Relation between the Atmospheric Boundary Layer and Impact Factors under Severe Surface Thermal Conditions

Yinhuan Ao,Cailian Jiang,Shihua Lyu,Zhaoguo Li,Jiangang Li,Minzhong Wang

doi:10.1155/2017/8352461

Abstract

This paper reported a comprehensive analysis on the diurnal variation of the Atmospheric Boundary Layer (ABL) in summer of Badain Jaran Desert and discussed deeply the effect of surface thermal to ABL, including the Difference in Surface-Air Temperature (DSAT), net radiation, and sensible heat, based on limited GPS radiosonde and surface observation data during two intense observation periods of experiments. The results showed that (1) affected by topography of the Tibetan Plateau, the climate provided favorable external conditions for the development of Convective Boundary Layer (CBL), (2) deep CBL showed a diurnal variation of three- to five-layer structure in clear days and five-layer ABL structure often occurred about sunset or sunrise, (3) the diurnal variation of DSAT influenced thickness of ABL through changes of turbulent heat flux, (4) integral value of sensible heat which rapidly converted by surface net radiation had a significant influence on the growth of CBL throughout daytime. The cumulative effect of thick RML dominated the role after CBL got through SBL in the development stage, especially in late summer, and (5) the development of CBL was promoted and accelerated by the variation of wind field and distribution of warm advection in high and low altitude.

Highlights

The Atmospheric Boundary Layer (ABL) is one of the important physical characteristics of the Land-Atmosphere interaction, and formation and development of ABL are related to surface fluxes such as net radiation and sensible heat
The development of ABL in desert in midsummer and late summer was analyzed based on the data from two limited-period field observations performed in Badain Jaran Desert, and formation of thick Convective Boundary Layer (CBL) was explored by use of climate background, RML, surface thermal condition, and atmospheric circulation
Our major conclusions as a case were as follows: (1) Affected by topography of the Tibetan Plateau, the desert area was characterized by dryness and being rainless with severe dry convection, which provided favorable external conditions for the development of CBL

Summary

Introduction

The ABL is one of the important physical characteristics of the Land-Atmosphere interaction, and formation and development of ABL are related to surface fluxes such as net radiation and sensible heat. It plays an important role in cloud formation, rain production, and other feedback in the coupled system [1, 2]. Eddy Covariance (EC, hereinafter) System was used widely for measuring surface fluxes of momentum, sensible heat, and water vapour in the field experiments [3], which are key to the understanding and prediction of other processes taking place within the ABL [4, 5]. The observation site is typical desert underlying surface, and desert-Gobi transition

Methods

Results

Conclusion