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Arctic Sea Ice Extent, Area, and Volume


ORH_wxman
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  • 2 weeks later...

We've seen 3 local peaks. One on Feb 15th, one on Mar 6, and the most recent on Mar 12 with a 5D average of 14.75 per NSIDC extent. We cannot eliminate the possibility of a higher max (the 2012 max occurred on Mar 20), but with each passing day the probability decreases. It looks to me like the melt season is going to start lower than it did last year.

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  • 2 weeks later...

https://nsidc.org/arcticseaicenews/2021/03/arctic-sea-ice-reaches-uneventful-maximum/

"On March 21, 2021, Arctic sea ice likely reached its maximum extent for the year, at 14.77 million square kilometers (5.70 million square miles), tying for the seventh lowest extent in the satellite record with 2007. This year’s maximum extent is 870,000 square kilometers (336,000 square miles) below the 1981 to 2010 average maximum of 15.64 million square kilometers (6.04 million square miles) and 360,000 square kilometers (139,000 square miles) above the lowest maximum of 14.41 million square kilometers (5.56 million square miles) set on March 7, 2017. Prior to 2019, the four lowest maximum extents occurred from 2015 to 2018."

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So this is interesting. Fram Strait export picking up with such an anomalous high pressure system with a countering LP just east. Yes 1089mb high forecasted over Greenland in a little over 3 days. We have had such large high pressure systems this year, earlier around Mongolia if I remember correctly back in December I dont believe broke the record there but was awfully close.

Impressive stuff this year. I worry about the ice on the Atlantic front to near the north pole especially this year with how low thickness values are to the norm.

gfs_z500_mslp_nhem_17.png

AMSR2_SIT_Last_month.gif

 

Edit it actually beat the world record

https://www.independent.co.uk/news/uk/home-news/world-record-high-air-pressure-mongolia-b1780381.html

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Thats pretty crazy to me. I dont think I have seen pressures higher than maybe mid 1060's mb around Greenland so if even the 1070-1080mb range verifies this may very well be a record, unfortunately my search has come up empty on the highest pressure reading from a station on Greenland's ice sheet unless others may know.

I just noticed the map I posted of ice thickness ended at the last day of February so here is hycoms depiction of the last 30 days fairly similar to AMSR where the highest values are but there are some differences that stick out such along the CAA and siberian sea region so it will be interesting to see which is closest to reality. Still both show issues on the Atlantic front to the north pole so they both seem to agree at least on that front.

 

I guess the one positive, if you really wanna call it that, is the lack of multi year thick ice what is left of it isn't being exported into the Atlantic to melt off. Ill have to see if I can find a multi year ice gif to show where we have the remaining portions of it and what is rather new thin ice. 

arcticictn_nowcast_anim30d.gif

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I could see it making a run at the low 1060's. :But I'll be extremely surprised if it hits 1070mb. There is going to be a pretty steep pressure gradient either way. The Euro actually shows slightly higher sustained winds than does the GFS even though it is much weaker with the anti-cyclone. It certainly looks like Fram export will be in high gear shortly.

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Little update I believe we measured the greenland high around 1065mb give or take a few mbs just south over the ocean had a slp of 1040s so seems reasonable with the potential of higher over the ice sheet. Always hard to know with a large portion of that region being 10-13k feet above sea level, so you know extrapolation. Still have quite the fram export event taking place as the low moves into the Central Arctic regions. Looks as though there may be a day or two of slowing down on export but man it looks like it picks right back up in mid to long range. Really hope this is not a sign of a major ice depletion situation.

With such strong export Ice is reaching Iceland, this happens from time to time but I dont recall it being the case this time of year. Again maybe the one nice thing is we aren't exporting some of the multi year ice that is left, what little there still is.

Very worrisome of what may come this summer.

arcticicespddrf_nowcast_anim30d.gif

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  • 1 month later...

Two theories have emerged as to why the September 2012 record minimum has held on for so long.  There  is probably a piece of truth to both of them. But it’s interesting how every other time of the year has set new minimum records since 2012. So one of these years we’ll eventually surpass the record. Last year came the closest.

https://climate.nasa.gov/news/2817/with-thick-ice-gone-arctic-sea-ice-changes-more-slowly/

With thick ice gone, Arctic sea ice changes more slowly

Kwok's research, published today in the journal Environmental Research Letters, combined decades of declassified U.S. Navy submarine measurements with more recent data from four satellites to create the 60-year record of changes in Arctic sea ice thickness. He found that since 1958, Arctic ice cover has lost about two-thirds of its thickness, as averaged across the Arctic at the end of summer. Older ice has shrunk in area by almost 800,000 square miles (more than 2 million square kilometers). Today, 70 percent of the ice cover consists of ice that forms and melts within a single year, which scientists call seasonal ice.

