We investigated the decadal changes in the different types of summer mean precipitation over China across the mid-1990 s based on observational datasets.The spatial variations in the observed decadal changes were esti...We investigated the decadal changes in the different types of summer mean precipitation over China across the mid-1990 s based on observational datasets.The spatial variations in the observed decadal changes were estimated by comparing the present day(PD)time period of 1994–2011 with an earlier period of 1964–1981.The summer total precipitation increased in southern China and decreased in northern China from the early period to the PD.The increases of precipitation in southern China were due to increases in the frequency of heavy and moderate rainfall,whereas the decreases over northern China were mainly due to decreases in the frequency of moderate and light rainfall.Based on a set of numerical experiments using an atmospheric general circulation model coupled with a multilevel mixed-layer ocean model,we found that the increase of precipitation frequency forced by greenhouse gases is the main reason of increasing precipitation over southern and northeastern China,while the decrease of frequency caused by anthropogenic aerosol(AA)induces the decreasing precipitation over northern China.The water vapor flux convergence and water vapor flux strengthen in southern China and northeastern China by anthropogenic greenhouse gases.This distribution is also conducive to precipitation in most of southern China and northeastern China.Under the control of weakened southwesterly winds and 850-h Pa divergence,precipitation decreases over northern and southwestern China by AA.展开更多
A zonal domain,primitive equation model is used in this paper to study the influences of the main sea surface tem- perature anomaly(SSTA)areas over the Pacific on precipitation in 1991.Some numerical experiments are m...A zonal domain,primitive equation model is used in this paper to study the influences of the main sea surface tem- perature anomaly(SSTA)areas over the Pacific on precipitation in 1991.Some numerical experiments are made and the mechanisms of the influences are discussed.The results show that the influences of the SSTA are mainly confined within the tropical and the subtropical regions.The direct effect of the SSTA is to change the exchanges of the sensible heat and the water vapour between the air and the sea,through the consequent changes of temperature and the flow fields and the feedback process of condensation,the SSTA finally affects precipitation.展开更多
基金Supported by the National Natural Science Foundation of China(41905091)Support Plan of the National Science and Technology(2015BAC03B04)+1 种基金Fund Project of the National Meteorological Center Forecaster(Y201904)Buwen DONG is supported by the UK National Centre for Atmospheric Science-Climate(NCAS-Climate)at the University of Reading。
文摘We investigated the decadal changes in the different types of summer mean precipitation over China across the mid-1990 s based on observational datasets.The spatial variations in the observed decadal changes were estimated by comparing the present day(PD)time period of 1994–2011 with an earlier period of 1964–1981.The summer total precipitation increased in southern China and decreased in northern China from the early period to the PD.The increases of precipitation in southern China were due to increases in the frequency of heavy and moderate rainfall,whereas the decreases over northern China were mainly due to decreases in the frequency of moderate and light rainfall.Based on a set of numerical experiments using an atmospheric general circulation model coupled with a multilevel mixed-layer ocean model,we found that the increase of precipitation frequency forced by greenhouse gases is the main reason of increasing precipitation over southern and northeastern China,while the decrease of frequency caused by anthropogenic aerosol(AA)induces the decreasing precipitation over northern China.The water vapor flux convergence and water vapor flux strengthen in southern China and northeastern China by anthropogenic greenhouse gases.This distribution is also conducive to precipitation in most of southern China and northeastern China.Under the control of weakened southwesterly winds and 850-h Pa divergence,precipitation decreases over northern and southwestern China by AA.
基金The paper is supported by the National Natural Science Foundation of China.
文摘A zonal domain,primitive equation model is used in this paper to study the influences of the main sea surface tem- perature anomaly(SSTA)areas over the Pacific on precipitation in 1991.Some numerical experiments are made and the mechanisms of the influences are discussed.The results show that the influences of the SSTA are mainly confined within the tropical and the subtropical regions.The direct effect of the SSTA is to change the exchanges of the sensible heat and the water vapour between the air and the sea,through the consequent changes of temperature and the flow fields and the feedback process of condensation,the SSTA finally affects precipitation.
