South African drought, deconstructed
Drought is a slow onset, recurring and inevitable feature of South Africa's climate. This research deconstructs the meteorological processes underlying drought and its impacts on surface temperature and vegetation in the more productive eastern half of South Africa. We use an index area 22–31°S...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Elsevier
2021-09-01
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| Series: | Weather and Climate Extremes |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2212094721000323 |
| _version_ | 1818691987632553984 |
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| author | Hector Chikoore Mark R. Jury |
| author_facet | Hector Chikoore Mark R. Jury |
| author_sort | Hector Chikoore |
| collection | DOAJ |
| description | Drought is a slow onset, recurring and inevitable feature of South Africa's climate. This research deconstructs the meteorological processes underlying drought and its impacts on surface temperature and vegetation in the more productive eastern half of South Africa. We use an index area 22–31°S, 22–32°E and extract monthly satellite and reanalysis data in the period 1979–2019. Drought intensity is determined by i) vegetation color, ii) soil moisture, iii) maximum air temperature and iv) net outgoing longwave radiation. Global drivers are represented by tropical Pacific and Indian Ocean sea temperatures. Composite and regression analysis of drought reveals a mid-tropospheric anticyclone over Namibia induces equatorward flow and subsidence that drives away atmospheric moisture. This feature is associated with the Pacific El Niño, positive Indian Ocean Dipole and an accelerated westerly jet stream. Ocean warming east of Madagascar draws NW-cloud bands there. The advection of anticyclonic vorticity from the South Atlantic and standing atmospheric Rossby wave-trains are key features of South African drought. Dry spells in the summers of 2015, 2016 and 2019 were more intense than 1983 and 1992, as reflected by S-pan potential evaporation measurements >14 mm/day. Despite water deficits, maize yields and river discharge appear stable, due to the uptake of scientific advice and innovative engineering. |
| first_indexed | 2024-12-17T12:50:38Z |
| format | Article |
| id | doaj.art-c6393f6d659948ecb3596efbb6f8244f |
| institution | Directory Open Access Journal |
| issn | 2212-0947 |
| language | English |
| last_indexed | 2024-12-17T12:50:38Z |
| publishDate | 2021-09-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Weather and Climate Extremes |
| spelling | doaj.art-c6393f6d659948ecb3596efbb6f8244f2022-12-21T21:47:37ZengElsevierWeather and Climate Extremes2212-09472021-09-0133100334South African drought, deconstructedHector Chikoore0Mark R. Jury1Unit for Environmental Sciences and Management, North-West University, Vanderbijlpark, 1900, South AfricaPhysics Dept, University of Puerto Rico Mayagüez, PR, 00681, United States; University of Zululand, KwaDlangezwa, 3886, South Africa; Corresponding author. Physics Dept, University of Puerto Rico Mayagüez, PR, 00681, United States.Drought is a slow onset, recurring and inevitable feature of South Africa's climate. This research deconstructs the meteorological processes underlying drought and its impacts on surface temperature and vegetation in the more productive eastern half of South Africa. We use an index area 22–31°S, 22–32°E and extract monthly satellite and reanalysis data in the period 1979–2019. Drought intensity is determined by i) vegetation color, ii) soil moisture, iii) maximum air temperature and iv) net outgoing longwave radiation. Global drivers are represented by tropical Pacific and Indian Ocean sea temperatures. Composite and regression analysis of drought reveals a mid-tropospheric anticyclone over Namibia induces equatorward flow and subsidence that drives away atmospheric moisture. This feature is associated with the Pacific El Niño, positive Indian Ocean Dipole and an accelerated westerly jet stream. Ocean warming east of Madagascar draws NW-cloud bands there. The advection of anticyclonic vorticity from the South Atlantic and standing atmospheric Rossby wave-trains are key features of South African drought. Dry spells in the summers of 2015, 2016 and 2019 were more intense than 1983 and 1992, as reflected by S-pan potential evaporation measurements >14 mm/day. Despite water deficits, maize yields and river discharge appear stable, due to the uptake of scientific advice and innovative engineering.http://www.sciencedirect.com/science/article/pii/S2212094721000323South AfricaDroughtEl NiñoIndian ocean dipoleRossby wave trains |
| spellingShingle | Hector Chikoore Mark R. Jury South African drought, deconstructed Weather and Climate Extremes South Africa Drought El Niño Indian ocean dipole Rossby wave trains |
| title | South African drought, deconstructed |
| title_full | South African drought, deconstructed |
| title_fullStr | South African drought, deconstructed |
| title_full_unstemmed | South African drought, deconstructed |
| title_short | South African drought, deconstructed |
| title_sort | south african drought deconstructed |
| topic | South Africa Drought El Niño Indian ocean dipole Rossby wave trains |
| url | http://www.sciencedirect.com/science/article/pii/S2212094721000323 |
| work_keys_str_mv | AT hectorchikoore southafricandroughtdeconstructed AT markrjury southafricandroughtdeconstructed |