Atmospheric Chemistry and Aerosol Dynamics

2000 ◽  
pp. 353-374
Author(s):  
J. Feichter
Keyword(s):  
Atmospheric Chemistry ◽  
Aerosol Dynamics

scholarly journals Aerosol dynamics within and above forest in relation to turbulent transport and dry deposition

2016 ◽  
Vol 16 (5) ◽  
pp. 3145-3160 ◽  
Author(s):  
Üllar Rannik ◽  
Luxi Zhou ◽  
Putian Zhou ◽  
Rosa Gierens ◽  
Ivan Mammarella ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Dry Deposition ◽  
Particle Deposition ◽  
Turbulent Transport ◽  
Flux Measurement ◽  
Vertical Transport ◽  
Forest Site ◽  
Aerosol Dynamics ◽  
Order Of Magnitude ◽  
The Impact

Abstract. A 1-D atmospheric boundary layer (ABL) model coupled with a detailed atmospheric chemistry and aerosol dynamical model, the model SOSAA, was used to predict the ABL and detailed aerosol population (characterized by the number size distribution) time evolution. The model was applied over a period of 10 days in May 2013 to a pine forest site in southern Finland. The period was characterized by frequent new particle formation events and simultaneous intensive aerosol transformation. The aim of the study was to analyze and quantify the role of aerosol and ABL dynamics in the vertical transport of aerosols. It was of particular interest to what extent the fluxes above the canopy deviate from the particle dry deposition on the canopy foliage due to the above-mentioned processes. The model simulations revealed that the particle concentration change due to aerosol dynamics frequently exceeded the effect of particle deposition by even an order of magnitude or more. The impact was, however, strongly dependent on particle size and time. In spite of the fact that the timescale of turbulent transfer inside the canopy is much smaller than the timescales of aerosol dynamics and dry deposition, leading us to assume well-mixed properties of air, the fluxes at the canopy top frequently deviated from deposition inside the forest. This was due to transformation of aerosol concentration throughout the ABL and resulting complicated pattern of vertical transport. Therefore we argue that the comparison of timescales of aerosol dynamics and deposition defined for the processes below the flux measurement level do not unambiguously describe the importance of aerosol dynamics for vertical transport above the canopy. We conclude that under dynamical conditions reported in the current study the micrometeorological particle flux measurements can significantly deviate from the dry deposition into the canopy. The deviation can be systematic for certain size ranges so that the time-averaged particle fluxes can be also biased with respect to deposition sink.

Modelling Iodine Particle Formation and Growth from Seaweed in a Chamber

2005 ◽  
Vol 2 (4) ◽  
pp. 271 ◽  
Author(s):  
L. Pirjola ◽  
C. D. O'Dowd ◽  
Y. J. Yoon ◽  
K. Sellegri
Keyword(s):  
Steady State ◽  
Atmospheric Chemistry ◽  
Cluster Formation ◽  
Theoretical Framework ◽  
Particle Formation ◽  
New Particle Formation ◽  
Theoretical Frameworks ◽  
Aerosol Dynamics ◽  
Ultra Fine Particle ◽  
Particle Formation And Growth

Environmental Context.Iodine is an important trace species in the marine atmosphere. It contributes to ozone depletion and new particle formation. In recent years, its importance has been realised, however, there is still a gap in our knowledge, from a theoretical framework, of the dominant mechanisms leading to new particle formation and previous theoretical frameworks have not been adequately developed or well understood. This paper presents a state-of-the-art theoretical framework for evaluating the prediction of iodine oxide nucleation and subsequent aerosol growth. Abstract. A sectional atmospheric chemistry and aerosol dynamics box model (AEROFOR) was further developed and used to simulate ultra-fine particle formation and growth from seaweed in a chamber flushed with particle-free atmospheric air. In the model, thermodynamically stable clusters were formed by dimer nucleation of OIO vapour, whose precursor was assumed to be molecular I2 emitted by seaweed. Fractal geometry of particles was taken into account. For the I2 fluxes of (0.5–1.5) × 109 cm−3 s−1 the model predicted strong particle bursts, the steady state concentrations of I2 vapour and particles larger than 3 nm were as high as 4 × 109–1.2 × 1010 cm−3 and 5.0 × 106–9.2 × 106 cm−3 respectively. The steady state was reached in less than 150 s and the predicted growth rates of 3–6 nm particles varied in the range of 1.2–3.6 nm min−1. Sensitivity of the size distribution against I2O3 cluster formation, an extra condensable vapour, the photolysis rate of the OIO vapour as well as against the density of (OIO)n-clusters was discussed. The modelled results were in good agreement with the chamber measurements performed during the BIOFLUX campaign in September, 2003, in Mace Head, Ireland, confirming that I2 emissions and nucleation of iodine oxides can largely explain the coastal nucleation phenomenon.

scholarly journals Aerosol dynamics within and above forest in relation to turbulent transport and dry deposition

2015 ◽  
Vol 15 (14) ◽  
pp. 19367-19403 ◽  
Author(s):  
Ü. Rannik ◽  
L. Zhou ◽  
P. Zhou ◽  
R. Gierens ◽  
I. Mammarella ◽  
...  
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Time Scales ◽  
Atmospheric Chemistry ◽  
Dry Deposition ◽  
Particle Deposition ◽  
Vertical Transport ◽  
Forest Site ◽  
Aerosol Dynamics ◽  
The Impact

