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Niall Dollard

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Re: The 2019 melting season
« Reply #6300 on: September 03, 2019, 06:19:47 PM »
The NOAA-ESRL temperatures for August are out and show just  how warm the Arctic was over summer.
https://www.esrl.noaa.gov/psd/cgi-bin/data/timeseries/timeseries1.pl

Thanks for that link DavidR.

I made a timeseries plot (80 to 90N) but didnt quite get the same figures you did. May,June and July 2019 came out at top place for surface temperature. August came in 2nd place (just behind last year).

Maybe I am using slightly different inputs to your plot ?

Freegrass

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Re: The 2019 melting season
« Reply #6301 on: September 03, 2019, 07:14:06 PM »
Worldview 1-3 Sept shows a 15-30 km movement of that cracked ice towards fram.
There's one float - around 20 km long, shaped like an egg, closest to Greenland - that's quite the race machine... Look at it go!

https://go.nasa.gov/2LizH74
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Freegrass

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Re: The 2019 melting season
« Reply #6302 on: September 03, 2019, 07:42:34 PM »
Topic: The 2019 melting season  (Read 777777 times)
That was too beautiful to let go... ;D
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Steven

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Re: The 2019 melting season
« Reply #6303 on: September 03, 2019, 08:08:38 PM »
The NOAA-ESRL temperatures for August are out and show just  how warm the Arctic was over summer.
https://www.esrl.noaa.gov/psd/cgi-bin/data/timeseries/timeseries1.pl

I made a timeseries plot (80 to 90N) but didnt quite get the same figures you did. May,June and July 2019 came out at top place for surface temperature. August came in 2nd place (just behind last year).

DavidR is correct.  Make sure that you select the option "area weight grids: yes" to get proper area weighting.  If you don't select that option, the calculation is skewed toward the high latitudes (just like in the DMI 80N temperature graph).


philopek

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Re: The 2019 melting season
« Reply #6304 on: September 03, 2019, 08:25:35 PM »
I'm not sure if things will get ugly as the low will be a cold one and I be surprised given the area numbers stabilising we will see any huge surprises in extent(i'm leaning more and more extent will stay above 4 million now). It would seem the more compact looking CAB may of played a role why extent is not worse than it is now but as some others have said, the conditions in the 2nd part of August was perfect for ice retention as no doubt the end of August 2016 pattern would of lead to a much lower extent with that mega dipole that occured then(the total opposite to what happened in the last 2 weeks).

Weather patterns don't look too favourable for any early refreeze or anything that may suggest a significant cool down of the Arctic SST's to the next couple of months could well be interesting for different reasons!

Just discount the not so compact many 100k km2 and you'd end way below 4M km2.

The only thing we have to know these days is that 16% ice cover counts 100% as extent and distribution seam to be so widely spread and regular that we see stalling extent even though the open water between the ice is still increasing. Currently it's all about measurement methods and since we've rarely seen such a distribution on such a scale we can't compare current numbers with any other year except perhaps 2016 and that's where we shall end in close vicinity, around 4M km2 while 2 days of a bit higher drops would bring us below 4M km2.

Further we have to consider that 2016  started to refreeze within a a few days from now and in case we shall see another 10-14 days of average melt we would still end below 2016 and below 4M km2.

Nobody can tell, hence we have to watch and see like so often.
« Last Edit: September 04, 2019, 01:39:09 AM by philopek »

Niall Dollard

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Re: The 2019 melting season
« Reply #6305 on: September 03, 2019, 08:46:09 PM »
Make sure that you select the option "area weight grids: yes" to get proper area weighting.  If you don't select that option, the calculation is skewed toward the high latitudes (just like in the DMI 80N temperature graph).
Thanks for clarifying.

subgeometer

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Re: The 2019 melting season
« Reply #6306 on: September 04, 2019, 01:48:43 AM »
A clear view of the northern CAA yesterday shows very little ice obstructing Parry Channel, winds have pushed it all to the southern side. And the hole that's been appearing in the Lincoln Sea is as large as I've seen it.

