干旱气象基金项目(IAM201112)和沙漠气象科学基金(Sqj2012003)共同资助
摘要： 2013 年春季， 我国共出现了 7 次沙尘天气过程， 其中沙尘暴 2 次， 扬沙 5 次， 是沙尘天气频次总体偏少， 但发生时间偏早、 影响范围较广的一年。通过对 2012/2013 年冬季及 2013 年春季天气气候特征的分析表明:(1)2012/2013 年冬季， 西伯利亚高压脊较常年平均明显偏弱， 影响我国北方地区的西北气流及冷空气偏弱， 我国大部地区气温偏高， 不利于冬季土壤冻结， 土质较为疏松， 加之蒙古国及内蒙古大部地区纬向风为偏西风的正距平区， 有利于起沙及沙尘粒子向偏东方向输送， 这是造成2013 年沙尘天气早发的主要原因;(2)2013 年春季， 我国北方大部地区处于该弱脊脊前西北气流， 我国北方除东北地区气温较常年偏低外， 其他大部地区气温均偏高， 土壤解冻较早， 加之 3 ～4 月降水偏少， 植被状况偏差， 土质疏松， 是形成沙尘天气的主要原因;(3)气温偏高、 降水偏少、 土壤湿度降低，但 2013 年春季沙尘暴反而减少了， 说明这些因素并不是沙尘暴发生的直接因素， 而是造成沙尘暴发生的短期天气气候变化的间接原因。
2013 年春季， 我国共出现了 7 次沙尘天气过程， 其中沙尘暴 2 次， 扬沙 5 次， 是沙尘天气频次总体偏少， 但发生时间偏早、 影响范围较广的一年。通过对 2012/2013 年冬季及 2013 年春季天气气候特征的分析表明:(1)2012/2013 年冬季， 西伯利亚高压脊较常年平均明显偏弱， 影响我国北方地区的西北气流及冷空气偏弱， 我国大部地区气温偏高， 不利于冬季土壤冻结， 土质较为疏松， 加之蒙古国及内蒙古大部地区纬向风为偏西风的正距平区， 有利于起沙及沙尘粒子向偏东方向输送， 这是造成2013 年沙尘天气早发的主要原因;(2)2013 年春季， 我国北方大部地区处于该弱脊脊前西北气流， 我国北方除东北地区气温较常年偏低外， 其他大部地区气温均偏高， 土壤解冻较早， 加之 3 ～4 月降水偏少， 植被状况偏差， 土质疏松， 是形成沙尘天气的主要原因;(3)气温偏高、 降水偏少、 土壤湿度降低，但 2013 年春季沙尘暴反而减少了， 说明这些因素并不是沙尘暴发生的直接因素， 而是造成沙尘暴发生的短期天气气候变化的间接原因。
Abstract: In spring of 2013， there were seven times sand and dust weather processes including two sandstorm processes over North China，the frequency of sand and dust weathers was obviously few，but the occurrence time of dust storms was earlier and the influencing area was larger，so the synoptics and climatological characteristics in winter of 2012 and spring of 2013 were analyzed in this paper． Some results are obtained as follows:(1) In 2012/2013 winter，weaker cold air and higher temperature were not conducive to soil freezing，and at the same time，as a result of less precipitation in Xinjiang，west of Inner Mongolia，the ground surface vegetation condition was bad there． In addition，the zonal wind was the positive anomaly of westerly wind over Mongolia and the most region of Inner Mongolia，which was conductive to dust emission and dust particles conveying to east region，so that’ s why the occurrence time of duststorms was earlier in 2013． (2) In March and April of 2013， there was still fewer precipitation， lower soil humidity and higher temperature in most parts of northern China，so the soil thawed early and ground vegetation conditions couldn’ t be improved，which were important factors why the dust weathers occurred during this period． (3) Although it was higher temperature，fewer precipitation and lower soil moisture in spring of 2013，sandstorm weathers actually decreased，which showed these factors were not direct factors of dust storm occurrence，they were only indirect reasons for short － term climate change resulted in sanstorm occurring．
