Changes in Near-Surface Temperature in Ghana, West Africa and the links with Climatic Factors

Abstract Near-surface air temperature (NST) plays a critical role in the weather and climate systems. Understanding its variability and the associated influencing factors is extremely important due to its dynamic variations in space and time at global, continental, regional, and local scales. In this study, we first investigate the long-term changes of NST from 1981 to 2020 in Ghana by examining their Spatio-temporal characteristics using Climatic Research Unit (CRU) and Climate Prediction Centre (CPC) datasets. The two datasets showed increasing trends in the annual mean NST from 1981 to 2020, with the strongest warming ranging from 0.1 to 0.9 oC found over the last two decades. The Pruned exact linear-time algorithm is used to assess where the mean temperature experienced a significant change. The potential causes and implications of this shift are investigated by assessing changes in other climatic factors before and after the breakpoint of NST warming. The increases were characterized by abrupt NST changes in the linear trends when we compared warming in the current period (1998–2020) with the recent past (1981–1997), suggesting a clear shift in climate conditions. The mechanisms influencing the shifts in NST changes showed a strong relationship with land surface temperature (r = 0.81 and 0.82 for annual and the seasons) and the 500 hPa geopotential height (r = 0.67 0.74, and 0.72) for the annual, February to March (FMAM) and June to September (JJAS) seasons respectively. Suggesting recent changes in the atmosphere and land may be connected to NST variation in Ghana.