夏季风下的太湖风场-流场野外观测研究

为研究太湖风场特征、湖流特征以及不同类型风场对太湖湖流的影响，在太湖不同区域布设6台多普勒剖面流速仪和4座气象站，获取同步流场和风场数据，分析夏季风与湖流流场的关系。结果表明:(a)风场方面，空间分布具有不均匀性，各观测点间风速差异较大，各观测点间风向随风速减小而差异扩大化。(b)太湖流场具有明显的风生流特征:空间上，大风(时段平均风速在6.7 m/s以上)情况下，西部湖区出现逆时针环流，湖流分层不明显；小风(时段平均风速在3.8 m/s以下)情况下，没有明显的环流出现，上、下层湖流分层明显，各层流向相对稳定但不相同，补偿流发育。(c)流速方面，10 cm/s以下流速比率90%以上，局部区域水流速度在强风条件下可达20 cm/s。

Study on Taihu Lake' s wind field and flow field under summer monsoon

In order to obtain the characteristics of wind field and flow field as well as the influence of different types of wind fields on the flow field of Taihu Lake, 6 acoustic doppler current profilers(ADCP)and 4 meteorological stations were set up in different areas of Taihu Lake, and the synchronous data of flow field and wind field were obtained. The results show the floolwing: (a)The spatial distribution of wind field in Taihu Lake was not uniform, the wind speed varied greatly among 4 stations, and the difference of wind direction was expanded along with the decrease of wind speed. (b)The flow field in Taihu Lake had obvious characteristics of wind-generated flow. When the average wind speed was greater than 6. 7 m/s, there was a counterclockwise circulation that appeared in the western lake area, and there was no obvious flow stratification during this period. When the average wind speed was less than 3. 8 m/s, the circulation in the west fade away. However, the flow stratification was obviously developed, the current direction of each layer was relatively stable but different, and the compensation flow developed. (c)According to the observed data, the percentage of current speed less than 10 cm/s was more than 90%, and the current speed can reach 20 cm/s under strong wind conditions.