Todays EC/Windy forecast ups the winds a bit, and indicates another round of storms at the back end of the forecast. Still plenty of interesting things going on despite the lateness of the date

Edit: oops, I double posted the image of the CAA, and left out Lincoln Sea - fixed
« Last Edit: September 04, 2019, 02:20:37 AM by subgeometer »

subgeometer

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Re: The 2019 melting season
« Reply #6307 on: September 04, 2019, 02:10:38 AM »
GFS's 10 day outlook shows a story of 2 arctics. Inside a triangle with corners at Axel Heiberg FJI and Fram strait we can expect refreeze to commence and the holes to ice over whereas everywhere on the other side of the pole will struggle to drop below freezing, so bottom melt will continue.

I've attached the 10day average temperature map from Climate Reanalyzer

Eurasia will start to get seriously cold soon so I expect plenty of fireworks generated by the warm water surrounded by cold in the next couple of months

Shared Humanity

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Re: The 2019 melting season
« Reply #6308 on: September 04, 2019, 03:56:16 AM »
And the hole that's been appearing in the Lincoln Sea is as large as I've seen it.


I am no expert and I have only been following the Arctic for the last 7 or 8 years but I have never seen the Lincoln Sea in this poor of a condition.

sark

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Re: The 2019 melting season
« Reply #6309 on: September 04, 2019, 05:24:58 AM »
So, Month Five of -AO ?

How many days ago were we saying it would strengthen, GEFS?

the polar cell has been weak for too long.  more high height anti-cyclonic parcels of air will hit the North Pole as cut off blocks over the Arctic.  this thing isn't going away without a strong winter PV overhead, it'll be winter soon

I'll reserve my very last measure of alarm for November
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petm

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Re: The 2019 melting season
« Reply #6310 on: September 04, 2019, 05:32:48 AM »
Aug 28 - Sep 3

5-day per-pixel minimum v. original Bremen concentration

Freegrass

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Re: The 2019 melting season
« Reply #6311 on: September 04, 2019, 07:59:14 AM »
Wind @ Surface and Wind + Temp @ 1000hPa
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uniquorn

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Re: The 2019 melting season
« Reply #6312 on: September 04, 2019, 10:54:38 AM »
wipneus regional extent, CAB, sep3
https://sites.google.com/site/arcticseaicegraphs/regional
edit: 2016 green, 2018 brown
« Last Edit: September 04, 2019, 02:14:33 PM by uniquorn »

Freegrass

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Re: The 2019 melting season
« Reply #6313 on: September 04, 2019, 02:00:32 PM »
M'Clure strait has really opened up in the last few days.
https://go.nasa.gov/2PEdAfB
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philopek

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Re: The 2019 melting season
« Reply #6314 on: September 04, 2019, 02:12:22 PM »
.......everywhere on the other side of the pole will struggle to drop below freezing, so bottom melt will continue.


Please elaborate your opinion why surface temps would impact bottom melt ?

IMO bottom melt can continue even though the surface fresh waters or waters with poor salinity can show some freezing.

THX

philopek

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Re: The 2019 melting season
« Reply #6315 on: September 04, 2019, 08:04:29 PM »
This should have an impact considering the ice-situation in that exact region.

We basically need only two short lived or 1 persistent event of this exact kind, angle, speed, state of the ice etc. to go way down a few 100k and end up where we long thought we will.