Sea ice of any age is frozen ocean water. However, as sea ice survives through several melt seasons, its characteristics change. Multiyear ice is thicker, stronger and rougher than seasonal ice. It is much less salty than seasonal ice; Arctic explorers used it as drinking water. Satellite sensors observe enough of these differences that scientists can use spaceborne data to distinguish between the two types of ice.

Thinner, weaker seasonal ice is innately more vulnerable to weather than thick, multiyear ice. It can be pushed around more easily by wind, as happened in the summer of 2013. During that time, prevailing winds piled up the ice cover against coastlines, which made the ice cover thicker for months.

The ice's vulnerability may also be demonstrated by the increased variation in Arctic sea ice thickness and extent from year to year over the last decade. In the past, sea ice rarely melted in the Arctic Ocean. Each year, some multiyear ice flowed out of the ocean into the East Greenland Sea and melted there, and some ice grew thick enough to survive the melt season and become multiyear ice. As air temperatures in the polar regions have warmed in recent decades, however, large amounts of multiyear ice now melt within the Arctic Ocean itself. Far less seasonal ice now thickens enough over the winter to survive the summer. As a result, not only is there less ice overall, but the proportions of multiyear ice to seasonal ice have also changed in favor of the young ice.

Seasonal ice now grows to a depth of about six feet (two meters) in winter, and most of it melts in summer. That basic pattern is likely to continue, Kwok said. "The thickness and coverage in the Arctic are now dominated by the growth, melting and deformation of seasonal ice."

The increase in seasonal ice also means record-breaking changes in ice cover such as those of the 1990s and 2000s are likely to be less common, Kwok noted. In fact, there has not been a new record sea ice minimum since 2012, despite years of warm weather in the Arctic. "We've lost so much of the thick ice that changes in thickness are going to be slower due to the different behavior of this ice type," Kwok said.

Kwok used data from U.S. Navy submarine sonars from 1958 to 2000; satellite altimeters on NASA's ICESat and the European CryoSat-2, which span from 2003 to 2018; and scatterometer measurements from NASA's QuikSCAT and the European ASCAT from 1999 to 2017.


https://iopscience.iop.org/article/10.1088/1748-9326/abc047

 

Why has no new record-minimum Arctic sea-ice extent occurred since September 2012?

4. Discussion and conclusions

The behavior of Arctic sea ice during recent years has perplexed the scientific community. The ice extent has attained or flirted with new record lows during winter and spring months every year since 2012, raising the specter of hitting a new minimum in September. Instead, however, the ice-loss trajectory took a sharp turn in August or early September (except in 2020), averting a broken record. Responsible for the cessation was the formation of low pressure over the region, which brings clouds, reduced insolation, and winds conducive for expanding the ice cover. The consistency of this occurrence begs the question: why is it happening?

Here we offer evidence that the dramatic negative trend in spring snow cover over high-latitude land areas—one of the most conspicuous indications of anthropogenic climate change—may be an important contributor to this behavior. The early loss of snow cover creates a belt of positive temperature anomalies that distorts the typically monotonic poleward temperature gradient by creating an additional peak. Through the thermal wind relationship, a split jet is more likely to form, favoring conditions that trap and amplify Rossby waves that have been implicated in causing extreme summer weather events over northern hemisphere continents.

The second most prominent atmospheric state (PC2) during summer is associated with similar split-jet conditions, along with continental heatwaves in Asia, Scandinavia, northern North America, and ocean heatwaves in the North Atlantic and Pacific Oceans. This pattern is also significantly correlated with strong westerly winds over the Arctic during summer, creating cyclonic conditions that favor cloudiness and reduced transport of sea ice southward through the Fram Strait into the Greenland Sea. Moreover, since 2012, this second PC has exhibited several of its highest values in the record back to 1979, while a stretch of 6 yr (2007–2012) with its lowest values was accompanied by rapid declines in sea-ice extent.

