摘要
沙尘暴是对我国危害性极大的一种灾害性天气现象。我国沙尘暴的多发地区之一民勤地处河西走廊东北部,3面都被沙漠包围,自然环境极其恶劣。利用民勤地区长期观测的沙尘暴数据,对该地区沙尘暴发生的年际规律进行了研究,发现沙尘爆发总的趋势在减少,同时一定时期内伴随着波峰—波谷的振荡型变化。沙尘暴的爆发具有5a,15a的周期性,不同的季节稍有不同,春季和全年的沙尘暴爆发周期相似程度最高。利用NECP/NCAR资料,对典型年份的春季500hPa高度场进行年距平分析,发现了和民勤地区年沙尘暴爆频次相关的高度场特征,在奥加尔湖和巴尔喀什湖附近分别有一个高值系统和低值系统,他们可能同时出现也可能单独出现。当民勤地区春季处于高值控制时,民勤春季沙尘暴爆发的频次相对较少;反之,当民勤地区处于低值控制时,该地区春季沙尘暴的爆发频次就较多。
Sandstorm is a severe weather phenomenon in China. Locating in the northeast of Hexi corridor,Minqin is surrounded by deserts,under the bad natural environment,it is becoming one of the most sandstorm outbreak areas in China. Based on the longterm sandstorm observation in this region,the interannual rule of sandstorm breakout was studied. Results show that the general trend of sandstorm outbreak was reduced,and for a certain period it had the oscillation with peak or trough. The outbreak of sandstorm had 5 or 15 years periodic change,and in different seasons it has a slightly difference. Using NECP/NCAR data,the 500 hPa height field in spring of typical years was analyzed,and we found a height field feature that has a close realtionship with sandstorm breakout in Minqin area. Near the Obama hyjal lake and Balkhash Lake there was a high value system and a low value system,they may appear at same time or alone. When Minqin is controlled by high value system in spring,sandstorm will reduce,but when controlled by the low value system,sandstorm will be more in Minqin.
出处
《干旱气象》
2010年第4期401-406,共6页
Journal of Arid Meteorology
基金
国家自然科学基金项目"西北沙尘暴关键区近地面起沙特征的观测与数值研究"(40645027)
973计划前期研究专项课题"民勤的生态变化对起沙影响的特征观测与数值基础研究"共同资助
关键词
沙尘暴
小波分析
狭管效应
sandstorm
the wavelet analysis
narrow tube effect
