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Arctic sea ice / Re: Arctic Image of the Day
« on: Today at 03:08:47 AM »
https://phys.org/news/2021-01-climate-carbon-trends-million-years.html
It's not current news being from 2006, but it's still a lovely picture.
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How close to the surface does the subsurface warm water become vulnerable to release to the surface from a strong storm?...whoi itp120That temperature profile is very, very strange, and quite disturbing. Upwelling or intrusion from elsewhere, but strange, if not local, that a layer like that would slide along just under the top 25m of cold near-surface water.
The implied availability of local heat is significant.
Definitely looks like it depends on the year (and where the buoys are)
Something like this, but averages?
Definitely looks like it depends on the year (and where the buoys are)Yes, those are great! As uniquorn said, summary arrows on the color blotch summary would be perfect. The color scaling shows motion in the CAA and Beaufort Sea areas, but if the arrows show little directionality, that doesn't fit there being much "Gyreocity". My guess is that there will be some directionality in the expected directions, but the rather scattered and low velocities indicated by the large amount of purplish (and thus near zero) coloration is not impressively coherent. The name "Beaufort Gyre" gives the impression of some vast coherent whirlpool, even if it takes 3 or 4 years to make loop. The velocity color summary does not look very organized or coherent, or at least not enough to deserve a proper name as if it were some beast prowling the Arctic Ocean.
https://sci-hub.se/https://doi.org/10.1029/2018JC014379 rare serious treatment
https://cpom.org.uk/glimpsing-under-the-ice-measuring-the-ice-covered-arctic-ocean-from-space/
<snip>
Not a single buoy (or multi-buoy succession) over the last 40 years has ever completed the oft-pictured full gyre (per uniq's ongoing displays).
<snip>
"It's not completely clear what the 'floes' and 'leads' actually represent down on the ice as these features are below the resolution of any of the satellite tools used by nextSim. Whatever, they do seem to allow an accurate depiction of ice movement, notably the pick-up in Fram export in mid-November."
and <snip>
"The anisotropic nature of sea ice deformation is made evident by the analysis of satellite-imagery derived ice motion products which shows that high strain rates concentrate along oriented, linear-like faults, or leads, often termed “linear kinematic features” (Kwok, 2001). The signature of the strong heterogeneity and intermittency of sea ice deformation is the emergence of spatial and temporal scalings in the deformation fields over a wide range of scales."
I am not sure these seasonal forecasts are good for anything....If you are right about that, that's an awful lot of highly skilled time...wasted...
What's more, my observation is that the more open the Chukchi and the more iced over the Hudson, the warmer it is in Europe during winter. So here I plot Hudson % ice cover minus Chukchi %icecover on Dec 1, and European winter temp anomaly. Lo and behold
I still find 2018 the best analogue. We are cca 2 weeks behind:
RE": <snip> The trend in the sea ice decline has slowed considerably over the past 15 years, compared to the previous 15. Every year, the possibility of a BOE increases. However, the recent trend shows that it is highly unlikely prior to 2030.
Tamino/Grant Foster is/was the king of change point analysis.
And he did an analysis in 2015, based on extent anomaly data. For sea ice minimum, he found one change point, in 1996 if I read the graph correctly.
https://tamino.wordpress.com/2015/10/01/arctic-sea-ice-2/
<snip>As sea ice declines, a new Arctic state is emerging which due to the positive feedback mechanism outlined above may be pushing the system toward a tipping point."
https://www.researchgate.net/publication/339766641_Wind-Driven_Coastal_Upwelling_Near_Large_River_Deltas_in_the_Laptev_and_East-Siberian_SeasThere was another 2020 journal article 'somewhere' (maybe not ASIF) that discussed Siberian river heat discharge warming the Arctic Ocean. I've tried finding that other article without success. A link to it would be much appreciated.
“The Lena, Kolyma, and Indigirka rivers are among the largest rivers that inflow to the Arctic Ocean. Their discharges form a freshened surface water mass over a wide area in the Laptev and East-Siberian seas and govern many local physical, geochemical, and biological processes. In this study we report coastal upwelling events that are regularly manifested on satellite imagery by increased sea surface turbidity and decreased sea surface temperature at certain areas adjacent to the Lena Delta in the Laptev Sea and the Kolyma and Indigirka deltas in the East-Siberian Sea. These events are formed under strong easterly and southeasterly wind forcing and are estimated to occur during up to 10%–30% of ice-free periods at the study region. Coastal upwelling events induce intense mixing of the Lena, Kolyma, and Indigirka plumes with subjacent saline sea. These plumes are significantly transformed and diluted while spreading over the upwelling areas; therefore, their salinity and depths abruptly increase, while stratification abruptly decreases in the vicinity of their sources. This feature strongly affects the structure of the freshened surface layer during ice-free periods and, therefore, influences circulation, ice formation, and many other processes at the Laptev and East-Siberian seas.”
<snip>How much will the long-delayed freeze-up affect ice growth during the winter (and ice quality going into melt season)? We have no idea how cold the air will be between now and then. However we do have reanalysis products up through early November plus daily ice thinness from Smos-Smap and even rate of growth from Cryo2Smos.Great info A-Team. It would be great to have an average age metric to add to an Arctic Sea Ice Multi Metric Index. It seems like that info is embedded in the data used to create the ice age map. Specifically, do those data allow conversion into a daily "average ice days" value across a grid cell map of the Arctic Ocean, or the central Arctic seas? Or at least the CAB?
It's also feasible to make a map showing how many days each point in the Arctic Ocean has had an ice cover and what the 'deficiency' has been this season given the Laptev, ESS and Chukchi open water anomaly. <snip>----etc.
current Siberian anomaly for example ? .. https://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=3299.0;attach=290316;imageYou got me on that one! I was focused on global year-round land vs ocean warming. I look at the Arctic Ocean temp. anomaly on CR regularly, so you'd think the ocean vs land difference would have sunk in. Useful to be reminded of my ability to misperceive or misplace evidence.
<snip> The fall season is peak Arctic Amplification,My understanding is that Arctic amplification is primarily due to less ice Extent --> albedo decline --> more sunlight energy absorption by dark open water --> warmer water --> more ice melt --> less ice Extent. With very little sunlight reaching the Arctic at this time of year, how is it that fall is "peak Arctic amplification"?