气象学报2024，Vol.82Issue(3)：385-397,13.DOI:10.11676/qxxb2024.20230141
基于地基C波段垂直雷达的青藏高原大气边界层湍流特征研究
Turbulence characteristics in the convective boundary layer over the Qingzang plateau observed by a ground-based C-band vertical detection radar
摘要
Abstract
Based on observations of C-band frequency modulated continuous wave radar(BLHCR),L-band radiosonde data(BLHSD),gradient tower data and reanalysis data set(BLHERA5)at Naqu station in July and August 2014,the boundary layer height(BLH),turbulent statistical characteristics and turbulent spectrum in surface layer and mixing layer under different sensible heat fluxes(SH)and stability(z/L or BLHCR/L)conditions are analyzed.The main results are as follows:(1)There are significant correlation among BLHCR,BLHSD and BLHERA5,and the root mean square deviations among them are about 0.6 km.The BLHCR have significant daytime variation at Naqu,and the daily range of the median of BLHCR is approximately 0.7-0.8 km.At around 16:00 BT,BLHCR reaches its maximum value with a median value of approximately 1.2 km.(2)All of σw,σT and RwT in surface layer gradually increase with increased SH.The σT generally increases linearly,and the increase rates of σw and RwT gradually decrease when SH exceeds a certain threshold.When-z/L＜0.3,both σT and RwT rapidly increase with the increase of-z/L;when-z/L ≥0.3,the increase rate significantly decline.(3)The maximum value of σ2w in mixing layer occurs at a height of approximately(0.25-0.3)×BLHCR,with an average value of approximately 1.2-1.3 m2/s2.The σ2w in mixing layer under strongly unstable stratification is slightly less than that under weakly unstable stratification;the average value of σ2 in mixing layer increases with the increasing of SH.With the increase of z/BLHCR,σ2/w2 presents a first rapid increase and then gradually decreases,with the maximum value occurring at around 0.35×BLHCR.(4)With the increase of unstable stratification,the peak frequency of the normalized vertical velocity spectrum both in surface layer and mixing layer moves towards low frequency and its corresponding value(normalized power spectral density)increase.Both the scale of the turbulent vortex and turbulent intensity increase for strongly unstable stratification.关键词
大气边界层高度/青藏高原/频谱分析/湍流特征Key words
Atmospheric boundary layer height/Qingzang plateau/Spectrum analysis/Turbulence characteristics分类
天文与地球科学引用本文复制引用
洪岚,王寅钧,阮征,鲍艳松..基于地基C波段垂直雷达的青藏高原大气边界层湍流特征研究[J].气象学报,2024,82(3):385-397,13.基金项目
第二次青藏高原综合科学考察研究(2019QZKK0105)、水利部重大科技项目(SKS-2022072)、江苏省水利科技项目(2023022)、江苏省水利科学研究院自主科研项目(2023z034)、江苏省研究生科研创新计划项目(KYCX221167)、中国气象科学研究院基本科研业务费专项基金(2023Z008). （2019QZKK0105）
