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Messages - Sourabh

Pages: [1] 2
1
Arctic sea ice / Re: The 2019 melting season
« on: July 11, 2019, 06:53:52 AM »
Melting momentum discussed on the forum mainly focuses on May-June period, though I could be wrong here. I was wondering if there was any such thing as post-June melting momentum. I am remember it has been discussed previously, particularly during the melting season of 2016, when July made up for any lack of any May-June melting momentum.

Clear skies and high temperatures after 21-22 June  lasting until 15-20th July can also provide similar melting momentum. I remember Neven posted some criteria on how a perfect/ice-free Arctic melting season would unfold.

My question is whether 2019 could be a 'model' year towards such perfect melting season in which both pre-June and post-June melting momentum play a role.

If June was a 'heck of a month', can July be another 'heck of a month'?

Not calling you out personally but you are the third person to bring up July 2016 Being a big melt month.

But it wasn't very warm

I apologize if I mixed years. I remember reading it on the forum that some year. I checked JAXA extent and it could be 2015 or 2018 if not 2016 that remained nearly average year until July. Then, the melting rates increased. That year did not experience any specific ' big event' that contributed to higher melting.

So, my point was whether 2019 might be a new normal, where without any 'big or momorable events' (PAC/GAC/Dipoles), the minimum extent would be reached. Also, I wanted to understand whether there is such thing as 'post June' melting momentum.

2
Arctic sea ice / Re: The 2019 melting season
« on: July 11, 2019, 05:30:19 AM »
Melting momentum discussed on the forum mainly focuses on May-June period, though I could be wrong here. I was wondering if there was any such thing as post-June melting momentum. I am remember it has been discussed previously, particularly during the melting season of 2016, when July made up for any lack of any May-June melting momentum.

Clear skies and high temperatures after 21-22 June  lasting until 15-20th July can also provide similar melting momentum. I remember Neven posted some criteria on how a perfect/ice-free Arctic melting season would unfold.

My question is whether 2019 could be a 'model' year towards such perfect melting season in which both pre-June and post-June melting momentum play a role.

If June was a 'heck of a month', can July be another 'heck of a month'?

3
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: July 10, 2019, 09:53:51 PM »
Neven, the daily extent drops show two consecutive double-century drops. Is the latest one a record? (Graph from Alphabet Hotel above)

Consecutive double centuries happen every now and then. The most recent was July 27th to 29th last year, with with drops of 211k and 253k.
2014 had one too, between the 27th and 29th of June, with 228k and 275k

Welcome back BFV. I missed your special updates you used to provide earlier related to severity of melting seasons.

4
Arctic sea ice / Re: The 2017/2018 freezing season
« on: February 26, 2018, 03:00:34 PM »
Can anyone throw some light on the following pressure map? Can this be called a dipole? If so, how rare such dipoles are at end of winter seasons as compared to, say May/June, ?




Edited: somehow the above link is showing a different image that what is actually shown on the website.

http://ocean.dmi.dk/arctic/weather/arcticweather_imagecontainer.php

5
Arctic sea ice / Re: The 2017/2018 freezing season
« on: February 24, 2018, 02:40:51 PM »
I checked DMI graph and it seems quite odd. What kind of 'dipole' (if one can use this term here) is that? Is this pressure anomaly significant in anyway? Can there be any kind of warning/learning opportunity here?



As far as I know I do not remember seeing this kind of pressure anomaly since I started following this blog.

6
Arctic sea ice / Re: The 2017 melting season
« on: July 18, 2017, 06:47:40 AM »
Another century drop in IJIS extent.

Just wild thoughts:

2007 seems to have become new normal in case 2017 also ends up close to 2007 and 2016. Similarly, after next record losses event whenever that happens (say 2018  :P :P), 2012 may become new normal.  We will get new record year for benchmarking and the forum will get more energy that Arctic will for further discussion ;) ;)

7
Arctic sea ice / Re: IJIS
« on: July 05, 2017, 07:22:48 AM »

Want to bet on that?  ;)

In order to catch up with 2016, approximately 470,000 km2 of SIE must be lost by 9th July, which translates into roughly 95,000 km2 per day.

