Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1175/JAS-D-19-0104.1 |
Structural Changes in the African Easterly Jet and Its Role in Mediating the Effects of Saharan Dust on the Linear Dynamics of African Easterly Waves | |
Grogan, Dustin F. P.1; Nathan, Terrence R.2; Chen, Shu-Hua2 | |
2019-11-01 | |
发表期刊 | JOURNAL OF THE ATMOSPHERIC SCIENCES |
ISSN | 0022-4928 |
EISSN | 1520-0469 |
出版年 | 2019 |
卷号 | 76期号:11页码:3351-3365 |
文章类型 | Article |
语种 | 英语 |
国家 | USA |
英文摘要 | Analytical and numerical analyses are used to examine how structural changes to the African easterly jet (AEJ) mediate the effects of Saharan mineral dust aerosols on the linear dynamics of African easterly waves (AEWs). An analytical expression for the generation of eddy available potential energy (APE) is derived that exposes how the AEJ and dust combine to affect the energetics of the AEWs. The expression is also used to interpret the numerical results, which are obtained by radiatively coupling a simplified version of the Weather Research and Forecasting Model to a conservation equation for dust. The WRF-Dust model is used to conduct linear simulations based on five observationally consistent zonal-mean AEJs: a reference AEJ and four other AEJs that are obtained by perturbing the maximum meridional and vertical shear. For a dust distribution consistent with summertime observations over North Africa, the numerical simulations show the following: (i) Irrespective of the AEJ structure or the zonal scale of the AEWs, the dust increases the growth rates of the AEWs. (ii) The growth rates of the AEWs are optimized when the ratio of baroclinic to barotropic energy conversions is largest. (iii) When the energy conversions are sufficiently large, the zonal scale of the fastest-growing AEW shortens. The numerical results confirm the analytical analysis, which shows that the dust effects, which are modulated by the Doppler-shifted frequency, are strongest north of the AEJ axis, a region where the dust augments the preexisting meridional temperature gradient. |
英文关键词 | Atmosphere Africa Dynamics Large-scale motions Dust or dust storms Aerosol radiative effect |
领域 | 地球科学 |
收录类别 | SCI-E |
WOS记录号 | WOS:000490476800004 |
WOS关键词 | MINERAL DUST ; PHASE-III ; DISTURBANCES ; ENERGETICS ; AEROSOLS ; IMPACT ; WET |
WOS类目 | Meteorology & Atmospheric Sciences |
WOS研究方向 | Meteorology & Atmospheric Sciences |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/188134 |
专题 | 地球科学 |
作者单位 | 1.SUNY Albany, Dept Atmospher & Environm Sci, Albany, NY 12222 USA; 2.Univ Calif Davis, Atmospher Sci Program, Dept Land Air & Water Resources, Davis, CA 95616 USA |
推荐引用方式 GB/T 7714 | Grogan, Dustin F. P.,Nathan, Terrence R.,Chen, Shu-Hua. Structural Changes in the African Easterly Jet and Its Role in Mediating the Effects of Saharan Dust on the Linear Dynamics of African Easterly Waves[J]. JOURNAL OF THE ATMOSPHERIC SCIENCES,2019,76(11):3351-3365. |
APA | Grogan, Dustin F. P.,Nathan, Terrence R.,&Chen, Shu-Hua.(2019).Structural Changes in the African Easterly Jet and Its Role in Mediating the Effects of Saharan Dust on the Linear Dynamics of African Easterly Waves.JOURNAL OF THE ATMOSPHERIC SCIENCES,76(11),3351-3365. |
MLA | Grogan, Dustin F. P.,et al."Structural Changes in the African Easterly Jet and Its Role in Mediating the Effects of Saharan Dust on the Linear Dynamics of African Easterly Waves".JOURNAL OF THE ATMOSPHERIC SCIENCES 76.11(2019):3351-3365. |
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