Characteristics of Coastal Low-Level Jets in the Bohai Sea, China, During the Early Warm Season
Characteristics of Coastal Low-Level Jets in the Bohai Sea, China, During the Early Warm Season
复制标题
暖季初期渤海沿岸低空急流特征
DOI：
10.1029/2018jd029242
复制
发表时间：
2018
影响因子：
4.4
通讯作者：
Kong Hoiio
中科院分区：
文献类型：
--
作者：
Zhang Fan;Zhang Qinghong;Du Yu;Kong Hoiio
利用天气研究与预报模式输出的9 km水平分辨率资料，对2006-2011年暖季前期渤海沿岸低空急流（CLLJs）进行了研究。CLLJ主要发生在5月，此时大尺度低压位于研究区北部的陆地上空，太平洋高压位于研究区东南部。CLLJs的发生具有明显的日变化，有两个不同的高峰，一个在夜间，主要集中在中部地区，另一个在下午，主要集中在东西两侧有山的北方地区。动量收支分析表明，渤海夜间CLLJ的形成是由海陆热力对比触发的惯性振荡所致。敏感性试验表明，渤海北方西部山区太阳辐射不平衡引起的大气斜压性增强，是渤海北方午后CLLJ发生的主要原因。此外，东部地形起着主要的屏障作用，因此，通过地形阻挡到其西侧来捕获CLLJ。
We investigate coastal low-level jets (CLLJs) in the early warm season during 2006-2011 over the Bohai Sea using a 9-km horizontal resolution output data from the Weather Research and Forecasting model. CLLJs mainly occur in May when large-scale low is located over land to the north and the Pacific high is located to the southeast of the study area. The occurrence of the CLLJs exhibits an obvious diurnal cycle with two different peaks: one at night, located mainly in the central region, and the other in the afternoon, located in the northern region with mountains at both eastern and western sides. A momentum budget analysis shows that inertial oscillations, triggered by land-sea thermal contrast, results in the formation of nocturnal CLLJs in the Bohai Sea. In addition, sensitivity experiments show that the enhanced atmospheric baroclinicity, caused by unbalanced solar radiation over the western mountain of the northern region, dominates the occurrence of afternoon CLLJs in the northern area of the Bohai Sea. Besides that, the eastern topography plays a main role as barrier and, therefore, traps CLLJs by topography blocking to its western side.