So, bet is on. That is all we can do now. ;D

8
Arctic sea ice / Re: IJIS
« on: July 05, 2017, 06:10:35 AM »


I'll place money on the certainty that 2017 will move below 2016 within the next eight weeks, and stay there for some time.

Ah well you would have lost ... just! ;)

Not trying to be smart, but it does rather illustrate the folly of betting on the noise rather than the trend (sadly a much surer bet)

Eight weeks will complete next week. So, there are still six days left.  ;)

9
Arctic sea ice / Re: The 2017 melting season
« on: July 03, 2017, 04:24:57 PM »
Kindly delete if this has already been posted and I failed to notice this.

This forum, Neven's blog, and this melting season got some coverage.

https://www.newsdeeply.com/arctic/articles/2017/07/03/from-cryosphere-to-blogosphere-sea-ice-enthusiasts-track-arctic-melt

10
Arctic sea ice / Re: The 2017 melting season
« on: June 11, 2017, 07:56:50 AM »
IJIS SIE is showing steady decline for past week although not as fast as what happened in 2012 during same period.

What do you guys think of potential of melting momentum created so far this year as compared to 2012? Persistent open sky for so long and one of the lowest SIE  for the most period seem ideal for that.


11
Neven,

I eagerly wait for early updates on melting seasons before voting. This year, there has not been any updates yet from your side. Are you planning to write a post anytime soon?

12
Arctic sea ice / Re: 2017 sea ice area and extent data
« on: January 21, 2017, 01:22:17 PM »
If possible, can anyone post area numbers? What is happening to the area these days? :-\ :-\ :-\

Are we also experiencing shocking "recovery" in area as well?    ;) ;)

13
Arctic sea ice / Re: IJIS
« on: January 13, 2017, 05:50:51 AM »
Espen,

Is there something odd with IJIS graph values? Yesterday, they had values for 11th January (I think around 12.4). Today, they do not have that value.

Anyway, we are still behind the extent of 12.42 million km2 it was on 5th Jan. So, for seven days, the arctic ice is practically flat.

14
Arctic sea ice / Re: IJIS
« on: January 08, 2017, 08:47:26 AM »
IJIS down again today....

Antarctic is about to loose large portion of shelf.

Hurray !!!!  :(

15
Arctic sea ice / Re: 2016 sea ice area and extent data
« on: September 01, 2016, 05:56:01 PM »
BFV,

If possible, could you also show NSIDC comparison in form of chart as you do for IJIS extent? 

Thanks,
Sourabh

Sure. 5 day average or single day values? All years or just from 2007?

Thanks.

From 2007 only. I think we already passed the minimum value of other years. Use whatever numbers (5 days or single day) you have used for comparison in previous posts in same thread.

16
Arctic sea ice / Re: 2016 sea ice area and extent data
« on: September 01, 2016, 04:38:49 PM »
BFV,

If possible, could you also show NSIDC comparison in form of chart as you do for IJIS extent? 

Thanks,
Sourabh

17
Arctic sea ice / Re: Stupid Questions :o
« on: August 30, 2016, 11:15:32 AM »
I have a question on dipole. Are there multiple kinds of dipole formation in and around arctic?  For example

    High pressure at the pole and low pressure in the surrounding areas (as I think was in 2007/2012)?
    Current one in which low pressure at the pole and high pressure in the surrounding areas?


Which kind of pressure arrangement would be more severe for ice? If this question has been answered before, please point me to that post/thread.

