Support the Arctic Sea Ice Forum and Blog

Author Topic: The 2019 melting season  (Read 599006 times)

Rodius

  • New ice
  • Posts: 80
    • View Profile
  • Liked: 30
  • Likes Given: 4
Re: The 2019 melting season
« Reply #550 on: April 24, 2019, 06:23:39 AM »
Blocking highs are not something new, but their intensity and persistence in increasing. The record Greenland melt years of 2010 and 2012 were associated with strong high pressure over Greenland. Those were also bad years for the Arctic sea ice.

The coming together over the Arctic ocean of the Alaskan block and the Greenland block is particularly bad for sea ice because it creates a dipole that imports heat from the Pacific and exports ice through the Fram Strait.
A huge change in albedo is about to take place.

It appears that as part of the evolving conditions upwards of 1 million KM2 of snow cover in Siberia and Alaska are going to vanish in the next 5 days, as well as at least 2/3rds of the snow cover on the Chukchi and Beaufort.

This I think may qualify as "momentum".

Where did you read this?  Is there a website that tracks albedo?


https://cryospherecomputing.tk/NRTawp.html

Sterks

  • Guest
Re: The 2019 melting season
« Reply #551 on: April 24, 2019, 12:20:02 PM »
The weather forecast seems to settle on this torch from the Pacific starting on the weekend, has been described by others days ago.
What the EC shows in its +9 +10 days is that, as an aftermath of this atmospheric rearrangement, a strong Beaufort high would reappear, which might be pretty damning in May in case of persevering.
But this is all speculation. :-)

sark

  • Frazil ice
  • Posts: 203
  • not a scientist
    • View Profile
  • Liked: 73
  • Likes Given: 74
Re: The 2019 melting season
« Reply #552 on: April 24, 2019, 03:01:50 PM »
I am not a scientist.  I haven't even been watching very closely for an entire year, but I've been glancing at the situation in the Arctic for 20 years.  Eyes front now.

This doesn't look like a ridge, to me.  This looks like a short circuit.  The Arctic Ocean is warmer than the land.  What's happening now looks, again to an untrained eye, like the polar cell is being torn in two.

Whatever's left of cold air after this will certainly return to the Arctic in mid-May, according to pattern.  I'm hopeful more is left than appears to be in the forecast weather models.  It's uncomfortable to see GFS runs that look like mid-June of 2016 before May of 2019.

Still, the forecast temperature anomalies don't look insane.  This tormented flow pattern has somehow kept cold within 80N all winter.  I thought we'd see an ice free north pole in 2017 and that didn't happen.  Who knows, I'm just an outsider, but this has the feeling of something new & unique & damning.
I am not a scientist

jai mitchell

  • Nilas ice
  • Posts: 2030
    • View Profile
  • Liked: 70
  • Likes Given: 18
Re: The 2019 melting season
« Reply #553 on: April 24, 2019, 05:23:45 PM »
o boy


The anomaly is very strong.  however, it is also paired with a huuuuuuge inflow of atmospheric water vapor which will suppress solar heating and will also produce large snow on CAB.
That's the question, isn't it? We have been dealing with these dueling feedbacks since 2012 it seems. However, I suspect that it will not produce large snows, but rather, rain, at least over Beaufort / Chukchi / ESS (IMO, could easily be wrong).

FWIW I started documenting these kinds of blocking pattern/Arctic heat and WVx inflows through the Bearing Strait in March of 2014.  See thread here:  https://forum.arctic-sea-ice.net/index.php/topic,784.msg22395.html#msg22395
Haiku of Past Futures
My "burning embers"
are not tri-color bar graphs
+3C today

Jontenoy

  • New ice
  • Posts: 24
    • View Profile
  • Liked: 10
  • Likes Given: 1
Re: The 2019 melting season
« Reply #554 on: April 24, 2019, 06:00:50 PM »

