透视中国不同强度桑拿天日数的时空分异特征(1961-2017年)

Spatial-temporal Differentiation of Sauna Days with Different Intensities in China from 1961 to 2017

高温高湿超长待机的桑拿天气已成为当前城市居民生产生活面临的主要气象灾害风险之一。基于1961-2017年中国545个气象观测站点的日值最高气温和相对湿度数据,采用中国气象局中央气象台对桑拿天的定义,从气候态、变化趋势和波动特征三方面研究了中国不同强度桑拿天日数时空演变特征。结果表明:①1961-2017年中国气候态不同强度桑拿天日数呈东南高-西北低的空间分异格局,且不同年代同一强度的桑拿天日数空间分异格局相差较小,与整个研究时段对应强度的桑拿天日数空间分异格局具有良好的一致性。随着强度增加,中国桑拿天日数逐步减少。②1961-2017年中国不同强度桑拿天日数以胡焕庸线为界,呈东南增减镶嵌并以减少趋势为主,西北变化不大的空间分异格局。1991-2017年中国不同强度桑拿天日数变化趋势相比1961-1990年明显增加。③1961-2017年中国不同强度桑拿天日数以胡焕庸线为界,呈东南波动大-西北波动小的空间分异格局。且桑拿天和强桑拿天日数波动特征呈现出明显的三块式分布特征。1961-1990年和1991-2017年中国不同强度桑拿天日数波动特征与整个研究时段具有良好的一致性。1990年前后的波动差异特征主要集中在胡焕庸线附近及其东南地区,且波动差异以增大为主,表明1991-2017年中国东南不同强度桑拿天日数变异增加。

Sauna weather with high temperature,high humidity and long standby time has become one of the main meteorological hazards faced by urban residents.Based on the daily maximum temperature and relative humidity datasets of 545 meteorological observation stations in China from 1961 to 2017,the spatial-temporal evolution characteristics of sauna days with different intensities in China were studied from three aspects:climatic state,trend and fluctuation characteristics,using the standard of sauna days defined by the Central Meteorological Observatory of China Meteorological Administration.The results showed that:Firstly,the spatial pattern of sauna days with different intensities in China was high in southeast China and low in northwest China from 1961 to 2017,and the spatial pattern of sauna days with the same intensity in different research period had little difference,which was in good agreement with the spatial pattern of sauna days with corresponding intensities in the whole research period.With the increase of intensity,the sauna days in China decreases gradually.Secondly,the trend of sauna days with different intensities in China was bounded by Hu Huanyong Line from 1961 to 2017,showing a pattern of increasing or decreasing mosaic in the southeast China and mainly decreasing trend,while the spatial differentiation pattern in the northwest China changed little.The sauna days trend with different intensities in China increased significantly1991-2017 compared with 1961-1990.Thirdly,the fluctuation of sauna days with different intensities in China was bounded by Hu Huanyong Line,showing a spatial pattern of large fluctuation in the southeast China and small fluctuation in the northwest China.And the fluctuation of sauna days and heavy sauna days showed obvious threeblock distribution characteristics.The fluctuation characteristics of sauna days with different intensities in China from 1961 to 1990 and 1991 to 2017 were in good agreement with the whole research period.The fluctuation difference before and after 1990 mainly concentrated in the vicinity of Hu Huanyong Line and its southeast area,and the fluctuation differences increased mainly,indicating that the variation of sauna days with different intensities in the southeast China increased from 1991 to 2017.