What seems likely to be the most interesting period of the 2017 Arctic sea ice melting season is upon us! The PIOMAS gridded data hasn’t been released yet, but the overall volume numbers reveal that 2017 has now relinquished its “lowest ever” position to 2012. Here’s Wipneus’ graph of the volume data:
plus his anomaly plot:
Our favourite high resolution AMSR2 area and extent graphs now also allow comparison with 2012. Here’s how they look at the moment:
As you can see, round about now is when 2012 Arctic sea ice extent started to noticeably race ahead of the rest of the pack. Will 2017 follow suit? Are there any Arctic cyclones on the horizon for example? Well, the one forecast for August 4th hasn’t materialised. Here’s this morning’s Environment Canada synopsis:
However both ECMWF and GFS agree that a sub 985 hPa storm should have arrived by Sunday morning. Here’s the ECMWF version from MeteoCiel:
There’s stronger storms in the forecast further out, but once again we’ll believe them if and when we see them!
We’re keeping a close eye on the Northwest Passage once again this year. Most of the southern route is open already, but as we predicted the old ice in Larsen Sound has a lot of melting still to do. Here’s how it looked from the icebreaker Nordica a few days ago:
On top of that the old ice around O-Buoy 14 is currently rushing south down the McClintock Channel to replenish it. Here’s how that looks at the moment:
Meanwhile the melt along the Northern Sea Route is well ahead of last year. Here’s the University of Hamburg AMSR2 concentration map of the area:
There’s also now a lot of open water on the Pacific side of the Arctic, and Sunday’s cyclone is forecast to create a large area of 2 meter plus waves heading in the direction of the ice edge:
I expect that to have a noticeable effect on the already fragile sea ice by early next week, assuming the storm arrives as forecast! There is an ice mass balance buoy handily placed out on the ice in the path of the storm. Buoy 2017A is currently located near 77 N, 147 W, and its assorted sensors suggest the ice underneath it is now less than 20 cm thick:
Here’s how the area around the buoy looked a couple of weeks ago:
Image of 2017A from WARM 6 on July 18th 2017. NSF project: NSF OPP #1603548
The $64,000 question now is will the 2017 Arctic sea ice metrics stay in amongst the recent pack, or race after 2012 instead?
This morning’s synopsis from Environment Canada suggests the cyclone has bottomed out at a MSLP of 982 hPa:
Here’s how the cyclone looked from space yesterday:
I think that I can convince myself that the salinity profile from ice tethered profiler 97, currently located at 73° N, 134° W, reveals mixing from depth in the wake of the storm:
The synthetic aperture radar on the Sentinel 1B satellite can certainly see through the clouds, and reveals open water in the Central Arctic north of the Beaufort Sea yesterday evening (UTC):
Here is Wipneus’ latest AMSR2 concentration delta map:
The effects of this weekend’s storm are readily apparent! Just in case you’re wondering Wipneus reports:
Area: -172.0 (+324k vs 2016, +138k vs 2015, -669k vs 2014, -523k vs 2013, +493k vs 2012)
The next pulse of swell is currently forecast to be somewhat higher and longer period than the last one. This one is also taking aim at the Beaufort Sea MIZ:
According to Environment Canada the latest cyclone is already down to 980 hPa MSLP:
The MSLP of the current cyclone is now down to 976 hPA:
The latest WaveWatch III forecast has increased the predicted peak height and period of the resulting waves once again:
Large holes are appearing in the sea ice on the other side of the Arctic too. Take a look north of the Laptev Sea for example:
Meanwhile the current cyclone on the Pacific side of the North Pole appears to have bottomed out at 974 hPa:
Here’s the latest sea ice concentration one day delta map from Wipneus:
The waves are considerably smaller in the Beaufort Sea today, but not in the Bering Strait!
Here’s the latest one day delta map:
and here’s video showing the motion of sea ice in the Beaufort & Chukchi Seas so far this summer:
Here’s an animation from Wipneus revealing the effect of the two recent cyclones on the Pacific side, plus everything else that’s been going on in the Arctic:
Click the image to see a much larger (3.3 Mb) version.
AMSR2 Arctic sea ice extent has taken another tumble, and has dropped below 2016:
Only 2012 left to beat!
A PIOMAS mid month update has been released, including gridded thickness data. 2017 modelled volume has failed to follow 2012’s trajectory towards the September minimum, and is now on a par with 2011:
Watch this space!