PAPER TITLE :HISTORICAL AND PROJECTED CHANGES IN DAYTIME AND NIGHTTIME TEMPERATURE EXTREME EVENTS OVER NIGERIA AS SIMULATED BY SMHI-RCA4 REGIONAL CLIMATE MODEL

JOURNAL OF EARTH AND ATMOSPHERIC RESEARCH | VOLUME 1 NUMBER 1 2018

Paper Details

  • Author(s) : Ajayi V. O.
  • Abstract:

This study analyses the output of subset of the Coordinated Regional Climate Downscaling Experiment
(CORDEX) African domain to assess the maximum and minimum temperature based extreme indices over
Nigeria (latitudes 4‘“–14‘“N and longitudes 2‘“–15‘“E). The simple temperature indices were calculated
from daily minimum and maximum temperature data derived from SMHI-RCA4 model driven by nine
CMIP5 GCM for the period 1961-1990 for the baseline period, 2020-2059 for near future and 2060-2099 at
RCP4.5 scenario. The indices were calculated with python based Indices Calculation climate (ICCLIM)
software. The index considered in the study includesannual maxima of daily maximum and daily minimum
temperatures (warmest day and night, TXx and TNx), tropical nights (TR) and summer day at 30oC threshold
(SU30). The result shows that all the indices increased in most of the study area, TNx is projected to increase
by 1.2oC to 3oC in Nigeria in near future and by up to 4oC in the far future in comparison with the baseline
period of 1961-1990. TXx is however projected to change by average of 1.6-2.2oC while TR is expected to
increase by average of 20 days/year in the southern and up to 80 and 100 days/year in the middle and northern
belt in the near-future and far-future simulation respectively relative to the baseline period. The SU30 will
increase more in the cooler part of Nigeria than in the warmer part. In both near and far future, it is projected
that in the northern part, SU30 will in increase to less than 20 days/year while up to 40-60 days/year in the
Guinea coast and the Jos Plateau. The study concludes more days will experience temperature above 30oC
during the compared to the reference period. In the same vein, more days will experience nighttime minimum
temperature of above 20oC. This information is useful for policy makers, Agriculturist and healthcare
professionals in management of temperature induced disaster in the study area.

JOURNAL OF EARTH AND ATMOSPHERIC RESEARCH