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91
Arctic sea ice / Re: The 2020 melting season
« Last post by Pagophilus on Today at 03:03:15 AM »
Dr. Judah Cohen ....

“Impacts

Certainly, one of the biggest if not the biggest weather news story of the summer so far has been the high-pressure system/heat dome that setup over Siberia in June leading to record breaking high temperatures and wildfires across Siberia.  The exceptional warmth has caused sea ice to melt at a record pace in the Laptev Sea adjacent to Siberia and has contributed to an overall acceleration of sea ice melt for the entire Arctic basin over the past several weeks.  That high pressure system that sat over Siberia for much of June has now drifted into the Central Arctic centered near the North Pole.

Therefore, the circulation pattern in the Central Arctic is likely to be very different from recent Julys.  The circulation in the Central Arctic has been dominated by low pressure resulting in relatively cloudy, cool weather.  So even though Arctic sea ice at the end of the winter was at or near record low extent no new record annual minimums have been observed since 2012 because summer low pressure in the Central Arctic slowed sea ice melt. However, at a minimum for the first half of July, the Central Arctic will be dominated by high pressure favoring relatively sunny and warm weather, which is conducive to accelerated sea ice melt.  There does seem to be a higher probability that the sea ice minimum in 2020 will be lower than recent summers and may even challenge the record low of summer 2012.”
Thanks Rod.  Dr Cohen's clear, confirming summary was useful to me.
92
Arctic sea ice / Re: The 2020 melting season
« Last post by echoughton on Today at 03:02:36 AM »
Last year wasn't 2nd lowest in extent. Not even close. Or am I wrong again?
93
The politics / Re: The Trump Presidency
« Last post by vox_mundi on Today at 03:01:06 AM »
Fox News Edits Comrade Trump Out of Photo With Jeffrey Epstein and Ghislaine Maxwell at Mar-a-Lago
https://gizmodo.com/fox-news-edits-trump-out-of-photo-with-jeffrey-epstein-1844276574



Fox News broadcast a segment on Sunday about Ghislane Maxwell, the 58-year-old British socialite who was arrested by the FBI in New Hampshire last week and charged with the sex trafficking of children in the 1990s. Maxwell was a close friend of deceased pedophile Jeffrey Epstein and Fox aired a photo of Maxwell that should look familiar to anyone who followed reports of Epstein’s abuse of teenage girls. But there was one thing missing from the image that Fox put on screen: President Donald Trump.

The photo was taken at Trump’s Mar-a-Lago club in Palm Beach, Florida on February 12, 2000. Twitter users were the first to spot the strange edit by Fox News.

The news clip from Sunday, which is available on YouTube, shows the selective editing by Fox News to delete President Trump from the photo.



President Pedophile

Trump supporters are often reluctant to acknowledge Epstein’s ties weren’t just to well-known Democrats like Clinton and Richardson. Trump has extensive connections to Jeffrey Epstein and there are many photos and videos of the two men together over the years. Getty Images has a photo of Epstein with Trump at Mar-a-Lago in 1997, taken just a few years after one anonymous woman alleged she was raped by Trump when she was 13 at Epstein’s mansion.

What happens next with Maxwell’s case? A lot of people are predicting that she might meet a similar fate to Epstein, dying of “suicide,” before she can talk about her defense. And there’s one new fact that might rise the eyebrows of conspiracy theorists around the world: According to the New York Daily News, Maxwell might soon be sent to the same jail where Epstein died.
94
Arctic sea ice / Re: The 2020 melting season
« Last post by Paul on Today at 02:54:12 AM »
indeed Jim .. also a great day to look back at 2013 .. it looked like the end of the world in comparison to today .. yet it has become 'just another year' . b.c.

2013 was protected by the outer ice being slow to melt therefore all the dispersion that occurred that year did not come into play but it was a close run thing by the end of August as the CAB ice was full of holes quite extensively by then.

When one looks at the entirety of the 7 seas of the High Arctic a complementary story emerges. I attach a table of High Arctic sea ice area as at the 5th July. 2013 area is 1.17 million km2, 17.9% above the 2020 area for this date, and 19th lowest. How contrary was 2013 to show such high signs of melt in the Central Arctic Sea while the High Arctic seas outer ring do not.

