Ice studies off West Greenland 2006 Bureau of Minerals and Petroleum Government of Greenland Data compiled by Sine M Hvidegaard, Rene Forsberg, Susanne Hanson Danish National Space Center Leif Toudal Ørsted DTU

West Greenland ice studies 2006 Basic objectives – Measure ice thickness and ridging – Calibrate airborne measurements by in-situ drilling – Compile historic data on ice distribution and drift – Measurement of ice drift with buyo

QAARSUT KANGERLUSSUAQ T12 West-Ice flight tracks 21/25 April 2006

Southern line – approx 3 km section. Numerous thick floes and ridges The swath shows colour- coded sea ice thickness data including the snow depth on top of the ice Laser ice thickness measurement m

. Laser ice thickness measurement Northern line – approx 2 km section. V10 is helicopter drill site position m

Average laser ice thickness 1.39 m 70.6 % 1.40 m 80.0 % 1.19 m 67.6 % 1.23 m 66.0 % 1.10 m 65.8 % 2.13 m 77.2 % 1.78 m 83.3 % 1.28m 72.9 % 1.63 m 73.5 % 1.29 m 66.1 % 1.33 m 63.8 % 1.32 m 83.6 % V1 – V2 V3 – V4 V5 – V6 Plot shows mean ice thickness for the E-W laser survey lines, for each 2° in longitude Numbers shown are the average thickness in meter and the % of ice thickness above 80 cm. The thickness includes snow depth and pressure ridge heights; floe ice thickness is therefore significantly less. Average of helicopter measurements on flat floes: 65 cm, with 40% > 80 cm

Ice-thickness distribution

In-situ ice-thickness measurements 40x40 m area selected corresponding approx. to in-situ measuring site Average of laser-scanner- derived ice thickness in area compared to average of drillings In-situ: 0.56 m Scanner: 0.79 m ± 0.30 m (std. dev.) Large variation in area is the main cause of the difference

PointIce thickness range (cm) Average thickness, (cm) Aver. snow depth, (cm) V V V (two floes) 915 V V Uummannaq fast ice (6 pts) In-situ ice-thickness measurements

In-situ/laser measurement comparison In-situ: 1.05 m Scanner: 1.44 m In-situ: 0.96 m Scanner: 0.78 m In-situ: 0.56 m Scanner: 0.79 m

End of the ice season (end of June) AMSR-E ICE AMSR-E ICE

Distribution of sea ice 2004–2006 Amimations of sea-ice distribution and cover 2004–05 (left) and (right) Sea ice cover: Purple:~100 % Red: > 90 % Orange: > 70–85 % Yellow: > ~50 % Green: ~30 % Blue-green: 10–20 % Blue: no ice or noise

Drift of polar multi-year ice Polar multi-year ice has a higher roughness than first-year ice – seen as bright green or yellow areas along the east coast of Canada Note that this ice does not drift into Greenland waters

25-year statistics Minimum number of ice-free days Average number of ice-free days

Recent statistics Minimum number of ice free days 25-year statistics Minimum number of ice free days 2000–2005 statistics

Ice stations 2006/04/26 Drift track 2006/04/26–2006/06/12 Sea ice studies 2006

Radar image June 12, km 2006 drift buyo experiment

Comparison between buoy drift statistics 2006 and the 20 year satellite ice drift statistics Good correspondence, but satellite may under-estimate extreme values Percentage of days in May where ice drift exceeds 10 km/day Yellow areas have few datapoints! Ice drift in May 2006 buoy 20-year average

Pechora Sea Beaufort Sea Sakhalin Caspian Sea Priraz Kara Oil production in ice-infested waters White Rose

Ice free (# of days) Velocity (>10 km/day)Area definition mean [min-max][% of days with data] Sakhalin 200 [ ] N E Baffin Bay [ ] [100–250] N 54-61W Pechora 193 [ ] N 52-55E Priraz 160 [98-223] N 56-58E Kara 122 [50-192] N 62-65E Beaufort 51 [0-140] N W Comparison with other areas

Conclusions