Summer rainfall over NC correlated negatively with the SLP averaged for the area from 105°E to 120°E, and from 30°N to 35°N, but positively to that for the area from 120°E to 130°E, and from 20°N to 25°N Therefore, an index of EASM was de- fined by the difference of averaged SLP over the two regions.
The anomalous mode of SST in the tropical Asian-Australian monsoon area has significant positive correlation with the summer rainfall over the middle reach of the Yangtze River and the vicinity south to it.
(5) There is a apparent positive correlation between summer precipitation in northwest China and SSTA(7~9 monthly averaged in former year)in middle-east equator pacific Ocean, especially the higher correlation in the 'Key regions' (150° W~110°W, 15°S~5°N) .
The summer precipitation is noted increased above 95% confidential level in the centers of Yangtze Delta,Poyanghu plain and the upper Xiang-Han river area; which increasing rates are 25.8 mm/10a,69.4 mm/10a and 31.0 mm/10a.
The verifications of the summer precipitation and temperature forecasts for Yunnan province show that the operational forecast average scores of this model can reach 79.6% and 87.0% in 1995-1999, respectively.
The annual NDVI variation in the upper watershed mainly covered with shrub and grass was closely related to the precipitation in summer,and the correlated area was up to 13.74×10~4 km~2.In the regions nearby the upper and middle reaches mainly covered with grass and shrub,which accounted for 9.91×10~4 km~2,the NDVI was related to precipitation in July.
The relationship between summer rainfall over China and the shear of zonal wind at 850 hPa and 200 hPa was analyzed by the method of SVD. Result shows a good relation between summer rainfall in the reaches of the Yangtze River and the shear of zonal wind at 850 hPa and 200 hPa over the northeast of Australian.
Composite microwave index (CMI) method is used with the satellite SSM/I data to retrieve summer rainfall rate over 96°E-127°E, 17°N-44°N.
The effects of ENSO on summer rainfall are not so significant as on autumn and winter rainfall in China.
The operational seasonal forecasting of the summer rainfall in China
In this paper, the evolution of intraseasonal oscillation over the South China Sea and tropical western Pacific area and its effect to the summer rainfall in the southern China are studied based on the ECMWF data and TBB data) analyses.
The intraseasonal oscillation (convection) over the South China Sea and tropical western Pacific area is closely related to the summer rainfall (convection) in the southern China.
The summer precipitation of area to the north of the Yellow River often decreases in El Ni?o years.
An analysis is made on the anomaly of the general circulation wihch gives rise to summer precipitation and drought-flood occurrences in the country.
Climatic change has the features of increasing remarkably in winter temperature and decreasing obviously in summer precipitation.
Analyses reveal that the thermal anomaly of the underlying surface of the Tibetan Plateau in the previous winter and spring is one of the key influencing factors for the subsequent summer precipitation over MRYR.
Comparison of products from ERA-40, NCEP-2, and CRU with station data for summer precipitation over China
Synergy between the feedbacks increases precipitation in autumn, winter and spring, and reduces precipitation in summer.
Therefore, it is suggested that significant insolation duration and high temperature due to less precipitation in summer of the current year increase the radial growth of B.
Two main annual events affect particle settling in Lake La Cruz: (1) Following an event of massive calcium precipitation in summer that caused water whiting, a maximum flux of chlorophyll a and derivatives towards the sediment was registered.
Fuji: Observations of gases, aerosols and precipitation in summer,1993 and 1994
However, precipitation in summer has increased 5 to 100 percent since 1977.
The characters of experiments of prediction on monthly mean atmospheric circulation, seasonal predic-tion and seasonal forecast of summer rainfall over China are summarized in the present paper.
The variability of the summer rainfall over China is analyzed using the EOF procedure with a new parameter (namely, mode station variance percentage) based on 1951-2000 summer rainfall data from 160 stations in China.