干旱区生态环境知识资源中心(Arid): 极端干旱区大气边界层厚度时间演变及其与地表能量平衡的关系

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	极端干旱区大气边界层厚度时间演变及其与地表能量平衡的关系
其他题名	Temporal variety of boundary layer height over deep arid region and the relations with energy balance
	张杰 1; 张强2 ; 唐从国 1
来源期刊	生态学报
ISSN	1000-0933
出版年	2013
卷号	33 期号:8 页码:2545-2555
中文摘要	主要采用ECMWF的地表和大气产品分析了中国西北极端干旱区大气边界层厚度与地表能量通量的时间变化特征,同时,结合探空加强观测分析了大气边界层演变的可能因素。得出:西北极端干旱区大气边界层厚度呈现出季节性的年际和年代际变化,夏季大气边界层厚度呈下降趋势,春、秋季节呈现出先增加后降低的趋势,冬季以阶段性降低趋势为主,20世纪80年代是大气边界层厚度的转折时期;感热通量是极端干旱区大气边界层发展的主要热力因素;由于夏季净辐射量、地气温差、粗糙度以及风速等因子随时间演变而呈降低趋势,潜热通量呈增加趋势,导致了边界层高度形成的热力作用减弱,边界层厚度降低;同时,粗糙度和风速也是大气边界层发展的主要动力因素,由于边界层粗糙度和风速降低,促使垂直风切变减小,湍流动力作用减弱,也会导致边界层厚度降低。
英文摘要	Based on a European Centre for Medium-Range Weather Forecasts (ECMWF) product and observed radiosonde data, we investigated temporal variations of boundary layer height (BLH) over arid regions and their relationship with energy balance. Moreover, possible factors affecting BLH change are analyzed by combining the above data. We discovered seasonal and interannual variations of BLH in arid regions of northern China. In the past 44 years, BLH in summer continuously decreased. BLH in spring and autumn increased before the 1980s and decreased afterward. BLH in winter periodically decreased. There was an adjustment period of BLH in the 1980s. Change in BLH is influenced by dynamic and thermodynamic factors. Surface sensible heat flux (SSHF) is the main thermodynamic factor affecting seasonally decreasing and interannual variations. Over the past 44 years, SSHF decreased continuously in summer and winter. SSHF in spring and autumn increased before the 1980s and decreased shortly afterward, which resulted in heat exchange and BLH decrease. With respect to diurnal variation, BLH clearly varied with SSHF. During its development stage, the convective boundary layer (CBL) may begin to break through the stable boundary layer (SBL) and enter the remnant layer when SSHF is greater than 100 W/m~2; the CBL develops with increasing SSHF. The CBL is more than 3 km deep when the SSHF exceeds 250 W/m~2. During its maintenance and decline, the BLH shrinks with decreasing SSHF. As a component of net radiance (Rn), SSHF is affected not only by Rn, but also by surface latent heat flux (SLHF). Rn decreased and SLHF increased over the past 44 years, would result in decreasing SSHF according to energy balance. In addition, differences of the surface and air temperature are the main driving forces of thermal turbulence, it has a positive correlation with SSHF. Therefore, differences of the surface and air temperature cause decreasing SSHF. Wind turbulence and velocity are the dynamic factors involved in atmospheric boundary layer development. A decreasing trend of wind turbulence and speed prompts a decrease in vertical wind shear, which weakens dynamic turbulence and ultimately decreases BLH. Therefore, wind turbulence and SSHF have a positive correlation. With regarding to diurnal variation, the greater the friction velocity, the greater the CBL and BLH during the day in summer. Friction velocity has good correlation with CBL and BLH when the latter is less than 2.5 km, which shows that vertical wind shear can accelerate BLH development. However, wind shear has little effect on deep BLH. With decreasing wind shear, the SBL decreases at night. Mechanical turbulence may support CBL development in winter. Agricultural acreage changed in the 1980s, which reduced roughness and thereby decreased thermal transmission. This decreases SSHF and ultimately BLH. Analyzed from a dynamics viewpoint, the less the surface roughness, the smaller the friction velocity and vertical wind shear, all of which are adverse to dynamic turbulence and BLH development. Aside from the above factors, SSHF and BLH are affected by total shortwave radiance, surface albedo, longwave radiance, and others. These factors are potentially affected by land use and land cover, climate warming, radiance effects of aerosols, atmospheric circulation change, and soil humidity change caused by precipitation change. These topics require further research.
中文关键词	大气边界层厚度 ; 极端干旱区 ; 感热通量 ; 地表净辐射
英文关键词	boundary layer height(BLH) deep arid region surface sensible heat flux surface net radiance
语种	中文
国家	中国
收录类别	CSCD
WOS类目	METEOROLOGY ATMOSPHERIC SCIENCES
WOS研究方向	Meteorology & Atmospheric Sciences
CSCD记录号	CSCD:4822521
来源机构	中国气象局兰州干旱气象研究所
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/229990
作者单位	1.南京信息工程大学, 气象灾害江苏省省部共建教育部重点实验室, 南京, 江苏 210044, 中国; 2.中国气象局兰州干旱气象研究所, 兰州, 甘肃 730020, 中国
推荐引用方式 GB/T 7714	张杰,张强,唐从国. 极端干旱区大气边界层厚度时间演变及其与地表能量平衡的关系[J]. 中国气象局兰州干旱气象研究所,2013,33(8):2545-2555.
APA	张杰,张强,&唐从国.(2013).极端干旱区大气边界层厚度时间演变及其与地表能量平衡的关系.生态学报,33(8),2545-2555.
MLA	张杰,et al."极端干旱区大气边界层厚度时间演变及其与地表能量平衡的关系".生态学报 33.8(2013):2545-2555.