Observations of Melt Pond Evolution and Sea Ice Albedo Chris Polashenski 1 and Don Perovich 2 1 Thayer School of Engineering, Dartmouth College Hanover NH, 2 US Army Corps of Engineers CRREL Laboratory Hanover NH
Observations of Melt Pond Evolution and
Sea Ice Albedo
Chris Polashenski1 and Don Perovich2
1 Thayer School of Engineering, Dartmouth College Hanover NH, 2 US Army Corps of Engineers CRREL Laboratory Hanover NH
Key Questions:
• What is the albedo of a melt pond? • How much area is covered by ponds?
6/4/2008
6/6/2008
6/7/2008
6/8/2008
6/9/2008
Channel
6/12/2008
6/14/2008
6/15/2008
6/17/2008
Drainage Flooding Growth
Date 2009
No Drainage
Ponds drain through
macroscopic holes
-Flow stops in holes -Ice permeable
-Ponds at sea level -Growth dictated by
ice freeboard
Spatial Coverage Detail, Scene Repeatability
MY Ice
Mixed Ice
FY Ice
MY Ice
FY Ice
Pond Volume Parameterization CCSM CICE 4.0
New pond volume = old pond volume + 10% of the new melt water
CICE 4.0 Documentation
Pond fraction is related to pond depth by a factor of 0.8
Comparing CICE 4.0 to Observations
CICE 4.0 Predicted Pond Fraction Observed Pond Fraction
Comparing CICE 4.0 to Observations
CICE 4.0 Predicted Pond Fraction Observed Pond Fraction
Difference - 60 MJ/m^2 Enough to melt ~20cm Ice
Summary • First year ice is becoming more prevalent in the Arctic • FY ponds behave is quite differently from MY ponds • Early season ponds on FYI form above hydrostatic
equilibrium and have large coverage • Duration of this flooding could significantly effect melt. • Understanding the mechanisms which control meltwater
drainage is crucial for modeling FY ponds
• If you have unpublished melt pond coverage data, I’d like to collaborate with you!
Thank You Collaborators
Don Perovich, Zoe Courville, Dave Finnegan
Barrow Arctic Science Consortium
NSF Grant No. ARC-0454900