Thanks,
Sourabh

18
Arctic sea ice / Re: The 2016 melting season
« on: August 29, 2016, 09:32:30 AM »
Guys,

I have a question. Which kind of pressure arrangement would be more severe for ice: current one in which low pressure at the pole and high pressure in the surrounding areas OR high pressure at the pole and low pressure in the surrounding areas (edit: as I think was in 2007/2012)?

If this question has been answered before, please point me to that post/thread.

Thanks,
Sourabh

19
Arctic sea ice / Re: The 2016 melting season
« on: July 07, 2016, 11:00:30 AM »
NSIDC says only the first half of June was slower than average in ice melt.

The second half of June was way above average and the month as a whole was slightly above average.

Which provides evidence that refutes arguments that June as a whole was a dud.

https://nsidc.org/arcticseaicenews/2016/07/extent-loss-slows-then-merges-back-into-fast-lane/

There's the 30-year average, and then there's the 'new normal' average. Here are the JAXA SIE June average daily decrease for the 2007-2016 period:

2007: 66,750
2008: 60,972
2009: 58,760
2010: 76,892
2011: 69,105
2012: 81,368
2013: 68,914
2014: 77,597
2015: 46,452
2016: 48,445

Average of average: 65,534

Neven,

Last two years seem to have "abnormally" low melt rate during June. Does it indicate any permanent shift in Arctic ice melting and freezing cycles? Both years started low winter extent. So, there is not much "easy-to-melt-ice" to begin with. That ice simply did not form during winter unlike other years that would be available for melting during May/June. So despite slow/low/average melting year, 2015 and likely 2016 may end up among the lowest years in terms of extent.

So, along with melting momentum in summar, can there be any "anti-freezing" momentum during early winter due to far more ocean during May/June? If there is more open ocean, that might slow down freezing of ice.

20
Arctic sea ice / Re: IJIS
« on: June 16, 2016, 07:27:06 AM »
Jim,

Nice chart.

I think early June losses may continue to decline possibly due to the fact that there is no ice left to lose for that time period. The ice extent that would generally be lost during early June is either non-existent or getting lost during May.

It is as if there is some kind of monthly/weekly quota for ice in Arctic regions that is allowed to be lost during particular time period.

21
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: June 05, 2016, 05:49:09 PM »
Thanks Wipneus,

So, melt extent, as Richard said, refers to area of ice with wet surface. But, how can you be sure that it is melt pond and not open water? Is this why you are using thickness maps to include only those areas that have non-zero thickness and some water/melt surface?

Also, is rapid rise in melt extent precursor to rapid drop in area? Because  area is declining rapidly for past three days (more than 320k), and in your graph, melt extent is also increasing.

22
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: June 05, 2016, 01:50:15 PM »
Wipneus,

Silly question:

What is melt extent? What does bottom graph represent?

23
Neven,

I noticed that you stopped mentioning CAPIE in your updates. Last month when you were on leave, I requested Wipneus to do that.

http://forum.arctic-sea-ice.net/index.php/topic,1457.msg76805.html#msg76805

I couldn't interpret the graph. If possible, could you compare CAPIE to see how bad or good this year is so far as compared to last few years? We are far ahead in terms of volume, area, extent. So, if we also maintain lead in CAPIE, I think we can break the record even if  weather remains in the middle (not too conducive, but also not too cold).

24
Arctic sea ice / Re: The 2016 melting season
« on: June 05, 2016, 09:39:07 AM »
Next ten days are going to be interesting to watch as 2012 starts its madness from tomorrow. Wipneus's area data is telling us that area is declining rapidly (250k in two days).

As Jdallen on IJIS thread pointed out, ice is spreading out, which is slowing down rate of decline in extent. But, at the same time, more melt ponds and thus melting momentum is being created. I think extent numbers will also be in free fall in next two or three days.


It would be really ominous if 2016 follows 2012 June madness, given clear sky, lowest volume, lowest extent etc.

