通过对1961~2010年北京-天津-河北及其周边区域均一化处理的194个站点的气温分析,得到了该区域近50年的年平均和季节平均温度日较差的时空变化特征。结果表明:区域内北部及西部的高原与山区的年平均日较差较大,中部和东部的平原、沿海、大城市与孤立的山区的年平均日较差较小,各个季节的季节平均日较差具有类似特征,在春季、秋季、冬季和夏季依次减弱。区域年平均日较差近50年下降趋势为0.21 °C (10 a)~(-1),在平原及南部区域下降趋势最明显,季节平均日较差在大部分地区呈明显下降趋势,下降趋势由大到小依次为冬季、春季、夏季和秋季。
英文摘要:
Based on a daily homogenized surface temperature dataset of 194 meteorological stations in Beijing-Tianjin- Hebei and its surrounding area, the seasonal and annual diurnal temperature range (DTR) characteristics are evaluated. The averaged DTR from 1961 to 2010 in the western and northern plateau and mountainous area of this region is larger, whereas it is smaller in the middle, southern and eastern plain, and urban and coastal areas. Above all, in the isolated mountainous area, the DTR is at a minimum. The seasonal DTR distribution is similar to the multi-year averaged DTR distribution. The seasonally averaged DTR values in the spring, autumn, winter, and summer are successively weaker. The DTR from 1961 to 2010 in this region generally shows a decreasing trend, at 0.21 °C (10 a)~(-1). Most of the stations show a downward trend, and the decreasing trend is obvious in the plain and southern area. The DTR decreasing trends, from large to small, are winter, spring, summer, and autumn, successively.