Assessment of 1979-89 Inter-annual Trends in Arctic Basin Ice Draft as Measured by U.S. Nuclear Submarines

北冰洋准永久海冰覆盖是北部高纬度气候系统的核心组成部分，海冰浓度和厚度的长期变化可以作为北极大范围气候变化的重要替代指标。虽然冰浓度和范围的年际差异相对容易从微波卫星图像中记录下来，但厚度的变化需要对直接现场观测进行分析。这个项目是为了分析美国潜艇在穿越北冰洋时用向上看的声纳获得的选定海冰吃水剖面。这些数据自1975年以来定期获得，但尚未经过严格审查，也没有与其他现场和遥感环境数据相联系。预计所提出的统计技术将足够精确，可以在年代际尺度上揭示北极冰厚的年际变化，这可能是半球气候变化的早期指标。

The quasi-permanent sea ice cover of the Arctic Ocean is a central component of the northern high latitude climate system, and secular changes in the concentration and thickness of the sea ice can be important proxy indicators of wide-spread arctic climate variations. While interannual differences in ice concentration and extent are relatively easily documented from microwave satellite imagery, variations in thickness require the analysis of direct in- situ observations. This project is an effort to analyze selected sea ice draft profiles obtained with an upward looking sonar by U.S. submarines while crossing the Arctic Ocean. These data have been obtained routinely since 1975, but have not yet been subjected to a rigorous examination, nor have they been related to other in situ and remotely sensed environmental data. The proposed statistical techniques are expected to be sufficiently precise to reveal interannual variations in the arctic ice thickness on the decadal time scale, which may be an early indicator of hemispheric climate change.