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Messages - grixm

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1
Arctic sea ice / Re: The 2020 melting season
« on: April 03, 2020, 11:19:22 AM »
Extreme Fram export continues:

2
Arctic sea ice / Re: The 2020 melting season
« on: April 01, 2020, 08:19:28 AM »
Has anyone else noticed this odd protrusion between northern greenland and Svalbard island. It has been there for a while and it looks like it should just break off but it hasn't. Or is it normal?

The ice is anchored to the seabed below. In 2012 there was a similar long and relatively thin protrusion, but even as it started to shatter in July, it still held on for a while even as the part connecting it to the mainland broke off: https://worldview.earthdata.nasa.gov/?v=269947.6895835763,-1001118.4511475239,925307.6895835763,-656030.4511475239&p=arctic&t=2012-07-20-T10%3A00%3A00Z

You can see there is an area of shallow water around there too:

3
Arctic sea ice / Re: The 2020 melting season
« on: March 29, 2020, 09:00:10 AM »
March 28th, 2020:
     13,559,443 km2, a drop of -19,954 km2.
     2020 is now the lowest on record.   :P

Greatest comeback since the 2005 UEFA Champions League Final

4
Greenland and Arctic Circle / Greenland 2020 Melting Season
« on: March 24, 2020, 08:40:12 AM »
Since we clarified that the SMB thread should be for SMB data/discussion only, I am making a general-purpose melting season thread for Greenland like from last year.

I'd like to start by asking wtf is going on in the Freya Glacier webcam? Am my eyes deceiving me or was there a lot of snow melting yesterday despite being March and -20C?

Some resources:

SMB data: http://polarportal.dk/en/greenland/surface-conditions/ (And gerontocrat's thread)
Melt extent data and news: https://nsidc.org/greenland-today/
A webcam: https://www.foto-webcam.eu/webcam/freya1/


5
Antarctica / Re: PIG has calved
« on: March 23, 2020, 03:04:13 PM »
You can also see one of the rifts in the southern sheet has clearly lengthened.

6
Antarctica / Re: PIG has calved
« on: March 18, 2020, 10:34:20 PM »
(this GIF is NOT animating. I converted this still picture to a GIF to reduce the file size)

GIFs are not good for file size. You can make it ten times smaller with little degradation as a jpeg

7
Consequences / Re: 2020 ENSO
« on: March 18, 2020, 04:12:33 PM »
The 3.4 index has risen to the highest daily value in months:


8
Arctic sea ice / Re: The 2020 melting season
« on: March 15, 2020, 06:09:51 PM »
Some fast ice in Laptev and Kara is starting to crack. Maybe just because of drift, not melting. Click to play.

9
The Freya glacier webcam is back up and the sun has started to come out. There's not that much snow, either.

https://www.foto-webcam.eu/webcam/freya1/

PS: Is this thread just for SMB data? If so, there is no general 2020 greenland season thread yet.

10
Arctic sea ice / Re: The 2019/2020 freezing season
« on: March 14, 2020, 07:19:56 PM »
Speaking of melting, the 2020 melting season thread is open BTW.

Shouldn't we all switch there now?

Link >> https://forum.arctic-sea-ice.net/index.php/topic,3017.0.html

Feels a bit early still, and the thread hasn't been made a sticky, but I guess I will change if I post about melting.

11
Arctic sea ice / Re: The 2019/2020 freezing season
« on: March 14, 2020, 06:44:36 PM »
It's a bit too cloudy to tell but there doesn't appear to be much sign of refreeze yet on the open leads east of Wrangel Island.
Chukchi Sea, https://go.nasa.gov/3aMQDfY (contrast),mar14, uni-hamburg amsr2-uhh, feb13 inset.
click for full resolution

It has been quite warm in this area the last day (and will stay warm too). It's even possible we might see some surface melt during the day.


12
Arctic sea ice / Re: The 2019/2020 freezing season
« on: March 12, 2020, 10:24:27 PM »
Has anyone notices that there is a large "valley" in the Fram strait in the DMI thickness map? If that's accurate then the ice near the pole could be unusually weak this year.


13
Antarctica / Re: PIG has calved
« on: March 08, 2020, 02:38:48 PM »
In case anyone is interested, I boosted and normalized the contrast of baking's gif


14
Antarctica / Re: PIG has calved
« on: March 06, 2020, 09:16:29 AM »
My guess is that Cork 3 will no longer be within the southern shear margin by March 5, 2020.

You mean 2021?  ;)

15
Antarctica / Re: PIG has calved
« on: March 03, 2020, 04:12:28 PM »
Is it just me or is the sentinel-2 photos posted so far really dark and hard to make out? No offence to the posters. Here is an overview of the ZOD, somewhat brighter.


