't really cause massive loss. Weaker ice may not hold up as well to storms, but from an ice-preservation standpoint I assume we'd rather have a stormy summer than a clear-sky summer. 

13
Arctic sea ice / Re: The 2018 melting season
« on: April 17, 2018, 09:54:10 PM »
Thanks for expanding on that a bit, always useful to see what others are looking at. SWE is way up but extent is still pretty standard, not sure what to make of that (other than the fact I've been enjoying the north american ski season the past few years).

14
Arctic sea ice / Re: The 2018 melting season
« on: April 17, 2018, 08:59:10 PM »
bbr2314 is there a reason you are going with the North America version of that graph? The melting trend is much more noticeable on the Northern Hemisphere version.

15
Arctic sea ice / Re: The 2018 melting season
« on: April 13, 2018, 03:19:16 PM »
The Bering sea is quickly racking up warming anomaly, last season set a record of ~160 MJ/m2 by the end of June, this season is on pace to double that. My understanding of this data is that it doesn't account for cloud cover (hence the 'potential'), but its another metric into the unusual season on that side of the world.

https://sites.google.com/site/cryospherecomputing/warming-potential/graphs

16
Arctic sea ice / Re: The 2017/2018 freezing season
« on: February 22, 2018, 01:16:36 AM »
The DMI 80n anomaly will likely be even higher for the next four days, anything above 260 would be pretty rare for this time of year so it'll be interesting to see what the final numbers are.

17
Arctic sea ice / Re: The 2017/2018 freezing season
« on: February 15, 2018, 11:15:39 PM »
The latest d10 forecast on cci is shocking, but since its so far out I'm inclined to wait a few days and see if the models still think that once its closer.

18
Arctic sea ice / Re: The 2017/2018 freezing season
« on: October 06, 2017, 08:09:48 PM »
FDD trends might be lining up with 2016, but its too early to tell. The big story last year was the extremely warm moments in the fall, that + the global area/extent graphs generated enough buzz that the media reported on it (and I suspect resulted in a bunch of new readers on this forum, including myself), I'll be curious to see if we get anything similar this year.

20
Arctic sea ice / Re: IJIS
« on: May 27, 2017, 08:18:05 PM »
Comparing 2016/2017 on Hycom shows how much extra we have on the Atlantic side, until that melts out it'll help "cover" losses in other areas.

21
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: May 27, 2017, 05:15:22 PM »
Wind forecast 24 hours from now looks pretty dire on nullschool, it then proceeds to get worse. If this plays out it'll be the ultimate experiment in attempting to clog the Nares.

https://earth.nullschool.net/#2017/05/28/1500Z/wind/surface/level/orthographic=-60.36,85.27,2758/loc=-56.263,82.716

22
Arctic sea ice / Re: The 2017 melting season
« on: May 25, 2017, 11:03:00 PM »
It seems the first-year ice bowl has just about arrived at the north pole, this feature has been pretty easy to track on the HYCOM 365.
https://www7320.nrlssc.navy.mil/hycomARC/navo/arcticictn_nowcast_anim365d.gif

Judging by how mobile the surviving ice was last fall/winter, it looks like first-year ice from the Laptev sea all the way to the pole.


24
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: May 16, 2017, 07:34:26 PM »
Worldview images from today show another large jump in cracking area, almost the entire region looks compromised.

25
Arctic sea ice / Re: The 2017 melting season
« on: May 12, 2017, 07:09:38 PM »
Relatively large jump in SST compared to yesterday (that area has been around -1.2C), with more heat on the way it'll be interesting to see if it gets any worse.

https://earth.nullschool.net/#current/ocean/primary/waves/overlay=sea_surface_temp/orthographic=-94.59,89.02,826/loc=171.724,70.557

28
Arctic sea ice / Re: The 2017 melting season
« on: May 06, 2017, 05:42:23 PM »
Here's a similar thickness comparison using HYCOM.

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Arctic sea ice / Re: Latest PIOMAS update (May)
« on: May 03, 2017, 09:29:43 PM »
PIOMAS definitely trending down, we'll have to go to war with the army we have...

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Arctic sea ice / Re: Latest PIOMAS update (April)
« on: April 29, 2017, 08:57:28 PM »
This seems a bit out of scope for a discussion of current PIOMAS numbers, might be better suited in a new thread?

