| Summary: | Seasonal ice cover off Canada's east coast was examined in relation to synoptic scale atmospheric events. Ice concentration information derived from Nimbus-7 scanning multichannel microwave radiometer (SMMR) measurements of surface brightness temperatures, supplemented by AES composite ice charts, provided timely coverage of the study area during the 1971/72, 1980/81 and 1984/85 ice seasons, 1971/72 and 1984/85 seasons with high ice concentrations and 1980/81 a season with low concentrations. Atmospheric variability was monitored using the 850 hPa height at three upper air stations along the western edge of the study region. Additional information was drawn from storm track records, providing an indication of surface variability. Properties of specific storm events were obtained from the storm track data, permitting evaluation of the ice response to passing synoptic disturbances. Results of this investigation indicate that, (1) passive microwave-derived ice information can be used to monitor high frequency variability in the marginal ice, (2) despite short time series, spectral relationships between ice concentration variability and 850 hPa pressure height indicate a strong association between the two at synoptic frequencies zone, and (3) variability in ice cover extent and concentration can be related to the passage of individual synoptic events.
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