横断山区洱海流域局地环流观测分析  

Observation and Analysis of Local Circulation in the Erhai Basin of the Hengduan Mountain Area

作　　者：付志嘉[1,2] 杨澄 彭娟[1,2] FU Zhijia;YANG Cheng;PENG Juan(Dali Meteorological Service/Dali National Climate Observatory,Dali 671003,China;Dali Mountain Meteorological Field Science Experimental Base of CMA,Dali 671003,China;Research Center for Disastrous Weather over Hengduan Mountains&Low-Latitude Plateau of CMA,Kunming 650034,China)

机构地区：[1]大理市气象局/大理国家气候观象台,大理671003 [2]中国气象局大理山地气象野外科学试验基地,大理671003 [3]中国气象局横断山区(低纬高原)灾害性天气研究中心,昆明650034

出　　处：《高原山地气象研究》2025年第1期77-87,共11页Plateau and Mountain Meteorology Research

基　　金：云南省科技厅科技计划项目(202305AM070004);云南省气象局第四批青年科技创新团队建设项目(2022QN06);中国气象科学研究院基本科研业务费专项(2020Z006)。

摘　　要：受限于气象观测资料的数量与质量,目前对横断山区洱海流域近地层局地环流的整体认识尚有不足。本文基于2017—2021年横断山区洱海流域14个自动气象站逐时观测资料,统计分析了该地区实际风与局地风的时空分布特征与局地环流结构。结果表明:实际风平均风速大值区位于洱海中部东、西两侧山区,东侧玉案山地区比西侧苍山地区风速更大。实际风平均风速和盛行风向在不同季节均有显著差异。年平均局地风速春季最大,夏季最小,其占实际风的比例在30%(冬季)到35%(秋季)之间。局地风速的u、v分量在正(负)距平维持时长、日振幅、最强正(负)距平出现时间上均存在明显的季节差异。研究区域存在结构和强度不同的南、北支局地环流,其分界大致位于洱海中部地区,两支局地环流受山谷风和湖陆风叠加影响,白天为谷风和湖风,夜间为山风和陆风,且谷风和湖风强于山风和陆风,局地环流在东部强于西部,南支局地环流强于北支。两支局地环流的强度和风向转换发生在日出时(北京时07—09时)和日落时(17—20时)。Due to the lack of meteorological observation data,the overall understanding of the subsurface local circulation in the Erhai Basin of Hengduan Mountain area was still insufficient.Based on the hourly observation data of 14 automatic weather stations from 2017 to 2021,the temporal and spatial distribution characteristics of the actual wind and local wind and the local circulation structure in the region were analyzed statistically.The results show that the maximum mean wind speed is located in the mountainous areas on the east and west sides of the central Erhai lake,and the wind speed in the Yu’an mountain area on the east side is higher than that in the Cangshan mountain area on the west side.The mean wind speed and prevailing wind direction have significant differences in different seasons.The annual mean local wind speed is maximum in spring and minimum in summer,accounting for 30%(winter)to 35%(autumn)of the actual wind.The u and v components of local wind speed have significant seasonal differences in the maintenance time of positive(negative)anomaly,daily amplitude and occurrence time of the strongest positive(negative)anomaly.There are two local circulations with different structures and strengths in the study area,namely the southern and northern branches,and the boundary is located in the central part of Erhai lake.The two local circulations are affected by the superposition of mountain-valley breeze and lake-land breeze.The valley and lake breezes in the daytime are stronger than the mountain and land breezes in the nighttime.The local circulation in the eastern part is stronger than that in the western part,and the southern branch is stronger than the northern branch.The intensity and wind direction changes of the two branches occur at sunrise(07:00—09:00)and sunset(17:00—20:00).

关 键 词：局地环流 时空分布 横断山区洱海流域 

分 类 号：P425.41[天文地球—大气科学及气象学]