Passive versus Active Transport of Saharan Dust Aerosols by African Easterly Waves
Theory and modeling are combined to reveal the physical and dynamical processes that control Saharan dust transport by amplifying African easterly waves (AEWs). Two cases are examined: active transport, in which the dust is radiatively coupled to the circulation; passive transport, in which the dust...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-11-01
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| Series: | Atmosphere |
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| Online Access: | https://www.mdpi.com/2073-4433/12/11/1509 |
| _version_ | 1827677300532969472 |
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| author | Dustin F. P. Grogan Terrence R. Nathan |
| author_facet | Dustin F. P. Grogan Terrence R. Nathan |
| author_sort | Dustin F. P. Grogan |
| collection | DOAJ |
| description | Theory and modeling are combined to reveal the physical and dynamical processes that control Saharan dust transport by amplifying African easterly waves (AEWs). Two cases are examined: active transport, in which the dust is radiatively coupled to the circulation; passive transport, in which the dust is radiatively decoupled from the circulation. The theory is built around a dust conservation equation for dust-coupled AEWs in zonal-mean African easterly jets. The theory predicts that, for both the passive and active cases, the dust transports will be largest where the zonal-mean dust gradients are maximized on an AEW critical surface. Whether the dust transports are largest for the radiatively passive or radiatively active case depends on the growth rate of the AEWs, which is modulated by the dust heating. The theoretical predictions are confirmed via experiments carried out with the Weather Research and Forecasting model, which is coupled to a dust conservation equation. The experiments show that the meridional dust transports dominate in the passive case, while the vertical dust transports dominate in the active case. |
| first_indexed | 2024-03-10T05:42:07Z |
| format | Article |
| id | doaj.art-54f91537d556442ca447f11d964889be |
| institution | Directory Open Access Journal |
| issn | 2073-4433 |
| language | English |
| last_indexed | 2024-03-10T05:42:07Z |
| publishDate | 2021-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Atmosphere |
| spelling | doaj.art-54f91537d556442ca447f11d964889be2023-11-22T22:25:27ZengMDPI AGAtmosphere2073-44332021-11-011211150910.3390/atmos12111509Passive versus Active Transport of Saharan Dust Aerosols by African Easterly WavesDustin F. P. Grogan0Terrence R. Nathan1Atmospheric Sciences Research Center, University at Albany, State University of New York, Albany, NY 12222, USAAtmospheric Science Program, Department of Land, Air and Water Resources, University of California Davis, Davis, CA 95616, USATheory and modeling are combined to reveal the physical and dynamical processes that control Saharan dust transport by amplifying African easterly waves (AEWs). Two cases are examined: active transport, in which the dust is radiatively coupled to the circulation; passive transport, in which the dust is radiatively decoupled from the circulation. The theory is built around a dust conservation equation for dust-coupled AEWs in zonal-mean African easterly jets. The theory predicts that, for both the passive and active cases, the dust transports will be largest where the zonal-mean dust gradients are maximized on an AEW critical surface. Whether the dust transports are largest for the radiatively passive or radiatively active case depends on the growth rate of the AEWs, which is modulated by the dust heating. The theoretical predictions are confirmed via experiments carried out with the Weather Research and Forecasting model, which is coupled to a dust conservation equation. The experiments show that the meridional dust transports dominate in the passive case, while the vertical dust transports dominate in the active case.https://www.mdpi.com/2073-4433/12/11/1509African easterly wavesSaharan dust transport |
| spellingShingle | Dustin F. P. Grogan Terrence R. Nathan Passive versus Active Transport of Saharan Dust Aerosols by African Easterly Waves Atmosphere African easterly waves Saharan dust transport |
| title | Passive versus Active Transport of Saharan Dust Aerosols by African Easterly Waves |
| title_full | Passive versus Active Transport of Saharan Dust Aerosols by African Easterly Waves |
| title_fullStr | Passive versus Active Transport of Saharan Dust Aerosols by African Easterly Waves |
| title_full_unstemmed | Passive versus Active Transport of Saharan Dust Aerosols by African Easterly Waves |
| title_short | Passive versus Active Transport of Saharan Dust Aerosols by African Easterly Waves |
| title_sort | passive versus active transport of saharan dust aerosols by african easterly waves |
| topic | African easterly waves Saharan dust transport |
| url | https://www.mdpi.com/2073-4433/12/11/1509 |
| work_keys_str_mv | AT dustinfpgrogan passiveversusactivetransportofsaharandustaerosolsbyafricaneasterlywaves AT terrencernathan passiveversusactivetransportofsaharandustaerosolsbyafricaneasterlywaves |