Abstract

JURY, Mark R. Climate trends across South Africa since 1980. Water SA [online]. 2018, vol.44, n.2, pp.297-307. ISSN 1816-7950.  http://dx.doi.org/10.4314/wsa.v44i2.15.

Observed and simulated climate trends across South Africa in the period 1980-2014 are studied. Observed CRU3/CAMS (Climate Research Unit v3 / Climate Analysis and Monitoring System) air temperatures have increased by 0.02°C-yr^-1 while NOAA/SODA sea temperatures have risen by 0.03°Gyr^-1 in the Agulhas Current. A poleward expansion of the South Atlantic high in NCEP2/MERRA (National Center for Environmental Prediction v2 / Modern-Era Retrospective analysis for Research and Applications) has produced a trend toward south-easterly flow which contributes to a moist-east/dry-west pattern. Observed CHIRPS2 rainfall and NDVI vegetation fraction show no appreciable trend except near Cape Town where drier conditions in the period 1980-2014 correspond with enhanced coastal upwelling. CMIP5 model projections for rainfall up to 2050 reflect drying, except in the eastern coastal plains. While inter-annual fluctuations of South African rainfall overshadow linear trends, temperature increases account for 32% of observed variance.

Keywords : South Africa; climate change; satellite era.

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