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Author Topic: Winter Temperatures in the Arctic  (Read 975 times)

Cid_Yama

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Winter Temperatures in the Arctic
« on: October 25, 2018, 02:25:12 AM »
A reminder of what happened just 8 months ago:


Quote
(Today, on Sunday February 25, 2018 at 0900 UTC — temperatures rose to above freezing at the North Pole, 34 F. What would typically be a summer-time temperature for this furthest north location of our world happening during February. )

The persistent weather patterns necessary for such an event were already well in play. At the surface, warm air was continuously running northward just east of Greenland — born pole-ward by powerful storms and frontal systems. At the upper levels of the atmosphere, a huge plug of warm air was developing. One that invaded the stratospheric levels of the atmosphere by the week of February 4-11. This plug, in synergy with surface warming, tore apart the heart of cold at the roof of our world that we call the Polar Vortex.

(Daily mean temperatures for the entire region of the Arctic above the 80 degree north latitude line rocketed upward to new records over recent weeks. Most recent temperatures are comparable to those typically seen during late May.)

Over the past 72 hours, gale force warm, southerly winds gathered in the Atlantic, then blasted north.

At this point, we were starting to see some seriously outlandish temperatures in the higher latitude regions. Cape Morris Jesup, which is the furthest north location on Greenland, by Friday the 23rd experienced a 6 C or 43 F temperatures on the shores of what should be a frozen solid Arctic Ocean just 400 miles from the North Pole.

The average high temperature in Cape Morris Jesup is -20 degrees Fahrenheit during February — making Friday’s reading a whopping 63 degrees F warmer than average. For reference, a similar departure for Washington, DC would produce a 105 degree day in February.

But it wasn’t just Cape Morris Jesup that was experiencing July-like conditions for the Arctic during February. For the expanding front of that ridiculously warm winter air by Sunday had expanded into a plume stretching tens of thousands of square miles and including a vast zone of temperatures spiking from 45 to 54+ degrees F above normal.

It appears that this particular warming event — the highlight of an ongoing polar warming of the past few weeks — is without precedent in the Arctic during February.

link


Add to that, that the Arctic ice is breaking up months early and being transported out through both the Fram and Nares when it should be frozen fast, we are seeing an unprecedented collapse of the Arctic ice in the very heart of what should be winter.

Not to mention the Bering Strait where it is just disappearing.

"For my part, whatever anguish of spirit it may cost, I am willing to know the whole truth; to know the worst and provide for it." - Patrick Henry

Dharma Rupa

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Re: Winter Temperatures in the Arctic
« Reply #1 on: October 25, 2018, 02:21:46 PM »
That would, I assume, be the spike at about day 50:

Niall Dollard

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Re: Winter Temperatures in the Arctic
« Reply #2 on: December 15, 2018, 05:54:38 PM »
It seems like it is next to impossible to get the DMI N80 red line (ECMWF model) close to the green 1958-2002 mean line, especially so in the final 4 months of the year.

I do not know how the red line is derived - I've heard it said that the temperatures are more concentrated towards the actual pole itself (rather than calculated as an average of points within the 80N circle). It would be useful to know exactly how it is done.

Nevertheless I think this image highlights exactly why it is so difficult now to get to the mean line. In the image three quadrants are behaving very much in line with the old mean. Lots of pink colour which indicates sub -30 C (the green line mean now is approx. -28 C). However the quadrant nearest Svalbard is way higher with plenty of blue to be seen ( -2 C to -5 C).

With the Atlantic front so far north, it is next to impossible to get this quadrant anyway near -30 C. Prior to 2002, this was not the case. 

oren

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Re: Winter Temperatures in the Arctic
« Reply #3 on: December 16, 2018, 08:23:29 AM »
I do not know how the red line is derived - I've heard it said that the temperatures are more concentrated towards the actual pole itself (rather than calculated as an average of points within the 80N circle). It would be useful to know exactly how it is done.

From a link on the DMI website:
Quote
Since the data are gridded, it is
straight forward to deduce the average temperature North of 80 degree North.
However, since the model is gridded in a regular 0.5 degree grid, the mean
temperature values are strongly biased towards the temperature in the most
northern part of the Arctic! Therefore, do NOT use this measure as an actual
physical mean temperature of the arctic. The 'plus 80 North mean temperature'
graphs can be used for comparing one year to an other.
It's not weighted by area but by degree, hence the circle 89-90 has the same weight as the much larger circle 80-81.

Peter Ellis

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Re: Winter Temperatures in the Arctic
« Reply #4 on: December 16, 2018, 12:30:00 PM »
Easiest way to visualise this is to appreciate that DMI are effectively calculating the average temperature across a Mercator projection of the globe.The further North you go, the bigger the distortion.