首页|南阳市1960-2013年高温日数变化特征及原因分析

南阳市1960-2013年高温日数变化特征及原因分析

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根据国家气象信息中心气象资料室1960-2013年南阳市地面气象月报表的观测资料,采用线性回归、简单相关系数法、M-K突变检验和Morlet小波分析等方法,研究了南阳市高温日数的变化特征,结果表明:1960-2013年南阳市共出现788次高温日;出现高温日数最多的是2013年,为37天;1987年无高温日.南阳市高温日数6月份最多,占高温天气发生总次数的36.7%;9月最少,占总次数的2.2%.从1960-2013年高温日的逐年分布情况可以看出,54 a间高温日数整体呈下降趋势,倾向率为-1.59天/10a.南阳市年高温日数在20世纪70年代的降低是一突变,具体是从1971年开始.由南阳高温日数小波系数实部图可见,高温日数存在多重时间周期尺度上的嵌套复杂结构现象,包含了多个不同尺度的周期变化,南阳年高温日数变化存在3个明显的周期振荡,分别是10 ~ 12 a、26 ~28 a和50~51 a的尺度.从小波方差图中可以看出,12a、28 a、50 a存在峰值,其中尺度50 a峰值最高,能量最大;其次是尺度12a的.高温日数较多年比高温日数较少年6-8月500 hPa平均环流场副高西伸脊点更偏西;高温日数较多年500 hPa平均环流场更为平直,以纬向环流为主,不利于冷空气南下,因此多睛热天气.高温日数较少年环流场上华北地区波动幅度更大,冷空气和降水天气过程较多.1960-2013年5-9月降水量呈增加趋势,这也相应地减少了高温天气.1960-2013年5-9月南阳市日照时数一直处于下降趋势,日照时数的下降也使高温日数减少.
Variation Characteristics and Cause Analysis of High-temperature Days from 1960 to 2013 in Nanyang
Based on the monthly surface meteorological observation data of Nanyang city,which provided by National Meteorological Information Center (NMIC),using linear regression,simple correlation coefficient,Mann-Kendall mutation test and Morlet wavelet analysis,the variation characteristics of high-temperature (HT) days from 1960 to 2013 in Nanyang city were analyzed.The results showed that there were 788 HT days appeared from 1960 to 2013,the most days was 2013 with 37 HT days,while there was no HT day in 1987.The HT days occurred most in June,and least in September,which account is 36.7% and 2.2%.The HT days showed a decline trend during 1960-2013 with the rate of-1.59 day/10a.There was a mutation when days reduced in 1970s,which was beginning in 1971.The real part figure of wavelet coefficient of Nanyang HT days showed there was multi-time scales characters of HT days number.The variation of Nanyang HT days had three significant periodic oscillation in 10-12 a,26-28 a and 50-51 a time scale.From the wavelet variance figure,there were peaks of 12 a,28 a,50 a;the 50 a peak was highest and with the maximum energy,the 12 a peak followed.The western end of the ridge of Western Pacific Subtropical High (WPSH) in more HT days years was at west side of that in less HT days years,which was in 500 hPa mean circulation field during June to August.In more HT days years,the mean circulation field was more straightly,with zonal circulation mainly,and made it hard for the cold air southward,so the sunny hot weather days were more.In less HT days years,the volatility of circulation field in North China was bigger,and cold air and precipitation weather days were more.From May to September during 1960-2013 in Nanyang,the precipitation increased,and the sunshine duration decreased,both of those led to HT days decreased.

high temperature characteristicslinear trendmutation testwavelet analysiscause of high temperatureNanyang city

陈建新、闫瑛、周鑫、陈燕、易伟霞、陈宇、温洛

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南阳市气象局,河南南阳473000

高温特征 线性趋势 突变检验 小波分析 高温原因 南阳市

中国气象局预报员专项淮河流域气象开放研究基金

CMAYBY2015-045HRM201302

2015

气象与环境科学
河南省气象局

气象与环境科学

CSTPCD
影响因子:1.28
ISSN:1673-7148
年,卷(期):2015.38(2)
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