We hypothesize that these observations are connected, and while we cannot establish cause-and-effect and not every year will follow this chain of linkages, a negative feedback on the decline in sea-ice extent initiated by early spring snow-melt may provide a plausible explanation for the recent puzzling behavior of the late-summer sea-ice behavior. We note that the summers of 2019 and 2020, characterized by high values of PC1 and low values of PC2 (in contrast to most years since 2012), recorded near-record-low minimum sea-ice extent during September (Richter-Menge et al 2019; http://nsidc.org/arcticseaicenews/), suggesting that these atmospheric patterns during JJA may provide some predictive information for the annual sea-ice minimum. It should be noted that this application of EOF analysis reveals statistical relationships only, and future research will require targeted modeling experiments to verify causal mechanisms. These experiments might include comparisons of atmospheric patterns under conditions of climatological snow cover and soil moisture versus those projected for the late 21st century under continued greenhouse gas forcing. A further research opportunity could apply these atmospheric patterns to test the ability of climate models to simulate observed relationships between rates of sea-ice loss, large-scale circulation regimes, and extreme summer weather in mid-latitudes.

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  • 2 weeks later...
On 5/27/2021 at 5:05 PM, roardog said:

The melt season is starting off kind of boring this year.

Prob not going to threaten the new record this year unless the pattern changes. The ensembles don't look overly exciting as they are producing a strengthening vortex over the CAB through the solstice. We need that to reverse and show strong high pressure to get the ice into better position to threaten 2012.

We're kind of tracking the 2010s average on a lot of metrics at the moment.

 

 

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On 5/27/2021 at 5:05 PM, roardog said:

The melt season is starting off kind of boring this year.

Thats a good thing to hear in this day and age with the current conditions of the ice. What's interesting to watch with even the fractured mess that is the ice up there we have managed an average of last decades ice (2010s extent and sea ice area). I feel like while we have been use to seeing how the Arctic can handle large volumes of ice 4m+ thick volumes, this new norm of ~2m thick ice across the arctic is interesting to see how it goes through time. How the Arctic is trying to balance itself out while not being able to release heat properly. I worry about the looming idea of a rather strong nino to come about. Wonder if we can get the AO to work properly in peak seasons to maybe help the situation better with releasing heat and keeping it out.

 

Time will tell of course.

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Around now is when we start tracking NSIDC area....and the reason I like to track this is NSIDC area is a good proxy for melt ponds due to the SSMI/S satellite it uses being "fooled" by melt ponds into thinking it is open water, so the area metrics respond to them. And we care about melt ponds in June because they are the best predictor of both minimum area and extent from this time range. Far better than extent metrics or non-SSMI/S area metrics.

Anyways, 2021 area on 6/15 was 8.63 million sq km, here are how previous years were in relation to that number (negative means that year had less ice)

2020: -130k

2019: -370k

2018: +250k

2017: +200k

2016: -190k

2015: +40k

2014: +170k

2013: +280k

2012: -640k

2011: -110k

2010: -120k

2009: +750k

2008: +300k

2007: -50k

 

 

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  • 2 weeks later...
While we were all distracted by the historic Pacific Northwest Heatwave of 2021 the 5-day daily extent in the NH dropped below 2020 for this date. It is now the 4th lowest for this date.
Are we looking at different data? Cause, the chart shows it is still above 2012...395018554171274b1ca35c14bebfa3b5.jpg

Sent from my LGL322DL using Tapatalk

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NSIDC area numbers:

2021: 7.16 million sq km

2020: -90k

2019: -310k

2018: +450k

2017: +270k

2016: -20k

2015: +370k

2014: +360k

2013: +520k

2012: -450k

2011: -80K

2010: -360k

2009: +870k

2008: +510k

2007: -20k

 

2021 is somewhat on the lower end in the post-2007 era, but not threatening a new record. After two more days of data, I'll post my prediction for final minimum like every year. Unless we see some drastic changes, a new record min will be all but ruled out.

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7.09 million sq km is the NSIDC area today....usually I want to see something around 6.60 million sq km or lower by tomorrow to have a plausible shot at a new record. Preferably lower than 6.5 million sqkm.....2012 was 6.42 on the 7/1 data (which isn't reported until 7/2)

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1 hour ago, ORH_wxman said:

7.09 million sq km is the NSIDC area today....usually I want to see something around 6.60 million sq km or lower by tomorrow to have a plausible shot at a new record. Preferably lower than 6.5 million sqkm.....2012 was 6.42 on the 7/1 data (which isn't reported until 7/2)

Given the excursions we've just had on the West coast, I'd not be overly confident in historic trends. Clearly things can and do change on a dime

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15 hours ago, Weatherdude88 said:

 

This is a thread about the northern hemisphere cryosphere. 

Bringing up isolated weather events thousands of miles from the arctic and urban heat islands, is creating a straw man at best (Dunning Kruger effect at worst).

 

lol @ isolated.... clearly you're the blind leading the blind.

People are thinking this is some isolated event....did they conveniently forget it hit 100 in Siberia just last year and they had a 6 month AVERAGE of 20 F above normal?...are people really this DUMB?

 

 

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