Abstract:

To understand the climate change in Dianzhong region, Yunnan Province, the near-surface observations from 1963 to 2013 in four cities (i.e. Kunming, Chuxiong, Yuxi, and Qujing) were analyzed. Significant warming trend was found in the past 51 years in all the four cites. Comparing the warming trend in different seasons, it was found that the warming rate was fastest in winter. The warming phenomenon was most significant in Kunming, which might be relevant to the urbanization there in the past decades. The annual precipitation presented a slightly decreasing trend. The precipitation increased in the dry seasons (spring and winter), while decreased in the wet seasons (summer and autumn). In the four cities, the decrease of precipitation was most significant in Kunming, while it was slight in Chuxiong. In addition, the decrease of relative humidity was found, and the different between the seasons is not huge. The correlations between different meteorological variables can also be found through the wavelet analysis. It was found that the 36-year cycle of temperature was relevant to that of relative humidity, and the 16?32 years cycle of relative humidity was also related to that of precipitation in Dianzhong region.

Key words: Dianzhong region, morlet wavelet, statistical analysis, climate change

摘要：

利用1963—2013年4个国家基本/基准站(昆明、楚雄、玉溪和曲靖)的近地面温度、相对湿度和降水量的观测资料, 对云南滇中地区近 51 年来的气象要素的变化特征进行统计分析。结果显示: 近 51 年来, 滇中地区增温趋势明显, 冬季的增温幅度最大, 昆明市作为上述滇中城市中发展最快的城市, 年增温趋势是 4 个城市中最明显的; 滇中地区年降水量呈波动减少趋势, 冬、春季降水量增加而夏、秋季减少, 昆明市年降水量的降幅最大, 楚雄市只呈微弱的上升趋势; 4 个城市年均及各季节的相对湿度均呈显著下降趋势, 各季节的降幅差别不大。通过小波分析, 发现滇中地区不同气象要素的周期变化具有一定的相关性: 在 36年时间尺度上, 相对湿度的干(湿)中心与气温的暖(冷)中心对应; 在 16~32 年时间尺度上, 相对湿度的干(湿)中心与降水量的弱(强)中心对应。

关键词: 滇中地区, 小波分析, 统计分析, 气候变化