Arctic Sea Ice Anomalies And Interannual Summer Precipitation In North China Relations And Its Interdecadal Changes

The features of the interannual relationship between winter sea-ice extent of Davis strait and rainfall of North China and the interdecadal variability of its interannual relationship are analyzed by Using UK/GISST sea-ice data-set of Hadley , monthly 500Hpa height field of NCEP/NCAR reanalysis data and monthly rainfall data from 160 stations in China. The results are as follows:The extent of arctic sea-ice has apparent characteristics of interannual, interdecadal variability and decreasing trend during the last 50 years in winter.Winter sea-ice extent of Davis Strait which is strong information for July rainfall of North China is negatively correlated with July rainfall of North China. When winter sea-ice extent of Davis Strait increases(decreases), July rainfall of North China decreases(increases).The apparent characteristics of interdecadal variability of interannual relationship between winter sea-ice extent of Davis Strait and Summer, July and August rainfall of North China are: The strongly negative correlation between winter sea-ice extent of Davis Strait and Summer rainfall of North China turns into bad correlation. The strongly negative correlation between winter sea-ice extent of Davis Strait and July rainfall of North China turns into weaker correlation. The strongly negative correlation between winter sea-ice extent of Davis Strait and August rainfall of North China turns into bad correlation. All the turn-point year is around 1974. Another feature of interdecadal variability of interannual relationship between winter sea-ice extent of Davis Strait and Summer, July and August rainfall of 160 stations is that The interannual correlation pattern have changed from East-West pattern to "+-+" North -South pattern around 1974.The interdecadal characteristics of correlation distribution pattern of interannual relationship between winter sea-ice extent of Davis Strait and Summer, July 500hpa height of Northern hemisphere are: "-+-" pattern from the beginning of Novoya Zemlya island, by way of Balkhash lake to Japan sea which is strongly negatively correlated with the rainfall of North China at the same period before 1974and "+-" pattern from the beginning of Ural mountains ,by way of Bujr lake to Hetao basin which is badly correlated with the rainfall of North China at the same period after 1974. The interdecadal characteristics of correlation pattern of interannual relationship between winter sea-ice extent of Davis Strait and August 500hpa height of Northern hemisphere is "+-+"pattern from Ural Mountains to north of sea of Okhotsk which is strongly negatively correlated with the August rainfall of North China before 1974,and it has not apparent correlation pattern in Europe-Asia continent after 1974.