大气科学Issue(6)：1081-1094,14.DOI:10.3878/j.issn.1006-9895.1503.14257
大气对春季东海黑潮锋响应的气压调整机制分析
Analysis of the Pressure Adjustment Mechanism in the Atmospheric Response to the Spring Kuroshio Front over the East China Sea
摘要
Abstract
By using Quick Scatterometer (QuickSCAT), Advanced Very High Resolution Radiometer (AVHRR) and Tropical Rainfall Measuring Mission (TRMM) high-resolution satellite data and Climate Forecast System Reanalysis (CFSR) reanalysis data, the pressure adjustment mechanism in the atmospheric response to the spring Kuroshio front (KF) in the East China Sea is investigated along with its interannual variability. Results show that the spring KF lies to the northwest of the Kuroshio warm tongue with a southwest–northeast orientation, which is parallel to the isobars of large-scale background sea level pressure (SLP). The local SLP gradient between the warm water in the southeast of the KF (SE-KF) and the cold water in the northwest of the KF (NW-KF) will superimpose on the large-scale SLP background gradient, causing the resultant northwest-to-southeast SLP gradient to reach its maximum near the KF, and the 10 m vector wind speed thus being strongest there. Due to the friction factor, such a vector wind will be a north-northeast (NNE) wind. The difference in the component of the NNE wind along (across) the KF will produce cyclonic shear vorticity (convergence in wind speed) over the SE-KF, thereby forming ascending motion and enhanced precipitation. In contrast, over the NW-KF, there is anticyclonic shear vorticity (divergence in wind speed) along (across) the KF and descending motion and weak rainfall. A secondary circulation across the KF is thereby induced. On the interannual timescale, a stronger (weaker) spring KF corresponds to a stronger (weaker) local SLP gradient between the NW-and SE-KF. The stronger (weaker) local SLP gradient, superimposed on the large-scale SLP background gradient, will produce stronger (weaker) NNE wind, thus making cyclonic shear vorticity, convergence in wind speed, ascending motion and precipitation all stronger (weaker) over the SE-KF, and making anticyclonic shear vorticity, divergence in wind speed, and descending motion all stronger (weaker) over the NW-KF, ultimately leading to stronger (weaker) secondary circulation across the KF. This indicates that the pressure adjustment mechanism still exists on the interannual timescale.关键词
东海黑潮锋/春季/气压调整机制/海表面风/年际变化Key words
Kuroshio front/East China Sea/Spring/Pressure adjustment mechanism/Sea surface wind/Interannual variability分类
天文与地球科学引用本文复制引用
李智,刘宣飞,李传浩..大气对春季东海黑潮锋响应的气压调整机制分析[J].大气科学,2015,(6):1081-1094,14.基金项目
江苏高校优势学科建设工程资助项目PAPD （）
