Recurrent daily OLR patterns in the Southern Africa/Southwest Indian Ocean region, implications for South African rainfall and teleconnections

Fauchereau, Nicolas; Pohl, Benjamin; Reason, C. J. C.; Rouault, Mathieu; Richard, Yves

doi:10.1007/s00382-008-0426-2

Cited by 127 publications

(175 citation statements)

References 34 publications

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“…The allyear nature of rainfall of this region is in strong contrast to the pronounced seasonality that characterizes rainfall over most of South Africa: the country is largely a summer rainfall region (e.g. Fauchereau et al 2009), with winter rainfall occurring over the southwestern Cape area ( Fig. 1) (e.g.…”

Section: Introductionmentioning

confidence: 87%

A synoptic decomposition of rainfall over the Cape south coast of South Africa

et al. 2014

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Section: Introductionmentioning

confidence: 87%

A synoptic decomposition of rainfall over the Cape south coast of South Africa

et al. 2014

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“…A large proportion of southern African rainfall is associated with TTT systems (Harrison 1984), particularly heavy rainfall (Hart et al 2013). TTTs are therefore a good target for evaluation in terms of impact relevance and might also be an indicator of the credibility of modeled regional dynamics: the location and character of tropical convection, storm tracks, subtropical highs, and the Angola low might all influence the formation of TTCBs (Todd et al 2004;Fauchereau et al 2009;Hart et al 2010;Ratna et al 2013;Macron et al 2014).…”

Section: Pan-africanmentioning

confidence: 99%

Evaluating Climate Models with an African Lens

James

Washington

Abiodun

et al. 2018

Bulletin of the American Meteorological Society

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“…8 Model simulated DJF mean climatology (1991/1992-2010/2011) of total rainfall (mm/day, left panel), convective rainfall (%, middle panel) and stratiform rainfall (%, right panel) Washington and Preston 2006;Fauchereau et al 2009). In any attempt to employ a RCM for short and longer-term prediction, it is important to determine if the RCM is capable of capturing the observed interannual variability.…”

Section: Interannual Variabilitymentioning

confidence: 99%

Performance assessment of three convective parameterization schemes in WRF for downscaling summer rainfall over South Africa

et al. 2013

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Austral summer rainfall over the period 1991/1992 to 2010/2011 was dynamically downscaled by the weather research and forecasting (WRF) model at 9 km resolution for South Africa. Lateral boundary conditions for WRF were provided from the European Centre for medium-range weather (ECMWF) reanalysis (ERA) interim data. The model biases for the rainfall were eval-uated over the South Africa as a whole and its nine prov-inces separately by employing three different convective parameterization schemes, namely the (1) Kain-Fritsch (KF), (2) Betts-Miller-Janjic (BMJ) and (3) Grell-Devenyi ensemble (GDE) schemes. All three schemes have gener-ated positive rainfall biases over South Africa, with the KF scheme producing the largest biases and mean absolute errors. Only the BMJ scheme could reproduce the intensity of rainfall anomalies, and also exhibited the highest cor-relation with observed interannual summer rainfall variability. In the KF scheme, a significantly high amount of moisture was transported from the tropics into South Africa. The vertical thermodynamic profiles show that the KF scheme has caused low level moisture convergence, due to the highly unstable atmosphere, and hence con-tributed to the widespread positive biases of rainfall. The negative bias in moisture, along with a stable atmosphere and negative biases of vertical velocity simulated by the GDE scheme resulted in negative rainfall biases, especially over the Limpopo Province. In terms of rain rate, the KF scheme generated the lowest number of low rain rates and the maximum number of moderate to high rain rates associated with more convective unstable environment. KF and GDE schemes overestimated the convective rain and underestimated the stratiform rain. However, the simulated convective and stratiform rain with BMJ scheme is in more agreement with the observations. This study also docu-ments the performance of regional model in downscaling the large scale climate mode such as El Nin˜o Southern Oscillation (ENSO) and subtropical dipole modes. The correlations between the simulated area averaged rainfalls over South Africa and Nino3.4 index were -0.66, -0.69 and -0.49 with KF, BMJ and GDE scheme respectively as compared to the observed correlation of -0.57. The model could reproduce the observed ENSO-South Africa rainfall relationship and could successfully simulate three wet (dry) years that are associated with La Nin˜a (El Ni˜no) and the BMJ scheme is closest to the observed variability. Also, the model showed good skill in simulating the excess rainfall over South Africa that is associated with positive sub-tropical Indian Ocean Dipole for the DJF season 2005/2006.

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Recurrent daily OLR patterns in the Southern Africa/Southwest Indian Ocean region, implications for South African rainfall and teleconnections

Cited by 127 publications

References 34 publications

A synoptic decomposition of rainfall over the Cape south coast of South Africa

A synoptic decomposition of rainfall over the Cape south coast of South Africa

Evaluating Climate Models with an African Lens

Performance assessment of three convective parameterization schemes in WRF for downscaling summer rainfall over South Africa

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