| 2000—2020年西太平洋热带气旋路径对江淮梅雨期降水的影响研究 |
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| 引用本文： | 汪铃儿,陈科艺.2000—2020年西太平洋热带气旋路径对江淮梅雨期降水的影响研究[J].热带气象学报,2023(4):632-642. |
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| 作者姓名： | 汪铃儿 陈科艺 |
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| 作者单位： | 成都信息工程大学大气科学学院,四川 成都 610225 |
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| 摘 要： | 选用2000—2020年自动站降水资料、热带气旋最佳路径数据集（CMA-STI）以及欧洲中期天气预报中心ERA5再分析资料,发现不到半数的热带气旋活动伴随江淮地区暴雨发生,且仅有3成的热带气旋存在时,江淮地区日降水达到当年梅雨期日均降水。除个别“转向型”及登陆后继续东移、北上的“西北型”热带气旋外,七成左右的热带气旋大多伴随有梅雨减弱现象,并利用WRF模式及热带气旋Bogus方法对2017年热带气旋“苗柏”和2019年热带气旋“丹娜丝”进行数值模拟,分析热带气旋的存在对梅雨季节降水的影响机制。结果表明：在模式能较好地模拟出两个热带气旋的路径及降水落区、强度的基础上,对比移除热带气旋前后的试验,西北路径的热带气旋“苗柏”登陆前,南缘偏西气流加强低空急流,江淮地区切变线加强,登陆后低压北抬,副高稳定,形成有利于降水的环流形势;剔除“苗柏”后,低空急流断裂,副高南退,水汽输送带南移,长江中下游地区降水减少。转向型热带气旋“丹娜丝”北移,伴随副高北抬,对流性不稳定减小,垂直上升运动减弱,西太平洋的水汽被大量输送到热带气旋中心附近,故输送至江淮地区的水汽减弱,降水减少,促使梅雨提前结束;而剔除“丹娜丝”影响后,副高稳定,东部降水增加,梅雨季尚能持续。
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| 关 键 词： | 数值模拟 热带气旋路径影响 梅雨季节降水 |
EFFECTS OF TROPICAL CYCLONE TRACKS OVER THE WESTERN PACIFIC ON PRECIPITATION DURING MEIYU PERIOD IN JIANGHUAI FROM 2000 TO 2020 |
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| WANG Linger,CHEN Keyi.EFFECTS OF TROPICAL CYCLONE TRACKS OVER THE WESTERN PACIFIC ON PRECIPITATION DURING MEIYU PERIOD IN JIANGHUAI FROM 2000 TO 2020[J].Journal of Tropical Meteorology,2023(4):632-642. |
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| Authors: | WANG Linger CHEN Keyi |
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| Institution: | School of Atmospheric Sciences, Chengdu University of Information Technology,Chengdu, Sichuan 610225,China |
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| Abstract: | Abstract: Based on the precipitation data of automatic weather stations, CMA-STI and ERA5 data from 2000 to 2020, this paper found that, less than half of the tropical cyclone activities were accompanied by heavy rain that occurred in the Jianghuai region, and only 30% of the tropical cyclones were in the company of daily precipitation in the Jianghuai area reaching the average daily amount in the Meiyu period of that year. Except for a few "path-turning type" tropical cyclones and "northwest-traveling type" tropical cyclones that continued to move eastward or northward after landfall, most of the other tropical cyclones were accompanied by the weakening of Meiyu. The WRF model and the built-in TC bogus method were used to simulate the 2017 typhoon Merbok and the 2019 typhoon Danas to verify the influence mechanism of TC on Meiyu. The results show that the model well simulated the path, precipitation area and intensity of the two typhoons. By comparing the tests before and after the removal of the typhoons, it was found that the "northwest-traveling type" typhoon Merbok strengthened a low-level jet with the westward airflow at the southern edge at the early stage, a Yangtze-Huaihe valley shear strengthened, a low pressure headed northward after landing, and a subtropical high was stable, forming a circulation situation favorable for precipitation. After removing Merbok, the low-level jet broke, the subtropical high retreated southward, the water vapor in the South China Sea could not be transported to the Yangtze-Huaihe valley, and the precipitation in the middle and lower reaches of the Yangtze River decreased. With the northward movement of both the path-turning type typhoon Danas and the the subtropical high, convective instability decreased and vertical ascending motion weakened. A large amount of water vapor from the western Pacific was transported to the vicinity of the typhoon eye. The water vapor transport and precipitation in the Yangtze-Huaihe valley decreased and the Meiyu was interrupted. After removing Danas, the precipitation in the east increased, the subtropical high was stable, and the Meiyu was maintained. |
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| Keywords: | Numerical simulation The impact of tropical cyclone Meiyu Precipitation |
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