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Thank you for accepting that there is some tidal movement. My interest is mostly at the shelf breaks, where that measly movement might be amplified by the rapid change in depth.
<>The tides are always there doing their bits with eddies and some fast ice breakup (e.g. in the CAA) but the ice north of Greenland does not melt and retreat north every summer.I expect that shelf break melt will become a more accepted part of the melting season as the arctic moves to a higher percentage FYI. Without a constant supply of MYI, north of Greenland could start to look more like north of FJL/Svalbard, dependent on wind direction.
Shelf break front simulationThis is exactly the kind of movement seen in the FJL/Svalbard gap. click
Here is a sample cross-section from an idealized shelf break front simulation. The contours are salinity, the colorfill velocity.
These thickness graphs, while useful, never have materialized in a complete meltout.They might be more representative of the ice state than a one day difference image.
Direct solar isolation melt we have observed:Solar daily radiation per week still around
75-80N: as late as August 20th.
70-75N: end of August.
About Warm Buoy & SideKick
JAMSTEC WARM (Warming and Irradiance Measurements) Buoy project has started to comprehend temporal changings of oceanic enviornment from ice-covered season toward open-water season. Thr WARM Buoy and Side Kick system (see below) was deployed at ICEX 2020 camp station in Beaufort Sea. These systems measure vertical structure of water mass (temperature and salinity) and chlorophyll-a fluorensence from surface to 60-m depth for every 1-hour and send via iridium satellite communication system (see real-time data page). SideKick monitors daily time series of upper-ice views (see gallery pages).
We kindly acknowledge US Navy Arctic Submarine Laboratory and Pacific Gyre Inc. for their kind support for this project. For your information, please also see UpTemp0 web site by University of Washington and WARM Buoy project of Old Dominion University.
About Warm Buoy & SideKick
JAMSTEC WARM (Warming and Irradiance Measurements) Buoy project has started to comprehend temporal changings of oceanic enviornment from ice-covered season toward open-water season. Thr WARM Buoy and Side Kick system (see below) was deployed at ICEX 2020 camp station in Beaufort Sea. These systems measure vertical structure of water mass (temperature and salinity) and chlorophyll-a fluorensence from surface to 60-m depth for every 1-hour and send via iridium satellite communication system (see real-time data page). SideKick monitors daily time series of upper-ice views (see gallery pages).
We kindly acknowledge US Navy Arctic Submarine Laboratory and Pacific Gyre Inc. for their kind support for this project. For your information, please also see UpTemp0 web site by University of Washington and WARM Buoy project of Old Dominion University.
In recent years MYI has drifted down the Nares and been 'pulverised'. A process that I think I understand. So far this year ice in the Lincoln Sea melts 'in situ' while possibly drifting west. But there are no 'goodbye waves' which can be seen further south in the Parry channel.PMFBI and stating the obvious - I wonder this too. You can't always eyeball the 90% below the waterline.I get that, but can you actually see it? or measure it? I picked one floe that was easy. Normally we see 'goodbye waves' but I assume some other process happens in open water in the 'crack'.I keep wondering how much of that ice is still MYI, and how much is FYI. MYI ice melts away from the top, and refreezes at the bottom. So how much of that MYI is really still MYI, and not FYI that was added through winter?
edit: ok. It was easy to fine 'glue ice' melting too.
A graphic showing wind-driven ice movementAscat shows ice movement. It doesn't necessarily have to be wind driven. Fram Strait is a clear example.
Whoi bouys show sustained bottom melt in the Beaufort at least to 75N. They also show a quick spike in salinity the last couple days. A sign of near surface overturning of the fresh water layer.Best not to read too much into the recent itp114 profile, both itp113 and 114 profilers have been stuck below 250m for the last few days due to high drift speed. More details here
If that is the case the layer below it is torching.
Good clear view north of CAA Greenland. Some contrast adjustments.Following up on rotation north of Lincoln Sea
Signs of rotationin the middlejust north of Lincoln
As it happens, a new user just posted about the same buoys, see above.Welcome indeed!