25
Arctic sea ice / Re: IJIS
« on: May 28, 2016, 05:29:19 AM »
Thanks Espen for removing lines for all other years. This graph makes comparison much easier to see.

Looks like some slow down has begun. Lets if if it is harbinger of "calm before the storm" or signal of "after a storm comes calm".

26
Arctic sea ice / Re: IJIS
« on: May 25, 2016, 06:24:50 AM »
I was expecting that based on Wipneus's shadow data on NSIDC ice extent. NSIDC extent figure decreased by century yesterday. I do not know if there is a direct correlation between NSIDC and IJIS. 

27
Arctic sea ice / Re: 2016 sea ice area and extent data
« on: May 15, 2016, 07:19:23 PM »
Thanks Wipneus,

Neven generally divides CT area with IJIS extent to get CAPIE.

In your graph, three different sources of compactness are telling different stories. In NSIDC compactness, 2016 is lower range as compared to other years. But, in Uni Hamburg, it is in upper range.

I was thinking if compactness is also low during May with already lower extent, then this year is likely to be extraordinary. With open skies and lots of melt ponds, there could be possibility of a significant melting momentum. But, I leave the intellectual interpretation of the data to you, Chris, and Neven.

28
Arctic sea ice / Re: 2016 sea ice area and extent data
« on: May 15, 2016, 06:36:56 PM »
Wipneus,

I should have asked this here, and not in the melting season thread.

If possible and if it is not too much to ask, could you also make an updated CAPIE chart to show how this year is doing as compared to previous years? Generally, Neven does that, but just like arctic ice, he has disappeared from this forum lately ( ;D).

29
Arctic sea ice / Re: The 2016 melting season
« on: May 15, 2016, 06:03:34 PM »
I was going through old posts on Neven's blog. I was particularly interested in June 2012 and June 2015, as 2015 stalled and 2012 dropped rapidly. One of the common factors was melt ponds (measured by CAPIE). It would be interesting to know current state of CAPIE to know about potential of this year's melting momentum.

Is there anyway to find that out, as CT area updates are no longer available.

30
Arctic sea ice / Re: 2016 sea ice area and extent data
« on: May 15, 2016, 05:55:39 PM »
BFV,

I also missed your updates. Given the recent IJIS drops, your next update would be more interesting.

31
Arctic sea ice / Re: The 2016 melting season
« on: May 02, 2016, 08:13:57 AM »
This is the first time in which temperature has been above average so far. If we look at past four DMI temperature graph, every year remained below average for almost entire May and June. So, this year with already less ice (in extent, area, and volume) and higher temperature, things might become really interesting in coming two or three weeks.



32
Arctic sea ice / Re: IJIS
« on: April 28, 2016, 05:48:15 AM »
All hell is going to break lose if things continue down this path. We broke the record again. Earliest year SIE going below 12.5

Another thing I noticed is that this is the first year in almost all years when avg. temperature on DMI is never went below average even for a day. The red line is above green line since the beginning of the year. Even 2012 went below average for few days. I do not know how important this is, but this definitely seems to be an anomaly.

33
Arctic sea ice / Re: IJIS
« on: April 23, 2016, 08:23:13 AM »
I am very excited for such an interesting melting season, but bit sad at the same time.

This is crazy and alarming. This year seems to be ahead of other years in many ways (in an alarming sense). This year there was already less ice and/or thin ice to begin with. So far early melting momentum is already causing a steady melting of ice every day. There are no signs that future melting rate will be moderated. All weather indicators according to several comments in other posts point to conditions very conducive to melting.

This year, there is a high probability that 2012 record will be broken.

34
Arctic sea ice / Re: IJIS
« on: April 01, 2016, 07:18:34 PM »
It is bit off topic, but if 2016 does break all the records the reactions from deniers will be as shown in the video



PS: Apologies if it offends anyone or it has been discussed before. I only intended it to be funny.