Sterks

  • Guest
Re: The 2019 melting season
« Reply #555 on: April 24, 2019, 06:23:07 PM »
Thank you. It's good to be reminded of how screwed things are when we zoom out a bit.
This melting season no exception, and the feeling is that the 2018-2017 mini rebound is over, and if I am wrong it doesn't matter (zoom out).
And we got the orange-gutan wanting to make sure the little hopes we could have are vain.

werther

  • Grease ice
  • Posts: 727
    • View Profile
  • Liked: 11
  • Likes Given: 0
Re: The 2019 melting season
« Reply #556 on: April 24, 2019, 08:23:22 PM »
Took a glance at Worldview today. Not my favourite medium. I used to work a lot on the Rapid response-tiles. Not available anymore. But I’m still capable to look at some spots out of 15 years of experience. Yes, still with you…
Inspired by 2 meter temps through DMI and volume projected by PIOMAS, it seemed not that bad a winter for sea ice. Worldview reveals that is mostly illusive. There are a multitude of influences at work. Just some make it to our attention. As Bering is mostly Pacific by now, sea ice in front of fast ice is crunched and mobile in East Siberian, Chukchi and Beaufort Seas, Baffin Bay ice looks vulnerable and 4 MK Central Basin is torn by long leads, things don’t look a little better at all. The big crunch didn’t happen in ’17 nor in ’18. But it can happen any year now.

forkyfork

  • New ice
  • Posts: 40
    • View Profile
  • Liked: 3
  • Likes Given: 0
Re: The 2019 melting season
« Reply #557 on: April 24, 2019, 10:11:07 PM »
once again a -nao modeled days 6-10 is turning into pacific centered blocking. this has been happening since 2013. click to animate

psymmo7

  • New ice
  • Posts: 33
    • View Profile
  • Liked: 8
  • Likes Given: 4
Re: The 2019 melting season
« Reply #558 on: April 24, 2019, 10:31:44 PM »
Slightly off topic but yet another sign of arctic warming - the break up of ice on the Yukon yesterday was the second earliest ever recorded and only 8 hours behind  the earliest breakup on the same date in 2016

Sebastian Jones

  • Frazil ice
  • Posts: 299
    • View Profile
  • Liked: 42
  • Likes Given: 34
Re: The 2019 melting season
« Reply #559 on: April 25, 2019, 02:11:04 AM »
Slightly off topic but yet another sign of arctic warming - the break up of ice on the Yukon yesterday was the second earliest ever recorded and only 8 hours behind  the earliest breakup on the same date in 2016
Technically this was indeed the second earliest break up, but while the indicator ( a post is placed out on the river ice connected to a clock, when the ice moves, the post pulls a pin from the clock, which stops and records the official time of break up) showed break up, in actual fact almost all the ice is still intact. Photos of the river condition are regularly posted on the site yukonriverbreakup.com. This morning's pic shows the open water at the top left, where the "tripod" was. We should have another pic in an hour or so!

DavidR

  • Grease ice
  • Posts: 724
    • View Profile
  • Liked: 21
  • Likes Given: 2
Re: The 2019 melting season
« Reply #560 on: April 25, 2019, 02:21:24 AM »
Slightly off topic but yet another sign of arctic warming - the break up of ice on the Yukon yesterday was the second earliest ever recorded and only 8 hours behind  the earliest breakup on the same date in 2016
Technically this was indeed the second earliest break up, but while the indicator ( a post is placed out on the river ice connected to a clock, when the ice moves, the post pulls a pin from the clock, which stops and records the official time of break up) showed break up, in actual fact almost all the ice is still intact. Photos of the river condition are regularly posted on the site yukonriverbreakup.com. This morning's pic shows the open water at the top left, where the "tripod" was. We should have another pic in an hour or so!
Of course April 23rd this year was the 113th day of the year, while April 23rd 2016 was the 114th day of the year. But who is counting, its still early.
Toto, I've a feeling we're not in Kansas anymore

