DOI: 10.1002/jgrd.50161
论文题名: A large-eddy simulation of the phase transition of ammonium nitrate in a convective boundary layer
作者: De Brugh J.M.J.A. ; Ouwersloot H.G. ; De Arellano J.V.-G. ; Krol M.C.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 2 起始页码: 826
结束页码: 836
语种: 英语
Scopus关键词: Aerosols
; Air
; Ammonia
; Atmospheric movements
; Atmospheric thermodynamics
; Boundary layers
; Large eddy simulation
; Mixing
; Nitric acid
; A1. largeeddy simulations (LES)
; Boundary layer heights
; Convective boundary layers
; Gas-aerosol partitioning
; Lower atmospheric boundary layers
; Statistical properties
; Temporal variability
; Turbulent properties
; Nitrates
; aerosol
; ammonia
; ammonium nitrate
; convective boundary layer
; large eddy simulation
; mixing ratio
; nitric acid
; partitioning
; phase transition
; relative humidity
; turbulence
英文摘要: Under warm and dry conditions, ammonium nitrate aerosol outgasses to form ammonia and nitric acid in the lower atmospheric boundary layer. In the upper boundary layer, where the temperature is lower and the relative humidity is higher, nitric acid and ammonia condense back to the aerosol phase. Measurements show that aerosol nitrate mixing ratios increase with altitude, confirming this phase transition. Since phase equilibrium is not reached instantaneously, updrafts transport aerosol-poor air from the surface to high altitudes and aerosol-rich air subsides from high altitudes to the surface under turbulent conditions. As a result, the partitioning deviates from equilibrium, so the horizontal and temporal variabilities of the aerosol nitrate mixing ratio are enhanced and a continuous downward aerosol nitrate flux emerges. We postulate that observations of this variability and flux should not be interpreted as instrument noise and deposition of nitrate. In an idealized large-eddy simulation (LES) experiment of a convective boundary layer, we find that the larger variability and flux occurred at about one third of the boundary layer height. Both are largest when the gas-aerosol partitioning time scale is assumed to be about half the time scale of turbulence. Our LES result shows negatively skewed nitrate mixing ratios. Under colder conditions, a smaller fraction of ammonium nitrate aerosol outgasses at the surface, so the absolute effect of nitrate repartitioning becomes smaller. However, dimensionless statistical properties do not change as long as the turbulent properties of the boundary layer remain similar. This indicates that the identified processes are also present under colder conditions. © 2012. American Geophysical Union. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/63993
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Department of Meteorology and Air Quality, Wageningen University, Wageningen, Netherlands; Department of Earth, Environment and Life Sciences, TNO, Research Group Climate, Air and Sustainability, Utrecht, Netherlands; Max Planck Institute for Chemistry, Mainz, Germany; Institute for Marine and Atmospheric Research, Utrecht, Netherlands; Netherlands Institute of Space Research, Utrecht, Netherlands
Recommended Citation:
De Brugh J.M.J.A.,Ouwersloot H.G.,De Arellano J.V.-G.,et al. A large-eddy simulation of the phase transition of ammonium nitrate in a convective boundary layer[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(2)