On Tanzania’s Precipitation Climatology, Variability, and Future Projection

Climate

Liping Deng¹  Brennan Bean²  Binod Pokharel³  S.-Y.Simon Wang³  Krishna Borhara³ 

[1]College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang 524088, Guangdong, China

[2]Department of Mathematics and Statistics, Utah State University, Logan, UT 84322, USA

[3]Department of Plants, Soils and Climate, Utah State University, Logan, UT 84322, USA

关键词: east africa;    tanzania;    climatology;    rainfall variability;    trend analysis;    empirical orthogonal functions;    indian ocean;    el niño-southern oscillation;    projection;   

DOI  :  10.3390/cli8020034

来源: DOAJ

【 摘 要 】

We investigate historical and projected precipitation in Tanzania using observational and climate model data. Precipitation in Tanzania is highly variable in both space and time due to topographical variations, coastal influences, and the presence of lakes. Annual and seasonal precipitation trend analyses from 1961 to 2016 show maximum rainfall decline in Tanzania during the long rainy season in the fall (March−May), and an increasing precipitation trend in northwestern Tanzania during the short rainy season in the spring (September−November). Empirical orthogonal function (EOF) analysis applied to Tanzania’s precipitation patterns shows a stronger correlation with warmer temperatures in the western Indian Ocean than with the eastern-central Pacific Ocean. Years with decreasing precipitation in Tanzania appear to correspond with increasing sea surface temperatures (SST) in the Indian Ocean, suggesting that the Indian Ocean Dipole (IOD) may have a greater effect on rainfall variability in Tanzania than the El Niño-Southern Oscillation (ENSO) does. Overall, the climate model ensemble projects increasing precipitation trend in Tanzania that is opposite with the historical decrease in precipitation. This observed drying trend also contradicts a slightly increasing precipitation trend from climate models for the same historical time period, reflecting challenges faced by modern climate models in representing Tanzania’s precipitation.

【 授权许可】

Unknown