Without this kind of events we gonna see <4M but >3.7M km2


aperson

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Re: The 2019 melting season
« Reply #6317 on: September 04, 2019, 09:40:55 PM »
I've been watching Lingling and Dorian recently, and I'm interested that they both undergo extratropical transition and integrate their momentum into the jet stream around the same time:



Dorian and Lingling are the symmetrically opposite 968mb lows here. Their angular momentum seems to enhance a dipole pattern, and the timing of their momentum transfer will be critical to how it sets up here. Regardless of the exact configuration, it looks like this will split the initiating tropospheric polar vortex into two lobes and allow a major heat/moisture intrusion from the Pacific



As we enter peak hurricane season, it's important to remember that one of the major heat engines that moves heat from equator to pole are tropical cyclones, so watching their activity will be critical to see how the freezing season initiates (or fails to)

This to me indicates that the melting season is not over yet and way may see losses for the next two weeks. I would be stunned if the AO does not go negative again in the next two weeks, but then again I'm just a naive observer and not a pro meteorologist.

Edit: And after looking at this month's PIOMAS, I really wonder if this will push the Sept 15 update into first place.
« Last Edit: September 04, 2019, 10:06:13 PM by aperson »
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Freegrass

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Re: The 2019 melting season
« Reply #6318 on: September 04, 2019, 10:54:57 PM »
Ice extent on this day in 2019 vs 2012.

We need a very big storm to catch up! But I think 2019 will beat 2012 in volume easily with all that thick ice gone...

https://go.nasa.gov/2LlwpA7
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Aleph_Null

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Re: The 2019 melting season
« Reply #6319 on: September 04, 2019, 11:05:28 PM »
This movie uses hind/forecast format: fact succeeded by fiction (9/1 to 9/8), with a pause on the now-frame for comparison purposes (9/4 at 1500UTC). The Nullschool geniuses must like IWPD, they made it look like the Vincent overlay.

Instantaneous Wind Power Density: measure of power available in the wind: ½ρv3, where ρ is air density and v is wind velocity.

Frame-increments (from Nullschool) are 3 hours. We're at 850 hPa.
« Last Edit: September 04, 2019, 11:20:00 PM by Aleph_Null »

subgeometer

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Re: The 2019 melting season
« Reply #6320 on: September 05, 2019, 03:19:50 AM »
.......everywhere on the other side of the pole will struggle to drop below freezing, so bottom melt will continue.


Please elaborate your opinion why surface temps would impact bottom melt ?

IMO bottom melt can continue even though the surface fresh waters or waters with poor salinity can show some freezing.

THX

Perhaps I should have said - "so bottom melt can continue unhindered"

What's unusual about the suggestion that there's a relationship between atmospheric temperatures and melting/freezing of sea ice? Once surface air temps drop below about -10C bottom-freezing will begin, at some surface air temp between that and -2C e is an equilibrium between freezing and melt, no doubt affected by any underlying warmth in the ocean waters.

Air has much lower heat capacity than water, so when temps aren't much above or below freezing its effects are muted, but when surface air temps are +4C(like the Lincoln has repeatedly experienced this season) or -40C(old-school winter) it most definitely has a significant effect

petm

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petm

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Re: The 2019 melting season
« Reply #6322 on: September 05, 2019, 04:29:46 AM »
It seems that a lot more ice has melted out in the Beaufort this year than virtually any other year. The only recent year that is maybe worse is 2015. This year is a lot worse than 2012 (notwithstanding the remaining tongue).

Attached: North of Prince Patrick Island (CAA), early Sept 2019, 2015, 2012 (relatively cloud-free days).

https://go.nasa.gov/2LiEJ3r
« Last Edit: September 05, 2019, 04:39:14 AM by petm »

subgeometer

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Re: The 2019 melting season
« Reply #6323 on: September 05, 2019, 04:35:55 AM »
A few frames from Climate Reanalyser (at 33, 99 and 186 hours out)with yesterdays Bremen extent map marked to show where I think melt will cease very soon and freezing perhaps begin(perhaps I've drawn the area a little too large?), and where melt will continue.

Its looking like we're for a series of massive influxes of warmth (and storminess - N Pacific storms are showing signs of penetrating the Arctic  basin more often, wrapping around Chukotka)from the Pacific, and some from the Atlantic as well

petm

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Re: The 2019 melting season
« Reply #6324 on: September 05, 2019, 05:38:24 AM »
Aug 29 - Sep 4

5-day per-pixel minimum v. original Bremen concentration

Aluminium

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Re: The 2019 melting season
« Reply #6325 on: September 05, 2019, 07:17:58 AM »
August 31 - September 4.

