scholarly journals Influence of atmospheric in-cloud aqueous-phase chemistry on global simulation of SO<sub>2</sub> in CESM2

2021 ◽  
Author(s):  
Wendong Ge ◽  
Junfeng Liu ◽  
Kan Yi ◽  
Jiayu Xu ◽  
Yizhou Zhang ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
The United States ◽  
Cloud Microphysics ◽  
So2 Oxidation ◽  
Atmospheric Pollutant ◽  
Global Simulation ◽  
Ph Values ◽  
Community Earth System Model ◽  
Sulfate Formation ◽  
Phase Chemistry

Abstract. Sulfur dioxide (SO2) is a major atmospheric pollutant and precursor of sulfate aerosols, which influences air quality, cloud microphysics and climate. Therefore, better understanding the conversion of SO2 to sulfate is essential to simulate and predict sulfur compounds more accurately. This study evaluates the effects of in-cloud aqueous-phase chemistry on SO2 oxidation in the Community Earth System Model version 2 (CESM2). We replaced the default aqueous-phase reactions with detailed HOx-, Fe-, N- and carbonate chemistry and performed a global simulation for 2014–2015. Compared with the observations, the results incorporating detailed aqueous-phase chemistry greatly reduced SO2 overestimation. This overestimation was reduced by 0.1–10 ppbv in most of Europe, North America and Asia and more than 10 ppbv in parts of China. The biases in annual simulated SO2 concentrations decreased by 46 %, 41 %, and 22 % in Europe, the United States and China, respectively. Fe-chemistry and HOx-chemistry contributed more to SO2 oxidation than N-chemistry. Higher concentrations of soluble Fe and higher pH values could further enhance the oxidation capacity. This study emphasizes the importance of detailed aqueous-phase chemistry for the oxidation of SO2. These mechanisms can improve SO2 simulation in CESM2 and deepen understanding of SO2 oxidation and sulfate formation.

scholarly journals Influence of atmospheric in-cloud aqueous-phase chemistry on the global simulation of SO<sub>2</sub> in CESM2

2021 ◽  
Vol 21 (21) ◽  
pp. 16093-16120
Author(s):  
Wendong Ge ◽  
Junfeng Liu ◽  
Kan Yi ◽  
Jiayu Xu ◽  
Yizhou Zhang ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Cloud Microphysics ◽  
So2 Oxidation ◽  
Cloud Droplets ◽  
Atmospheric Pollutant ◽  
Global Simulation ◽  
Mixing Ratios ◽  
The Usa ◽  
Community Earth System Model ◽  
Phase Chemistry

Abstract. Sulfur dioxide (SO2) is a major atmospheric pollutant and precursor of sulfate aerosols, which influences air quality, cloud microphysics, and climate. Therefore, better understanding the conversion of SO2 to sulfate is essential to simulate and predict sulfur compounds more accurately. This study evaluates the effects of in-cloud aqueous-phase chemistry on SO2 oxidation in the Community Earth System Model version 2 (CESM2). We replaced the default parameterized SO2 aqueous-phase reactions with detailed HOx, Fe, N, and carbonate chemistry in cloud droplets and performed a global simulation for 2014–2015. Compared with the observations, the results incorporating detailed cloud aqueous-phase chemistry greatly reduced SO2 overestimation. This overestimation was reduced by 0.1–10 ppbv (parts per billion by volume) in most of Europe, North America, and Asia and more than 10 ppbv in parts of China. The biases in annual simulated SO2 mixing ratios decreased by 46 %, 41 %, and 22 % in Europe, the USA, and China, respectively. Fe chemistry and HOx chemistry contributed more to SO2 oxidation than N chemistry. Higher concentrations of soluble Fe and higher pH values could further enhance the oxidation capacity. This study emphasizes the importance of detailed in-cloud aqueous-phase chemistry for the oxidation of SO2. These mechanisms can improve SO2 simulation in CESM2 and deepen understanding of SO2 oxidation and sulfate formation.

scholarly journals An advanced scheme for wet scavenging and liquid-phase chemistry in a regional online-coupled chemistry transport model

2013 ◽  
Vol 13 (3) ◽  
pp. 1177-1192 ◽  
Author(s):  
C. Knote ◽  
D. Brunner
Keyword(s):  
Aqueous Phase ◽  
Climate Model ◽  
Transport Model ◽  
Measurement Data ◽  
Coupled System ◽  
Cloud Microphysics ◽  
Microphysics Scheme ◽  
Meteorological Model ◽  
Wet Scavenging ◽  
Phase Chemistry