In spring of 2013， there were seven times sand and dust weather processes including two sandstorm processes over North China，the frequency of sand and dust weathers was obviously few，but the occurrence time of dust storms was earlier and the influencing area was larger，so the synoptics and climatological characteristics in winter of 2012 and spring of 2013 were analyzed in this paper． Some results are obtained as follows:(1) In 2012/2013 winter，weaker cold air and higher temperature were not conducive to soil freezing，and at the same time，as a result of less precipitation in Xinjiang，west of Inner Mongolia，the ground surface vegetation condition was bad there． In addition，the zonal wind was the positive anomaly of westerly wind over Mongolia and the most region of Inner Mongolia，which was conductive to dust emission and dust particles conveying to east region，so that’ s why the occurrence time of duststorms was earlier in 2013． (2) In March and April of 2013， there was still fewer precipitation， lower soil humidity and higher temperature in most parts of northern China，so the soil thawed early and ground vegetation conditions couldn’ t be improved，which were important factors why the dust weathers occurred during this period． (3) Although it was higher temperature，fewer precipitation and lower soil moisture in spring of 2013，sandstorm weathers actually decreased，which showed these factors were not direct factors of dust storm occurrence，they were only indirect reasons for short － term climate change resulted in sanstorm occurring．
中图分类号:
［ 1］叶笃正， 丑纪范， 刘纪远， 等． 关于我国华北地区沙尘天气的成因与治理对策［J］． 地理学报， 2000， 55(5):513 －521．［ 2］王世功， 杨民， 齐斌， 等． 甘肃河西走廊沙尘暴对兰州市空气污染的影响［J］． 中国沙漠， 1999， 19(4):354 －358．［ 3］康杜娟， 王会军． 中国北方沙尘暴气候形势的年代际变化［J］．中国科学(D 辑， 地球科学)， 2005， 35(11):1096 －1102．［ 4］刘国梁， 郝丽珍． 中国沙尘暴的下降趋势与气候变迁的对比［J］． 中国环境科学， 2003， 23(4):341 －343．［ 5］王可丽， 江灏， 吴虹． 2001 年春季中国北方沙尘暴的环流动力结构分析［J］． 高原气象， 2002， 21(3):303 －308．［ 6］程鹏， 王宝鉴， 孔祥伟， 等． 河西走廊一次强沙尘暴天气的螺旋度诊断［J］． 干旱气象， 2013， 31(1):144 －149．［ 7］陈静， 许彦慧， 蔡文玮． 内蒙古中西部地区一次沙尘暴天气的动力诊断［J］． 干旱气象， 2011， 29(3):330 －335．［ 8］赵俊荣， 刘振新． 准噶尔盆地南缘一次强沙尘暴成因分析［J］．干旱气象， 2009． 27(4):362 －366．［ 9］李小岚， 张宏升． 我国沙尘天气微气象学和湍流输送特征研究进展［J］． 干旱气象， 2010， 28(3):256 －254．［ 10］赵明瑞， 杨晓玲， 滕水昌． 甘肃民勤地区沙尘暴变化趋势及影响因素［J］． 干旱气象， 2012， 30(3):421 －425．［ 11］高振荣， 邵亮， 李光林． 敦煌地区沙尘天气特征分析［J］． 干旱气象， 2010， 28(1):59 －64．［ 12］牛若芸， 薛建军． 2002 年春季我国沙尘天气特征及成因分析［J］． 气象， 2003， 29(7):43 －48．［ 13］牛若芸， 周自江， 刘月巍， 等． 2003 年春季沙尘天气异常偏少成因分析［J］． 气候与环境研究， 2004， 9(1):24 －33．［ 14］牛若芸． 2004 年春季沙尘天气显著偏少成因分析［J］． 气象科技， 2007， 35(1):92 －95．［ 15］牛若芸， 蔡芗宁， 邹旭恺． 2005 年我国沙尘天气的若干特征分析［J］． 气候与环境研究， 2007， 12(3): 358 －364．［ 16］段海霞， 赵建华， 李耀辉． 2011 年春季中国北方沙尘天气过程及其成因［J］． 中国沙漠， 2013， 33(1):179 －186．
地址： 甘肃省兰州市东岗东路2070号，中国气象局兰州干旱气象研究所 730020