Marginal Ice zone

Some definitions:

• Wadhams (1986) : "that part of the ice cover which is close enough to the open ocean boundary to be affected by its presence".

• Mohn Sverdrup Center: “The marginal ice zone (MIZ) is defined as the area where open ocean processes, including specifically ocean waves, alter significantly the dynamical properties of the sea ice cover.”

Where is the Marginal Ice Zone ?

Standard deviation of sea ice concentration. 1979-2009

The variability of ice concentration outline areas where marginal ice zone exists

September March

More mixed ocean/ice regions after 2007 ?

Average sea ice concentration in March and September, for ice concentration greater than 15% - North of 80N.

There appears to be a shift in mean Arctic Ocean ice concentration after 2007. Reprocessing of 2010-2013 data will reveal more… (spring 2014)

Surface temperature in MIZ

• Reanalysis used to create ice, in situ and SST match-ups

• Matches in East Greenland Current

•Large SST within region with mixed ice and ocean

• Similar signal for ARC and Pathfinder

Validating SST products in MIZ

• Reanalysis sea ice-in situ + satellite match-ups

•Remarkable small and stable bias for ice concentration < 60 %

Ice and Sea Surface Temperature- in situ measurements from Oden 2012

Simultaneous sampling from Monkey Island:•Thermal InfraRed surface temperatures•Ship air temperatures•L-Band microwave integrated temperatures•Photo based ice concentration setup

Measuring Ice concentration- in situ

GoPro photo of Arctic sea ice (crosstrack from Monkey Island). Oden, Summer 2012.

Photo classification: White is Ice, colors are No-Ice

GoPro photo ice concentration sampling in 1-minute resolution.(38 periods of three hours)

Marginal Ice Zone - temperatures and IC

3-hour sampling of coincident measurements of ship air temperatures (blue), TIR skin temperatures (green) and photo determined ice concentrations.

IC varying between 0.3 and 0.8 -> Skin temperatures reflect alternately water, ice and mixing temperatures.

IC correlated with skin temperatures -> water is colder than ice surface.

The air temperature is the coldest of 5 ship thermometers. However, the measurement must be read with causion as ship heating may influence the measure…

Metop-A SST + MIZ + IST product • IST algorithm

• SST algorithm

• MIZ (linear combination of IST + SST)

• T10.8 determines the algorithm

• Level 3 fields available at: polarportal.dk

Summary/Challenges

• MIZ covers large parts of the Arctic ocean

• Indications that larger percentage of ice covered waters have smaller concentration

• In situ ice concentration data set available

• Interesting IC and ST relationship

Future work

• Determine the SST signal within MIZ for different ic conc, regions and seasons

• Compare SST and Metop-a in MIZ

• Determine the impact of SST gradients in MIZ on SST performance

• Collect in situ observations in MIZ

• Verify and update MIZ algorithm in Metop-A

• Use SST versus IC relationship in Arctic Level 4

High latitude DMI-ISAR deployments• 7 week deployed at ODEN icebreaker• Autonomous deployment July-November 2013

• Planned• Activ circumpolar expedition (2014, 2015)• RAL line, Denmark-Greenland