2018.

UCMiami

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Re: The 2019 melting season
« Reply #6326 on: September 05, 2019, 08:21:09 AM »

Freegrass

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Re: The 2019 melting season
« Reply #6327 on: September 05, 2019, 10:41:12 AM »
Wind @ Surface and Wind @ Surface + Total Precipitable Water

I've added 24 hours of yesterday's weather on today's weather videos, because I wanted to capture that storm from start to end. The forecast of this storm has been going from a 6 beaufort storm to a 5 beaufort storm, and now it's back to a 6, almost 7 beaufort storm. So it's strengthened again! And the reason for this strengthening can be seen best with the TPW forecast. You can clearly see how this storm is feeding again on the Russian heat, and when that heat is cut off, the storm turns light brown (cold), and dies... Beautiful!
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gerontocrat

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Re: The 2019 melting season
« Reply #6328 on: September 05, 2019, 12:36:55 PM »
August Area, Extent & Volume losses may have been low, but SST anomalies continued to climb and expand.

I wish I had saved the images from the beginning of the melting season. But I did not. mea culpa.
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Alphabet Hotel

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Re: The 2019 melting season
« Reply #6329 on: September 05, 2019, 01:01:18 PM »
Melt continues on the ESS arm or whatever it's called. (Does it have a name?)

click to animate

Freegrass

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Re: The 2019 melting season
« Reply #6330 on: September 05, 2019, 01:35:30 PM »
The Latest Weather Forecast is showing a very nasty little storm popping up in the Laptev sea. Will this storm mix up the warm surface waters enough to bring them all the way down to the ocean floor? That would really be bad news for the methane hydrates...
« Last Edit: September 05, 2019, 02:06:41 PM by Freegrass »
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Ktb

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Re: The 2019 melting season
« Reply #6331 on: September 05, 2019, 01:56:10 PM »
SST anomalies continued to climb and expand.

The coloring being used in the Bering is nothing short of spectacular. I do not remember seeing it being used before.
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Freegrass

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Re: The 2019 melting season
« Reply #6332 on: September 05, 2019, 04:04:02 PM »
Melt continues on the ESS arm or whatever it's called. (Does it have a name?)
I don't know how to call it, other than a BMFG piece of solid ice. I wonder if it will break off and float away in the next few days, because the ice that attaches it to the CAP looks very weak.

https://go.nasa.gov/2PMKGdr

Edit: It looks like it was already detached last week.
https://go.nasa.gov/2PLEXnX
« Last Edit: September 05, 2019, 04:56:30 PM by Freegrass »
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jdallen

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Re: The 2019 melting season
« Reply #6333 on: September 05, 2019, 05:12:24 PM »
And the hole that's been appearing in the Lincoln Sea is as large as I've seen it.


I am no expert and I have only been following the Arctic for the last 7 or 8 years but I have never seen the Lincoln Sea in this poor of a condition.
+1
I agree - it's astonishing.

Here's how it *should* look.
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philopek

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Re: The 2019 melting season
« Reply #6334 on: September 05, 2019, 05:32:15 PM »
Once surface air temps drop below about -10C bottom-freezing will begin,a significant effect

All that is and has been clear but thanks for the resume, always useful.

While the original topic has been clarified because your little resume appears to be a follow up of the former, it's perhaps worth to mention that the orignal post was about around this time and the -10C etc. are not yet happening which is why i mentioned "fresh water" and "water with low salinity" that would start to freeze at higher temps than -10C.

gerontocrat

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Re: The 2019 melting season
« Reply #6335 on: September 05, 2019, 05:55:41 PM »
And the hole that's been appearing in the Lincoln Sea is as large as I've seen it.


