2023年秋季海洋天气评述

2023年秋季（9—11月）北半球极涡为单极型分布，中高纬度地区呈5波型，欧亚大陆西风环流较为平直，西风带槽脊较弱。我国近海共出现16次8级以上大风过程，其中热带气旋大风过程3次，热带气旋与冷空气共同影响的大风过程3次，冷空气和温带气旋共同影响的大风过程3次，冷空气大风过程7次。西北太平洋和南海共生成4个热带气旋，热带气旋活动较常年偏少，全球其他海域生成热带气旋22个。近海出现2.0 m以上大浪过程17次，大浪日数占秋季总日数约71%。近海海面温度较常年平均偏高。

Autumn 2023 marine weather review

The main characteristics of the atmospheric circulation in the autumn (from September to November) of 2023 are as follows. The polar vortex is characterized by a single-pole type in the Northern Hemisphere and the circulations present a 5-wave mode in middle and high latitudes. In Eurasia, the circulation pattern of the westerly wind belt is flat without significant ridge and trough. In the offshore areas of China, there are 16 gale events above Beaufort scale 8, including three by tropical cyclones, three jointly by tropical cyclones and cold air, three by cold air and extratropical cyclones, and 7 by cold air. There are 4 tropical cyclones generated over western North Pacific and the South China Sea, while 22 tropical cyclones are named in other oceans. Tropical cyclone activities are less than the climate normal. There are 17 sea wave events with wave height greater than 2.0 m, with large wave days accounting for about 71% of the total number of days in this autumn. The sea surface temperature of offshore areas of China is higher than the climate normal.