午夜欧美大片免费观看,欧美激情综合五月色丁香,亚洲日本在线视频观看,午夜精品福利在线

Based on the meteorological data of 20 stations in Beijing form 1981 to 2010, the daily comfort indexes in 20 stations and the annual averages of warmest and coldest comfort indexes in urban and rural areas are calculated, as well as hot days, extreme hot days, cold days and severe cold days. The time and spatial variation characteristics of comfort indexes in urban and rural sites are analyzed, and the differences between urban and rural comfort indexes are compared. The results show that in the 1980s, there was no obvious difference between urban and rural sites in the warmest comfort index under the hot standard; however, since the 1990s, the summer comfort was warming obviously, and hot days and extreme hot days increased significantly, especially in the plain area. The spatial distribution of hot days and extreme hot days constantly extended, which extended to the most part of the urban area except for the eastern Chaoyang district after 2000. 〖JP2〗The warming magnitude was larger in urban areas than in rural areas, and it was warmer in plain areas than in mountain areas. The winters were warmer in Urban areas than in rural areas, and cold days and severe cold days were also less in the urban areas than in rural areas. The gap became obvious gradually from the mid and late 1980s, and the biggest gap can be up to 10 to 20 days in a year. The severe cold area reduced since the 1990s, and the cold days reduced 10 days compared with the 1980s.〖JP〗