石家庄地区夏季高温日数变化特征分析

利用石家庄地区17个地面气象观测站极端最高气温≥38℃的高温日数,分析了高温日数的时空分布特征,以求为精细化预报提供一些参考。运用线性倾向估计或多项式拟合曲线、墨西哥帽小波分析、Mann-Kendall突变检验等方法对石家庄地区5个代表站高温日数变化特征进行了分析。结果表明:石家庄地区高温日的出现次数表现为山区及丘陵地带高于平原地带;高温日线性增多趋势在市区及西南部山区偏强,西北部山区、东南部平原相对较弱,而东北部平原高温日呈弱的线性减少趋势;21世纪以来高温日数呈显著上升趋势,但增多的开始时间平原地带晚于山区及丘陵地带,并且,10a以下短周期内各站均处于高温日偏多期,而东南部平原在长周期内处于高温日偏少期。通过对典型高温日影响因素的分析发现:特殊地形下的焚风效应、中低空暖气团的维持以及城市化效应,均对高温强度有加剧作用。

Variation Analysis on High-temperature Days in Summer in Shijiazhuang

Based on high-temperature days data（maximum temperature ≥38℃） from 17 meteorological stations in Shijiazhuang,the variation of high-temperature days in 5 representative stations was analyzed,by using linear regression,polynomial fitting curve,Mexican hat wavelet analysis and Mann-Kendall mutation test.The results showed that high-temperature days in mountain and hill region were higher than that in plain region.Linear increasing trend of high-temperature days was stronger in urban and southwest mountain,weaker in northwest mountain and southeast plain,but high-temperature days in northeastern plain showed a weak linear decreasing trend.High-temperature days increased significantly since the 21^st century,but the beginning date of increasing in plain region was later than in mountain and hill region.Moreover,all stations with high-temperature days were high stage in less than 10-year cycle,but it was different in southeast plain region.The results indicated that foehn effect in special topography,the maintenance of warm air mass in low-altitude and the urbanization effect had strengthened high-temperature.