Da. Etkin et Ro. Ramseier, A COMPARISON OF CONVENTIONAL AND PASSIVE MICROWAVE SEA-ICE DATASETS FOR HUDSON-BAY, Atmosphere-ocean, 31(3), 1993, pp. 359-378
A sea-ice dataset derived from passive microwave data acquired by the
Scanning Multichannel Microwave Radiometer (SMMR) is compared with a c
onventional sea-ice dataset from Ice Branch, Atmospheric Environment S
ervice, Canada. The conventional set uses data from several sources in
cluding ships of opportunity, reconnaissance aircraft, satellite photo
graphs and climate stations. The comparison was made for a 3-year peri
od from 1979 to 1981 over Hudson Bay, an area that is covered with fir
st-year ice only. For 8 of the 12 months of the year, monthly area-ave
rage ice concentrations are within one tenth; larger differences are e
vident during periods of melting and freeze-up. Extensive ponding on f
irst-year ice during the melt season is interpreted as open water by t
he SMMR algorithm, leading to significant ''errors'' in the passive mi
crowave dataset. By comparing the two datasets, we were able to show t
he extent of ponding on the ice for a complete seasonal melt cycle. Du
ring freeze-up the algorithm, under some conditions, provides a better
estimate of the amount of ice than a conventional dataset owing to th
e difficulty of observing the presence of new ice.