Abstract. Clouds are reaction chambers for atmospheric trace gases and aerosols, and the associated precipitation is a major sink for atmospheric constituents. The regional chemistry-climate model COSMO-ART has been lacking a description of wet scavenging of gases and aqueous-phase chemistry. In this work we present a coupling of COSMO-ART with a wet scavenging and aqueous-phase chemistry scheme. The coupling is made consistent with the cloud microphysics scheme of the underlying meteorological model COSMO. While the choice of the aqueous-chemistry mechanism is flexible, the effects of a simple sulfur oxidation scheme are shown in the application of the coupled system in this work. We give details explaining the coupling and extensions made, then present results from idealized flow-over-hill experiments in a 2-D model setup and finally results from a full 3-D simulation. Comparison against measurement data shows that the scheme efficiently reduces SO2 trace gas concentrations by 0.3 ppbv (−30%) on average, while leaving O3 and NOx unchanged. PM10 aerosol mass was increased by 10% on average. While total PM2.5 changes only little, chemical composition is improved notably. Overestimations of nitrate aerosols are reduced by typically 0.5–1 μg m−3 (up to −2 μg m−3 in the Po Valley) while sulfate mass is increased by 1–1.5 μg m−3 on average (up to 2.5 μg m−3 in Eastern Europe). The effect of cloud processing of aerosols on its size distribution, i.e. a shift towards larger diameters, is observed. Compared against wet deposition measurements the system tends to underestimate the total wet deposited mass for the simulated case study.

scholarly journals Further improvement of wet process treatments in GEOS-Chem v12.6.0: Impact on global distributions of aerosol precursors and aerosols

2020 ◽  
Author(s):  
Gan Luo ◽  
Fangqun Yu ◽  
Jonathan M. Moch
Keyword(s):  
Nitric Acid ◽  
Black Carbon ◽  
Aqueous Phase ◽  
Dry Deposition ◽  
The United States ◽  
Surface Mass ◽  
Wet Process ◽  
Wet Surface ◽  
Phase Chemistry ◽  
Mass Concentrations

Abstract. Wet processes, including aqueous phase chemistry, wet scavenging, and wet surface uptakes during dry deposition, are important for global modeling of aerosol precursors and aerosols. In this study, we improved the treatments of these wet processes in the GEOS-Chem v12.6.0, including pH calculation for cloud, rain, and wet surface, fraction of cloud available for aqueous phase chemistry, rainout efficiencies for various types of cloud, empirical washout by rain and snow, and wet surface uptakes during dry deposition. We compared simulated surface mass concentrations of aerosol precursors and aerosols with surface monitoring networks over the United States, Europe, Asia, and Arctic regions, and showed that the model results with the updated wet processes agree better with measurements for most species. With the implementation of these updates, normalized mean biases (NMB) of surface nitric acid, nitrate, and ammonium are reduced from 78 %, 126 %, and 45 % to 13 %, 24 %, and 6.2 % over US sites, from 56 %, 105 %, and 91 % to −20 %, −5.1 %, and 22 % over Europe sites, and from 121 %, 269 %, and 167 % to −18 %, 40 %, and 86 % over Asia sites. Comparison with surface measured SO2, sulfate and black carbon at four Arctic sites indicated that these species simulated with the updated wet processes match well with observations except large underestimation of black carbon at one of the sites. Furthermore, we compared model simulation with aircraft measurement of nitric acid and aerosols during ATom-1 and ATom-2 periods and found seasonal variation and vertical profile of these species have been successfully improved by considering the updated wet processes. The investigation of impacts of updated wet process treatments on surface mass concentrations indicated that the updated wet processes have strong impacts on the global means of nitric acid, sulfate, nitrate, and ammonium and relative small impacts on the global means of sulfur dioxide, dust, sea salt, black carbon, and organic carbon.

scholarly journals An advanced scheme for wet scavenging and liquid-phase chemistry in a regional online-coupled chemistry transport model

2012 ◽  
Vol 12 (10) ◽  
pp. 26099-26142
Author(s):  
C. Knote ◽  
D. Brunner
Keyword(s):  
Aqueous Phase ◽  
Climate Model ◽  
Transport Model ◽  
Measurement Data ◽  
Coupled System ◽  
Cloud Microphysics ◽  
Microphysics Scheme ◽  
Meteorological Model ◽  
Wet Scavenging ◽  
Phase Chemistry

