【摘要】 利用1961—2004年宁夏逐日最高、最低气温资料,分析了宁夏44a来最高、最低气温的变化趋势。结果表明:宁夏的最高、最低气温表现出了明显的变化趋势,最高气温<0℃的日数减少,>30℃的日数增加;在年平均最低气温升高的同时,极冷日数也在增加,相对于1961—1990年的平均值,20世纪90年代和21世纪最初的4a年极冷日数分别增加了1.1d和0.7d,距平百分率分别达350%和275%。更多还原

【Abstract】 The trends in daily frequency of maximum and minimum temperatures over the last 44 years were analyzed using the daily maximum and minimum temperature data from 1961 to 2004 in Ningxia,by classifying the temperatures into 38 levels.It was found that daily frequency of maximum temperature below 0℃ decreased while that over 30℃ increased.The annual average minimum temperature increased,meanwhile the daily frequency of extremely low temperature also increased by 350%-275% in 1991-2004 relative to 1961-1990.Therefore,the extreme trends of temperature are obvious in Ningxia.更多还原