sark

  • Frazil ice
  • Posts: 203
  • not a scientist
    • View Profile
  • Liked: 73
  • Likes Given: 74
Re: The 2019 melting season
« Reply #561 on: April 25, 2019, 04:00:34 AM »
the latest ECMWF run.  https://imgur.com/a/kXSSEUx
« Last Edit: April 25, 2019, 05:02:29 AM by sark »
I am not a scientist

oren

  • Young ice
  • Posts: 4177
    • View Profile
  • Liked: 677
  • Likes Given: 1190
Re: The 2019 melting season
« Reply #562 on: April 25, 2019, 05:04:23 AM »
Took a glance at Worldview today. Not my favourite medium. I used to work a lot on the Rapid response-tiles. Not available anymore. But I’m still capable to look at some spots out of 15 years of experience. Yes, still with you…
Inspired by 2 meter temps through DMI and volume projected by PIOMAS, it seemed not that bad a winter for sea ice. Worldview reveals that is mostly illusive. There are a multitude of influences at work. Just some make it to our attention. As Bering is mostly Pacific by now, sea ice in front of fast ice is crunched and mobile in East Siberian, Chukchi and Beaufort Seas, Baffin Bay ice looks vulnerable and 4 MK Central Basin is torn by long leads, things don’t look a little better at all. The big crunch didn’t happen in ’17 nor in ’18. But it can happen any year now.
Good points. And indeed, it can happen any year now.

jdallen

  • Young ice
  • Posts: 3003
    • View Profile
  • Liked: 174
  • Likes Given: 168
Re: The 2019 melting season
« Reply #563 on: April 25, 2019, 06:34:17 AM »
Where did you read this?  Is there a website that tracks albedo?
One of our users, Tealight has built a whole slew of marvelous tools to follow Albedo.

https://forum.arctic-sea-ice.net/index.php/topic,1749.0.html
This space for Rent.

bbr2314

  • Nilas ice
  • Posts: 1694
    • View Profile
  • Liked: 150
  • Likes Given: 42
Re: The 2019 melting season
« Reply #564 on: April 25, 2019, 09:16:21 AM »
Tonight's model consensus for D5-10:


b_lumenkraft

  • Guest
Re: The 2019 melting season
« Reply #565 on: April 25, 2019, 09:35:14 AM »
This is what Bbr is talking about:

Pavel

  • Frazil ice
  • Posts: 179
    • View Profile
  • Liked: 3
  • Likes Given: 1
Re: The 2019 melting season
« Reply #566 on: April 25, 2019, 03:00:33 PM »
Melt ponds in the north Pole and whole CAB in the early May? The DMI north of 80 temperatures above 0C 6 weeks earlier than usual?

Vergent

  • Grease ice
  • Posts: 573
    • View Profile
  • Liked: 2
  • Likes Given: 1
Re: The 2019 melting season
« Reply #567 on: April 25, 2019, 05:04:09 PM »
Where did you read this?  Is there a website that tracks albedo?
One of our users, Tealight has built a whole slew of marvelous tools to follow Albedo.

https://forum.arctic-sea-ice.net/index.php/topic,1749.0.html

You can track albedo from Topaz4 using Godiva2;

http://thredds.met.no/thredds/godiva2/godiva2.html?server=http://thredds.met.no/thredds/wms/topaz/dataset-topaz4-arc-myoceanv2-be

Last year it was based on imported data. I don't know about this year. Look for the data to jump on Mondays, that is when they import data.

SimonF92

  • New ice
  • Posts: 47
    • View Profile
  • Liked: 13
  • Likes Given: 8
Re: The 2019 melting season
« Reply #568 on: April 25, 2019, 05:17:46 PM »
Melt ponds in the north Pole and whole CAB in the early May? The DMI north of 80 temperatures above 0C 6 weeks earlier than usual?

