African low‐level jets and their importance for water vapor transport and rainfall
Uncertainty in the future evolution of tropical rainfall is linked to circulation changes under warming. In Africa, a key barrier to interpreting rainfall changes is our limited understanding of water vapor transport across the continent. Here, we show that a series of nocturnal easterly Low-Level J...
| Main Authors: | , , |
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| Format: | Journal article |
| Language: | English |
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AGU
2020
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| _version_ | 1826315330528477184 |
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| author | Munday, C Washington, R Hart, N |
| author_facet | Munday, C Washington, R Hart, N |
| author_sort | Munday, C |
| collection | OXFORD |
| description | Uncertainty in the future evolution of tropical rainfall is linked to circulation changes under warming. In Africa, a key barrier to interpreting rainfall changes is our limited understanding of water vapor transport across the continent. Here, we show that a series of nocturnal easterly Low-Level Jets (LLJs), which form in the valleys punctuating the East African rift system, transport the majority of water vapor to central Africa from the Indian Ocean. There is a robust connection between strengthened LLJs and drought in eastern and southern Africa at interannual timescales, mediated by an increase in low-level divergence and water vapor export. Analysis of climate model simulations at a wide range of resolutions (250–4.5 km) suggests that grid lengths <60 km are needed to simulate the salient structures of LLJs. The failure of coarse resolution models to capture LLJs is linked with biases in rainfall climatology and variability across the continent. |
| first_indexed | 2024-09-25T04:12:00Z |
| format | Journal article |
| id | oxford-uuid:4fbaba19-3d02-4392-a6cd-9815021a50aa |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-12-09T03:23:45Z |
| publishDate | 2020 |
| publisher | AGU |
| record_format | dspace |
| spelling | oxford-uuid:4fbaba19-3d02-4392-a6cd-9815021a50aa2024-11-22T18:32:03ZAfrican low‐level jets and their importance for water vapor transport and rainfallJournal articlehttp://purl.org/coar/resource_type/c_545buuid:4fbaba19-3d02-4392-a6cd-9815021a50aaEnglishBulkUploadREACH articlesAGU2020Munday, CWashington, RHart, NUncertainty in the future evolution of tropical rainfall is linked to circulation changes under warming. In Africa, a key barrier to interpreting rainfall changes is our limited understanding of water vapor transport across the continent. Here, we show that a series of nocturnal easterly Low-Level Jets (LLJs), which form in the valleys punctuating the East African rift system, transport the majority of water vapor to central Africa from the Indian Ocean. There is a robust connection between strengthened LLJs and drought in eastern and southern Africa at interannual timescales, mediated by an increase in low-level divergence and water vapor export. Analysis of climate model simulations at a wide range of resolutions (250–4.5 km) suggests that grid lengths <60 km are needed to simulate the salient structures of LLJs. The failure of coarse resolution models to capture LLJs is linked with biases in rainfall climatology and variability across the continent. |
| spellingShingle | Munday, C Washington, R Hart, N African low‐level jets and their importance for water vapor transport and rainfall |
| title | African low‐level jets and their importance for water vapor transport and rainfall |
| title_full | African low‐level jets and their importance for water vapor transport and rainfall |
| title_fullStr | African low‐level jets and their importance for water vapor transport and rainfall |
| title_full_unstemmed | African low‐level jets and their importance for water vapor transport and rainfall |
| title_short | African low‐level jets and their importance for water vapor transport and rainfall |
| title_sort | african low level jets and their importance for water vapor transport and rainfall |
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