New developments in the representation of Saharan dust sources in the aerosol–climate model ECHAM6-HAM2
In the aerosol–climate model ECHAM6-HAM2, dust source activation (DSA) observations from Meteosat Second Generation (MSG) satellite are proposed to replace the original source area parameterization over the Sahara Desert. The new setup is tested in nudged simulations for the period 2007 to 2008. The...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2016-02-01
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| Series: | Geoscientific Model Development |
| Online Access: | http://www.geosci-model-dev.net/9/765/2016/gmd-9-765-2016.pdf |
| _version_ | 1811300184590647296 |
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| author | B. Heinold I. Tegen K. Schepanski J. R. Banks |
| author_facet | B. Heinold I. Tegen K. Schepanski J. R. Banks |
| author_sort | B. Heinold |
| collection | DOAJ |
| description | In the aerosol–climate model ECHAM6-HAM2, dust source activation (DSA)
observations from Meteosat Second Generation (MSG) satellite are proposed to
replace the original source area parameterization over the Sahara Desert.
The new setup is tested in nudged simulations for the period 2007 to 2008.
The evaluation is based on comparisons to dust emission events inferred from
MSG dust index imagery, Aerosol Robotic Network (AERONET) sun photometer observations, and satellite
retrievals of aerosol optical thickness (AOT).<br><br>The model results agree well with AERONET measurements especially in terms
of seasonal variability, and a good spatial correlation was found between
model results and MSG-SEVIRI (Spinning-Enhanced Visible and InfraRed Imager) dust AOT as well as Multi-angle Imaging SpectroRadiometer (MISR) AOT. ECHAM6-HAM2 computes a more realistic
geographical distribution and up to 20 % higher annual Saharan dust
emissions, using the MSG-based source map. The representation of dust AOT is
partly improved in the southern Sahara and Sahel. In addition, the spatial
variability is increased towards a better agreement with observations
depending on the season. Thus, using the MSG DSA map can help to circumvent
the issue of uncertain soil input parameters.<br><br>An important issue remains the need to improve the model representation of
moist convection and stable nighttime conditions. Compared to sub-daily DSA
information from MSG-SEVIRI and results from a regional model, ECHAM6-HAM2
notably underestimates the important fraction of morning dust events by the
breakdown of the nocturnal low-level jet, while a major contribution is from
afternoon-to-evening emissions. |
| first_indexed | 2024-04-13T06:47:30Z |
| format | Article |
| id | doaj.art-51985f1cf36c4092ba88bad4f65bd512 |
| institution | Directory Open Access Journal |
| issn | 1991-959X 1991-9603 |
| language | English |
| last_indexed | 2024-04-13T06:47:30Z |
| publishDate | 2016-02-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Geoscientific Model Development |
| spelling | doaj.art-51985f1cf36c4092ba88bad4f65bd5122022-12-22T02:57:31ZengCopernicus PublicationsGeoscientific Model Development1991-959X1991-96032016-02-019276577710.5194/gmd-9-765-2016New developments in the representation of Saharan dust sources in the aerosol–climate model ECHAM6-HAM2B. Heinold0I. Tegen1K. Schepanski2J. R. Banks3Leibniz Institute for Tropospheric Research (TROPOS), Leipzig, GermanyLeibniz Institute for Tropospheric Research (TROPOS), Leipzig, GermanyLeibniz Institute for Tropospheric Research (TROPOS), Leipzig, GermanyLeibniz Institute for Tropospheric Research (TROPOS), Leipzig, GermanyIn the aerosol–climate model ECHAM6-HAM2, dust source activation (DSA) observations from Meteosat Second Generation (MSG) satellite are proposed to replace the original source area parameterization over the Sahara Desert. The new setup is tested in nudged simulations for the period 2007 to 2008. The evaluation is based on comparisons to dust emission events inferred from MSG dust index imagery, Aerosol Robotic Network (AERONET) sun photometer observations, and satellite retrievals of aerosol optical thickness (AOT).<br><br>The model results agree well with AERONET measurements especially in terms of seasonal variability, and a good spatial correlation was found between model results and MSG-SEVIRI (Spinning-Enhanced Visible and InfraRed Imager) dust AOT as well as Multi-angle Imaging SpectroRadiometer (MISR) AOT. ECHAM6-HAM2 computes a more realistic geographical distribution and up to 20 % higher annual Saharan dust emissions, using the MSG-based source map. The representation of dust AOT is partly improved in the southern Sahara and Sahel. In addition, the spatial variability is increased towards a better agreement with observations depending on the season. Thus, using the MSG DSA map can help to circumvent the issue of uncertain soil input parameters.<br><br>An important issue remains the need to improve the model representation of moist convection and stable nighttime conditions. Compared to sub-daily DSA information from MSG-SEVIRI and results from a regional model, ECHAM6-HAM2 notably underestimates the important fraction of morning dust events by the breakdown of the nocturnal low-level jet, while a major contribution is from afternoon-to-evening emissions.http://www.geosci-model-dev.net/9/765/2016/gmd-9-765-2016.pdf |
| spellingShingle | B. Heinold I. Tegen K. Schepanski J. R. Banks New developments in the representation of Saharan dust sources in the aerosol–climate model ECHAM6-HAM2 Geoscientific Model Development |
| title | New developments in the representation of Saharan dust sources in the aerosol–climate model ECHAM6-HAM2 |
| title_full | New developments in the representation of Saharan dust sources in the aerosol–climate model ECHAM6-HAM2 |
| title_fullStr | New developments in the representation of Saharan dust sources in the aerosol–climate model ECHAM6-HAM2 |
| title_full_unstemmed | New developments in the representation of Saharan dust sources in the aerosol–climate model ECHAM6-HAM2 |
| title_short | New developments in the representation of Saharan dust sources in the aerosol–climate model ECHAM6-HAM2 |
| title_sort | new developments in the representation of saharan dust sources in the aerosol climate model echam6 ham2 |
| url | http://www.geosci-model-dev.net/9/765/2016/gmd-9-765-2016.pdf |
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