过去30年北京地区大气对流边界层高度的变化特征及其影响因素  

Variation Characteristics and Influencing Factors of Atmospheric Convective Boundary Layer Height over Beijing Region in the Past 30 Years

作　　者：赖悦 李林 王辉 张宏文 夏芸洁 韦涛 孟磊 LAI Yue;Li Lin;WANG Hui;ZHANG Hongwen;XIA Yunjie;WEI Tao;MENG Lei(Beijing Meteorological Observation Center,Beijing 100089;Beijing Municipal Climate Center,Beijing 100089)

机构地区：[1]北京市气象探测中心,北京100089 [2]北京市气候中心,北京100089

出　　处：《气象》2024年第12期1417-1428,共12页Meteorological Monthly

基　　金：中国气象局创新发展专项(CXFZ2022J058、CXFZ2023J061);北京市科学技术协会2022—2024年度青年人才托举工程项目;中国气象局气象能力提升联合研究专项(23NLTSQ011);北京市气象局重点创新团队(BMB2024ZD05)共同资助。

摘　　要：大气对流边界层高度的演变对天气和气候变化具有重要影响,目前关于北京地区对流边界层高度的气候特征研究较少。利用1992—2022年的高分辨率ERA5再分析资料,研究了过去30年北京地区对流边界层高度的气候特征。首先使用无线电探空观测数据评估了ERA5大气对流边界层高度数据的表现,结果显示ERA5可以很好地再现探空观测的对流边界层高度变化特征。其次研究了对流边界层高度的年际变化、季节变化和日变化特征,以及对流边界层高度与关键气象要素的相关性。结果表明,过去30年春季和秋季的对流边界层高度分别以61.6 m·(10 a)^(-1)和13.1 m·(10 a)^(-1)的速率呈逐年减小趋势,夏季和冬季的对流边界层高度分别以2.9 m·(10 a)^(-1)和7.7 m·(10 a)^(-1)的速率呈逐年增加趋势。春季、夏季、秋季、冬季中午时段的对流边界层高度中位数分别约为1700、1100、950、800 m。春季在全年四个季节中的对流边界层高度发展最高,是因为春季地表感热通量最大,同时大气层结的不稳定程度最强。通过分析对流边界层高度与感热通量、位温直减率、地气温差的相关关系,发现在春季,当感热通量每增大100 W·m^(-2)时,对流边界层高度升高615 m;当位温直减率每增大1℃·km^(-1)时,对流边界层高度升高1376 m;当地气温差增大1℃时,对流边界层高度升高175 m。The temporal evolution of atmospheric convective boundary layer height(CBLH)has an important impact on weather and climate change,but there are few studies on the CBLH climatology in the Beijing Region.This study presents the CBLH climatology in Beijing by using high resolution ERA5 reanalysis data during 1992-2022.The ERA5 CBLH is first evaluated against radiosonde-derived CBLH.ERA5 can reproduce the CBLH variation characteristics by sounding reasonably well.Then,the interannual,seasonal and diurnal variations of the CBLHs,as well as the correlation between the CBLH and key meteorological parameters are analyzed.The results show that in the past 30 years,the CBLHs in spring and autumn have decreased at the rate of 61.6 m per decade and 13.1 m per decade,respectively,while that in summer and winter have increased at the rate of 2.9 m per decade and 7.7 m per decade,respectively.The median values of CBLH at noon in spring,summer,autumn,and winter are about 1700 m,1100 m,950 m,and 800 m,respectively.The CBLH in spring is the highest among the four seasons because of the large surface sensible heat flux and the weak atmospheric stability.By analyzing the relationship between CBLH and sensible heat flux,potential temperature lapse rate and difference of surface temperature and air temperature(T_(s)-T_(a)),we have found that in spring,when the sensible heat flux increases by 100 W·m^(-2),the CBLH increases by 615 m;when the potential temperature lapse rate increases by 1℃·km^(-1),the CBLH increases by 1376 m;and when the T_(s)-T_(a) increases by 1℃,the CBLH increases by 175 m.

关 键 词：对流边界层高度(CBLH) 再分析资料 无线电探空 变化特征 影响因素 

分 类 号：P412[天文地球—大气科学及气象学] P467