Geology Reference
In-Depth Information
partner with the responsibility for managing space con-
tracts in the private sector. The goal of the Mould Bay
experiment was to monitor the surface conditions and
structural aspects of ice growth and aging processes from
the stage of young to second year. The Jet Propulsion
Laboratory (JPL), University of Kansas, the University
of Washington, and the U. S. Naval Research Laboratory
(NRL) also joined this project as part of the Radarsat‐
Firex project. Data were obtained to identify changes
of physical, chemical, and electrical properties of sea
ice with age. During the time of the project Mould Bay
weather station and hence Environment Canada pro-
vided all the necessary logistical support from the site
indicated in Figure 5.1b. The staff of the weather station
meticulously noted down all the necessary aspects of
water and sea ice conditions in the bay in conjunctions
with the weather data during, as well as between, the
field trips by the scientific teams. This enhanced data
collection during the entire period of the project includ-
ing the long periods of extremely cold and dark polar
nights. The station was closed in 1997.
During the project's period, AES operated the Motorola
APS‐94 SLAR onboard a four‐engine Electra aircraft
that used to produce real‐time imagery for ice reconnais-
sance (Figure 5.3). This was an X‐band (9.1-9.4 GHz)
imaging radar with HH polarization using an incidence
angle of 45°. The aircraft was also equipped with two
Vinten 70 mm film cameras and a few other instruments.
The aircraft overflew the area on three occasions during
the autumn of 1981: (1) on 19 September when the bay
was ice free, (2) on 29 September when the ice cover was
only 5 days old and the ice was young (thickness less than
300 mm) and (3) on 21 October when the bay was covered
with new FY ice (thickness more than 300 mm). The
Electra also performed several overflights on 3 July, 1982
when the ice cover started to exhibit the summer melt.
SLAR data acquired on 21 October, with resolution cell
of approximately 30 × 200 m, was of outstanding quality
and is shown in Figure 5.4. As can be seen in the figure, a
large variety of differing types of MY ice floes were found
surrounded by new ice in the Crozier Channel. These were
fairly mobile, giving rise to open leads in some places. A
major area of study was a large MY ice floe (about 6.5 × 8
km). This mobile floe exhibited very uniform hummock
and melt pond formation. Profiles of ice properties from
the surface down to a 1 m depth were collected along with
backscatter measured using a ground‐based scatterometer
system. More details on the SLAR system and its role on
ice monitoring in Canadian waters can be found in
Sutton
[1991]. The remote sensing component of the experiment
also included flights of the airborne passive microwave
sensor RP‐3A of the NRL. An image of the Mould Bay
from that sensor is shown in Figure 5.5 in which 11 snow/
ice measuring stations (numbered 1-8) along an experi-
mental line, marked by large oil drums, are also shown
with their approximate locations. Actually, these stations
were about 1 km apart and the exact locations of stations
2 and 3 are shown in Figure 5.4. An additional station,
designated as an AES station was located 300 m from the
eastern shoreline, not very far from the weather station.
A synopsis of the ice in the Mould Bay is presented
since it is relevant to the subsequent discussions. During
the spring of 1981, the 30 km long Mould Bay with its
length oriented in the north‐south direction, as shown on
the map, in Figure 5.1b, was covered with ice. Some of
this ice cover was expected to remain in the bay. However,
during the late summer of 1981 all of the ice in the bay
moved out with the exception of a few small grounded
pieces of MY ice near the shore in the southern end.
These MY pieces also disappeared eventually, leaving a
clear bay when the winter season began. Thus the entire
bay without any ice debris became an ideal “mesoscale”
Figure 5.3
AES Electra equipped with SLAR flying over Mould Bay on 3 July, 1982; note the near absence of snow
on the land and the mountains across the bay (photo by N. K. Sinha, unpublished).
