Spatial and Temporal Variability of Sea-Ice Draft Near the North Pole from ULS Data, 1975 - 2005

提供资金用于分析1975-2005年的潜艇和系泊向上看声纳（ULS）数据，重点是北极地区（NPR，北纬870度以北），那里的潜艇数据最密集，系泊数据解决了多个年度周期。美国海军最近的解密工作使可用的潜艇数据增加了一倍，每年将有4到5个系列的数据来自美国国家公共电台的系泊潜艇。潜艇在剖面上的覆盖范围很密集，但在时间上是零星的。系泊ULS的覆盖范围在时间上是密集的，但在空间上是稀疏的。将分析几个辅助数据集：来自国际北极浮标计划的海冰运动学、热力学和大气环流数据，估计的海冰年龄每月场，以及来自耦合海洋/冰模型的强迫和输出变量。平均冰吃水将被统计地描述。在不同大小的空间/时间窗口中对ULS数据进行分组，估计样本统计量和置信限，并执行多元回归分析，将显示这种描述在不同分辨率下的准确性。将使用相关技术和平均厚度预算方程的诊断分析来研究ULS数据和辅助数据之间的关系，以确定模型和数据之间的可变性和差异的原因。海冰厚度是气候变率的重要诊断指标。它是估算海冰质量平衡所必需的，因此对世界海洋淡水收支和温盐环流（全球输送带）有影响。该项目的结果将使我们能够更好地估计过去以及可能在海底数据很少或没有数据的情况下（如未来十年很可能出现的情况）在北极地区的冰流变化。该研究将增加对冰流时空变异性的认识和理解，包括其成因，并提供更可靠的样本统计和NPR趋势估计。

Moritz 0612944Funds are provided to analyze submarine and moored upward-looking sonar (ULS) data from 1975-2005, focusing on the North Polar Region (NPR, north of 87o N) where the submarine data are densest and moored data resolve multiple annual cycles. Recent declassifications by the U.S. Navy have doubled the available submarine data, and 4 or 5 annual series will be available from moored ULS in NPR. Coverage by the submarines is dense along the profile, but sporadic in time. Coverage by the moored ULS is dense in time, but sparse in space. Several ancillary datasets will be analyzed: sea-ice kinematics, thermodynamic and atmospheric circulation data from the International Arctic Buoy Program, estimated monthly fields of sea-ice age, and forcing and output variables from a coupled ocean/ice model. The mean ice draft will be described statistically. Binning the ULS data in space/time windows of varying size, estimating sample statistics and confidence limits, and performing multiple regression analysis will show how accurate this description is at different resolutions. Relationships between the ULS data and the ancillary data will be studied, using correlation techniques and diagnostic analysis of the budget equation for mean thickness, in order to identify causes of variability and discrepancies between the model and data. Sea ice thickness is an important diagnostic for climate variability. It is required for estimation of the sea ice mass balance and, consequently, has implications for the world ocean's fresh water budget and thermohaline circulation (the global conveyer belt). Results of this project will permit improved estimation of ice draft variability in the NPR during the past and, potentially, at times when there are few or no submarine data, as is likely to be the case during the next decade. The study will increase knowledge and understanding of the spatial and temporal variability of ice draft, including its causes, and provide more robust estimates of sample statistics and trends in NPR.