I doubt DMI will go past 0 that soon, there is still a lot of cold kicking around

uniquorn

  • Nilas ice
  • Posts: 1256
    • View Profile
  • Liked: 565
  • Likes Given: 106
Re: The 2019 melting season
« Reply #569 on: April 25, 2019, 08:33:41 PM »
JAXA RGB, jan1-apr24.

uniquorn

  • Nilas ice
  • Posts: 1256
    • View Profile
  • Liked: 565
  • Likes Given: 106
Re: The 2019 melting season
« Reply #570 on: April 25, 2019, 09:44:59 PM »
Wipneus amsr2-uhh regional extent chart for bering.
https://sites.google.com/site/arcticseaicegraphs/regional
Comparison of bering/chukchi using uni-hamburg amsr2-uhh mar1-apr24 for 2018 and 2019.

magnamentis

  • Guest
Re: The 2019 melting season
« Reply #571 on: April 25, 2019, 11:07:05 PM »
something tells me we're in for a nasty drop from day 2-5

what i find interesting is in how many places the ice is opening significantly despite temps around -10 and lower.

if reanalyzer forecast, not just anomaly but factual temps above zero running across the arctic and ending in the beaufort gyre we possibly see a few very early flash-melting events in the bering, chucky, as well as baffin and greenland sea. somehow for a short time most of the already weakened corners will be under attack simultaneously.

at least one can get the impression.
« Last Edit: April 25, 2019, 11:50:37 PM by magnamentis »

Neven

  • Administrator
  • First-year ice
  • *****
  • Posts: 7019
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 601
  • Likes Given: 399
Re: The 2019 melting season
« Reply #572 on: April 25, 2019, 11:23:46 PM »
Quote
something tells me we're in for a nasty drop from day 2-5

On the one hand, yes, because there will be strong winds and anomalous temps obliterating the recent increase/stall in the Bering and Chukchi Seas. On the other hand, the same massive winds will push ice towards the Barentsz and Greenland Seas.

But in the long run, this should be bad for the ice. Melt pond May is just around the corner.

Here's the latest ECMWF forecast for the coming 6 days, showing the cluster of isobars, running all the way from the Pacific and the Atlantic, pressure gradient will be around 40 hPa, which isn't bad for a dipole (but not as bad as the 60+ hPa pressure gradient in August 2016):
Il faut comparer, comparer, comparer, et cultiver notre jardin

Neven

  • Administrator
  • First-year ice
  • *****
  • Posts: 7019
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 601
  • Likes Given: 399
Re: The 2019 melting season
« Reply #573 on: April 25, 2019, 11:41:09 PM »
Here's the GFS temp anomaly forecast for the coming 7 days (from Climate Reanalyzer):
Il faut comparer, comparer, comparer, et cultiver notre jardin

magnamentis

  • Guest
Re: The 2019 melting season
« Reply #574 on: April 25, 2019, 11:48:41 PM »
Here's the GFS temp anomaly forecast for the coming 7 days (from Climate Reanalyzer):

sorry that i was late, had both temps and anomalies almost ready

as to wind drift, yes i agree of course while that is accompanied with:

a) very strong winds

b) for the season very high temps (above zero in parts)

c) pushed into relatively warm atlantic waters where waves and heat will
.   probably give it the rest that will make the outlook for the rest of the season
.   even worse somehow and then what will happen in the greenland see where
.   it could almost vanish if the forecast is 100% accurate which i hope it's not.

what interest me is your take on the game heat+wave-action against replenishing wind-driven
new ice flushed out into the barentz ?

Neven

  • Administrator
  • First-year ice
  • *****
  • Posts: 7019
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 601
  • Likes Given: 399
Re: The 2019 melting season
« Reply #575 on: April 26, 2019, 12:14:48 AM »
what interest me is your take on the game heat+wave-action against replenishing wind-driven
new ice flushed out into the barentz ?

I'm not sure yet. Maybe, as you say, big drops. Or expansion on the Atlantic side dampens drops on the Pacific side. Of course, the expansion on the Atlantic side isn't good for the ice in the longer term, because it melts out at those lower latitudes (but maybe not right away, because it's end of April).

