彭艳玉,刘煜,郜倩倩. 2022. El Ni?o次年夏季中国地区云的变化特征及其与降水的关系[J]. 气象学报, (0):-, doi:[doi]
El Ni?o次年夏季中国地区云的变化特征及其与降水的关系
The variation characteristics of clouds and their relationship with precipitation over China in El Ni?o decaying summer.
投稿时间:2021-11-18  修订日期:2022-04-25
DOI:
中文关键词:  El Ni?o,夏季,降水,云,相关关系,线性关系
英文关键词:El Ni?o, Summer, Precipitation, Cloud, Correlation, Linear relationship
基金项目:国家重点基础研究规划项目
作者单位邮编
彭艳玉 中国气象科学研究院 100081
刘煜 中国气象科学研究院 100081
郜倩倩 中国气象科学研究院 100081
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中文摘要:
      [资料和方法]基于1961~2010年中国地面台站和卫星观测等多种数据,[目的1]对不同类型El Ni?o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,[目的2]并探讨了云的变化特征与总降水异常之间的复杂联系。[结果]结果表明:站点数据中,El Ni?o事件次年夏季总云量和低云量的异常和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状的出现频率有所增加。云量和降水的异常在全国范围内表现出显著的正相关关系;在通过显著性检验的正相关站点,云量和降水异常之间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。卫星数据中,El Ni?o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关系;黄河以南地区总降水变化主要来源于对流降水的异常,其贡献比例高达80%。[结论]中国东部地区低云对降水具有很好的指示作用;El Ni?o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加有关。El Ni?o事件的发生使得次年夏季中国季风区对流活动增强,对流云云量增加,云层增厚,云顶向上发展,故而对流降水增加,异常雨带形成。
英文摘要:
      Based on various datasets, including ground stations and satellites observation in China from 1961 to 2010, this paper analyzes the variation characteristics of clouds and different types of precipitation over China in the decaying summer of two types of El Ni?o events (eastern Pacific El Ni?o and central Pacific El Ni?o), and also discusses the complex relationship between the variation characteristics of cloud and total precipitation anomalies. The results demonstrate that the anomalies of total cloud amount and low cloud amount in El Ni?o decaying summer are about the same as those of precipitation for the station datasets. Low cloud forms such as cumulonimbus, nimbostratus, and stratocumulus have become more common. A considerable positive association exists between cloud amount anomalies and precipitation anomalies over China. At the stations where the positive correlation passed the significance test, the linear relationships between cloud amount anomalies and precipitation anomalies are clear and also passed 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 amount of high cloud and deep convective cloud, optical thickness, and cloud water path are positively connected with precipitation anomalies of station records, according to relevant studies of satellite datasets. The convective precipitation anomalies, which accounts for up to 80% of total precipitation in the regions south of the Yellow River, is the major cause of fluctuation in total precipitation. Low clouds are good predictors of precipitation in eastern China. The fluctuation of convective precipitation is primarily responsible for the anomalies in total precipitation in southern China in El Ni?o decaying summer, and the abnormal rise of convective precipitation is directly associated with the anomalous increase of deep convective clouds. El Ni?o events would boost convective activity in China"s monsoon zone in the following summer if they occurred. Specifically, it results in the increase of deep convective cloud amount, the thickening of cloud layer, and the upward development of cloud top, which eventually leads to an increase of convective precipitation and the formation of abnormal rain bands.
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