Abstract. One dimensional atmospheric boundary layer (ABL) model coupled with detailed atmospheric chemistry and aerosol dynamical model, the model SOSAA, was used to predict the ABL and detailed aerosol population (characterized by the number size distribution) time evolution. The model was applied over a period of ten days in May 2013 for a pine forest site in southern Finland. The period was characterized by frequent new particle formation events and simultaneous intensive aerosol transformation. Throughout this study we refer to nucleation, condensational growth and coagulation as aerosol dynamical processes, i.e. the processes that govern the particle size distribution evolution. The aim of the study was to analyze and quantify the role of aerosol and ABL dynamics in vertical transport of aerosols. It was of particular interest to what extent the fluxes above canopy deviate due to above mentioned processes from the particle dry deposition on the canopy foliage. The model simulations revealed that the particle concentration change due to aerosol dynamics can frequently exceed the effect of particle deposition even an order of magnitude or more. The impact is however strongly dependent on particle size and time. In spite of the fact that the time scale of turbulent transfer inside canopy is much smaller than the time scales of aerosol dynamics and dry deposition, letting to assume well mixed properties of air, the fluxes at the canopy top frequently deviate from deposition inside forest. This is due to transformation of aerosol concentration throughout the ABL and resulting complicated pattern of vertical transport. Therefore we argue that the comparison of time scales of aerosol dynamics and deposition defined for the processes below the flux measurement level do not unambiguously describe the importance of aerosol dynamics for vertical transport within canopy. We conclude that under dynamical conditions the micrometeorological particle flux measurements such as performed by the eddy covariance technique do not generally represent the dry deposition. The deviation can be systematic for certain size ranges so that the conclusion applies also to time averaged particle fluxes.

scholarly journals The global impact of the transport sectors on atmospheric aerosol in 2030 – Part 1: Land transport and shipping

2015 ◽  
Vol 15 (2) ◽  
pp. 633-651 ◽  
Author(s):  
M. Righi ◽  
J. Hendricks ◽  
R. Sausen
Keyword(s):  
Atmospheric Chemistry ◽  
Atmospheric Aerosol ◽  
Radiative Forcing ◽  
Global Climate ◽  
Climate Impact ◽  
Radiation Budget ◽  
Intergovernmental Panel ◽  
Surface Level ◽  
Aerosol Dynamics ◽  
The Impact

Abstract. Using the EMAC (ECHAM/MESSy Atmospheric Chemistry) global climate-chemistry model coupled to the aerosol module MADE (Modal Aerosol Dynamics model for Europe, adapted for global applications), we simulate the impact of land transport and shipping emissions on global atmospheric aerosol and climate in 2030. Future emissions of short-lived gas and aerosol species follow the four Representative Concentration Pathways (RCPs) designed in support of the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. We compare the resulting 2030 land-transport- and shipping-induced aerosol concentrations to the ones obtained for the year 2000 in a previous study with the same model configuration. The simulations suggest that black carbon and aerosol nitrate are the most relevant pollutants from land transport in 2000 and 2030 and their impacts are characterized by very strong regional variations during this time period. Europe and North America experience a decrease in the land-transport-induced particle pollution, although in these regions this sector remains a major source of surface-level pollution in 2030 under all RCPs. In Southeast Asia, however, a significant increase is simulated, but in this region the surface-level pollution is still controlled by other sources than land transport. Shipping-induced air pollution is mostly due to aerosol sulfate and nitrate, which show opposite trends towards 2030. Sulfate is strongly reduced as a consequence of sulfur reduction policies in ship fuels in force since 2010, while nitrate tends to increase due to the excess of ammonia following the reduction in ammonium sulfate. The aerosol-induced climate impact of both sectors is dominated by aerosol-cloud effects and is projected to decrease between 2000 and 2030, nevertheless still contributing a significant radiative forcing to Earth's radiation budget.

scholarly journals Implementation of aerosol data assimilation in WRFDA (V4.0.3) for WRF-Chem (V3.9.1) using the MADE/VBS scheme

2021 ◽  
Author(s):  
Soyoung Ha
Keyword(s):  
Data Assimilation ◽  
Atmospheric Chemistry ◽  
Meteorological Data ◽  
Wrf Model ◽  
Basis Set ◽  
Weather Research And Forecasting ◽  
Systematic Bias ◽  
Dynamics Model ◽  
Aerosol Dynamics

Abstract. The Weather Research and Forecasting model data assimilation (WRFDA) system, initially designed for meteorological data assimilation, is extended for aerosol data assimilation for the WRF model coupled with Chemistry (WRF-Chem). An interface between WRF-Chem and WRFDA is built for the Regional Atmospheric Chemistry Mechanism (RACM) chemistry and the Modal Aerosol Dynamics Model for Europe (MADE) coupled with the Volatility Basis Set (VBS) aerosol schemes. This article describes the implementation of the new interface for assimilating PM2.5, PM10, and four gas species (SO2, NO2, O3, and co) on the ground. And the effects of aerosol data assimilation are briefly examined through a month-long case study during the Korea-United States Air Quality (KORUS-AQ) period. It is demonstrated that the 3DVAR analysis can lead to consistent forecast improvements up to 26 %, diminishing most systematic bias errors for 24 h.

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