Seasonal and spatial variations of global aerosol optical depth: multi-year modelling with GEOS-Chem-APM and comparisons with multiple-platform observations
Recent AeroCom phase II experiments showed a large diversity in aerosol optical depth (AOD) among 16 detailed global aerosol models, which contributes to the large uncertainty in the predicted aerosol radiative forcing. The GEOS-Chem-APM, a global size-resolved aerosol model, can be considered as a...
Main Authors: | , |
---|---|
Format: | Article |
Language: | English |
Published: |
Stockholm University Press
2015-07-01
|
Series: | Tellus: Series B, Chemical and Physical Meteorology |
Subjects: | |
Online Access: | http://www.tellusb.net/index.php/tellusb/article/view/25115/pdf_26 |
_version_ | 1811291092914536448 |
---|---|
author | Xiaoyan Ma Fangqun Yu |
author_facet | Xiaoyan Ma Fangqun Yu |
author_sort | Xiaoyan Ma |
collection | DOAJ |
description | Recent AeroCom phase II experiments showed a large diversity in aerosol optical depth (AOD) among 16 detailed global aerosol models, which contributes to the large uncertainty in the predicted aerosol radiative forcing. The GEOS-Chem-APM, a global size-resolved aerosol model, can be considered as a representative AeroCom II model. In this study, multi-year AOD data (2004–2012) from ground-based Aerosol Robotic Network (AERONET) measurements and Moderate Resolution Imaging Spectroradiometer (MODIS), Multi-angle Imaging SpectroRadiometer (MISR) and Sea-viewing Wide Field-of-view Sensor (SeaWiFS) satellite retrievals are used to evaluate the performance of GEOS-Chem-APM in capturing observed seasonal and spatial AOD variations. Compared to the observations, the modelled AOD is overall good over land, but quite low over ocean possibly due to low sea salt emission in the model and/or higher AOD in satellite retrievals, specifically MODIS and MISR. We chose 72 AERONET sites having at least 36 months data available and representative of high spatial domain to compare with the model and satellite data. Comparisons in various representative regions show that the model overall agrees well in the major anthropogenic emission regions, such as Europe, East Asia and North America. Relative to the observations, the modelled AOD is systematically lower in biomass burning regions such as South Africa and South America possibly due to uncertainties in emission inventory, but slightly higher in North Africa likely associated with stronger dust emissions in the model. The model is able to capture the realistic seasonal cycle in all regions, including the peak of AOD in major dust events months and biomass burning seasons. The simulated inter-annual variability is overall consistent with the observations, which is distinctly shown in South Africa and South America with strong inter-annual variability compared to other regions. |
first_indexed | 2024-04-13T04:24:11Z |
format | Article |
id | doaj.art-a178bb361b8f4cb5a75ec72862621695 |
institution | Directory Open Access Journal |
issn | 1600-0889 |
language | English |
last_indexed | 2024-04-13T04:24:11Z |
publishDate | 2015-07-01 |
publisher | Stockholm University Press |
record_format | Article |
series | Tellus: Series B, Chemical and Physical Meteorology |
spelling | doaj.art-a178bb361b8f4cb5a75ec728626216952022-12-22T03:02:36ZengStockholm University PressTellus: Series B, Chemical and Physical Meteorology1600-08892015-07-0167011510.3402/tellusb.v67.2511525115Seasonal and spatial variations of global aerosol optical depth: multi-year modelling with GEOS-Chem-APM and comparisons with multiple-platform observationsXiaoyan Ma0Fangqun Yu1 Key Laboratory for Aerosol Cloud-Precipitation of China Meteorological Administration, Earth System Modeling Center, Nanjing University of Information Science and Technology, Nanjing, China Atmospheric Sciences Research Center, State University of New York, Albany, NY, USARecent AeroCom phase II experiments showed a large diversity in aerosol optical depth (AOD) among 16 detailed global aerosol models, which contributes to the large uncertainty in the predicted aerosol radiative forcing. The GEOS-Chem-APM, a global size-resolved aerosol model, can be considered as a representative AeroCom II model. In this study, multi-year AOD data (2004–2012) from ground-based Aerosol Robotic Network (AERONET) measurements and Moderate Resolution Imaging Spectroradiometer (MODIS), Multi-angle Imaging SpectroRadiometer (MISR) and Sea-viewing Wide Field-of-view Sensor (SeaWiFS) satellite retrievals are used to evaluate the performance of GEOS-Chem-APM in capturing observed seasonal and spatial AOD variations. Compared to the observations, the modelled AOD is overall good over land, but quite low over ocean possibly due to low sea salt emission in the model and/or higher AOD in satellite retrievals, specifically MODIS and MISR. We chose 72 AERONET sites having at least 36 months data available and representative of high spatial domain to compare with the model and satellite data. Comparisons in various representative regions show that the model overall agrees well in the major anthropogenic emission regions, such as Europe, East Asia and North America. Relative to the observations, the modelled AOD is systematically lower in biomass burning regions such as South Africa and South America possibly due to uncertainties in emission inventory, but slightly higher in North Africa likely associated with stronger dust emissions in the model. The model is able to capture the realistic seasonal cycle in all regions, including the peak of AOD in major dust events months and biomass burning seasons. The simulated inter-annual variability is overall consistent with the observations, which is distinctly shown in South Africa and South America with strong inter-annual variability compared to other regions.http://www.tellusb.net/index.php/tellusb/article/view/25115/pdf_26aerosol optical depthGEOS-Chem-APMMODISMISRSeaWiFSAERONET |
spellingShingle | Xiaoyan Ma Fangqun Yu Seasonal and spatial variations of global aerosol optical depth: multi-year modelling with GEOS-Chem-APM and comparisons with multiple-platform observations Tellus: Series B, Chemical and Physical Meteorology aerosol optical depth GEOS-Chem-APM MODIS MISR SeaWiFS AERONET |
title | Seasonal and spatial variations of global aerosol optical depth: multi-year modelling with GEOS-Chem-APM and comparisons with multiple-platform observations |
title_full | Seasonal and spatial variations of global aerosol optical depth: multi-year modelling with GEOS-Chem-APM and comparisons with multiple-platform observations |
title_fullStr | Seasonal and spatial variations of global aerosol optical depth: multi-year modelling with GEOS-Chem-APM and comparisons with multiple-platform observations |
title_full_unstemmed | Seasonal and spatial variations of global aerosol optical depth: multi-year modelling with GEOS-Chem-APM and comparisons with multiple-platform observations |
title_short | Seasonal and spatial variations of global aerosol optical depth: multi-year modelling with GEOS-Chem-APM and comparisons with multiple-platform observations |
title_sort | seasonal and spatial variations of global aerosol optical depth multi year modelling with geos chem apm and comparisons with multiple platform observations |
topic | aerosol optical depth GEOS-Chem-APM MODIS MISR SeaWiFS AERONET |
url | http://www.tellusb.net/index.php/tellusb/article/view/25115/pdf_26 |
work_keys_str_mv | AT xiaoyanma seasonalandspatialvariationsofglobalaerosolopticaldepthmultiyearmodellingwithgeoschemapmandcomparisonswithmultipleplatformobservations AT fangqunyu seasonalandspatialvariationsofglobalaerosolopticaldepthmultiyearmodellingwithgeoschemapmandcomparisonswithmultipleplatformobservations |