东海黑潮锋区低云的特征与影响机制研究

项目名称： 东海黑潮锋区低云的特征与影响机制研究

项目编号： No.41505003

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 天文学、地球科学

项目作者： 刘敬武

作者单位： 中国海洋大学

项目金额： 21万元

中文摘要： 海表面温度锋（简称海洋锋）通过调节海洋大气边界层（MABL），对区域气候具有重要影响。低云形态是边界层层结和动力状态的一种“可视化”表现，常被发现在海洋锋附近发生突变。同时考虑到东海黑潮处于东亚季风区，大气背景环流和MABL均具有较强的季节变化。本项目拟针对“东海黑潮锋使低云形态发生突变的物理机制，及其在不同季风背景下的差异”这一重要科学问题，开展气候学研究。以东海黑潮锋区的低云为主要研究对象，本研究将利用星载激光-微波雷达资料和长期对低云状的人工观测数据，刻画该海区低云形态（如云状、云顶/底高度和平滑程度等）和相态的空间分布特征及其季节变化规律；利用岛屿探空、走航观测和再分析资料，以MABL的层结和动力结构变化为切入点，研究东海黑潮锋影响低云形态的机理，进而揭示其在不同季风背景下的差异。本项目将为认识和理解海洋锋调节MABL的物理过程提供新视角，丰富小尺度海洋-大气相互作用的理论。

中文关键词： 低云；东海黑潮锋；海洋大气边界层；小尺度海洋-大气相互作用；星载激光雷达

英文摘要： Sea surface temperature (SST) fronts play a crucial role in regional climate by modulating marine atmospheric boundary layer (MABL). The morphology of low-level clouds, to some extent, is a visualization of MABL stratification and dynamical structure and often found to change sharply near SST fronts. Because the East China Sea Kuroshio (ECSK) is located in the East Asian monsoon domain, local background atmospheric circulation and MABL feature strong seasonal variations. This project will carry out a climate research focusing on the following important scientific question: How does the ECSK front cause steep low-cloud changes in morphology? and its difference under different monsoonal circulations. By considering the low-level clouds near the ECSK front as a major research subject, we will use the data from spaceborne lidar-radar and morphological low-cloud types from human observations to depict the main spatial characteristics in morphology (e.g. morphological types, cloud top/base heights and their horizontal homogeneity), and phase of low-level clouds and their seasonal variations. Using atmospheric soundings on islands, in situ observations, and reanalysis data to study the spatial and temporal changes in stratification and dynamical MABL structure, we try to understand the mechanism of how the ECSK front influencing low-level clouds, and reveal the differences under different monsoonal circulations. This project will provide a new perspective to interpreting how SST fronts influencing overlaying MABL, and enrich the theory of small-scale air-sea interaction.

英文关键词： low-level clouds;the East China Sea Kuroshio front;marine atmospheric boundary layer;small-scale air-sea interaction;spaceborne lidar