scholarly journals Insights into an Asian dust event sweeping Beijing during April 2006: Particle chemical composition, boundary layer structure, and radiative forcing

2010 ◽  
Vol 115 (D18) ◽  
Author(s):  
Weijie Wang ◽  
Tiantao Cheng ◽  
Renjian Zhang ◽  
Xuan Jia ◽  
Zhiwei Han ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Chemical Composition ◽  
Radiative Forcing ◽  
Layer Structure ◽  
Asian Dust ◽  
Dust Event ◽  
Boundary Layer Structure

scholarly journals The impact threshold of the aerosol radiation forcing on the boundary layer structure in the pollution region

2020 ◽  
Author(s):  
Dandan Zhao ◽  
Jinyuan Xin ◽  
Chongshui Gong ◽  
Jiannong Quan ◽  
Yuesi Wang ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Radiative Forcing ◽  
Layer Structure ◽  
Atmospheric Environment ◽  
Absolute Difference ◽  
Air Pollution Control ◽  
Aerosol Radiative Forcing ◽  
Boundary Layer Structure ◽  
Improvement Measures ◽  
The Impact

Abstract. Recently, there has been increasing interest in the relation between particulate matter (PM) pollution and atmospheric boundary layer (ABL) structure. However, this has yet to be fully understood because most studies have been superficial. This study aimed to qualitatively assess the interaction between PM and ABL structure in essence, and to further quantitatively estimate the effects of aerosol radiative forcing (ARF) on the ABL structure. Multi-episode contrastive analysis stated the key to determining whether haze outbreak or dissipation was the ABL structure (i.e., stability and turbulence kinetic energy (TKE)) satisfied relevant conditions. However, it seemed that the ABL structure change was in turn highly related to the PM level and ARF. |SFC-ATM| (SFC and ATM is respectively the ARF at the surface and interior of the atmospheric column) is the absolute difference between ground and atmosphere layer ARFs, and the change in |SFC-ATM| is linearly related to the PM mass concentration. However, the influence of ARF on the boundary layer structure is nonlinear. With increasing |SFC-ATM|, the TKE level exponentially decreased, which was notable in the lower layers/ABL but disappeared above the ABL. Moreover, the threshold of the ARF effects on the ABL structure was determined for the first time, namely, once |SFC-ATM| exceeded ~ 55 W m−2, the ABL structure would quickly stabilize and would thereafter change little with increasing ARF. The threshold of the ARF effects on the boundary layer structure could provide useful information for relevant atmospheric environment improvement measures and policies, such as formulating the objectives of phased air pollution control.

scholarly journals The impact threshold of the aerosol radiative forcing on the boundary layer structure in the pollution region

2021 ◽  
Vol 21 (7) ◽  
pp. 5739-5753
Author(s):  
Dandan Zhao ◽  
Jinyuan Xin ◽  
Chongshui Gong ◽  
Jiannong Quan ◽  
Yuesi Wang ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Radiative Forcing ◽  
Layer Structure ◽  
Atmospheric Environment ◽  
Absolute Difference ◽  
Air Pollution Control ◽  
Aerosol Radiative Forcing ◽  
Boundary Layer Structure ◽  
The Impact ◽  
Aerosol Radiative

Abstract. Recently, there has been increasing interest in the relation between particulate matter (PM) pollution and atmospheric-boundary-layer (ABL) structure. This study aimed to qualitatively assess the interaction between PM and ABL structure in essence and further quantitatively estimate aerosol radiative forcing (ARF) effects on the ABL structure. Multi-period comparative analysis indicated that the key to determining whether haze outbreak or dissipation occurs is whether the ABL structure satisfies the relevant conditions. However, the ABL structure change was in turn highly related to the PM level and ARF. |SFC−ATM| (SFC and ATM are the ARFs at the surface and interior of the atmospheric column, respectively) is the absolute difference between ground and atmosphere layer ARFs, and the |SFC−ATM| change is linearly related to the PM concentrations. However, the influence of ARF on the boundary layer structure is nonlinear. With increasing |SFC−ATM|, the turbulence kinetic energy (TKE) level exponentially decreased, which was notable in the lower layers or ABL, but disappeared at high altitudes or above the ABL. Moreover, the ARF effects threshold on the ABL structure was determined for the first time, namely once |SFC−ATM| exceeded ∼55 W m−2, the ABL structure tends to quickly stabilize and thereafter change little with increasing ARF. The threshold of the ARF effects on the boundary layer structure could provide useful information for relevant atmospheric-environment improvement measures and policies, such as formulating phased air pollution control objectives.

Unsteady dynamics of turbulent flow in the wakes of barchan dunes modulated by overlying boundary-layer structure

2021 ◽  
Vol 920 ◽  
Author(s):  
Nathaniel R. Bristow ◽  
Gianluca Blois ◽  
James L. Best ◽  
Kenneth T. Christensen
Keyword(s):  
Boundary Layer ◽  
Turbulent Flow ◽  
Layer Structure ◽  
Boundary Layer Structure ◽  
Barchan Dunes

Abstract

scholarly journals Thermal boundary layer structure in convection with and without rotation

2020 ◽  
Vol 5 (11) ◽  
Author(s):  
Robert S. Long ◽  
Jon E. Mound ◽  
Christopher J. Davies ◽  
Steven M. Tobias
Keyword(s):  
Boundary Layer ◽  
Thermal Boundary Layer ◽  
Layer Structure ◽  
Boundary Layer Structure
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