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Messages - mabarnes

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1
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 22, 2020, 07:07:20 PM »
I know nothing, but I'd say that low pressure = clouds = less heat out into space. Aint it so?

Hey thank you for the response.  I was wondering about that - but I read something about tropical storms in the Pacific and convection transferring warmer (moist) air up to where it can radiate out from there ... I would figure the Arctic may be different as it's so much colder (Scoop! LOL) and maybe the clouds formed block IR from the sea surface ... geez Louise this weather thing can get complicated....

I'm really curious about this stuff so again, thank you.


2
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: August 05, 2020, 07:21:01 PM »
  .. or not ! .. I've got things covered .. I offered to cover Gero in circumstances like this a year or 2 ago so now i am .. however I'm delighted to see community in action .. b.c.

I echo the sentiment of others, G has been a tremendous resource - please let me (us) know what we can do - I have years of experience in data recovery, if needed.  (It sounds like the drives should be intact ... but whatever I can do to help).

 ::)

3
Arctic sea ice / Re: Latest PIOMAS update (January 2020)
« on: February 07, 2020, 06:57:24 AM »
PIOMAS Volume as at 31 January 2020  18,283 km3


First, thanks again G ... appreciate all you do.

OCD Alert (mine lol) - in the comparison table (4th graphic), the cell that reads "2019 More (+) or Less (-) than" ... should say "2020" ...

4
Arctic sea ice / Re: The 2019/2020 freezing season
« on: February 01, 2020, 06:30:57 AM »

I for one am surprised that there is any correlation at all. And if this is real and not statistical noise, what could be the mechanism behind it?


A possible mechanism?  The smaller the floating ice "cap" on the Arctic Ocean, the more open water is able to radiate heat to space, especially once the sun sets for a long period - six months at the pole, less further south but still substantial (112 days at Svalbard).  Perhaps the greater amount heat that "bleeds" from the ocean during this period influences the January extent?

Just takin' a shot.  Question for grixm - my slightly baked theory (microwaved?) would suggest September extent as the independent variable (x-axis) ... is it the other way around because your postulating "more in spring -> less in September" ...?  Thanks

5
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: December 31, 2019, 05:43:04 AM »
I will be traveling on the next 7 hours, so I will appreciate if someone else updates the ADS JAXA data.

Thank you.

JAXA 12/30 Extent 12,287,365 sq. km.
Gain of 37,861 sq. km.

I used the same years as Juan has been using in the graph ... table will have to wait for the man himself eh ...  8)

6
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: December 27, 2019, 07:27:02 AM »
With low cloud cover leaving the Arctic open to radiate unimpaired to space, plus "offshore" (quotes to signify of the ice mass as well as land) winds over the peripheral seas and cold temperatures, 2019 is closing out with a bang for ice formation. 

Interesting situation ... extent is second only to 2014 for the date, for the decade, and exceeds end-of-year extent for 4 of the years.  Chart shows the current numbers vs. the rest of decade, and what would be needed to end the year "on top" - looks like top 3 or 4 is makeable, #1 for the decade of the "twenty-teens" a long shot ...

Table - red indicates year at left is LESS than 2019, or LOSS would be needed to equal on 12/31.
Color bands in gif green, blue, light blue demarcate 10 to 0, 0 to -10, and -10 to -20 C.

To the "old hands" out there ... wondering if this is what the "old normal" used to look like...? 
A glimpse of the past, for a week at least...?

7
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: December 25, 2019, 05:29:07 AM »
Dec 24 & 25 JAXA Extent back up, or now up, or ... here they are:

Dec 23 - 11,985,836    - gain of 122,375
Dec 24 - 12,064,159    - gain of   78,323

A cold wind from Santa's sleigh to the ice...?  Merry Christmas!

8
Shout out - for the humor and civility to Blumenkraft.  After I stopped laughing, I read the entire topic stream (next time, in advance eh) ... the cracks have been a big issue since 2016.  For what it's worth, and since I didn't see it on here yet, here's the most cited paper I could find on the Petermann ice tongue, it's speed, the grounding line, all that.  Sharing is caring ... I'm told lol.

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2007GL031765

9
Well hallelujah ... it does look like ice.  Dirty or very thin.  Guess it's re-freezing given the temps.  Thanks man ....

(BTW - anybody know where the grounding line actually is?)

10
Was checking out Petermann today - the plot thickens.  For reference I put together a graphic of the last giant floe I remember (July 2012) along with yesterday's view of the glacier from the same source.  Looks like the tongue of the glacier has advanced idk, 8-10 km since 2012.

While doing this, I also looked at yesterday's high-res image and danged if my "floater" conception needs revision - there's visible (what sure looks like) rock as the floor of the cracks.  Now I'm wondering if it's "just" an uneven grounding line, maybe meltwater pulses below the glacier cause the cracking ... stumped, at least for now.

Anyway, that's all I have, curious as always....

11
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: August 30, 2019, 06:42:30 PM »
PIOMAS volume provides monthly data, soon... DMI does have a daily tracker. I searched the forum for any comments on its validity and didn't see anything concerning, feel free to correct me.

http://ocean.dmi.dk/arctic/icethickness/images/FullSize_CICE_combine_thick_SM_EN_20190828.png
I am waiting for this, will help tell us how much of the stall is due to dispersion vs a real stall in melting.
Biases in PIOMAS are discussed here:
http://psc.apl.uw.edu/research/projects/arctic-sea-ice-volume-anomaly/validation/

PIOMAS won't help a lot at this stage because it overstates the volume of thin ice. With more thin ice widely distributed the PIOMAS volume estimate may hold up despite a reality of less ice. The last few days appear to have spread the ice and lowered the concentration which will lead to an increase in the error in the PIOMAS estimate.

