Winter sea-ice thicknesses in the Weddell Sea and their variability over the past 24 years
Sandra Schwegmann 1 , Priska Hunkeler 1 , Stefan Hendricks 1 , Peter Lemke 1 , Christian Haas 2 , Thomas Krumpen 1 , Robert Ricker 1
1 Alfred Wegener Institute for polar and marine research
2 York University
ANT-XXIX/6: the recent winter experiment
ANT-XXIX/6 08.06.-12.08.13
Cape Town – Punta Arenas Winter experiment
9 drilling stations - Sea ice thickness - Freeboard
- Snow depth
Objectives
Regional Sea Ice Thickness Distribution
Thermodynamic & Dynamic Ice Growth
Remote Sensing Validation Data
CryoSat-2 SMOS
Method Development
Improved Resolution (1D 2D)
Objectives
Regional Sea Ice Thickness Distribution
Thermodynamic & Dynamic Ice Growth
CryoSat-2 Comparison to other winter data SMOS
Distribution 1992 vs. 2013
Sea ice thickness Snow depth
70
60
50
40
30
20
10
0
Frequency 2013
240 220 200 180 160 140 120 100 80 60 40 20 0
Sea ice thickness (cm) 110
100 90 80 70 60 50 40 30 20 10 0
Frequency 1992
2013 1992
60
50
40
30
20
10
0
Frequency 2013
100 90 80 70 60 50 40 30 20 10 0
Snow depth (cm) 160
140
120
100
80
60
40
20
0
Frequency 1992
2013 1992
• Sea-ice thickness distribution comparable
• Snow depth much higher in 2013
Retro Drilling-GEM comparison
0 20 40 60 80 100 120 140 160 180 200
21. Jun. 26. Jun. 1. Jul. 6. Jul. 11. Jul.
RD TIT
GEM TIT
RD sdev
GEM sdev
RD mode
Gem Mode
Winter - early spring expeditions
ANT-VIII/2
06.09. – 31.10.1989 Weddell Sea, Spring
ANT-X/4
21.05. – 06.08.1992 Weddell Sea, Winter
ANT-XXIII/7
24.08. – 29.10.2006
Western Weddell Sea, Winter-Spring
ANT-XXIX/6
08.06. – 12.08.2013 Weddell Sea, Winter
ANT-XXIX/7
14.08. – 16.10.2013
Western Weddell Sea, Winter-Spring ANT-VIII/2
Augstein et al., Ber. Polarforsch. 84(1991)
Sea-ice thickness comparison
800
700
600
500
400
300
200
100
0
3.5 3.0
2.5 2.0
1.5 1.0
0.5 0.0
24 22 20 18 16 14 12 10 8 6 4 2 0 1989
2006 2013 (ANT-29/7) 70
60
50
40
30
20
10
0
Frequency 2013
240 220 200 180 160 140 120 100 80 60 40 20 0
Sea ice thickness (cm) 110
100 90 80 70 60 50 40 30 20 10 0
Frequency 1992
2013 1992
• Sea-ice thickness distribution comparable between 1989 and 2013
• 2006 shows higher sea-ice thickness
Snow depth comparison
1.4 1.2
1.0 0.8
0.6 0.4
0.2 0.0
900 800 700 600 500 400 300 200 100 0
50 45 40 35 30 25 20 15 10 5 0 1989
2006 2013 (ANT-29/7) 60
50
40
30
20
10
0
Frequency 2013
100 90 80 70 60 50 40 30 20 10 0
Snow depth (cm) 160
140
120
100
80
60
40
20
0
Frequency 1992
2013 1992
• Snow depth much higher than in every other year
Freeboard comparison
50
40
30
20
10
0
Frequency 2013
-30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30
Freeboard (cm) 60
55 50 45 40 35 30 25 20 15 10 5 0
Frequency 1992
2013 (ANT-29/6) 1992
500 450 400 350 300 250 200 150 100 50 0
Frequency 1989
-0.30 -0.20 -0.10 0.00 0.10 0.20 0.30
Freeboard (m)
14
12
10
8
6
4
2
0
Frequency 2006/2013
1989 2006 2013 (ANT-29/7)
