Stephen F. Ackley

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An autumn bloom of sea-ice algae was observed from February to June of 1992 within the upper 0.4 meter of multiyear ice in the Western Weddell Sea, Antarctica. The bloom was reliant on the freezing of porous areas within the ice that initiated a vertical exchange of nutrient-depleted brine with nutrient-rich seawater. This replenishment of nutrients to the(More)
Antarctic sea ice cover has shown a slight increase in overall observed ice extent as derived from satellite mapping from 1979 to 2008, contrary to the decline observed in the Arctic regions. Spatial and temporal variations of the Antarctic sea ice however remain a significant problem to monitor and understand, primarily due to the vast-5 ness and(More)
Sea-ice conditions were observed using the ASPeCt observation protocol on three cruises in improved in the fall period when conditions were colder. This improvement was in the explainable variance of >70%, although in situ concentration was underestimated (albeit consistently) by the satellite imagery in fall.
This paper discusses a method for using the reflected signal from a stepped-frequency radar system to obtain the electrical permittivity and conductivity in a thin layer at the flat surface of a (possibly inhomogeneous) body. The method is based on a band-limited version of geometrical optics. 1. INTRODUCTION. This work is motivated by the problem of remote(More)
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