Investigation of Tidal Aliasing and Climate Scale Processes in Sea Ice and Their Influence on Oceanic-Atmospheric Heat/Momentum Balances...

9818645汉森这项拟议的工作是研究如何利用卫星数据来提高我们对北极和南极海冰覆盖的运动影响大气和海洋之间的热量和动量交换的过程的理解。 关键变量是海冰的差异运动：即辐合、辐散和切变，这会产生开阔水域，并显著增加大气-海洋交换率。这项工作涉及差异运动中的短周期或高频变化，这些变化如此之快，以至于无法通过连续的卫星通过来解决。 大部分卫星获得的冰的运动数据是在三天的时间尺度上，目前的能力可扩展到一天。 这不足以解决周期小于一天的潮汐和惯性振荡引起的运动，本提案采用一种富有想象力的统计方法，从采样率为每天一次或更低的数据记录中恢复这些振荡的振幅。 它基于这样的前提：潮汐和惯性振荡的功率出现在数据记录的统计中，并附加假设：如果这些振荡的频率是明确定义的（就像潮汐和惯性振荡的情况一样），那么它们的影响仅限于观察到的数据记录的特定且可预测的部分。 该方法将通过比较威德尔海冰营地的观测结果进行测试，在那里直接测量潮汐和惯性振荡的力量，同步卫星图像，这些振荡的功率将在统计上恢复。从这个项目中得到的技术可能会通过引入更好和更现实的数值方法来更准确地确定南极大气和海洋的结构。近似海冰的形成和具有全球联系的水团变化过程。

9818645HansonThis proposed work is a study of how satellite data can be used to improve our understanding of the process by which the movement of the arctic and antarctic sea ice cover affects the exchange of heat and momentum between the atmosphere and the ocean. The key variable is differential motion of the sea ice: i.e. convergence, divergence, and shear, which produces areas of open water and significantly increases the atmosphere-ocean rates of exchange.The effort is concerned with short-period or high frequency variations in the differential motion, that are so rapid that they cannot be resolved by successive satellite passes. The bulk of satellite-derived ice motion data is on a three-day time scale with current capabilities extending down to one day. This is insufficient to resolve motions resulting from tides and inertial oscillations that have a period less than one day.This proposal uses an imaginative statistical approach to recover the amplitude of these oscillations from a data record whose sampling rate is once per day or lower. It is based on the premise that the power of tidal and inertial oscillations appears in the statistics of the data record, with the additional hypothesis that if the frequency of these oscillation is well-defined (as is the case for tides and inertial oscillations) then their effect is limited to a specific and predictable part of the observed data record. The approach will be tested by comparing observations from the Weddell Sea Ice Camp, where the power of tidal and inertial oscillation was measured directly, with synchronous satellite imagery, where the power of these oscillations will be recovered statistically.Potentially the techniques derived from this project will allow more accurate determinations of the structure of the antarctic atmosphere and oceans by introducing better and more realistic numerical approximations to sea ice formation and water mass modification processes that have global connections.