TITLE:
Assessment of the Spatio-Temporal Trends of Annual Extreme Temperature Indices over Tanzania during the Period of 1982-2022
AUTHORS:
Justus Renatus Mbawala, Huixin Li, Daudi Mikidadi Ndabagenga, Jiani Zeng, Peter Nicky Mlonganile
KEYWORDS:
Climate Extremes, Absolute Extreme Temperature, Percentile Extreme Temperature, Mann-Kendall Test, NASA
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.12 No.1,
January
15,
2024
ABSTRACT: Extreme weather and climatic phenomena, such as heatwaves, cold waves,
floods and droughts, are expected to become more common and have a significant
impact on ecosystems, biodiversity, and society. Devastating disasters are
mostly caused by record-breaking extreme events, which are becoming more
frequent throughout the world, including Tanzania. A clear global signal of an
increase in warm days and nights and a decrease in cold days and nights has
been observed. The present study assessed the trends of annual extreme
temperature indices during the period of 1982 to 2022 from 29 meteorological
stations in which the daily minimum and maximum data were obtained from
NASA/POWER. The Mann-Kendall and Sen slope estimator were employed for trend
analysis calculation over the study area. The analyzed data have indicated for
the most parts, the country has an increase in warm days and nights, extreme
warm days and nights and a decrease in cold days and nights, extreme cold days and nights. It has been disclosed that the number of warm
nights and days is on the rise, with the number of warm nights trending
significantly faster than the number of warm days. The percentile-based extreme
temperature indices exhibited more noticeable changes than the absolute extreme
temperature indices. Specifically, 66% and 97% of stations demonstrated
positive increasing trends in warm days (TX90p) and nights (TN90p),
respectively. Conversely, the cold indices demonstrated 41% and 97% negative
decreasing trends in TX10p and TN10p, respectively. The results are seemingly
consistent with the observed temperature extreme trends in various parts of the
world as indicated in IPCC reports.