Representation of historical climate and extreme indices (1950-2013) by CMIP6 models and future scenarios of climate change in Mexico

Abstract

The spatio-temporal characteristics of the mean climate and extreme indices in Mexico
were explored in a first stage using the observational dataset Livneh et al. (2015).
The main findings for this first part show that for the period 1981-2013, temperature
warmed at a rate of 0.14°C/decade and precipitation decreased at a rate of 4.4 mm/decade.
Maximum temperature increased at a larger rate (0.22°C/decade) than the minimum temperature
(0.04°C/decade) during the same period. Overall, extreme temperature and precipitation indices
show positive trends during the period 1950-2013. A second stage consisted on evalute the ability
of CMIP6 models to reproduce the historical mean climate of Mexico. The results show that
overall the skill of models has improved, although some are better to reproduce the warming of
temperature (e.g. CAMS-CSM1-0, CNRM-ESM2-1) than the decline of precipitation in the country
(e.g. CAMS-CSM1-0, GISS-E2-1-G). Similarly, CMIP6 models show low agreement in reproducing
the spatial features of extreme indices. The final stage look at the projected changes to the mean
state of the climate and to the extreme indices. The results show that the mean temperature in
Mexico is projected to increase between 0.9-1.8°C for SSP126 and between 2.6-5.7°C for SSP585
by 2100. The annual precipitation change is projected between 6.6 to -7.7% for SSP126 and
between -2.0 to -10.8% for SSP585 by 2100. Similarly, the projected changes for the majority of
the extreme indices appear larger for SSP585 than for SSP126.

Date of Award	24 Jan 2023
Original language	English
Awarding Institution	University of Bristol
Supervisor	Rory J Bingham (Supervisor) & Dan Lunt (Supervisor)