The Impact of Orography on the African Easterly Wave Stormtrack
| Autor: | James O. H. Russell, Anantha Aiyyer, Joshua Dylan White |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Convection
Atmospheric Science 010504 meteorology & atmospheric sciences Baroclinity Diabatic Tropical wave FOS: Physical sciences Terrain Orography Numerical weather prediction 01 natural sciences Geophysics (physics.geo-ph) Physics - Geophysics Physics - Atmospheric and Oceanic Physics Geophysics 13. Climate action Space and Planetary Science Climatology Atmospheric and Oceanic Physics (physics.ao-ph) Earth and Planetary Sciences (miscellaneous) Geology 0105 earth and related environmental sciences Orographic lift |
| DOI: | 10.48550/arxiv.2103.08350 |
| Popis: | We examined the sensitivity of African easterly waves (AEWs) to elevated terrain over North Africa using a numerical weather prediction model. We formed five ensembles of simulated AEW activity with orographic features independently reduced in four key regions. The ensemble members consisted of 10 consecutive AEW seasons simulated separately. From the ensembles, the southern AEW stormtrack was most sensitive to the reduction of the Ethiopian highlands. Energy budgets showed that diminished diabatic heating associated with precipitating convection was the likely driver of the weaker AEWs. Baroclinic overturning was the dominant pathway for this response. The northern AEW stormtrack was most sensitive to the reduction of the Hoggar and Tibesti mountains. In this case, a reduction in the vertical shear and diminished baroclinic energy conversions from the background state was associated with weaker AEWs. Through terrain reduction, our results provide a view of thermodynamic and dynamic feedback in AEWs that is complementary to what has been shown in past studies. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|