8 Satellite Microwave Radar Observations of Antarctic Sea Ice
8.5.2.2
Coastal Shallow Water Buoy Drift
In Figure 10, a comparative correlational analysis is made for the 5 month long drift of
Ice Station Weddell (ISW) in the western Weddell Sea in 1992 (ISW Group 1993), together with hourly winds. ISW was located on an old ice floe just off the continental shelf
break at 54 0 W in the region of perennial ice (Drinkwater 1997). Its motion, in contrast,
lee velocity acvf
Wind velocity acvf
Velocity ccvf
1.0
1.0
1.0
0.8
0.8
0.8
0.6
0.6
0.6
J
0.4
J
0.4
J 0.4
0.2
0.2
-0.4
-0.4
-0.4
0 10 20 30 40 50
0 10 20 30 40 50
-40 -20 0 20 40
time lag, day
time lag, day
time lag. day
Ice velocity
Wind velocity
Cross amplitude
auto spectrum
auto spectrum
spectrum
4
4
4
3
3
3
~
!:
~
\ 2
\ 2
\ 2
U
u
u
10 100 100010000
10 100 1000 10000
10 100 100010000
period. h
period. h
period, b
Phase
100
.j
.go 0
Ii'
-100
10 100 100010000
10 100 1000 10000
period. h
period. b
Fig. 10. a-h. Auto-covariance functions and normalized variance spectra of GPS-derived ice drift and
wind speeds for Ice Station Weddell. For further details, see text