Thats the flaw in the NSIDC charts, it does not pick up dispersion very well at all. You only need too look at the worldview charts for the end of August in 2013 too see how the dispersion right now in July turned into a shocker by then. If that outer ice melted quicker, any warmer SSTS would of attacked that quite vulnable ice quite easily imo but it was literally saved by the bell and the water frozed and the ice pack was quite extensive in the end. Of course at the other end of the scale, years 2012 and 2016 was not so fortunate and in particular 2016 ice pack looked awful.

It's why I still have the theory dispersion in the longer term is worse than perhaps melt ponds and compaction. Last year had a more compact pack but still finish 2nd lowest but I believe very warm SSTS played it part then and we could see similar this year as the SSTS are quite high in the Laptev sea. If there was more ice in the Laptev sea and the ESS i would say even getting under 4 million could be a big ask but I do think it's quite likely this year.
95
Arctic sea ice / Re: The 2020 melting season
« Last post by Rod on Today at 02:40:28 AM »
Dr. Judah Cohen has posted a new long term outlook for arctic weather patterns.

It is very technical (I have read it three times and I still don’t understand it), but some of our amateur meteorologists might enjoy reading it.

“Arctic Oscillation and Polar Vortex Analysis and Forecasts
July 6, 2020”

https://www.aer.com/science-research/climate-weather/arctic-oscillation/

Some highlights:

“Impacts

Certainly, one of the biggest if not the biggest weather news story of the summer so far has been the high-pressure system/heat dome that setup over Siberia in June leading to record breaking high temperatures and wildfires across Siberia.  The exceptional warmth has caused sea ice to melt at a record pace in the Laptev Sea adjacent to Siberia and has contributed to an overall acceleration of sea ice melt for the entire Arctic basin over the past several weeks.  That high pressure system that sat over Siberia for much of June has now drifted into the Central Arctic centered near the North Pole.

Therefore, the circulation pattern in the Central Arctic is likely to be very different from recent Julys.  The circulation in the Central Arctic has been dominated by low pressure resulting in relatively cloudy, cool weather.  So even though Arctic sea ice at the end of the winter was at or near record low extent no new record annual minimums have been observed since 2012 because summer low pressure in the Central Arctic slowed sea ice melt. However, at a minimum for the first half of July, the Central Arctic will be dominated by high pressure favoring relatively sunny and warm weather, which is conducive to accelerated sea ice melt.  There does seem to be a higher probability that the sea ice minimum in 2020 will be lower than recent summers and may even challenge the record low of summer 2012.”


I also thought this comment was interesting based on some discussions upthread:

“Longer Term

30–day

The latest plot of the polar cap geopotential height anomalies (PCHs) currently shows normal to above normal PCHs in both the troposphere and the lower stratosphere with normal to below normal PCHs in the mid-stratosphere (Figure 11).  However, PCHs in the lower stratosphere are predicted to reverse to normal to below normal while PCHs in the troposphere are predicted to remain mostly positive (Figure 11).  The GFS forecasts of a reversal to cold stratospheric PCHs have been overdone much of the spring and I wouldn’t consider the forecast reliable.”

The first Figure below is Figure 11.  The second one is Figure 13 in the article.

96
Antarctica / Re: Pine Island Glacier (PIG) Calving and Discussion
« Last post by interstitial on Today at 02:38:54 AM »
Paolo: I appreciate all the work you have done to estimate flow speeds. I know how much work it is. What are the units on your graphs?


The pine island glacier web site updates erratically and sometimes its months between updates. During those times I have tried to use polarview images and found the resolution is too low to accurately use as Paolo did. I went to the source website and downloaded the 500 mb .tiff file and tried to open it just shows black. If anyone knows what I am doing wrong please let me know
97
Consequences / Re: Hurricane Season 2020
« Last post by Phoenix on Today at 02:20:22 AM »
Lot's of action popping up in the East Pacific. Most noteworthy is Depression 5E which is forecast to peak at a Cat 2 hurricane in 3 days before moving NW into cooler waters. No land impacts anticipated.

