2017年中国气候主要特征及主要天气气候事件

摘要

Climate in China was at a normal level in 2017 and relatively fewer climate disasters occurred. Annual mean temperature 10.39℃ over China was 0.84℃ higher than normal years.In terms of high tem-perature,July and September had the highest temperature compared to that in the same periods since 1951,and the day highs at 113 stations broke the historical records.The annual mean precipitation over China was 641.3 mm,which increased 1.8% than normal years.Compared with the normal,precipitation was less in winter and more in summer,and approached normal in spring and autumn.The daily rainfall at 31 stations exceeded historical extremes,of which many stations were found in the areas where torrential rain seldom occurs.Besides,the continuous precipitation at 47 stations exceeded historical extremes.Pre-cipitation in the pre-flood season in South China and in rainy season in Southwest China decreased by 9% and 4%,respectively.Precipitation in Meiyu season increased by 6% but was significantly less than that of 2015 and 2016.The rainy season in North China was shortened by 10 days and the rainfall was 28% less than normal.However,the autumn rainfall in West China increased by 49%,getting to the highest since 1984.The rainy season in Northeast China was short with rainfall 14% less than normal.Moreover,rain-storm processes presented frequently,and extremely severely,resulting in great damages.There were more landing typhoons,which were more frequent,concentrated and regionally overlapping.High temperature occurred for more days in China,appearing early in northern China but more intense in sou-thern China.The effects of other disasters such as drought,freezing,snowstorms,dust in spring and haze were light.%2017年,我国气候属于正常年景,气候灾害偏轻.全国平均气温10.39℃,较常年偏高0.84℃,7和9月为1951年以来同期最高,全国有113站日最高气温突破历史极值.全国平均降水量641.3 mm,比常年偏多1.8%.全国降水冬季偏少,夏季偏多,春、秋季接近常年.全国31站日降水量突破历史极值,其中多站出现在暴雨少发地区;47站连续降水量突破历史极值.华南前汛期和西南雨季雨量分别偏少9%、4%;梅雨季雨量偏多6%,但较2015和2016年明显偏少;华北雨季偏短10 d,雨量偏少28%;华西秋雨雨量偏多49%,为1984年来最多;东北雨季短,雨量偏少14%.暴雨过程频繁、重叠度高、极端性强,暴雨洪涝损失偏重;登陆台风多、时间集中,登陆点重叠;高温日数多,北方高温出现早、南方高温强度大.其他灾害如干旱、低温冷冻、雪灾、春季沙尘和霾天气影响偏轻.