Polarstern Arcwatch 2023

[Niall Dollard]

Decided it was better to open a new thread for updates on the latest Polarstern expedition across the Arctic.

Attached image shows current buoy locations and data downloads are available here :

https://data.meereisportal.de/relaunch/buoy.php?buoytype=all&region=all&buoystate=all&expedition=Polarstern_PS138-Arcwatch_2023&submit1=Anzeigen&active-tab1=method&ice-type=buoy&lang=de&timeline=buoy&active-tab2=buoy&showMaps=y&dateRepeat=n

Just recently one of the buoys has drifted into Russian sea area and they may not be able to visit it again !

[gerontocrat]

Just recently one of the buoys has drifted into Russian sea area and they may not be able to visit it again !

I believe that Sovereign Territory only extends 12 miles from the shore. while the Exclusive Economic Zone in theory extends 200 miles from shore.

So in theory Polarstern can chase that buoy into the economic zone, but I wouldn't. Many of Russia's icebreakers have guided missiles on board & lots of other nasty stuff. Just wave goodbye and wait to be accused of sending a spy-buoy against Russia.

[Jim Hunt]

It look like Polarstern will be off the Marine Traffic chart shortly:

[Niall Dollard]

Thermistor Buoy 104 was Deployed on Date and Time (UTC): 09.08.2023 13:00
at Position (Lat/Lon): 83.99260/32.3549

Ice thickness was 0.98m and ice freeboard was 0.15m

With 240 thermistors at spacing 2cm.

The buoy has drifted a little south and was at 83.6 latitude on 28th.

The first attachment shows the air temperature for the buoy. It peaked on the morning of the 15th.

I've attached 2 graphs showing the temps at all the thermistors 1 to 240 (Thermistor number is on the X axis) for both the morning of the 15th when the air temp was at its highest (6°) and graph for 28th August when air temp was at -2.4°.

Am I correct in thinking that circa thermistor T40 to T50 (0.8m to 1m depth?) is at the boundary layer between sea ice and sea water? And sunlight on the 15th is penetrating through the ice to raise thermistor temperatures to  between +3° and +4° in the first 30cm of ice?

[Richard Rathbone]

Am I correct in thinking that circa thermistor T40 to T50 (0.8m to 1m depth?) is at the boundary layer between sea ice and sea water? And sunlight on the 15th is penetrating through the ice to raise thermistor temperatures to  between +3° and +4° in the first 30cm of ice?

That's the air at +3° and +4°. The thermistors are out of the top of the ice as well as out the bottom.

It looks to me that the top of the ice is about T40, and that there's been quite a bit of bottom melt since deployment.

[Niall Dollard]

This is the Buoy Deployment report (and pic).

[Niall Dollard]

Polarstern at the North Pole on Sept 7th.

Also image of new ice at 88°N.

Marcel Nicolaus informs us that they will show a live stream of their dive below the ice on 14 September 16:00 CEST.

Link to be posted on his twitter link.

[Niall Dollard]

More from Marcel.

A widespread, deep snow cover near the Pole. 18cm deep.

That would slow down the re-freeze.