If this weather or similar keeps up, it should be possible for 2019 to stay close to 2016 during May. Here's the JAXA SIE graph for May:
Il faut comparer, comparer, comparer, et cultiver notre jardin

GoSouthYoungins

  • Nilas ice
  • Posts: 1011
    • View Profile
  • Liked: 62
  • Likes Given: 109
Re: The 2019 melting season
« Reply #576 on: April 26, 2019, 02:36:38 AM »

what i find interesting is in how many places the ice is opening significantly despite temps around -10 and lower.


Polar amplification is caused largely by the ocean transporting heat poleward. Melt-from-below is the slow and steady that wins. Unfortunately.
big time oops

Thomas Barlow

  • New ice
  • Posts: 88
    • View Profile
  • Liked: 20
  • Likes Given: 19
Re: The 2019 melting season
« Reply #577 on: April 26, 2019, 03:36:17 AM »
Combining 2 images - April 25th on the left, and April 21st on the right to take out cloud -  you can see the broken ice is joined together now. I looked back in the years, and don't see this any other year doing that at this time of year. 2010 comes close on May 4th. A cracked and fractured icesheet from Nares to Fram now.
 
« Last Edit: April 26, 2019, 03:45:06 AM by Thomas Barlow »

Aluminium

  • Frazil ice
  • Posts: 345
    • View Profile
  • Liked: 295
  • Likes Given: 222
Re: The 2019 melting season
« Reply #578 on: April 26, 2019, 06:22:57 AM »
April 20-25.

jdallen

  • Young ice
  • Posts: 3003
    • View Profile
  • Liked: 174
  • Likes Given: 168
Re: The 2019 melting season
« Reply #579 on: April 26, 2019, 06:36:12 AM »
something tells me we're in for a nasty drop from day 2-5
Actually, I'm expecting extent to stay relatively flat, possibly even expand, but concentration to drop.  Basically, the mostly the same ice except spread over a wider area.

Still not good for what's coming.
This space for Rent.

uniquorn

  • Nilas ice
  • Posts: 1256
    • View Profile
  • Liked: 565
  • Likes Given: 106
Re: The 2019 melting season
« Reply #580 on: April 26, 2019, 10:35:21 AM »
Combining 2 images - April 25th on the left, and April 21st on the right to take out cloud -  you can see the broken ice is joined together now. I looked back in the years, and don't see this any other year doing that at this time of year. 2010 comes close on May 4th. A cracked and fractured icesheet from Nares to Fram now.
Agreed. edit: I should add that it is still cold enough for refreeze in those fractures, but the drift is too fast to make much difference.
Worldview terra modis, north greenland, apr8-24. Contrast enhanced to show fractures. 7days/sec.
More about nares here https://forum.arctic-sea-ice.net/index.php/topic,176.msg196830.html#msg196830
« Last Edit: April 26, 2019, 10:43:47 AM by uniquorn »

Gray-Wolf

  • Grease ice
  • Posts: 791
    • View Profile
  • Liked: 46
  • Likes Given: 149
Re: The 2019 melting season
« Reply #581 on: April 26, 2019, 12:11:22 PM »

I'm not sure yet. Maybe, as you say, big drops. Or expansion on the Atlantic side dampens drops on the Pacific side. Of course, the expansion on the Atlantic side isn't good for the ice in the longer term, because it melts out at those lower latitudes (but maybe not right away, because it's end of April).

If this weather or similar keeps up, it should be possible for 2019 to stay close to 2016 during May. Here's the JAXA SIE graph for May:

Hi Neven!

The extension of ice into the lower lat. areas of Barentsz has not been able to occur this past winter ( and many before!) so maybe there is heat enough to begin the degradation of the ice if shunted that way?

Then we have things like swells/salinity in that area also impacting any 'stray ice' pushed out that way?

