祁连山中段摆浪河21号冰川区微气象特征及降水的环流驱动研究  

Meteorological characteristics and precipitation circulation driving of the Bailanghe Glacier No.21 in the middle part of Qilian Mountains

作　　者：孙雯璇 杜文涛 陈记祖 蒋友严 徐志龙 刘鹏枭 王金牛[4] 贺建桥 罗立辉 康世昌 SUN Wenxuan;DU Wentao;CHEN Jizu;JIANG Youyan;XU Zhilong;LIU Pengxiao;WANG Jinniu;HE Jianqiao;LUO Lihui;KANG Shichang(Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;Lanzhou Regional Climate Center,Lanzhou 730020,China;Zhangye Meteorological Bureau of Gansu Province,Zhangye 734000,Gansu,China;Chengdu Institute of Biology,Chinese Academy of Sciences,Chengdu 610041,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院西北生态环境资源研究院,甘肃兰州730000 [2]兰州区域气候中心,甘肃兰州730020 [3]甘肃省张掖市气象局,甘肃张掖734000 [4]中国科学院成都生物研究所,成都610041 [5]中国科学院大学,北京100049

出　　处：《冰川冻土》2023年第3期1128-1141,共14页Journal of Glaciology and Geocryology

基　　金：国家重点研发计划(2022YFF0711704);中国气象局气候变化专题项目(QBZ202308);中国科学院西部之光青年学者项目;甘肃省自然科学基金项目(20JR10RA453);冰冻圈科学国家重点实验室开放课题(SKLCS-OP-2021-06)资助。

摘　　要：山地冰川因具有高反照率、冰川风、逆温层及高值降水等特征而形成了独有的局地微气候,尤其是作为高值降水中心,对径流变化具有重要影响。本文基于祁连山中段北坡摆浪河21号冰川末端(海拔4 350 m)2020年9月2日—2021年8月28日的气象观测资料,开展了微气象特征分析,与临近不同海拔、下垫面的同期降水以及祁连山典型冰川区降水进行了比较,并对最大降水事件过程开展环流成因分析。研究发现:摆浪河21号冰川区气温超过0℃的天数有84 d,集中在5—9月;冰川风盛行,不同于其他冰川区的山谷风循环;天气主要以多云为主;入射与反射短波辐射月最大值分别出现在5月和4月。摆浪河21号冰川降水主要集中在4—8月,降水频次和强度均随着云量的增加而增加。观测年最大降水事件(2021年7月25—27日)属于局地对流降水,中高纬西北-东南向水汽输送为降水区提供了大量水汽;低层辐合和高层辐散、层结不稳定造成了强烈的暖空气上升,加之降水区位于槽后脊前不断有冷空气输入,冷暖交汇促使降水发生。Alpine glacier areas have unique glacial microclimates due to the characteristics of high albedo,gla⁃cier wind,inversion layer and high-value precipitation,especially high-value precipitation is an important factor influencing the change of runoff.Based on the in-situ meteorological observations on the Bailanghe Glacier No.21 from 2nd September 2020 to 28th August 2021,the micrometeorological characteristic analysis was carried out,and the similarities and differences were compared with the simultaneous precipitation observations at differ⁃ent elevations and underlying surfaces in the vicinity and the precipitation observations in typical glacier areas of Qilian Mountains.Furthermore,the circulation mechanism of different types of precipitation events was ana⁃lyzed.The study shows that the number of days that the daily mean temperature exceeded 0℃is 84 days,only occurring from May to September.Bailanghe Glacier No.21 is dominated by glacier wind all year round,un⁃like the valley wind cycle in other glacier areas;the weather is mainly cloudy;the monthly maxima of incident and reflected shortwave radiation are in May and April,respectively.Precipitation in this region is mainly con⁃centrated in April-August,and both the frequency and intensity of precipitation increase with the increase of cloudiness.A typical precipitation process(July 25-27,2021)was selected to analyze the circulation drive.It was found that this precipitation process belongs to local convective precipitation in mountainous areas.The northwest-southeast-oriented water vapor transport belt from high latitude to mid-latitude provides water vapor.Moreover,low-level convergence and high-level dispersion,stratification instability and strong upward motion induce the warm air rising and the precipitation area is located in front of the ridge behind the trough with con⁃stant cold air input,and then the cold and warm convergence prompt precipitation to occur.

关 键 词：冰川微气象 降水 云量 环流机制 摆浪河21号冰川 

分 类 号：P404[天文地球—大气科学及气象学]