大气对小尺度海表温度结构的响应

Satellite observations have revealed a remarkably strong coupling between surface winds and sea-surface temperature (SST) on scales shorter than about 1000 km. Winds are stronger over warm water and weaker over cold water. Spatial variations in the SST field therefore result in spatial variations in the surface wind field, with wind stress curl that generates order 1 perturbations to open-ocean upwelling and alters the SST field itself. SST-induced motions penetrate beyond the marine atmospheric boundary layer (MABL) and potentially play a role in the general circulation of the atmosphere...Observational and modeling studies conducted to date have been limited to investigation of the coupling between SST and surface winds on scales of about 50 km and larger. From our previous research, we have shown that the observed characteristics of this air-sea interaction on these scales are well represented by the Weather Research & Forecasting (WRF) mesoscale atmospheric model. In many regions, SST variability occurs on scales much smaller than 50 km. The degree to which SST influences the atmosphere on these smaller scales has not been investigated. The focus of this proposed research is to investigate the scale dependence of the atmospheric response to SST on scales down to somewhat smaller than 10 km...The proposed research includes the development of a new high-resolution satellite-based SST product that builds upon the procedures that have been developed for the SST analyses that are now produced daily on a 1/4o grid in our previous funded project. The atmospheric response to SST will be investigated from simulations with the WRF model forced with idealized and real SST fields, including our new high-resolution SST fields. In addition to the surface wind response to SST, we are also interested in the SST influence on tropospheric wind and thermal structures. These modeling studies will be conducted for the Kuroshio Current System region where SST gradients are strong with small spatial scales.

近年来，利用海洋卫星微波散射计、辐射计和数值模式相结合的研究发现中小尺度海温结构会对海面风速及对流层大气产生深远的影响，但是这些研究限制在50公里以上的空间尺度。在系统回顾中小尺度海气相互作用在50-1000 km尺度的研究成果基础之上，本项目的研究目标是将该领域研究拓展到10 km以下的空间尺度，具体包括：（1）通过构建高分辨海表温度分析产品和使用高分辨合成孔径雷达海面风场，针对大洋西边界流海域和中国近海海域定量分析10-50 km尺度的海气耦合强度，并分析比较不同空间尺度下中小尺度海气相互作用的变化特征；（2）开发高分辨海洋大气边界层参数化方案，使用WRF数值模式进行一系列高分辨数值模拟，对小尺度海气相互作用的机理进行研究，阐明这一现象的物理机制和随空间尺度变化的物理过程，以及深入理解海面风场和对流层大气对不同空间尺度海温结构的响应特征。

近年来，利用海洋卫星微波散射计、辐射计和数值模式相结合的研究发现中小尺度海温结构会对海面风速及对流层大气产生深远的影响，但是这些研究限制在50公里以上的空间尺度。在系统回顾中小尺度海气相互作用在50-1000 km尺度的研究成果基础之上，本项目的研究目标是将该领域研究拓展到10 km以下的空间尺度，具体包括：（1）通过构建高分辨海表温度分析产品和使用高分辨合成孔径雷达海面风场，针对大洋西边界流海域和中国近海海域定量分析10–50 km尺度的海气耦合强度，并分析比较不同空间尺度下中小尺度海气相互作用的变化特征；（2）开发高分辨海洋大气边界层参数化方案，使用WRF数值模式进行一系列高分辨数值模拟，对小尺度海气相互作用的机理进行研究，阐明这一现象的物理机制和随空间尺度变化的物理过程，以及深入理解海面风场和对流层大气对不同空间尺度海温结构的响应特征。