摘要
2006年和2007年夏季在祁连山冷龙岭西段开展了地形云云量、云状、大气水汽、风场、雨滴谱和雨强等的综合探测试验,以分析祁连山地形云的特征。结果表明:①祁连山区夏季云量丰富,平均云量在6成以上。西南气流天气背景下总云量多达8成;②祁连山夏季无降水日大气水汽非常少,700 hPa以上层大气相对湿度大多在20%以下;③西南气流背景下祁连山南北侧山谷风的共同作用,气流昼间向山顶辐合,夜间向山谷辐散,当水汽条件充足时,极易抬升形成可以产生降水的地形云;④祁连山降水主要由小于1 mm的雨滴组成。
The orographic clouds structures of Qilian Mountains are analyzed based on the data of cloudage,cloud types,atmosphere vapor,wind field,raindrop spectrum,and rainfall intensity observed during 2006 and 2007 summer field campaign for Qilian Mountains Orographic Clouds Observation Study in the west part of Lenglongling in Qilian Mountains.The results indicate that： i.the cloudage is abundant in summer in Qilian Mountains,more than 60% on average and total cloudage is about 80% under southwest airflow pattern conditions.ii.Atmosphere vapor in Qilian Mountains is very rare during the no-rainfall days in summer,the atmosphere relative humidity above 700 hPa level is mostly less than 20%.iii.The airflows converge toward mountaintop during diurnal time while diverge toward valley during nighttime by due to the co-effects of mountain valley winds from south and north of Qilian Mountains under southwest airflow pattern conditions.It is very easy to uplift to form orographic clouds which is prone to produce precipitation when water vapor abundance.iv.The rainfalls in Qilian Mountains mostly come from the raindrops with diameters less than 1 mm.
出处
《地球科学进展》
CAS
CSCD
北大核心
2011年第10期1057-1070,共14页
Advances in Earth Science
基金
国家自然科学基金重点项目"西北地形云结构及降水机理研究"(编号:40533015)
公益性行业(气象)科研专项"地形云结构和人工增雨(雪)关键技术研究"(编号:GYHY200906024)资助
关键词
祁连山
地形云
探测
试验
Qilian Mountains
Orographic Clouds
Observation
Field Campaign
