Research On Changes Of Sea-Ice In Eurasian And Its Relationship With Air Temperature And Precipitation In China

Using some statistical methods, Arctic sea-ice in Eurasian continent for 1953.1-2002.12 and its relationship with climate of China was examined . The results show that almost all of the sea-ice in eight regions are decreasing , especially sharply in Europe , but there are even increasing trend of that in Asia . Seasonal character is that there is the more cute decreasing in the ice-melting time , i.e. in summer and fell. In winter and spring , some places show sea-ice increasing . The fact that sea-ice around Europe display the coincidental character, that is decreasing . On the contrary there are some differences among sea-ice in Asia , the changes in summer and fell seem from wave-like to substantial decreasing , the changes in winter and spring is a procession of increasing -decreasing -increasing. Times of abrupt change of sea-ice in different regions are also different, the time in Asia is in end of 1980's , which is later than that in Europe(the beginning of 1980's) . And times of Abrupt changes in spring /summer are little earlier than that in winter /fall. Wavelet analysis find the feature of frequency is regional and seasonal . Frequency of Europe is 10 years before the 1980's and shorter than 10 years after 1990's . In Asian , sea-ice has the frequency about 20 years and become shorter entering 1990's. To comparative them , that frequencies in Europe is much shorter than that in Asia is found . There are almost contrary pattern of general atmospheric circulation in the same condition of sea-ice in Europe and Asia . When there comes the deeper low in polar and stronger high in mid-latitude, the west wind turn stronger , leading the stronger North Atlantic WarmStream , then changing the energy in polar , the sea-ice in this area is decreasing , vice versa . When the low in polar is much deeper , the extent it controlled becoming smaller , sea-ice in Asia is less than normal. The structure of the abnormal pattern is equivalent-barotropical in troposphere . The relation between sea-ice around Eurasian and air temperature/rainfall is mainly in air temperature . It seems that sea-ice around Europe part has more operations and air temperature in winter has the most significant relation with sea-ice in Europe. Significant periods of relationship between sea-ice and air temperature are : air temperature in spring and summer are lagging sea-ice in Europe for 9 to 12 month , that in winter are lagging sea-ice in Europe for 18 month and air temperature in fell is lagging sea-ice in Asia for 9 month. When precipitation in spring (winter) is lagging sea-ice in Europe for 6 (24) month and in summer (fell) is lagging sea-ice in Asia for 24 (9) month , the substantial periods of relation between them are showing . The primary abnormal areas are : mid-reaches of Huang River , high-and mid-reaches of Yangtze River , North of China , Huai River and parts of Xinjiang.