Welcome, tobiasR.
for any feature to show means very deep disturbence Grakkel is about 3000m down but the area in question is opposite St. Anna.Not dismissing the idea out of hand but it is a big ask from 3000m down. It's possible that there is turbulence along the Lomonosov anyway due to a (modelled) convergence of currents. Mosaic buoys saw evidence of turbulence further south.
My eyes insist that under the thick cloud bands (in Worldview) AMSR2 concentration is higher than elsewhere, thus my conclusion/suspicion that if anything, current concentration might be jacked up by such artifacts, rather than jacked down.Agreed. amsr2 concentration is often represented as higher under cloud, so higher concentration streaks. It's the low radials that are the worry.
superimpose (and synchronize) the cyclone and the concentration imagesI think amsr2 is representing the state of the ice quite accurately in this case.
A quick view, after the worst part of the storm...uni-hamburg version, amsr2-uhh, beaufort-chukchi, jul18-29
ITP117 was deployed on a 1.35 m ice floe in the Beaufort Sea on September 19, 2019 at 80° 55.0 N, 135° 31.9 W as part of the Beaufort Gyre Observing System (BGOS) during the JOIS 2019 cruise on the CCGS Louis S. St. Laurent. On the same icefloe, a prototype Tethered Ocean Profiler (TOP), and a US Army Cold Regions Research and Engineering Laboratory (CRREL) Seasonal Ice Mass Balance Buoy 3 was also installed. The ITP is operating on a standard sampling schedule of 2 one-way profiles between 7 and 760 m depth each day and includes a fixed SAMI PCO2 with ODO and PAR at 6 m depth.This looks like the cryosphere simb sharing a floe with itp117
Atlantic waters north of Wrangel Island? In the Chukchi? Or the EES perhaps?According to the mercator model salinity at 34m depth, here with amsr2-uhh overlaid at 60%, atlantic waters reach almost 80N of Wrangel Island before turning back and eventually reaching the Fram.
Meanwhile, the Polarstern is currently in Fram Strait between Svalbard and Greenland. Prof Markus Rex, Leader of the MOSAiC Project and an atmospheric physicist at the Alfred Wegener Institute in Potsdam, is currently on board. As he reports: “All the ice around us has long-since broken up or been ground into fragments. But our MOSAiC floe, selected for the expedition back in October 2019, continues to offer an impressively stable basis for our work. Nevertheless, even this floe will soon end its lifecycle in the marginal ice zone. Today we measured a balmy 14 degrees Celsius 300 m above the floe, and the melting is in full swing. For the last phase of MOSAiC, our focus will be on the freezing phase: the last piece of the puzzle in our observations of the Arctic’s annual cycle. Accordingly, in the last phase we will proceed far to the north, where the freezing will soon begin.” This will most likely take place in mid-August, once the last resupply and exchange of research staff and crew have been completed.
The Central Arctic is currently much warmer than the long-term mean, continuing the trend that has been apparent since June this year. Average air temperatures at the 925 mb level (roughly 760 m above sea level) for the first half of July were unusually high over the central Arctic Ocean – up to 10 degrees Celsius. These above-average temperatures were connected to high sea-level pressure centred over the East Siberian and Chukchi Seas. Arctic temperatures along the Russian coast were near or slightly above average. This represents a significant change from June, when temperatures along the Siberian coast of the eastern Laptev Sea were up to 8 degrees Celsius above average. It is likely that these high temperatures, combined with ice movement away from the coast, initiated early ice retreat along the Russian coast, and the opening of the North-East Passage. At present, the ice extent is extremely low – the lowest level for this time of year since the beginning of satellite observation. Sea-ice extent in the Arctic has been at a historically low level since 1 July 2020. On 19 July, the ice extent was 570,000 km² lower than the former record low in 2019. This sea-ice loss is represents an area roughly the size of France. 26 July this difference reaches still a value of circa 260.000 km². The coming weeks will show how this will affect the overall ice development and the MOSAiC expedition.
What is the likelihood that the entire ice sheet will unfasten from the CAA and Greenland?Quite likely for a few days.
I believe this more of a coincidence than meets the eye. In normal years the deep Beaufort is much emptier of ice, the shallower ESS often has lots of ice at this stage. And this year the deep Laptev/CAB sector is ice-free.amsr2-uhh overlaid onto gmrt bathymetry, minimum jaxa dates, 2012-2018
