近40年我国东部夏季旱涝气候特征

采用服从 Person Ⅲ型分布的降水 Z 指标,分析了1951—1990年我国东部夏季旱涝的年际变化及演变趋势。使用经验正交函数分析、Schuster 周期图等方法揭示了旱涝分布、旱涝变化周期等气候特征。结果表明,我国东部大范围旱涝灾害平均2—3年一遇;华南、黄河、东北等区域呈干旱化趋势,长江、江淮向湿润化发展;旱涝变化存在3—6年准周期。     

近50年河西走廊地区降水均值突变特征分析

利用1960-2009年河西走廊地区16个测站的年和季降水资料,在对该区降水量进行气候分区的基础上,采用墨西哥帽小波函数,对该区域各代表站年和季降水的均值突变特征进行了小波分析,揭示了河西走廊地区降水变化的多时间尺度突变特征。结果表明,河西走廊地区降水量在1968,1973,1982,1991及2005年左右发生了均值...     

长江三角洲夏季降水异常及气候成因

根据长江三角洲地区61个气象站的1961--2007年夏季降水量资料,应用EOF和REOF等统计方法分析了长江三角洲地区夏季降水的时空分布及演变特征,并探讨了夏季降水异常类型的初步成因。结果表明：47a来长江三角洲地区夏季降水有比较明显的年代际变化,1980s开始有明显增加,该地区降水异常可以分为两种类型,分别为一致偏多（少）型和北多（少）南少（多）型,并且通过分析500hPa环流型势、副热带高压和ENSO事件的特征,初步探讨了降水异常的可能成因。     

沿120°E中纬度对流层—平流层下部气候变化及与臭氧变化的联系

利用1958~1995年海拉尔、沈阳、南京三地区地面至30 hPa标准层月平均气温资料,研究了近40年沿120°E、30°~50°N区域气候变率随高度、纬度和季节的分布特征,前、后两个20年气候变率的变动及其与亚欧不同地区臭氧变化的联系。结果指出：近20年来,该区域对流层中下部变暖速率随纬度显著增大,尤其在冬季;200 hPa以上变冷速率亦随高度及纬度显著增大,尤其在冬、春季。而前、后两个20年,高、低层气候变化趋势截然相反,这是一种年代际尺度气候变化。三地区各季节平流层下部变冷率（对流层中下部变暖率）随纬度增高而加大与邻近同纬带地区臭氧减少率随纬度增高而加大的现象基本对应,表明平流层下部因臭氧减少引起的辐射加热减少,可能是支配我国东部平流层下部变冷率（对流层中下部变暖率）随纬度增高而显著加大的一个重要因子。     

Characteristics and Diagnosis of the Landfalling Tropical Cyclones in the Guangdong-Hong Kong-Macao Greater Bay Area of China During 1981-2018

This paper applies statistical and synthetic analysis methods to study the characteristics of the three types of tropical cyclone (TC) that landed in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) from 1981 to 2018 and the reasons for the differences of TC-induced wind and precipitation. The results show that there are interdecadal changes in the frequency and intensity of the landfalling TCs in the GBA, with decreased frequency but increased intensity in the 2010s. The TCs that landed in the west of the Pearl River Estuary (PRE) have the most frequency and the strongest intensity during landing, which bring the strongest winds; the TCs that landed in the PRE have the least frequency and the shortest duration after landing, which cause the strongest precipitation; the TCs that landed in the east of the PRE have the relatively longest duration on the land. This study shows that near the center of the TCs that landed in the PRE, there is a weak anomalous cyclonic shear compared with the ones that landed in the west of the PRE. Compared with the TCs that landed in the east of the PRE, it is a confluence area of anomalous north wind and anomalous southwest wind, with better water vapor convergence and dynamic rising conditions, which is conducive to the formation of heavy precipitation. Compared with the TCs that landed in the PRE and in its east, there is a closed positive anomalous center of pressure gradient in the northwest center of the TCs that landed in its west, resulting in higher wind speeds in the west of the PRE. The characteristics of the three types of TCs in the GBA are highly related to TC-induced damage. In the future, the GBA needs to focus on preventing TCs landing in its west. Zhuhai, Jiangmen and Huizhou are key cities to guard against TCs. The results of this study provide foundations for effective management and reduction of TC disaster risks in the future construction of the GBA.