Analysis on the Climatic Characteristics of Cold Wave Processes with Different Indices in Urumqi
Based on the data of daily minimum temperature (TD) and daily mean temperature (TT)of Urumqi from 1951 to 2015,TD and TT were taken as the defining indexes to survey the processes of cold wave according to the GB of "Grades of clod wave", and the climatic characteristics of cold wave was analyzed by mathematical statistics. The results showed that there were significant differences in the frequency of cooling by both methods,and no significant decrease in the annual and seasonal time scales,the decreasing tendency of the TT method was significantly stronger than that of the TD method. 90% of the cooling process was maintained with 1~3d,and the longest days in the fall of November. 95.5% and 94.6% of the cooling process by two methods couldn't reach to standard of clod wave,the grades frequency of cold wave with two methods manifestations included:cold wave>strong cold wave>super strong. The frequency of cold wave were decreased in the annual and seasonal time scales,the peak period was appeared in April and in October and the frequent period of cold wave was appeared in the 1950s, the relatively less occurred period over the last 15 years. The development intensity of cold wave with TT method was weaker than TD method; The correlation analysis indicated that there was a negative correlation between frequency of cold wave and TD、TT. The analysis showed that TD was important parameters of the variation of cold wave frequency.
国家科技期刊平台
NSTL
万方数据
维普