We will see 'growth' via the collapse and spread of ice entering open waters but this will be illusory.
KOYAANISQATSI

ko.yaa.nis.katsi (from the Hopi language), n. 1. crazy life. 2. life in turmoil. 3. life disintegrating. 4. life out of balance. 5. a state of life that calls for another way of living.
 
VIRESCIT VULNERE VIRTUS

uniquorn

  • Nilas ice
  • Posts: 1256
    • View Profile
  • Liked: 565
  • Likes Given: 106
Re: The 2019 melting season
« Reply #582 on: April 26, 2019, 01:59:26 PM »
whoi ITP103-110 buoy location and temperatures, apr26.
ITP107 near the Chukchi plateau currently warmest at -3.125C
https://www.whoi.edu/page.do?pid=163096

GoSouthYoungins

  • Nilas ice
  • Posts: 1011
    • View Profile
  • Liked: 62
  • Likes Given: 109
Re: The 2019 melting season
« Reply #583 on: April 26, 2019, 03:55:53 PM »
2 northbound flares in the jet streams are forecast to enter the arctic in the next 4 days. The air they contain is currently over the northern pacific and the NE of the US. Apparently the main flare from the pacific will take refuge over the Beaufort sea, while the secondary system is set to head to cross Newfoundland, thru Baffin, and finally end up giving most of its energy to the primary system over Beaufort.

It is only 4 days out at this point, but still seems very open to change. I think forecasts are less stable when they are predicting multiple interacting oddities occurring at once.

If the forecast holds, it is terrible for ice. Lots of air and ocean warm from the Pacific will enter the arctic. At the same time fram and naires will see their export increase. Warmth in, ice out. Very bad.
« Last Edit: April 27, 2019, 02:54:23 AM by GoSouthYoungins »
big time oops

sark

  • Frazil ice
  • Posts: 203
  • not a scientist
    • View Profile
  • Liked: 73
  • Likes Given: 74
Re: The 2019 melting season
« Reply #584 on: April 26, 2019, 07:20:37 PM »
Follow the Quadrupole
I am not a scientist

binntho

  • Grease ice
  • Posts: 755
    • View Profile
  • Liked: 185
  • Likes Given: 52
Re: The 2019 melting season
« Reply #585 on: April 26, 2019, 08:22:33 PM »
Do you men "flares" or does "flair" have a special meteorological meaning?

bbr2314

  • Nilas ice
  • Posts: 1694
    • View Profile
  • Liked: 150
  • Likes Given: 42
Re: The 2019 melting season
« Reply #586 on: April 27, 2019, 12:20:20 AM »
2019 Big Block > 2016 Big Block


GoSouthYoungins

  • Nilas ice
  • Posts: 1011
    • View Profile
  • Liked: 62
  • Likes Given: 109
Re: The 2019 melting season
« Reply #587 on: April 27, 2019, 03:45:40 AM »
The Beaufort is breaking up fairly north today and the system moving in should give it a real whirl. Meanwhile the exit path for the system thru the fram straight (if the 5-10 day holds) would stir the lincoln sea mightily now that the whole area has seen its fast ice reduced by 80+% (also today).

I have a feeling the laptez bite will migrate toward greenland and out the fram strait over the next 9-12 months. There is some abnormally salty water in the coastal area, and the transpolar drift has been in strong effect recently. And ice north of greenland is not providing the resistance it historically has.