As the attached graph shows the over estimate of volume, on ice below 1m thick according to  submarine measurements, could be double what the submarines are seeing.

As long as the methodology of PIOMAS is consistent, it should be fine for comparison.  The operative comparison is not between model and reality, it's between model and previous years' model results. The r-squared ain't that bad. eh. 

Point is adjusting the previous years' model estimators to observed values, if done uniformly, wouldn't change any ratios.  It sure would change the estimate of latent heat of the entire ice mass, tho - so there is that.  Just my 2 cents....

12
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: August 30, 2019, 06:34:43 PM »

JAXA daily extent loss in the last 2 weeks very much below average and on this day up from a -0k extent loss to a below average 11k extent loss. Definitely not a one-off - this is an event.
...
Given that Arctic temperature anomalies have been consistently above average and that SSTs have been and are very high, this two week stall in extent (and now area) loss is a complete mystery to me.
____________________________________________________________

Gerontocrat - I've been keeping an eye on the ENSO index all year, about every day (for a side bet, the usual amount) ... I know the local temperatures seem contra-intuitive as you mentioned, but on a simple "seems" basis, it seems like the heat just shut off as insolation dropped latter half of August, and I can't help but notice the ENSO faded almost in unison with the melt stall.

Correlation implying Causation?  Yeah I know, but as a data-driven scientist (day job), it makes me take note.  So here's my question for an experienced ice tracker - the big melt came from the Pacific side ... so could that be what's "missing" from the late melt, Pacific heat...?  Curious what you think, as I said, I'm rank novice newbie to ice analysis.  Thanks.

13
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: August 30, 2019, 06:58:31 AM »
Since Juan is out ... my humble submission of a less complete pinch hit...:

JAXA Extent for August 29, 2019 - loss of 10,785 square km.

14
I believe the final end of the glacier is riding on a layer of water beneath it, as evidenced every time a giant berg breaks off and floats away ... I remember one that made the news in August 2012.  Those same cracks appeared in pretty much the same place in August 2018 (pic attached).

I'm far from fully informed on this kind of thing, but I think the end of most glaciers is actually floating on water beneath, and there's a "grounding" line upstream where it's still riding on land.  Maybe this has something to do with it...?  Perhaps somebody more knowledgeable on glaciers can help enlighten on this?  Interesting stuff....

15
Crazytown.  July 29-August 25 ... click to animate in new window.

16
Greenland and Arctic Circle / Re: Greenland 2019 Melt Season
« on: August 09, 2019, 04:26:40 PM »
The isolated blues on this map near the edges of the GIS, could they be related to the glaciers slumping toward the sea? Meaning an area close to the edge of the ice sheet is suddenly slightly higher because the glacier sped up?

Why else the isolated blues? The big mass of blue down in the SE corner makes sense.

Surface Mass Balance (SMB) = gains - losses ... from the surface.  Basically precipitation gains minus sublimation/ablation losses.  It doesn't include base melt losses or glacial calving losses.

The blue is in those area due to most of the precip hitting the east coast of Greenland this season.  If you look at the Aug 8 (not cumulative) map you can see the blue addition of the latest systems' precipitation in the daily map G posted right before yours.

Attached is is the 3 hour precip from right now (8:20 EST 8/9) showing the remnants of the systems, but you get the idea.  Still, the 8/8 map is red on the SE coast as the precip may have been rain at coastal altitudes, adding to the melt, or if snow, simply was falling on top of still melting melting - didn't "stick" as we used to say as kids.

Hope this helps.  I'm a lurker/newbie mahself so any corrections please and thanks.

Here's a good glossary on the topic:  https://unesdoc.unesco.org/ark:/48223/pf0000192525

17
Here's my stupid question, regarding "momentum."  I keep hearing that word - can someone enlighten me as to actual observations on such a thing...?  By this I mean serial correlation of extent and/or area ... any studies or data on this...?

Asking cuz at first-glance it seems to me counterintuitive - as ice melts, it cools the water, doesn't it?  As I recall it would cool 720 cubic km of water by 0.1 C to melt 1 cu km of ice, if it was only the water doing the heat transfer.  Is "momentum" something else entirely?  Weather?  Currents?

Appreciate any insight, thanks.  Been wondering ....

18
The politics / Re: The problem of social media
« on: July 04, 2019, 05:34:26 PM »
Wow.  Rather than comment about the law and human rights - here, Free Speech - I think I'll let this do the explaining far better. 

When it comes to government force policing speech, I would recommend extreme caution ... careful what you wish for, ladies and gents....


19
Greenland and Arctic Circle / Re: Greenland 2019 Melt Season
« on: May 03, 2019, 05:42:16 PM »
Hmmm....

20
The rest / Re: Climate change activists should not fly
« on: April 19, 2019, 02:31:23 AM »
You know, this is all predicated on aviation being the least efficient means of transportation. But is it? I've always heard that, but that doesn't mean it is true.

Take NYC to LA
Scenario 1 Boeing 747-400 in a "medium" 524 passengers in a typical two-class layout,
Scenario 2 262 medium sized cars on the Interstate,
Scenario 3 A cruise ship with 524 passengers going through the Panama Canal, and
Scenario 4 A passenger train (I suspect this would be best. I also suspect it is impossible in the Real World)

Roughly what would be the carbon emissions of these four trips? has anyone done the math?

I hate to say, "As economist, I find it helpful to find data and display it visually" ... ahh, what the heck.  From the US Dept of Energy....

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