Temporal Variation Characteristics of Climate Change in Henan Province in Recent 50 years

Temporal variation of temperature,precipitation,relative humidity,and sunshine hours were analyzed by using conventional statistical methods and Morlet wavelet transform,based on the daily meteorological data of 13 meteorological stations in Henan Province from 1961 to 2010.The results showed that the average temperature,the average maximum temperature,and the annual average minimum temperature showed the tendency of increase.The increasing trend of the average temperature and the average minimum temperature in the central and east were lower,while that of the maximum temperature in the west was highest but that of the central was lowest.The annual average precipitation showed increasing trend,but there was a decreasing trend in the north,and the mountainous area of west and north.The average sunshine hours decreased strongly.The annual average relative humidity showed decreased trend,while it had a increased trend in the most north and west,the central,and east areas.The main oscillation period of the average temperature and the annual average precipitation was 3-5a and 5-6a,respectively.