31
Arctic sea ice / Re: The Fast Transition
« on: April 28, 2017, 12:45:11 AM »
I've also seen some stalling of thickness in my HYCOM graphs, however that data is a little rough so I'm looking for the next PIOMAS numbers to hopefully shed some light.

32
Arctic sea ice / Re: The 2017 melting season
« on: April 25, 2017, 03:19:51 PM »
PIOMAS firmly has us in a volume anomaly, but area/extent are still in the same ballpark as years past. I'm concerned the square-cube law might throw a curveball in how fast/how much volume melts out.

33
Arctic sea ice / Re: The 2017 melting season
« on: April 08, 2017, 12:16:24 AM »
At this point in the season I'd expect volume to be the most informative feature for the minimum, I've been shying away from the area/extent graphs because I don't think they tell as much of the story for overall ice health at the end of the freeze.

34
Arctic sea ice / Re: Latest PIOMAS update (March)
« on: April 04, 2017, 09:48:28 PM »
The X axis starting before January really throws me off with these graphs, is the graphed data through the middle of March or all of March?

35
Arctic sea ice / Re: Latest PIOMAS update (March)
« on: April 04, 2017, 09:36:25 PM »
They didn't update the thumbnail, I've been staring at it all day!

Average thickness chart looks a little troubling.

36
Arctic sea ice / Re: The 2017 melting season
« on: March 30, 2017, 07:57:17 PM »
@Thomas That graph doesn't line up with what I'd expect just based on the FDD anomaly delta between the two years.

37
Arctic sea ice / Re: The 2017 melting season
« on: March 30, 2017, 12:06:36 AM »
I've been watching the Hycom CICE thickness plots (https://www7320.nrlssc.navy.mil/hycomARC/arctic.html) while I wait for the next PIOMAS update, so I decided to download all the images and try to extract some data from them.

For each day I get the total number of colored pixels, as well as the thickness associated with that color (ranging from 0 to 5 meters). With those numbers its pretty straightforward to graph total thickness as well as average thickness.

Right now the numbers are for all ice shown in the image, I'm hoping to eventually produce the numbers by region, I'm particularly interested to see the overall percentage of ice that is in the Fram.

38
Arctic sea ice / Re: The 2017 melting season
« on: March 26, 2017, 05:02:31 PM »
Looking at the DMI 80n graphs temps consistently start rising around day 100, whats the primary driver behind this, increase in solar energy?

39
Arctic sea ice / Re: The 2017 melting season
« on: March 24, 2017, 10:52:14 PM »
I think a fair amount of ice north of the Nares has been busy sliding towards the Fram instead of pressing on the arch, a trend which looks set to continue.

40
Arctic sea ice / Re: The 2017 melting season
« on: March 20, 2017, 11:42:16 PM »
Thanks for the tips, plenty of things to keep an eye on.

Definitely interested in watching the Beaufort sea, comparing March 20th across the past few years shows how stark the difference is.

41
Arctic sea ice / Re: The 2017 melting season
« on: March 20, 2017, 03:29:06 PM »
Before we get too deep into melting season, would some of the more seasoned posters mind giving a handful of things they will be keeping an eye on over the next few months to judge how 'good' or 'bad' the melt is going?

This will be my (and I suspect some others) first melting season so it'd be nice to know what to expect in general, as well as what to watch coming from such an extreme freezing season.

42
Arctic sea ice / Re: The 2016/2017 freezing season
« on: December 12, 2016, 03:25:48 PM »
The rub on machine learning for 16/17 freezing is that unless someone made it a big project I don't see it being that useful, perhaps only as good as forecasting ice disposition a few days into the future. With how unprecedented the past few weeks have been, I'd also be wary of a model that relied too much on historic data since it would have a hard time accounting for what we are seeing now.

Its a shame the NIPS slides didn't cover any deep learning, its also a shame that NIPS'16 just ended and I can't find anything about climate modeling in the presentations. Archimid, don't give AlphaGo too much credit, the paper google released on it is a bit technical but the entire system is pretty straightforward to understand. As with all things deep learning, the end result will depend on the quality and quantity of data available.

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