Articles | Volume 15, issue 6
https://doi.org/10.5194/os-15-1579-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/os-15-1579-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Environmental controls on marine productivity near Cape St. Francis, South Africa
Mark R. Jury
CORRESPONDING AUTHOR
Geography Department, University of Zululand, Kwadlangezwa, 3886, South Africa
Physics Department, University of Puerto Rico, Mayagüez, 00681, USA
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A unique link is found between the Caribbean GDP growth rate and the tropical climate system. Although the Pacific El Niño–Southern Oscillation governs some aspects of this link, the Walker circulation and associated humidity over the equatorial Atlantic emerge as leading predictors of economic prosperity in the central Antilles islands.
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The rate of change in the marine environment along the south coast of South Africa (32–37° S, 20–30° E) is studied using reanalysis observations for 1900–2015 and coupled ensemble model projections for 1980–2100. Although sea surface temperatures offshore are warming rapidly, a trend toward easterly winds and stronger shelf-edge currents have intensified nearshore upwelling (−0.03 °C yr−1) and contribute to a drier climate.
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A unique link is found between the Caribbean GDP growth rate and the tropical climate system. Although the Pacific El Niño–Southern Oscillation governs some aspects of this link, the Walker circulation and associated humidity over the equatorial Atlantic emerge as leading predictors of economic prosperity in the central Antilles islands.
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Mesoscale datasets are used to study coastal gradients in the marine climate and oceanography of False Bay, south of Cape Town. Building on past work, satellite and ocean–atmosphere reanalyses are used to gain new insights into the mean structure, circulation and meteorological features. HYCOM v3 hindcasts represent a coastward reduction of mixing that enhances stratification and productivity in False Bay during summer.
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The rate of change in the marine environment along the south coast of South Africa (32–37° S, 20–30° E) is studied using reanalysis observations for 1900–2015 and coupled ensemble model projections for 1980–2100. Although sea surface temperatures offshore are warming rapidly, a trend toward easterly winds and stronger shelf-edge currents have intensified nearshore upwelling (−0.03 °C yr−1) and contribute to a drier climate.
Mark R. Jury
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Preprint withdrawn
Short summary
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The climatic processes underlying drought in the SW Cape of South Africa are outlined. The area lies at the transition between the mid-latitude and sub-tropical regimes (34 S). There has been a gradual shift towards increased easterlies, longer dry summers and shorter wet winters. Consequently, water resources near Cape Town are drying up. High-resolution satellite reanalysis of land surface temperature and rainfall reveal the desiccating trends.
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Short summary
This research considers the physical environmental factors that underpin changes in ocean productivity over the shelf of South Africa, where coastal upwelling occurs next to a warm current. Statistical analysis of model assimilated data show that salinity and wind play prominent roles in changes of chlorophyll content, with possible consequences for the coastal fishery.
This research considers the physical environmental factors that underpin changes in ocean...