16
Science / Re: 2020 Mauna Loa CO2 levels
« on: March 01, 2020, 06:37:18 PM »
Interesting drop. Central European vegetation is starting it's spring growth and manufacturing in China is pretty down. I haven't followed the progress of northern hemisphere's spring elsewhere, might be additional reasons for this decrease in the speed of the rise.

The reason likely has nothing to do with that, it's just pure chance. It takes months for CO2 from the mainlands to mix and reach the measurement station on Hawaii.

17
Antarctica / Re: PIG has calved
« on: February 29, 2020, 09:55:11 PM »
The two rifts in the SIS have expanded and are clearly visible in the high-resolution Sentinel1 images. I think they are even longer, but the Sentinel2 images to confirm this are not available at the moment.  >:(  >:(

In an earlier shot "SR1" definitely seemed to extend further down as I reported in this post: https://forum.arctic-sea-ice.net/index.php/topic,429.msg250925.html#msg250925

18
Consequences / Re: COVID-19
« on: February 26, 2020, 09:22:55 PM »
grixm, might it be about this guy: https://www.thelocal.no/20200226/norwegian-student-tests-positive-for-coronavirus-in-italy

"a Norwegian citizen in Italy has been infected with coronavirus"

"He has been based in Italy for around six months but may have been in Norway as recently as last week..."

Nope, it was a new one: https://translate.google.com/translate?sl=auto&tl=en&u=https%3A%2F%2Fwww.nrk.no%2Fnorge%2Fforste-tilfelle-av-koronasmitte-i-norge-1.14920058

19
Consequences / Re: COVID-19
« on: February 26, 2020, 08:46:13 PM »
The Norwegian public health institute will hold a press conference in 15 minutes. I'm calling it, I bet they've found our first case.

20
Antarctica / Re: PIG has calved
« on: February 24, 2020, 10:15:35 PM »
The last couple of weeks has been pretty mild temperature-wise, but now it will get COLD. Will drop to under -20C by the end of this week, and the sea surface might start to refreeze a bit.

21
Consequences / Re: Chinese coronavirus
« on: February 23, 2020, 03:06:31 PM »
43 people infected in Iran, and 8 fatalities. Let's hope it's not a mutation.

There are almost certainly far more people actually infected.


Also, Italy cases is spiking, now at 129: https://www.repubblica.it/cronaca/2020/02/23/news/coronavirus_italia-249329434/

22
Antarctica / Re: PIG has calved
« on: February 23, 2020, 10:59:18 AM »
We can see the previous location of a small iceberg that calved from the cork area.

Also, is it just me or is this crack in the SIS growing too? There are hints of it in previous satellite shots, but I don't think I've seen it this clearly, or extending across the ridge/valley/feature below it.

EDIT: Also, blumenkraft, your image doesn't work


23
Antarctica / Re: Where is D-28 headed?
« on: February 18, 2020, 08:31:15 AM »
It is speeding up. It has moved around 20km north in the last four days. Click to play.

24
Consequences / Re: Chinese coronavirus
« on: February 17, 2020, 07:54:33 PM »
https://gisanddata.maps.arcgis.com/apps/opsdashboard/index.html#/bda7594740fd40299423467b48e9ecf6

showing increase in other locations(other than mainland China) from 780 to 1.3k but doesn't seem to show where these extra cases are. Perhaps it is mainland China but not yet correctly allocated to region?

It's probably a bug, earlier today there was a short window where it showed the "Other" (now "Diamond Princess") category as over 700 cases, before it quickly went back down. They probably by chance used that time to create the daily total.

25
Antarctica / Re: PIG has calved
« on: February 15, 2020, 09:34:50 AM »
Calving in the cork area / ZOD. Line is approximate




26
Antarctica / Re: Dotson Ice Shelf has calved
« on: February 13, 2020, 08:16:52 PM »
Quote
Between Feb 1 and Feb 11 a part of the Dotson Ice Shelf lost a 25*3 km piece of ice. The days in-between were too cloudy for an evaluation in EOSDIS, so a more exact dating is not possible.

To me it looks like it had already calved by the 1st. It had moved considerably by then if you compare it to a week or so before. It just hadn't completely drifted away from the shelf yet.

27
Antarctica / Re: PIG has calved
« on: February 13, 2020, 09:33:41 AM »
The iceberg(s) are hardly even recognizable anymore.


28
Arctic sea ice / Re: The 2019/2020 freezing season
« on: February 12, 2020, 11:03:12 AM »
Look at all these polynyas and cracking in the ESS/Laptev. Is this normal during peak freeze season?


