2019年冬季海洋天气评述

Winter 2019 marine weather review

2019年冬季(2019年12月—2020年2月)大气环流特征为:北半球的极涡呈偶极型分布,中高纬呈3波型分布,西风带槽脊较常年明显偏弱。位势高度距平场显示,东亚中纬度地区处于正距平区,东亚大槽强度弱,冷空气强度较常年同期偏弱,大风过程显著偏少,我国近海共出现7次明显的8级以上大风过程,冷空气和温带气旋共同影响的大风过程有2次,冷空气与热带气旋共同影响的大风过程有2次。浪高在2 m以上的海浪过程有10次。近海出现大范围的海雾过程12次,海雾区域主要出现在渤海、渤海海峡、黄海北部和中部海域、琼州海峡及北部湾,出雾时段多集中于夜间至早晨。海面温度随时间逐渐降低,其从北到南的温度差在冬季由22℃加大到27℃。西北太平洋和南海共有1个台风生成。

In winter 2019(from December 2019 to February 2020),the features of atmospheric circulation are as follows.The polar vortex in the Northern Hemisphere is distributed in a dipole type,the atmospheric circulation shows a three-wave pattern in the middle and high latitudes,and the trough and ridge in the westerlies are significantly weaker than those in normal years.The geopotential height anomaly field shows that the mid-latitude region of East Asia is in a positive anomaly zone,the cold air is weaker,and the gale process is significantly reduced due to the weak East Asia major trough.Seven gale processes stronger than 8 grade are observed in China's offshore waters,two of which are jointly influenced by cold air and extratropical cyclones,and another two gale processes are jointly influenced by cold air and tropical cyclones.There are 10 wave processes above two m.There are 12 large-scale sea fog processes in the coastal waters and sea fog mainly appears in Bohai Sea,Bohai Strait,the northern and central Yellow Sea,Qiongzhou Strait,and Beibu Gulf mostly from night to morning.The sea surface temperature gradually decreases with time and the temperature difference from north to south increases from 22℃to 27℃in winter.One tropical cyclone is active over western North Pacific and the South China Sea.