摘要
利用中国地面台站逐日降水资料和中国气象局上海台风研究所整编的热带气旋最佳路径资料研究了1978～2007年影响我国热带气旋降水强度的变化及其对我国东南沿海盛夏降水变化的影响。近30年影响我国东南沿海盛夏的热带气旋降水增加是导致我国东南沿海盛夏降水显著增加的主要原因。仅从热带气旋降水来看,东南沿海和内陆(包括江西、湖南东部和湖北南部)热带气旋降水强度显著增加,而影响热带气旋降水频次略有增加。通过对雨量站与引起降水热带气旋的中心距离的变化分析发现:内陆地区影响热带气旋距离显著下降,近距离热带气旋引起降水的增加,是该区域热带气旋降水强度增加的主要来源;而东南沿海地区近距离热带气旋降水增加不明显,热带气旋降水强度的增加主要由于同距离热带气旋降水强度的增加。热带气旋经过频次的空间的变化结果证实,近30年经过中国沿海的TC个数变化不大,仅福建沿海一带略有增加,而内陆地区则增加明显,且经过该区域时热带气旋移动速度变慢,这均与该区域近距离热带气旋降水的增加一致。
Changes in the intensity of tropical-cyclone-induced precipitation and its contribution to variations in the total late summer （July-August） precipitation in coastal southeastern China were investigated using daily rain gauge data and tropical cyclone best-track data for 1978-2007. An increase in tropical-cyclone-induced precipitation was the main reason for the increase in late summer precipitation along the southeastern coast of China in the last 30 years. The intensity of tropical-cyclone-induced rainfall both along the southeastern coast and inland increased significantly, while the rainfallfrequency changed little. The mean distance between the rain gauge and the center of the tropical cyclone was reduced in inland. The frequency of rainfall caused by nearby tropical cyclones appeared to have increased significantly and to have been the main source of the increase in tropical-cyclone-induced precipitation intensity. At the same time, in coastal southeastern China （where the precipitation induced by nearby tropical cyclones did not change much）, there was a general increase in the intensity of tropical cyclone precipitation that was not affected by the distance between the tropical cyclone and the rain gauge. This led to an increase in the mean intensity of the tropical cyclone induced precipitation measured at each rain gauge. The changes in the spatial distribution of the mean frequency of tropical cyclones in late summer over the last 30 years showed that the number of tropical cyclones that passed over the coast of China changed little, but the number of tropical cyclones passing through Fujian increased. The frequency of tropical cyclones passing over inland areas increased because of the increase in the number of cyclones and a decrease in the translation velocities of tropical cyclones passing through, which is consistent with the significant increase seen in the tropical-cyclone-induced precipitation.
出处
《气候与环境研究》
CSCD
北大核心
2013年第4期507-516,共10页
Climatic and Environmental Research
基金
国家重点基础研究发展计划2009CB421500
2013CB430300
公益性行业(气象)科研专项GYHY201206011
GYHY201106004
国家自然科学基金项目41005007
90815028
关键词
东南沿海
热带气旋
降水强度
Southeastern coast of China, Tropical cyclone, Precipitation intensity
