Observations of Melt Pond Evolution and Sea Ice Albedo
Transcript of Observations of Melt Pond Evolution and Sea Ice Albedo
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• If you have unpublished melt pond coverage data, I’d like to collaborate with you!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