Tropical Depression Five-E Discussion Number   1
NWS National Hurricane Center Miami FL       EP052020
400 PM CDT Mon Jul 06 2020

Satellite imagery shows that deep convection associated with the
low pressure area south of Mexico has become significantly better
organized since this morning.  ASCAT data from earlier this
afternoon suggested that the circulation was still somewhat
elongated, but since that time low cloud motions indicate that
the circulation has become better defined.  The scatterometer data
also revealed believable wind vectors of at least 30 kt, with
higher rain-inflated vectors within the deep convection. Based on
these data, advisories are being initiated on a 30-kt tropical
depression at this time.

The depression is located within a favorable environment consisting
of low vertical wind shear, warm sea-surface temperatures, and a
moist atmosphere.  As a result, steady strengthening is anticipated
over the next several days, and the NHC forecast calls for the
cyclone to become a hurricane in about 48 hours. The NHC intensity
forecast is in best agreement with the intensity consensus aids IVCN
and HCCA, but is not quite as bullish as the SHIPS guidance.  Given
the anticipated low wind shear conditions over the next few days, a
period of rapid strengthening is possible, and this intensity
forecast could be somewhat conservative. The cyclone is expected to
move over cooler waters in about 96 hours, which should cause
weakening by the end of the period. 


Since the depression is still in its formative stage, the initial
motion is a somewhat uncertain 295/11 kt. The depression is being
steered west-northwestward to the south of a large mid-level ridge
located over the south-central United States. A general
west-northwestward heading about around the same forward speed is
expected over the next several days.  The dynamical model guidance
is in fairly good agreement on this scenario and the NHC track
forecast lies near the various consensus aids.

FORECAST POSITIONS AND MAX WINDS

INIT  06/2100Z 10.5N  99.7W   30 KT  35 MPH
 12H  07/0600Z 11.2N 101.1W   35 KT  40 MPH
 24H  07/1800Z 12.1N 103.4W   45 KT  50 MPH
 36H  08/0600Z 13.0N 105.5W   55 KT  65 MPH
 48H  08/1800Z 14.1N 107.4W   65 KT  75 MPH
 60H  09/0600Z 15.0N 109.0W   75 KT  85 MPH
 72H  09/1800Z 15.7N 110.7W   85 KT 100 MPH
 96H  10/1800Z 17.2N 114.1W   85 KT 100 MPH
120H  11/1800Z 18.8N 118.7W   70 KT  80 MPH

$$
Forecaster Brown
98
Policy and solutions / Re: Renewable Energy
« Last post by Phoenix on Today at 01:21:51 AM »
I appreciate the attempt to explain interstitial. I guess I would need to see some kind of scheme to see how this additional flywheel is connected to the other working parts in order to maintain the frequency.



99
Arctic sea ice / Re: The 2020 melting season
« Last post by Phoenix on Today at 01:03:36 AM »

I'm afraid I don't see it.  As long as we have surface temps at or above zero and insolation, the havoc will continue unabated.  I see no respite.

So, you're of the opinion that a surface temperature of 0.5C and 2.0C will yield the same melt rate, all other factors being equal?

My sense is that a stronger temperature gradient between the ice and surrounding air will lead to a faster rate of energy transfer.
The direct transfer of heat from atmosphere to ice is trivial compared to that delivered by insolation. 

There has been a discussion on this topic earlier in the season which I link to in a separate thread below. It includes links to peer reviewed field research papers that quantify incremental melting impacts of heat waves to be greater than the impact of lost insolation when heat waves arrived under cloudy conditions.

https://forum.arctic-sea-ice.net/index.php/topic,3106.0.html

I don't disagree that insolation is extremely important and am not arguing that melt is going to be slow by any standard measure. I'm just saying that surface temps and WAA are not a trival factor.

100
Policy and solutions / Re: Renewable Energy
« Last post by interstitial on Today at 01:02:59 AM »
I am not an EE either but I will attempt to explain it someone will correct me if I am wrong. The frequency of power must be maintained when large loads or generation turn on and off. The small inverters and generators would burn up if they tried to resist frequency changes. Large rotating masses have significant inertia that resists speed changes when large load and generation are turned on or off and they are less likely to burn up.
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