Arctic Sea Ice

More on ice thickness from AWI

About two and half weeks ago the Alfred Wegener Institute for Polar and Marine Research (AWI) issued a press release to inform us of the fact that their research vessel and icebreaker Polarstern had arrived at the North Pole. In the blog post I dedicated to this news, I mentioned a snippet about their findings concerning ice thickness. I have finally come around to read a bit more on AWI's excellent Polarstern Blog, and have translated some more snippets about ice thickness. All the images come from the Polarstern Blog as well.

Schollensuche richtung Nordpol
the search for ice floes on the way to the North Pole

In order to document the ice conditions during our journey we observe the sea ice on an hourly basis. The ice conditions are logged following an international standard. Ice cover, type, thickness and the distribution and amount of melt ponds are recorded and documented with photographs. Ice thickness is estimated with a yardstick aboard the ship by observing the broken ice floes that are standing upright.

A broken ice floe with a thickness of approximately 1 m (image courtesy of Stefan Hendricks, Alfred Wegener Institute)

The first results from our observations show that the sea ice is relatively thin, young and unstable. Older multiyear ice, which used to be typical for this region in the past decades, makes up just 10 to 20% of the observed ice. Consequently we can travel and navigate through the ice much quicker than in the past, and do not get stuck. On top of that the journey is made easier by many stretches of open water which allow us to travel at a speed of 3 to 6 knots (5 to 10 km/h) from one measuring point to the other. This gives us more time for operating our ice and water stations.

Polarstern reaches North Pole

According to this press release by the Alfred Wegener Institute, the polar icebreaker Polarstern has reached the North Pole this morning, 22nd August at 9:42 AM CET.

The 55 scientists and technicians from 6 different countries are there to investigate the changes in the Arctic. Hence the name of their expedition: TransArc - Trans-Arctic survey of the Arctic Ocean in Transition.

I have translated one part of the press release that I found of particular interest:

Schauer was in the central Arctic for the last time in 2007 and this time around has found an ice cover that is similar to the one in the year that went into the history books as the year with the lowest sea ice cover since satellite measurements in 1979 began. The first ice thickness measurements confirm this: in 2011 as well as in 2007 most of the ice has an ice thickness of 0.9 m. In comparison, most of the ice in 2001 was measured at 2 m. That year total sea ice extent at the end of the melting season corresponded to the long term average.

This is the third time the Polarstern reached the North Pole. On September 7th 1991 it did so with the Swedisch research icebreaker Oden. Almost exactly 10 years later, September 6th 2001, there was a joint expedition with the American USCGC Healy.

Alfred Wegener Institute press release