29
Science / Re: 2020 Mauna Loa CO2 levels
« on: February 11, 2020, 03:17:38 PM »
Another record day: 416.08 ppm on February 11th

30
Consequences / Re: Weird Weather and anecdotal stories about climate change
« on: February 11, 2020, 12:27:13 PM »
We just broke the record for sea level in some parts of Norway, as well as close to the lowest ever surface air pressure. This is after a separate top-10-ever sea level event just a few weeks ago.

And january broke temperature and precipitation records as well. We've had exactly zero days of persisting snow in my city (Bergen) so far this winter even though there are usually weeks of it most years. It's been a weird start of the year.

31
Antarctica / Re: I never knew this was possible, Candles. ;D
« on: February 09, 2020, 06:11:18 PM »
Let's talk about variables that accompanied this event.

1) Today is the full moon.

2) In the last couple of days, there was a storm.

3) Temperatures above freezing.

4) You could see on the SAR shots that the surface was rather wet. Possible it even rained.


What else? Someone can think of something?

Not specific to this very day and it goes without saying, but we mustn't forget it is after all peak season, meaning regardless of the weather there are relatively warm sea temps, lots of sun, and no fast ice holding the glacier back.

32
Policy and solutions / Re: Bikes, bikes, bikes and more...bikes
« on: February 09, 2020, 11:47:26 AM »
Biking on compacted snow works fine on flat roads. But it's suicidal in a hilly city like mine. So sadly the lessons from that article is not applicable everywhere. "Luckily" it doesn't go below freezing that many days of the year anymore, though.

33
Antarctica / Re: PIG has calved
« on: February 09, 2020, 09:08:40 AM »
Finally, it's Calving Day



34
Antarctica / Re: PIG has calved
« on: February 06, 2020, 11:56:41 AM »
The whole rift wasn't captured, but the edge is full of slush indicating a lot of movement and debris. Or is it just the debris from the mini-calving yesterday?


35
Antarctica / Re: PIG has calved
« on: February 06, 2020, 10:34:04 AM »
Winds gusting at over 70 kts in the past 24 hours in the Amundsen Sea.  Just sayin' . . .

https://twitter.com/rdlarter/status/1225197471879647232

Worst conditions will come this friday and saturday, with above-freezing temperatures, rain/sleet, and winds that may reach 15 m/s sustained.


36
Arctic sea ice / Re: The 2019/2020 freezing season
« on: February 05, 2020, 07:39:22 PM »
RE grixm
https://forum.arctic-sea-ice.net/index.php/topic,2888.msg247928.html#msg247928

     I thought we were done with this, but I have another favor to ask.  Can you extend the early vs Sept. Extent comparison charts to April-August? 

    You showed above that there is no correlation of March to September, but surely there must be correlation by August.  This is probably in a journal article somewhere, but your charts are lovely and can be up to date to include 2019.  Seeing the data point spread would be really interesting.   

     For sporting interest, I'll wager such charts would show R2 around:
April 10%
May 20%
June 30%
July 50%
August 80%

    And if anybody did the same for Volume, that would be icing on the cake.

PS in case you zipped past binntho's post in the data thread at
https://forum.arctic-sea-ice.net/index.php/topic,2975.msg247842.html#msg247842
   The articles he cites there provide really nice long-term context for ASI variability and current situation.  Good stuff.










37
Arctic sea ice / Re: The 2019/2020 freezing season
« on: February 04, 2020, 08:11:40 PM »
Therefore, I experimented with instead normalizing the years to their predicted average extent from a linear regression of all the years.
Your method is skewed by the fact that the long-term extent losses are happening more rapidly in September than in January/February/March.

September extent in the last few years is about 40% lower than in the 1980s, whereas March extent has decreased by only 10%.  So your "normalized" March extent has an upward trend over the last few decades, whereas the normalized September extent has a downward trend.  So it's not surprising that you get a negative correlation between them.  But that correlation is spurious.

A more meaningful method is to detrend the data (see e.g. here for some background on detrending).  It turns out that the correlation between the detrended March extent and the detrended September extent is very weak: the correlation coefficient is  -0.029.

    Many thanks to grixm and Steven et al. for wrestling with the numbers.  It looks like the jury is still out on this one.  While counter-intuitve [more Extent early leads to less 8 months later (Jan-Sept), 7 (Feb-Sept.), or 6 March-Sept.)], the insulating ice theory at least sounds plausible. 
[..]

I normalized the months to the trend of its month alone, instead of to the whole year, like pointed out. And it seems Steven is correct. The correlation is gone..