35
The rest / Re: Free Access to Journal Articles
« on: February 24, 2016, 10:08:41 AM »
Neven,

I am not sure about access to specific websites or data related to CT or Arctic ice through this website. I doubt if you could do that as the website is designed mainly to make scientific article accessible free of charge.

So far, I have been able to access almost all articles from Elsevier, Springer, Wiley, Nature etc free of cost. So, if you need any peer-reviewed articles published in popular journals, you can immediately get pdf of that article through this website.

36
The rest / Free Access to Journal Articles
« on: February 24, 2016, 03:08:38 AM »
Guys,

In case you do not know, you can access scientific articles without paywall on www. sci-hub.io
This website is designed by a Russian scientist to protest against exorbitant prices charged by many publishers.

37
A-Team,

Sorry to ask a stupid (noob) question. Last year also, I was confused on the same image.

I am finding it difficult to visualize carving on the animation you posted (14 vs 16th). 16th Image looks better (solid ice sheet) and it seems lot of slush in 14th. Why is that? Did ice( water) refroze on 16th?


38
Arctic sea ice / Re: 2015 sea ice area and extent data
« on: July 29, 2015, 04:35:03 PM »
Wipneus,

Is it a temporary slowdown or does it look similar to what 2013 and 2014 experienced around the same time ?

39
Arctic sea ice / Re: Glossary ... for newbies and others
« on: July 15, 2015, 07:31:49 PM »
Okie dokie. Thanks

40
Arctic sea ice / Re: The 2015 melting season
« on: June 22, 2015, 12:18:41 PM »
Chris,

I was following the comments related to the post and I am not able to comment on your blog post due to firewall in office.

http://dosbat.blogspot.co.uk/2015/06/are-we-facing-crash-in-2015.html

So, I am commenting here.

I don't know if you have already read and discussed conclusions presented in this article, but it suggests that GAC -2012 was not a major factor in record ice retreat.  I thought it may be useful to the discussion on preconditioning of ice melt and summer ice cover.

http://onlinelibrary.wiley.com/doi/10.1002/grl.50190/full

I don't understand many of technicalities of weather, ice etc. I just follow Arctic ice blogs to get a concise summary from experts like you, Neven, or Wipneus, on an "immediate" apocalypse [:P].

41
Arctic sea ice / Re: IJIS/JAXA
« on: March 14, 2015, 10:06:19 AM »
Yay...

Does it mean we peaked? It is already mid March. I don't think we would have much gain left now.

42
Arctic sea ice / Re: IJIS/JAXA
« on: March 04, 2015, 05:44:01 PM »
Espen,

Could you please post the link to IJIS/JAXA sea-ice extent graph? Somehow, old link I bookmarked seems to have stopped working.

Thanks,
Sourabh

43
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: June 30, 2014, 08:33:43 AM »
Wipneus,

Has Arctic area dropped below 2012's levels for this day? I just checked CT, 2012 is much below than 2014.

44
Arctic sea ice / Re: 2014 sea ice area and extent data
« on: June 21, 2014, 05:32:22 PM »
Wipneus,

This is almost half a million drop in past three days. So, is there any possibility 2014 will catch up with 2012?

45
Arctic sea ice / Re: Early thoughts on 2014 min extent, area, volume
« on: January 22, 2014, 11:51:11 AM »
Could you also provide previous years' minimum for reference? That would be helpful in judging.

46
Arctic sea ice / Re: What is the cause of the PIOMAS volume loss?
« on: January 16, 2014, 10:35:50 PM »
Chris,

I see that the years that are frequently discussed here are 2007 and 2012. As I joined this forum last year, I did not know what was discussed during 2010 melting season. I find 2010 strange year. It had lower volume than 2007, but higher extent and area coverage than 2007. It is the only year with such anomaly. Was there any reason for it? Was it important?


47
Arctic sea ice / Re: What is the cause of the PIOMAS volume loss?
« on: January 15, 2014, 09:26:27 PM »
Thanks for the description.  I should start reading more about Arctic to become familiar with more technical terms and climatology.

