Heatwave Variability and Structure in South Africa during Summer Drought

Pronounced subsidence leading to summer drought over southern Africa causes warmer than average surface air temperatures or even heatwave (HW) conditions. We investigated the occurrence of HWs during South based on station data and ECMWF ERA5 reanalyses. Temperature observations from African Weather Service were analyzed for seasonality long-term trends (1981–2020) as background variability HWs. focused three severe El Niño Southern Oscillation (ENSO)-induced seasons, i.e., 1982/83, 1991/92, 2015/16, investigate HW characteristics. While 1997/98 was among strongest impacts not because it coincided with an intense Angola low, which allowed rain-bearing cloud bands form. Results showed that hottest months spread across austral season December February. Regions experiencing high mean maximum frequencies exhibited a strong ENSO signal, record occurring 2015/16. The establishment persistence middle-level high-pressure system Botswana/Namibia (Botswana High) appears trigger longest-lasting seasons. Botswana is usually coupled near-surface continental heat low and/or tropical warm advection towards affected region. It also found ENSO-induced events frequency Africa, such recent 2015/16 events. results this study contribute understanding wave dynamics in region rapid warming result climate change.