Abstract. Clouds are reaction chambers for atmospheric trace gases and aerosols, and the associated precipitation is a major sink for atmospheric constituents. The regional chemistry-climate model COSMO-ART has been lacking a description of wet scavenging of gases and aqueous-phase chemistry. In this work we present a coupling of COSMO-ART with a wet scavenging and aqueous-phase chemistry scheme. The coupling is made consistent with the cloud microphysics scheme of the underlying meteorological model COSMO. While the choice of the aqueous-chemistry mechanism is flexible, the effects of a simple sulfur oxidation scheme are shown in the application of the coupled system in this work. We give details explaining the coupling and extensions made, then present results from idealized flow-over-hill experiments in a 2-D model setup and finally results from a full 3-D simulation. Comparison against measurement data shows that the scheme efficiently reduces SO2 trace gas concentrations by 0.3 ppbv (−30%) on average, while leaving O3 and NOx unchanged. PM10 aerosol mass, which has been overestimated previously, is now in much better agreement with measured values due to a stronger scavenging of coarse particles. While total PM2.5 changes only little, chemical composition is improved notably. Overestimations of nitrate aerosols are reduced by typically 0.5–1 μg m−3 (up to −2 μg m−3 in the Po Valley) while sulfate mass is increased by 1–1.5 μg m−3 on average (up to 2.5 μg m−3 in Eastern Europe). The effect of cloud processing of aerosols on its size distribution, i. e. a shift towards larger diameters, is observed. Compared against wet deposition measurements the system underestimates the total wet deposited mass for the simulated case study. We find that while evaporation of cloud droplets dominates in higher altitudes, evaporation of precipitation can contribute up to 50% of total evaporated mass near the surface.

scholarly journals libcloudph++ 1.1: aqueous phase chemistry extension of the Lagrangian cloud microphysics scheme

2018 ◽  
Author(s):  
Anna Jaruga ◽  
Hanna Pawlowska
Keyword(s):  
Programming Languages ◽  
Aqueous Phase ◽  
Numerical Models ◽  
Cloud Condensation Nuclei ◽  
Cloud Microphysics ◽  
Chemical Processes ◽  
Cloud Droplets ◽  
Microphysics Scheme ◽  
Phase Oxidation ◽  
Phase Chemistry

Abstract. This paper introduces a new scheme available in the library of algorithms for representing cloud microphysics in numerical models named libcloudph++. The scheme extends the Lagrangian microphysics scheme available in libcloudph++ to the aqueous phase chemical processes occurring within cloud droplets. The representation of chemical processes focuses on the aqueous phase oxidation of the dissolved SO2 by O3 and H2O2. The Lagrangian Microphysics and Chemistry (LMC) scheme allows tracking the changes in the cloud condensation nuclei (CCN) distribution caused by both collisions between cloud droplets and aqueous phase oxidation. The scheme is implemented in C++ and equipped with bindings to Python which allow reusing the created scheme from models implemented in other programming languages. The scheme can be used on either CPU or GPU, and is distributed under the GPL3 license. Here, the LMC scheme is tested in a simple 0-dimensional adiabatic parcel model and then used in a 2-dimensional prescribed flow framework. The results are discussed with the focus on changes to the CCN sizes and compared with other model simulations discussed in the literature.

scholarly journals libcloudph++ 2.0: aqueous-phase chemistry extension of the particle-based cloud microphysics scheme

2018 ◽  
Vol 11 (9) ◽  
pp. 3623-3645 ◽  
Author(s):  
Anna Jaruga ◽  
Hanna Pawlowska
Keyword(s):  
Aqueous Phase ◽  
Numerical Models ◽  
Cloud Condensation Nuclei ◽  
Cloud Microphysics ◽  
Chemical Processes ◽  
Cloud Droplets ◽  
Microphysics Scheme ◽  
Phase Oxidation ◽  
Phase Chemistry ◽  
Phase Chemical

Abstract. This paper introduces a new scheme available in the library of algorithms for representing cloud microphysics in numerical models named libcloudph++. The scheme extends the particle-based microphysics scheme with a Monte Carlo coalescence available in libcloudph++ to the aqueous-phase chemical processes occurring within cloud droplets. The representation of chemical processes focuses on the aqueous-phase oxidation of the dissolved SO2 by O3 and H2O2. The particle-based microphysics and chemistry scheme allows for tracking of the changes in the cloud condensation nuclei (CCN) distribution caused by both collisions between cloud droplets and aqueous-phase oxidation. The scheme is implemented in C++ and equipped with bindings to Python. The scheme can be used on either a CPU or a GPU, and is distributed under the GPLv3 license. Here, the particle-based microphysics and chemistry scheme is tested in a simple 0-dimensional adiabatic parcel model and then used in a 2-dimensional prescribed flow framework. The results are discussed with a focus on changes to the CCN sizes and comparison with other model simulations discussed in the literature.

The Impact of the Aqueous Phase Chemistry of HNO4 on Gas Phase Tropospheric Chemistry

2001 ◽  
Vol 32 ◽  
pp. 269-270
Author(s):  
J.E. WILLIAMS ◽  
F.J. DENTENER ◽  
A.R. van den BERG
Keyword(s):  
Gas Phase ◽  
Aqueous Phase ◽  
Tropospheric Chemistry ◽  
Phase Chemistry ◽  
The Impact
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