Based on day-to-day minimal ground temperatures in 1961-2010 from 62 meteorological stations in Shanxi province,the variation characteristics of Shanxi＇s first frost were analyzed.The results show：Shanxi＇s average ...Based on day-to-day minimal ground temperatures in 1961-2010 from 62 meteorological stations in Shanxi province,the variation characteristics of Shanxi＇s first frost were analyzed.The results show：Shanxi＇s average first frost date was October 7,and the first frost date of the north was generally earlier than the south; the average first frost date had obvious negative correlations with altitude and latitude,and the correlation coefficients were respectively-0.85 and-0.82.M-K mutation test shows that the first frost date of most meteorological stations had mutations from 1961 to 2010,mainly in the years from 1981 to 2000,and the mutation year of the central area was generally later than the north and the south; the mutation year had negative correlations with altitude and latitude,and the correlation coefficients were respectively-0.45 and-0.51.The first frost dates of most stations had a delaying trend.Specifically,the large delaying scope region was located in the north and the mid-east,and the large advancing scope region was located in the south and the south central.The changing trend had negative correlations with altitude and latitude,and the correlation coefficients were respectively-0.30 and-0.37.Probabilities of the mild,the moderate and the severe first frost were 62％-82％,6％-26％ and 4％-22％,respectively,and the maximum probabilities appeared in the south central ＆ northeast,the central ＆ north central and the west ＆ north central.Correlation of altitude with first frost tends to be volatile upon frost grade and latitude has bigger impacts on first frost probabilities.展开更多
基金Supported by China National 973 Project(2012CB955903)Meteorological Key Technology Integration and Application Projects of China Meteorological Administration(CMAGJ2011M10)Natural Science Fund of Shanxi Province(2013011038)~~
文摘Based on day-to-day minimal ground temperatures in 1961-2010 from 62 meteorological stations in Shanxi province,the variation characteristics of Shanxi＇s first frost were analyzed.The results show：Shanxi＇s average first frost date was October 7,and the first frost date of the north was generally earlier than the south; the average first frost date had obvious negative correlations with altitude and latitude,and the correlation coefficients were respectively-0.85 and-0.82.M-K mutation test shows that the first frost date of most meteorological stations had mutations from 1961 to 2010,mainly in the years from 1981 to 2000,and the mutation year of the central area was generally later than the north and the south; the mutation year had negative correlations with altitude and latitude,and the correlation coefficients were respectively-0.45 and-0.51.The first frost dates of most stations had a delaying trend.Specifically,the large delaying scope region was located in the north and the mid-east,and the large advancing scope region was located in the south and the south central.The changing trend had negative correlations with altitude and latitude,and the correlation coefficients were respectively-0.30 and-0.37.Probabilities of the mild,the moderate and the severe first frost were 62％-82％,6％-26％ and 4％-22％,respectively,and the maximum probabilities appeared in the south central ＆ northeast,the central ＆ north central and the west ＆ north central.Correlation of altitude with first frost tends to be volatile upon frost grade and latitude has bigger impacts on first frost probabilities.