I am no expert and I have only been following the Arctic for the last 7 or 8 years but I have never seen the Lincoln Sea in this poor of a condition.
+1
I agree - it's astonishing.

Here's how it *should* look.
This is how it looked yesterday according to Sentinel-1b
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jdallen

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Re: The 2019 melting season
« Reply #6336 on: September 05, 2019, 06:53:41 PM »
Dorian's track:

https://www.nhc.noaa.gov/refresh/graphics_at5+shtml/151958.shtml?cone#contents

It will be interesting to see what effect of heat inputs from two hurricanes and (currently) two additional tropical disturbances will be in about a weeks time.

There may be no effect except to hinder freezing.  It is possible the heat may permit bottom melt to continue with a resulting late minimum.  I don't expect the numbers to be dramatic.  If melt does continue it will likely be at a trickle of 10-15K/day; at least that's my expectation.
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philopek

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Re: The 2019 melting season
« Reply #6337 on: September 05, 2019, 07:14:51 PM »
The weakest ice under full (90° Angle) attack

Windspeeds around 50km/h at a bit of a distance to the "Eye"

Some compaction will be the least impacting extent numbers, some melt still ongoing could
keep area drops in line with extent losses, despite higher concentration.

Freegrass

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Re: The 2019 melting season
« Reply #6338 on: September 05, 2019, 07:26:29 PM »
Look at this big piece of fast ice go poof in just 1 day... Today - one day later - it's blue ocean...
This is to the east of Greenland, in the Fram strait.

https://go.nasa.gov/2LmJBVg
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uniquorn

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Re: The 2019 melting season
« Reply #6339 on: September 05, 2019, 09:16:47 PM »
August Area, Extent & Volume losses may have been low, but SST anomalies continued to climb and expand.
I wish I had saved the images from the beginning of the melting season. But I did not. mea culpa.

A quick search didn't reveal DMI's SST file locations. NOAA's SST products going back to 2015 can be found here https://polar.ncep.noaa.gov/sst/ophi/ with a link to the archives.

Quote
A daily, high-resolution, real-time, global, sea surface temperature (RTG_SST) analysis has been developed at the National Centers for Environmental Prediction/Marine Modeling and Analysis Branch (NCEP / MMAB). The analysis was implemented in the NCEP parallel production suite 16 August 2005. It became fully operational on September 27, 2005.
The daily sea surface temperature product is produced on a twelfth-degree (latitude, longitude) grid, with a two-dimensional variational interpolation analysis of the most recent 24-hours buoy and ship data, satellite-retrieved SST data, and SST's derived from satellite-observed sea-ice coverage. The algorithm employs the following data-handling and analysis techniques:
    Satellite retrieved SST values are averaged within 1/12 o grid boxes with day and night 'superobs' created separately for each satellite;
    Bias calculation and removal, for satellite retrieved SST, is the technique employed in the 7-day Reynolds-Smith climatological analysis;
    Currently, the satellite SST retrievals are generated by a physically-based algorithm from the Joint Center for Satellite Data Assimilation. Retrievals are from NOAA-19 and METOP-A AVHRR data;
    SST reports from individual ships and buoys are separately averaged within grid boxes;
    The first-guess is the prior (un-smoothed) analysis with one-day's climate adjustment added;
    Late-arriving data which did not make it into the previous SST analysis are accepted if they are less than 36 hours old;
    Surface temperature is calculated for water where the ice cover exceeds 50%, using salinity climatology in Millero's formula for the freezing point of salt water:
        t(S) = -0.0575 S + 0.0017 S3/2 - 0.0002 S2,
    with S in psu.
    An inhomogeneous correlation-scale-parameter l, for the correlation function: exp(-d2/l2) , is calculated from a climatological temperature gradient, as
        l = min ( 450 , max( 2.25 / |grad T| , 100 )),
    with d and l in kilometers. "grad T" is in oC / km
Evaluations of the analysis products have shown it to produce realistically tight gradients in the Gulf Stream regions of the Atlantic and the Kuroshio region of the Pacific, and to be in close agreement with SST reports from moored buoys in both oceans. Also, it has been shown to properly depict the wintertime colder shelf water -- a feature critical in getting an accurate model prediction for coastal winter storms.