I was interpreting the first video. I was trying to argue that after 2000s, freshening has further stratified Arctic Ocean, in at least in some basins. So, during winter, mixing and transport of heat due to convection reduced. Therefore, deep ocean water no longer interact or mixes with upper layer, which is what I meant by two-sub systems, upper ocean layer and deeper ocean layer. Or, there could be multiple systems, one for each basin. Before influx of fresh water, deeper ocean interacted with upper layer through mixing in the previous century i.e. before 2000s.

(The link you provided has the paper you were excited about. I read that paper, though not completely. So, I may be missing many things. I will read it again to see what mistakes I am making. )

After 2000s, fresh water has thickened the upper layer. So, during winter mixing occurs but only within the upper layer, not in deep ocean unlike previous century , when mixing with deep ocean occurred. . Is that correct? In other words, fresh water influx is somewhat protecting ice melt. If it wasn't for fresh water, Arctic would be ice-free by now. Or did I get it totally opposite of what is correct?

48
Arctic sea ice / Re: What is the cause of the PIOMAS volume loss?
« on: January 15, 2014, 06:50:48 PM »
Crandles,

Thanks for the explanation. It was really helpful.

I am sure many models incorporate the effects of the fresh water. However, one of the videos I posted shows significant increase in fresh water content of Arctic Ocean.

My question is that can inflow of fresh water prevent other factors from becoming dominant although fresh water itself is not dominant? I can be completely wrong, but consider this theory:

Before large influx of fresh water, sources that provided heat to melt ice included solar radiations wind, and water mixing (deeper layer, Atlantic, Pacific etc.). But lots of fresh water created an independent or isolated pool of fresh water that melts or freezes without interacting with broader Arctic climate/ocean system. Imagine a very large 'saucer' near Beaufort floating in Arctic Ocean.

In other words, now we have two sub-systems in Arctic that are not interacting much. One sub-system composed of this pool, which is receiving heat only through sun and wind, but not much or at all from water mixing. Another sub-system, may be composed of bottom layer, which is receiving heat from mixing, but not enough from sun and wind. So, fresh water separated Arctic system in two smaller systems over period of years.

Before I think any further, I would like to see you thoughts over this crazy theory.

Btw,

I found this presentation. I  could not entirely understand the findings. So, if you don't mind going through it, I would appreciate that.

http://www.whoi.edu/fileserver.do?id=169345&pt=2&p=180769

49
Arctic sea ice / Re: What is the cause of the PIOMAS volume loss?
« on: January 15, 2014, 02:16:09 PM »
Dear Chris,

I wanted to ask if salinity influences Arctic sea-ice formation. Based on the video I posted, lots of fresh water is entering Arctic ocean. The following article also suggests that fresh water helps in protecting ice.

http://www.nasa.gov/topics/earth/features/earth20120104.html#.UtaIHvZSbas

http://www.bbc.co.uk/news/science-environment-16657122

Furthermore, as happening in Antarctica, sea-ice extent is increasing due to melting of glaciers that supply lots of fresh water. Can similar phenomenon occur in Arctic?

Can Russian floods and river runoffs have any correlation with  sea-ice losses? Lack of  fresh water would discourage ice formation and/or increase melting. So, may be in 2012, 2007, there wasn't enough fresh water, but remaining years had huge fresh water running into Arctic Basic due to flood in Canada or Russia. Therefore, other years including 2013 were not record melt years.

Does this proposition have any validity?

~Sourabh

50
Arctic sea ice / Re: What is the cause of the PIOMAS volume loss?
« on: January 14, 2014, 09:43:21 AM »
Hey Chris,

I am not qualified and/or experienced enough to add much, but I found these videos. I have shared first video before as well. It shows changes in ocean current in Arctic.





It might help you if you haven't seen this video before.

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