摘要
利用北方协同观测试验中夏季风影响过渡区榆中站、定西站和兴隆山站观测资料,分别代表草地、农田、混合型下垫面,采用通量廓线方法计算了各下垫面的粗糙度,分析了下垫面动力学粗糙度随风向、风速、摩擦速度和热力稳定度的变化特征及其与风速、热力稳定度的参数化关系.结果表明,动力学粗糙度随风向有明显的变化,因风向区间通量的不同而不同;动力学粗糙度与风速整体呈负相关,且在不同站点存在显著差异,在草地和混合型下垫面的相关性较好,而在农田下垫面相关性较差.动力学粗糙度与摩擦速度的关系相对较为复杂,在小摩擦速度区间随摩擦速度递增而递增,在大摩擦速度区间随摩擦速度的递增而递减.大气稳定时,粗糙度随热力稳定度呈显著负相关,大气活跃时,粗糙度随热力稳定度呈正相关.
The article utilized the observation data of the summer monsoon transition zone from the North- ern China synergy observation experiment which embraced Yuzhong, Dingxi and Xinglongshan stations, representing grassland, cropland and hybrid underlying surface. Aerodynamic roughness length was cal- culated by the flux profile method, and also respectively analyzed were the changing rule of aerodynamic roughness length along with wind velocity, wind direction, friction velocity and thermodynamic stability, parametric correlativity with wind speed and the thermal, stability. The study indicated that a significant variation trend appeared when the footprint area changed within the scope of four wind direction sec- tions. An inverse correlation appeared in roughness length and velocity and, more narrowly, aerodynamic roughness length decreased along with increasing wind velocity. The relationship reflected a significant difference when the station changed; the changes occurred intricately along with the friction velocity. To be specific, a superior correlation appeared in grassland and hybrid underlying surface while an inferior one in cropland. Roughness length and friction velocity were in a complex relationship in that the former increased when the latter varied in a small range, or vice versa. When atmosphere stood stable, roughness was significantly negatively correlated with thermodynamic stability, and vice versa.
作者
王凯嘉
张红丽
杜一博
张强
Wang Kai-jial;Zhang Hong-li;Du Yi-bo;Zhang Qiang(College of Atmospheric Sciences,Lanzhou University,Lanzhou 730000,China;Gansu Provincial Meteorological Bureau,Lanzhou 730020,China;Lanzhou Institute of Drought Weather of China Meteorological Administration,Key laboratory of Arid Cli-matic Change and Disaster Reduction of Gansu Province,Key Open Laboratory of Arid Climatic Changes and Disaster Reduction of China Meteorological Administration,Lanzhou 730020,China)
出处
《兰州大学学报（自然科学版）》
CAS
CSCD
北大核心
2018年第3期356-363,共8页
Journal of Lanzhou University(Natural Sciences)
基金
国家自然科学基金重点项目(41630426)
国家重点基础研究发展计划(973计划)项目(2013CB430206)
关键词
夏季风影响过渡区
动力学粗糙度
热力稳定度
通量源区
参数化关系
summer monsoon transition zone
aerodynamic roughness length
thermodynamic stability
flux footprint source area
parametric correlativity
