彭艳玉,刘煜,郜倩倩. 2022. 厄尔尼诺次年夏季中国地区云的变化特征及其与降水的关系. 气象学报,80(5):701-720. DOI: 10.11676/qxxb2022.049
引用本文: 彭艳玉,刘煜,郜倩倩. 2022. 厄尔尼诺次年夏季中国地区云的变化特征及其与降水的关系. 气象学报,80(5):701-720. DOI: 10.11676/qxxb2022.049
Peng Yanyu, Liu Yu, Gao Qianqian. 2022. Variation characteristics of clouds and their relationship with precipitation over China in El Niño decaying summers. Acta Meteorologica Sinica, 80(5):701-720. DOI: 10.11676/qxxb2022.049
Citation: Peng Yanyu, Liu Yu, Gao Qianqian. 2022. Variation characteristics of clouds and their relationship with precipitation over China in El Niño decaying summers. Acta Meteorologica Sinica, 80(5):701-720. DOI: 10.11676/qxxb2022.049

厄尔尼诺次年夏季中国地区云的变化特征及其与降水的关系

Variation characteristics of clouds and their relationship with precipitation over China in El Niño decaying summers

  • 摘要: 基于1961—2010年中国地面台站和卫星观测等多种数据,对不同类型厄尔尼诺事件次年夏季中国地区云的变化特征和不同类型降水的变化特征进行了分析,探讨云的变化特征与总降水异常的复杂联系。结果表明:站点数据中,厄尔尼诺事件次年夏季总云量和低云量的异常与降水异常分布形势大致相同;积雨云、雨层云和层积云等低云的出现频率有所增加。云量与降水异常在全国范围内表现出显著的正相关;通过显著性检验的正相关站点,云量与降水异常的线性关系也通过了显著性检验,总云量和低云量与降水的增加比例分别接近1:3和1:1。卫星观测数据中,厄尔尼诺事件次年夏季高云量、深对流云量、光学厚度和云水路径的变化与站点降水异常基本呈正相关;黄河以南地区总降水的变化主要来源于对流降水的异常,其贡献比例高达80%。中国东部地区低云对降水具有很好的指示作用;厄尔尼诺事件次年夏季南方地区总降水的异常主要来自对流降水的变化;对流降水异常增加与深对流云的异常增多有关。厄尔尼诺事件的发生使得次年夏季中国季风区对流活动增强,对流云云量增多,云层增厚,云顶向上发展,故而对流降水增加,异常雨带形成。

     

    Abstract: Based on various datasets, including observations of ground stations and satellites in China from 1961 to 2010, the variation characteristics of clouds and different types of precipitation over China were analysed in the decaying summers of two types of El Niño events (eastern Pacific El Niño and central Pacific El Niño), and the complex relationship between the variation characteristics of clouds and total precipitation anomalies was discussed. The results demonstrate that the anomalies of total cloud amount and low cloud amount in El Niño decaying summers are about the same as those of precipitation based on station observations. Low cloud forms such as cumulonimbus, nimbostratus, and stratocumulus have become more common. A significant positive correlation exists between cloud amount anomalies and precipitation anomalies over China. At stations where the positive correlation passes the significance test, the linear relationship between cloud amount anomalies and precipitation anomalies is clear and also passes the significance test. In the meantime, the growing ratios of total cloud amount and low cloud amount to precipitation are close to 1:3 and 1:1, respectively. Variations in cloud amounts of high cloud and deep convective cloud, cloud optical thickness and cloud water path are positively correlated with precipitation anomalies based on station records. Convective precipitation anomalies, which account for up to 80% of total precipitation in the regions south of the Yellow River, are the major cause of fluctuation in total precipitation. Low clouds are a good predictor of precipitation in eastern China. The fluctuation of convective precipitation is primarily responsible for the anomalies of total precipitation in southern China in El Niño decaying summers, and the abnormal increases in convective precipitation are directly associated with anomalous increases in deep convective clouds. An El Niño event can boost convective activities in China's monsoon zone in the subsequent summer. Specifically, it leads to increases in deep convective cloud amount and thickness of cloud layer and promotes upward development of cloud top. These effects eventually increase convective precipitation and result in the formation of abnormal rain band.

     

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