榆林市1951-2012年气温变化特征

Analysis on air temperature variation trend in Yulin from 1951 to 2012

榆林位于我国北方农牧交错带中部,生态环境脆弱,是全球变化响应的敏感地区。基于榆林市气象站1951—2012年历年逐日气温数据,运用线性回归分析、滑动平均、小波分析和M-K非参数检验的方法分析了该地区气温变化的特征和突变现象。结果表明:榆林市1951—2012年平均气温有增温趋势,线性倾向率为0.27℃?(10a)^(-1)。四季均在增温,其线性倾向率分别为0.26℃?(10a)^(-1)、0.07℃?(10a)^(-1)、0.21℃?(10a)^(-1)、0.56℃?(10a)^(-1),冬季增温最为明显,增加了2.8℃。年平均气温存在准3—7 a和25—28 a的周期变化,并在1994年前后发生突变。春季、秋季、冬季平均气温与年平均气温一致,增温趋势明显,而夏季相对较晚。

Background, aim, and scope Yulin is located in the middle of the patterns in northern China, with a fragile ecological environment, is a sensitive area of global change responses. Materials and methods Based on meteorological stations in Yulin, 1951-2012 calendar year daily air temperature data, using linear regression analysis, moving average, wavelet analysis, and Mann-Kendall to analyze the characteristics of temperature changes in the region and mutation phenomena. Results The results show that the average temperature was increasing during 1951-2012, and the linear tendency rate was 0.27 ℃.（10a）^-1. The annual average temperature has revealed the 3 to 7 and 25 to 28 quasi-periodic variation in the past 60 years, and the abrupt change has occurred in 1994. In temperature, the four seasons in linear trend rate were 0.26℃·（10a）^-1,0.07℃·（10a）^-1, 0.21 ℃·（10a）^-1, 0.56℃·（10a）^-1. Spring, autumn, winter mean temperature and annual average temperature, warming trend is obvious, but relatively late in summer. Discussion Due to the geographical position of Yulin, prone to drought, fragile ecological environment, in addition to the temperature affected by the atmospheric circulation, El Nino and La Nifia and other natural factors, but also the existence of man- made factors. Conclusions In general, from the beginning of twenty-first century, a downward trend in the basis of temperature in the city of Yulin will maintain the high temperature, The annual average temperature has revealed the 3 to 7 and 25 to 28 quasi-periodic variation, and the abrupt change has occurred in 1994. The four seasons are in increasing temperature, the most obvious increase in winter temperature, increase of 2.8 ℃. Recommendations and perspectives Analysis on the characteristics of temperature variation in Yulin, not only provides a theoretical basis for the development of agriculture and animal husbandry industry in the region, provide a theoretical basis for understanding the Maowusu Desert and its surrounding areas of environmental change, desertification and climate change science. In order to have a deep understanding of the forecast of the future temperature change and the response of the ecological environment in the region.