     Description of changes effective November 1, 2016
        The analysis now uses satellite SST retrieval data from the GOES satellites. In addition, the values of "SST" over land areas are now generated by an SOR Laplacian solver, which replaces the legacy "weaver" code.
    Description of changes effective August 26, 2016
        Handling of satellite SST retrieval data in the analysis was modified so the analysis will proceed in the absence of satellite data.

    Description of changes effective July 15, 2015
        Hot spots in the Sea of Azov and Caspian Sea were replaced by more temperate values of SST. Cool Congolese waters were replaced using a climatology from Robert Grumbine.
Here showing sep4, 2015-2019 for comparison.
edit: dates were in the wrong order, forgot scale
@bbr - hudson bay quite cool the last 2 years
« Last Edit: September 05, 2019, 09:55:53 PM by uniquorn »

gerontocrat

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Re: The 2019 melting season
« Reply #6340 on: September 05, 2019, 10:38:20 PM »
August Area, Extent & Volume losses may have been low, but SST anomalies continued to climb and expand.
I wish I had saved the images from the beginning of the melting season. But I did not. mea culpa.
A quick search didn't reveal DMI's SST file locations. NOAA's SST products going back to 2015 can be found here https://polar.ncep.noaa.gov/sst/ophi/ with a link to the archives.
Nice one, Uniquorn.

It's all there, but they don't make it easy to collate a history from all those directories. And I don't think I would have looked hard enough to follow the path from the main page without your post.
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slow wing

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Re: The 2019 melting season
« Reply #6341 on: September 06, 2019, 01:16:08 AM »
The weakest ice under full (90° Angle) attack

Windspeeds around 50km/h at a bit of a distance to the "Eye"

Some compaction will be the least impacting extent numbers, some melt still ongoing could
keep area drops in line with extent losses, despite higher concentration.

That's a low pressure system so it causes dispersion -- the opposite of compaction.

On your figure, I suggest you redraw your arrows at 45 degrees to the right of the actual wind directions displayed -- which is the direction the ice goes (Coriolis) -- and then you will see the dispersion.

subgeometer

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Re: The 2019 melting season
« Reply #6342 on: September 06, 2019, 04:57:22 AM »
A rare clear view of the North West Passage shows it more or less open now, though there still plenty of dispersed floes especially where it enters the Beaufort Sea(click to see in 500m resolation)

Skies are comparatively clear today in areas often completely obscured. so I've also attached a view of 86-88.5N on the Atlantic side of the pole showing a few holes and but also, reassuringly that most of the ice there is recognisable as considerable size floes and one of the Canadian sector  of the CAB, very dispersed, and not so reassuring

subgeometer

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Re: The 2019 melting season
« Reply #6343 on: September 06, 2019, 05:03:37 AM »
August Area, Extent & Volume losses may have been low, but SST anomalies continued to climb and expand.

I wish I had saved the images from the beginning of the melting season. But I did not. mea culpa.

The interface at DMI's site  is set up to step back and forward through the time series

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Re: The 2019 melting season
« Reply #6344 on: September 06, 2019, 07:35:45 AM »
Wind @ Surface and Wind + Temp @ Surface
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grixm

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Re: The 2019 melting season
« Reply #6345 on: September 06, 2019, 09:01:42 AM »
That's a low pressure system so it causes dispersion -- the opposite of compaction.

On your figure, I suggest you redraw your arrows at 45 degrees to the right of the actual wind directions displayed -- which is the direction the ice goes (Coriolis) -- and then you will see the dispersion.

It's pretty trippy how a low-pressure system which should intuitively drag stuff inwards to fill the void, actually ends up pushing things away instead.