38
Antarctica / Re: PIG has calved
« on: February 04, 2020, 03:49:35 PM »
Damn, not long now.

39
Arctic sea ice / Re: The 2019/2020 freezing season
« on: February 01, 2020, 10:36:06 AM »
Which brings me to a niggle: Your graph for January predicts a September average of 4.3 Mkm2 and not a September minimum of 4.3. Correct me if I am wrong! NSIDC September average for 2012 was an amazing 3.6 but both 2007 and 2019 came in at very close to 4.3.


Yes that is correct, I've edited the post

40
Arctic sea ice / Re: The 2019/2020 freezing season
« on: February 01, 2020, 09:15:14 AM »
Overnight I realized that my graphs has a big flaw, the fact that the years are normalized with themselves can induce a lot of autocorrelation. For example, if it is the case that a low september minimum is completely random, that would still increase the ratio of normalized winter extent vs normalized september extent, because the low september extent would drag the average for the whole year down, thus increasing the normalized winter extent. Furthermore, since calculating the normalized extent requires knowledge of the average for the whole year, it is not possible to predict anything with it beforehand.

Therefore, I experimented with instead normalizing the years to their predicted average extent from a linear regression of all the years. Now, it should be truly neutral, and also you can make predictions. Unfortunately, doing this does reduce the correlation a lot, but it is still there.

Now, we can make  a prediction for 2020 based on the january value. The high extent compared to the ever-decreasing trend makes this year stand out a lot, the normalized january extent is an all-time high: 1.322. See the red area on the january graph. Will this mean the september extent  will be very low like the graph suggests? Or does it mean the correlation will break down? If we trust the graph naively, the expected normalized september minimum average for this year is 0.42, which is 4.30 Mkm^2 (which is third lowest of all time, behind 2012 and barely 2007), with a lower uncertainty bound of ~2.97 Mkm^2 and a high bound of ~5.33 Mkm^2.




41
Arctic sea ice / Re: The 2019/2020 freezing season
« on: January 31, 2020, 10:39:56 PM »
Here I have plotted the normalized average extents in january, februrary and march, compared to september. Normalized meaning the value divided by the average value for the whole year. This means that the long-term trend of general melting is removed.

There seems to indeed be a strong correlation of high extent early season = low extent late season, for all three months graphed.






42
Policy and solutions / Re: Tesla glory/failure
« on: January 31, 2020, 09:00:43 AM »
I like Tesla and love electric vehicles in general, but as for the recent stock price activity, it is clearly a hype-fueled bubble. Personally, I've opened a short.

43
Antarctica / Re: PIG has calved
« on: January 29, 2020, 07:27:07 PM »
Just compared the Sentinel-1 images from this morning and yesterday, and yes it definitely looks like movement. See the gifs below. Notice how the southern edge appears to move, but the northern edge does not. It is rotating. I looked at the map scale and it looks like the southern edge surged around 100 meters. The cork also moved with it. Maybe some movement in the icebergs of rift 2 too.

44
Antarctica / Re: PIG has calved
« on: January 29, 2020, 07:04:56 PM »
Well folks you just check on the differential speeds from the InSAR records of PIG here:

http://www.cpom.ucl.ac.uk/csopr/iv/index.html?glacier_number=3&image_date=200112_200118#output

Which gives a velocity differential along the center of the glacier and useually tells me when there's been a significant change.

Looks like the data is 5 days old

45
Antarctica / Re: PIG has calved
« on: January 29, 2020, 08:35:09 AM »
It could be another angle or bad alignment, Grixm.

I thought so too but I compared other edges in the image and I can't see the same effect there, they look dead aligned.

46
Antarctica / Re: PIG has calved
« on: January 28, 2020, 10:12:57 PM »
Is it just me or is there significant movement of the whole front between the latest worldview image and yesterday's? 


47
Consequences / Re: Wildfires
« on: January 28, 2020, 08:16:46 PM »
And it will get worse over the next few days. Another burst of 40+ C weather is coming to the area.

48
Antarctica / Re: Melt lake on Nivlisen Ice Shelf
« on: January 28, 2020, 11:53:26 AM »
We got a cloud-free sentinel image on the 26th. And also the lake has mostly frozen over, or drained? I'm not experienced enough to tell the difference. If it has drained, does that have implications for future sea level? That's a pretty large meltwater drainage basin that would have found a way to the ocean.


49
Antarctica / Re: PIG has calved
« on: January 24, 2020, 05:03:15 PM »
Yep, tip fell off.

We'll have to tow it outside the environment.

50
Science / Re: 2019 CO2 emissions
« on: January 22, 2020, 07:30:40 PM »
Wow! Latest daily CO2 reading was 415.79 ppm, higher than at any date last year. And it's still winter!


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