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)
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)
To order the complete compilation report, use: ADA471691 The component part is provided here to allow users access to individually authored sections f proceedings, annals, symposia, etc. However, the component should be considered within [he context of the overall compilation report and not as a stand-alone technical report.
Mortality estimates are central to understanding tsetse fly population dynamics, but are difficult to acquire from wild populations. They can be obtained from age distribution data but, with limited data, it is unclear whether the assumptions required to make the estimates are satisfied and, if not, how violations affect the estimates. We evaluate the(More)
Geography is the study of the relationships between people and their environments, relationships that vary from place to place over the Earth. Students inquire into those factors responsible for the variable and changing character of Earth's surface, which over time has been transformed into the human habitat. Geography integrates physical science, social(More)
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