What is the best way to melt the arctic? The ice floats south into the atlantic. Particularly the thicker ice. Meanwhile the Pacific spews in.
big time oops

Maplike

  • NewMembers
  • New ice
  • Posts: 1
    • View Profile
  • Liked: 0
  • Likes Given: 6
Re: The 2019 melting season
« Reply #588 on: April 27, 2019, 04:36:47 AM »
According to the NSIDC chart, sea ice extent has been recovering, albeit minutely, in the past couple of days. How does this gel with the weather discussion here? Does it mean anything? Should we expect to see a rapid drop in the next few days?

https://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/

bbr2314

  • Nilas ice
  • Posts: 1694
    • View Profile
  • Liked: 150
  • Likes Given: 42
Re: The 2019 melting season
« Reply #589 on: April 27, 2019, 07:16:03 AM »
00z Good-for-sh*t has 576DM ridging over Beaufort @ hr 120 :o


b_lumenkraft

  • Guest
Re: The 2019 melting season
« Reply #590 on: April 27, 2019, 07:47:45 AM »
00z Good-for-sh*t has 576DM ridging over Beaufort @ hr 120 :o

Thanks for your updates on this Bbr. One question though. Could you provide a little more commentary in plain language, so non-meteorologist can understand you too?

Neven

  • Administrator
  • First-year ice
  • *****
  • Posts: 7019
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 601
  • Likes Given: 399
Re: The 2019 melting season
« Reply #591 on: April 27, 2019, 09:52:05 AM »
According to the NSIDC chart, sea ice extent has been recovering, albeit minutely, in the past couple of days. How does this gel with the weather discussion here? Does it mean anything? Should we expect to see a rapid drop in the next few days?

https://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/

We've discussed it a bit, further up-thread. Overall, I don't think the current weather set-up is good for the ice, but I'm not sure the impacts will be felt immediately.
Il faut comparer, comparer, comparer, et cultiver notre jardin

sark

  • Frazil ice
  • Posts: 203
  • not a scientist
    • View Profile
  • Liked: 73
  • Likes Given: 74
Re: The 2019 melting season
« Reply #592 on: April 27, 2019, 09:54:33 AM »
Thanks for your updates on this Bbr. One question though. Could you provide a little more commentary in plain language, so non-meteorologist can understand you too?

Decameter.  10's of meters.  when you go up until pressure is 500 millibars, you're at about 4700-5500 meters altitude.  So the 500mb anomaly shows you decameters from average. 

Heat makes air expand.  So higher 500mb areas are warmer.  Usually the pole is cold and the air is short so hot equator air tries to flow toward it to fill in the low.  But there's a twist, the Earth spins.  So it's kind of a spiral.

Anyway, the 500mb average for that area is like +36 decameters in height or 360 meters higher than normal.  As you can see, we only are playing with about 800 meters to begin with.

They're all talking about it like it's a ridge in the jet stream but i've never before seen two giant heat domes pop up and then slam together at the north pole, cutting the polar cell in half.  But I'm no scientist.
I am not a scientist

b_lumenkraft

  • Guest
Re: The 2019 melting season
« Reply #593 on: April 27, 2019, 10:00:09 AM »
Thanks a lot Sark! Now even i understand it. :)

bbr2314

  • Nilas ice
  • Posts: 1694
    • View Profile
  • Liked: 150
  • Likes Given: 42
Re: The 2019 melting season
« Reply #594 on: April 27, 2019, 10:02:05 AM »
Thanks for your updates on this Bbr. One question though. Could you provide a little more commentary in plain language, so non-meteorologist can understand you too?

Decameter.  10's of meters.  when you go up until pressure is 500 millibars, you're at about 4700-5500 meters altitude.  So the 500mb anomaly shows you decameters from average. 

Heat makes air expand.  So higher 500mb areas are warmer.  Usually the pole is cold and the air is short so hot equator air tries to flow toward it to fill in the low.  But there's a twist, the Earth spins.  So it's kind of a spiral.

Anyway, the 500mb average for that area is like +36 decameters in height or 360 meters higher than normal.  As you can see, we only are playing with about 800 meters to begin with.

They're all talking about it like it's a ridge in the jet stream but i've never before seen two giant heat domes pop up and then slam together at the north pole, cutting the polar cell in half.  But I'm no scientist.
Simultaneously it is going to snow in Chicago tomorrow and the 00z EURO shows ANOTHER snow event (no stickage) for Chicago on May 5th. Tomorrow's event stands a good chance of smashing the all-time late-season (4/25+) record for Chicago (which is 3" or so).

