| 摘要: |
| 基于2021年6月–2023年5月的风廓线雷达监测数据，综合分析了鄱阳湖湖区的风速风向特征、湖陆风活动规律及典型湖陆风事件的发展过程，主要结论如下：（1）湖区白天近地面风速普遍高于夜间，夏季主风向为东北风，其余季节为西南风。垂直风廓线符合幂次律，风廓线指数依次为：夏季（0.41）>春季（0.29）>冬季（0.26）>秋季（0.23）；（2）两年内共发生104次湖陆风事件，占比为14.3%，夏季最多（38次），秋季（24次）、春季（22次）次之，冬季最少（20次），春夏季湖风起始时间早于秋冬季，持续时间更长，陆风相反。无湖陆风日垂直风廓线指数为0.31，全天主风向均为西南风，湖陆风发生日的近地面风速更低，风速廓线指数为0.57，垂直风速变幅更大，且6–18时主风向为东北风；（3）典型湖陆风事件中，湖风高度在14时达到峰值440 m，持续时间为9小时；陆风高度在0时左右达到峰值760 m，持续时间为14小时，峰值高度与当日最高和最低温度同时出现。鄱阳湖湖陆风的季节性活动差异与湖泊面积和湖陆温差的季节性变化有关。本文可为研究季节性湖泊对大气边界层结构和局地环流的潜在影响提供科学参考。 |
| 关键词: 湖陆风 风廓线雷达 季节性湖泊 鄱阳湖 |
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| 基金项目:国家重点研发计划项目（2022YFC3204104）、国家自然科学基金联合重点项目（U2240219）、国家自然科学基金面上项目（42271121） |
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| Characteristics of lake-land breeze events in Poyang Lake based on wind profiling radar data |
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ZhaoLejun, ZhaoXiaosong1, FanXingwang1, WangLimei1, LouTing2, KongYunning3, XuLigang1
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1.Nanjing Institute of Geography and Limnology， Chinese Academy of Sciences;2.School of Ecology and Applied Meteorology，Nanjing University of Information Science＆Technology;3.Faculty of Geographical Science，Beijing Normal University
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| Abstract: |
| We analyzed the characteristics of wind speed and direction, and the general patterns of lake-land breezes as well as the process of typical events, based on wind profiling radar data near the Poyang Lake from June 2021 to May 2023. Main conclusions are as follows: (1) The surface-layer wind speed was generally higher in daytime than in nighttime. The prevailing wind direction was northeast in summer, and was southwest in other seasons. The vertical wind profile conformed to the power law, with the wind profile index in a decreasing order as summer (0.41) > spring (0.29) > winter (0.26) > autumn (0.23). (2) A total of 104 lake-land breezes (14.3%) occurred in the study period, most (38 times) in summer, second in autumn (24 times), third in spring (22 times), and least (20 times) in winter. The lake breezes were longer-lasting and started earlier in spring and summer than in autumn and winter, while the opposite is true for the land breezes. When no land-lake breezes occurred, the southwest winds persisted throughout the day and night, and the wind profile index was 0.31. The surface-layer wind speed was generally lower when lake-land breezes occurred. The wind profile index was 0.57 with the northeast winds prevailing between 6:00–18:00. (3) Lake breezes in general peaked at 14:00 with a maximum height of 440 m, whereas land breezes in general peaked at midnight with a maximum height of 760 m. The seasonally varying patterns in lake-land breezes were related to changing water surfaces and contrasting land-water temperatures of the Poyang Lake. This paper provides preliminary conclusions for understanding the potential role of seasonally flooding lakes in local atmospheric circulation and boundary layer structure. |
| Key words: lake-land breeze wind profiling radar seasonal lake Poyang Lake |
