sea ice modelling, forecasting, and validation activities at
Post on 02-Feb-2016
59 Views
Preview:
DESCRIPTION
TRANSCRIPT
Sea ice modelling, forecasting, and validation activities at
Alfred Wegener Institute (AWI), Bremerhaven, Germany
Christian Haas
• Modelling• Thickness profiling• SAR remote sensing
• Operating stand-alone & coupled ice-
ocean dynamic/thermodynamic models
after Hibler & Lemke, Semtner• Viscous-plastic & elastic viscous plastic
rheologies• Arctic and Antarctic• Modified and improved by Fischer,
Harder, Kreyscher, Hillmer, Lieser• Focus on climate system studies• New: Finite element (FE) modelling
[1/km][1/km]
Ridge frequency
Variability of Arctic sea-ice volume
1951-1999
Spatial thickness and drift trends
1951-19991951-1999
Temperature anomalies in the Arctic Ocean
AWI-NAOSIM
Temperature flux through Fram Strait
1997 Temperature
Anomaly(450 m depth)
FE ModelMotivationMotivation• Accurate Mesh Refinement and Adaptive
Meshes• Variational Formulation for Complex Rheologies
SSM/I observations Sea ice model data 8.3.98 8.3.98
Assimilation (OI)
Model run (7 days)
SSM/I observations Sea ice model data15.3.98 15.3.98
Assimilation (OI)
Model run (5 days)
SSM/I observations Sea ice model data20.3.98 20.3.98
Comparison
Assimilation Scheme
SSM/I (observed) Model (stand-alone) Model (assimilation)
Result of Assimilation
EM thickness profiles
SIMS:Sea Ice Monitoring System
Helicopter-borne EM profiling
EM Bird
Typical EM bird thickness profile and distribution
Ice thickness variability in the Transpolar Drift:1991, 1996, 1998 & 2001
Ice Ridging Information for Decision Making in Shipping
600
500
400
300
200
100
0
Num
ber
of m
easu
rem
ents
86420
Ice thickness, m
030315Mode = 1.3 mMean = 1.55 +- 1.12 m
3000
2000
1000
0
Num
ber
of m
easu
rem
ents
86420
Ice thickness, m
030316Mode = 0.2 mMean = 0.32 +- 0.38 m
500
400
300
200
100
0
Num
ber
of m
easu
rem
ents
86420
Ice thickness, m
030312Mode = 1.9 mMean = 2.49 +- 1.49 m
6
5
4
3
2
1
0
4442403836x10
3
500
400
300
200
100
0
Num
ber
of m
easu
rem
ents
86420
Ice thickness, m
030315_3Modes = 0.2 m, 0.8 m, 1.9 mMean = 1.42 +- 1.03 m
Sea Ice Thickness Observation System
Polarstern
Integration of SAR imagery for algorithm development and extrapolation to larger ice
regimes
Sea Ice Thickness Observation System
top related