Ice studies off West Greenland 2006

Bureau of Minerals and Petroleum

Government of Greenland

Data compiled bySine M Hvidegaard, Rene Forsberg, Susanne Hanson

Danish National Space CenterLeif 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

68.014

68.012

-57.900

-57.880

-57.860

-57.840

0.0 1.0 2.0 3.0m

.

Laser ice thickness measurement

Northern line – approx 2 km section. V10 is helicopter drill site position

71.025

71.020-56.32 -56.30 -

56.28-56.25

0.0 1.0 2.0 3.0m

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

V3-V4

00,020,040,060,08

0,10,120,14

0 2 4 6 8 10

Ice thickness, m

Pd

f

V1 - V2

0

0,02

0,04

0,06

0,08

0,1

0,12

0 2 4 6 8 10

Ice thickness, m

Pd

f

Ice-thickness distribution

Helicopter overflight, V5 - V6

0

0,05

0,1

0,15

0,2

0 2 4 6 8 10

Ice thickness, m

Pdf

Between Helicopter overflight and coast line,

0

0,05

0,1

0,15

0,2

0,25

0,3

0 2 4 6 8 10

Ice thickness, m

Pd

f

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

Point Ice thickness

range (cm)

Average thickness,

(cm)

Aver. snow

depth, (cm)

V10 45-60 53 3

V11 22-40 32 1

V13 42-140 (two floes)

91 5

V14 39-60 45 2

V15 98-105 102 3

Uummannaq fast ice(6 pts)

25-52 44 4

In-situ ice-thickness measurements

In-situ/laser measurement comparison

In-situ: 1.05 mScanner: 1.44 m

In-situ: 0.96 mScanner: 0.78 m

In-situ: 0.56 mScanner: 0.79 m

End of the ice season (end of June)

AMSR-E ICE 20050701 AMSR-E ICE 20060628

Distribution of sea ice 2004–2006

• Amimations of sea-ice distribution and cover 2004–05 (left) and 2005-06 (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 track2006/04/26–2006/06/12

Sea ice studies 2006

Radar image June 12, 2006

20060426

20060612

50 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/dayYellow areas have few datapoints!

Ice drift in May

2006 buoy

20-year average

Pechora Sea

Beaufort Sea

Sakhalin

Caspian Sea

PrirazKara

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 [180-245] 49 53-54N 143-145E

Baffin Bay [2000-2005]

60-250[100–250]

27

68-71N 54-61W

Pechora

193 [112-278] 11 69-70N 52-55E

Priraz

160 [98-223] 11 69-70N 56-58E

Kara

122 [50-192] 12 71-72N 62-65E

Beaufort

51 [0-140] 6 70.5-71.5N 145-150W

Comparison with other areas

Conclusions