This is all occurring as SWE is still at very high levels. Last year North America persisted while Eurasia cratered, this year, Eurasia has persisted and while NA has dropped, it is still +1SD vs. average, although hemispheric extent is closer to normal.





The collapse of the "old regime" between 2007 and 2012 and evolution into a new state appears to be accelerating rather quickly now, and I fear for the consequences over the next few years, although they will certainly be fascinating to watch unfold.  :)

Last 365 days of temp anomalies attached below as well.
« Last Edit: April 27, 2019, 10:11:56 AM by bbr2314 »

gerontocrat

  • First-year ice
  • Posts: 5808
    • View Profile
  • Liked: 956
  • Likes Given: 18
Re: The 2019 melting season
« Reply #595 on: April 27, 2019, 11:14:15 AM »
According to the NSIDC chart, sea ice extent has been recovering, albeit minutely, in the past couple of days. How does this gel with the weather discussion here? Does it mean anything? Should we expect to see a rapid drop in the next few days?
There are often discussions on what might be future extreme weather events, e.g. this one due to start building up this weekend and maximising next week.

However, in the last few days conditions have not been that good for sea ice loss and this shows up in the data. i.e. sea ice extent today depends on what happened before and what is happening now, not what might happen in the future.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Tor Bejnar

  • Young ice
  • Posts: 2908
    • View Profile
  • Liked: 252
  • Likes Given: 145
Re: The 2019 melting season
« Reply #596 on: April 27, 2019, 03:42:23 PM »
According to the NSIDC chart, sea ice extent has been recovering, albeit minutely, in the past couple of days. How does this gel with the weather discussion here? Does it mean anything? Should we expect to see a rapid drop in the next few days?
...
Welcome Maplike to the ASIF (Arctic Sea Ice Forum)!
When the Arctic weather appears to be 'bad' and extent doesn't drop, some interpret this to mean the ice is breaking up and spreading, allowing SIA (sea ice area) to decline while maintaining SIE (sea ice extent).  [For frequently used abbreviations, see Glossary.]
Arctic ice is healthy for children and other living things.

Tom_Mazanec

  • Grease ice
  • Posts: 854
    • View Profile
    • Planet Mazanec
  • Liked: 107
  • Likes Given: 28
Re: The 2019 melting season
« Reply #597 on: April 27, 2019, 06:08:27 PM »
According to the NSIDC chart, sea ice extent has been recovering, albeit minutely, in the past couple of days. How does this gel with the weather discussion here? Does it mean anything? Should we expect to see a rapid drop in the next few days?
...
Welcome Maplike to the ASIF (Arctic Sea Ice Forum)!
When the Arctic weather appears to be 'bad' and extent doesn't drop, some interpret this to mean the ice is breaking up and spreading, allowing SIA (sea ice area) to decline while maintaining SIE (sea ice extent).  [For frequently used abbreviations, see Glossary.]

Could you help me understand the difference between "area" and "extent"? I thought they were the same thing...millions of square kilometers?
SHARKS (CROSSED OUT) MONGEESE (SIC) WITH FRICKIN LASER BEAMS ATTACHED TO THEIR HEADS

gerontocrat

  • First-year ice
  • Posts: 5808
    • View Profile
  • Liked: 956
  • Likes Given: 18
Re: The 2019 melting season
« Reply #598 on: April 27, 2019, 06:17:27 PM »
Could you help me understand the difference between "area" and "extent"? I thought they were the same thing...millions of square kilometers?
Read all about it...

https://cryospherecomputing.tk/doc.html  (explanation from Tealight)
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Tor Bejnar

  • Young ice
  • Posts: 2908
    • View Profile
  • Liked: 252
  • Likes Given: 145
Re: The 2019 melting season
« Reply #599 on: April 27, 2019, 06:19:24 PM »
Arctic ice is healthy for children and other living things.