Freegrass

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Re: The 2019 melting season
« Reply #6346 on: September 06, 2019, 09:24:02 AM »
That's a low pressure system so it causes dispersion -- the opposite of compaction.

On your figure, I suggest you redraw your arrows at 45 degrees to the right of the actual wind directions displayed -- which is the direction the ice goes (Coriolis) -- and then you will see the dispersion.

It's pretty trippy how a low-pressure system which should intuitively drag stuff inwards to fill the void, actually ends up pushing things away instead.
It actually isn't... A low pressure system creates a bulge on the ocean surface, so ice would have to travel up a slope to get to the center of that bulge. High pressure systems create a dent in the ocean surface, so the ice falls into that pit towards the center...

I'm pretty sure this is completely inaccurate, but can there be some truth to this?
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Glenn_Tamblyn

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Re: The 2019 melting season
« Reply #6347 on: September 06, 2019, 10:25:02 AM »
That's a low pressure system so it causes dispersion -- the opposite of compaction.

On your figure, I suggest you redraw your arrows at 45 degrees to the right of the actual wind directions displayed -- which is the direction the ice goes (Coriolis) -- and then you will see the dispersion.

It's pretty trippy how a low-pressure system which should intuitively drag stuff inwards to fill the void, actually ends up pushing things away instead.
It actually isn't... A low pressure system creates a bulge on the ocean surface, so ice would have to travel up a slope to get to the center of that bulge. High pressure systems create a dent in the ocean surface, so the ice falls into that pit towards the center...

I'm pretty sure this is completely inaccurate, but can there be some truth to this?


Try reading this article about Ekman Transport https://en.wikipedia.org/wiki/Ekman_transport

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binntho

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Re: The 2019 melting season
« Reply #6348 on: September 06, 2019, 10:29:43 AM »
That's a low pressure system so it causes dispersion -- the opposite of compaction.

On your figure, I suggest you redraw your arrows at 45 degrees to the right of the actual wind directions displayed -- which is the direction the ice goes (Coriolis) -- and then you will see the dispersion.

It's pretty trippy how a low-pressure system which should intuitively drag stuff inwards to fill the void, actually ends up pushing things away instead.
It actually isn't... A low pressure system creates a bulge on the ocean surface, so ice would have to travel up a slope to get to the center of that bulge. High pressure systems create a dent in the ocean surface, so the ice falls into that pit towards the center...

I'm pretty sure this is completely inaccurate, but can there be some truth to this?
I can't really visualize this. If gravity could move the ice down the slope, it would simply even out the water bulge as well.
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Freegrass

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Re: The 2019 melting season
« Reply #6349 on: September 06, 2019, 10:48:20 AM »
That's a low pressure system so it causes dispersion -- the opposite of compaction.

On your figure, I suggest you redraw your arrows at 45 degrees to the right of the actual wind directions displayed -- which is the direction the ice goes (Coriolis) -- and then you will see the dispersion.

It's pretty trippy how a low-pressure system which should intuitively drag stuff inwards to fill the void, actually ends up pushing things away instead.
It actually isn't... A low pressure system creates a bulge on the ocean surface, so ice would have to travel up a slope to get to the center of that bulge. High pressure systems create a dent in the ocean surface, so the ice falls into that pit towards the center...

I'm pretty sure this is completely inaccurate, but can there be some truth to this?


Try reading this article about Ekman Transport https://en.wikipedia.org/wiki/Ekman_transport

Movements on a spinning sphere aren't always intuitive
Thank you Glenn, I will certainly look at that! It was on my to do list...

I can't really visualize this. If gravity could move the ice down the slope, it would simply even out the water bulge as well.
I actually started writing that down as a joke, but then started wondering if there could be some truth to this. But mainly, I was joking, because the wind would of course have a much bigger impact on the ice than gravity.
« Last Edit: September 06, 2019, 11:00:40 AM by Freegrass »
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