Evaluation of Historical CMIP6 Model Simulations of Seasonal Mean Temperature over Pakistan during 1970–2014

Rizwan Karim,Guirong Tan,Fei Liu,Brian Ayugi,Hassen Babaousmail

doi:10.3390/atmos11091005

Abstract

This work employed recent model outputs from coupled model intercomparison project phase six to simulate surface mean temperature during the June–July–August (JJA) and December–January–February (DJF) seasons for 1970–2014 over Pakistan. The climatic research unit (CRU TS4.03) dataset was utilized as benchmark data to analyze models’ performance. The JJA season exhibited the highest mean temperature, whilst DJF displayed the lowest mean temperature in the whole study period. The JJA monthly empirical cumulative distribution frequency (ECDF) range (26 to 28 °C) was less than that of DJF (7 to 10 °C) since JJA matched closely to CRU. The JJA and DJF seasons are warming, with higher warming trends in winters than in summers. On temporal scale, models performed better in JJA with overall low bias, low RMSE (root mean square error), and higher positive CC (correlation coefficient) values. DJF performance was undermined with higher bias and RMSE with weak positive correlation estimates. Overall, CanESM5, CESM2, CESM2-WACCM, GFDL-CM4, HadGEM-GC31-LL, MPI-ESM1-2-LR, MPI-ESM1-2-HR, and MRI-ESM-0 performed better for JJA and DJF.

Highlights

The surface temperature increase has placed scientists on alert since the post-industrial era for its harmful impacts on the earth’s ecosystems and human welfare in general
From 1901 to 2007, the area-weighted mean temperature over Pakistan was recorded as 0.64 ◦ C, and it is constantly increasing at 0.06
The results indicated a warming pattern of temperature over most of Pakistan (0.01 °C –0.06 °C/year), except for models such as CESM2-WACCM, CNRM-ESM2-1, and

Summary

Introduction

The surface temperature increase has placed scientists on alert since the post-industrial era for its harmful impacts on the earth’s ecosystems and human welfare in general. South Asia is the most vulnerable to climate change, under temperature increase, threatening one fourth (1.8 billion) of the global population [4,5]. Melting Himalayan glaciers under noticeable warming rates, Atmosphere 2020, 11, 1005; doi:10.3390/atmos11091005 www.mdpi.com/journal/atmosphere. Atmosphere 2020, 11, 1005 variability in seasonal precipitation, and frequency of extreme events have damaged the economy, agriculture, livelihoods, infrastructure, and general welfare of this region [6]. The glaciers of Hindu Kush, Himalayas, and Karakorum are melting rapidly under global warming, further deteriorating the population anguishes by triggering floods, glacial lake outburst floods, land erosion, infrastructure damage, and loss of human lives [9]. From 1901 to 2007, the area-weighted mean temperature over Pakistan was recorded as 0.64 ◦ C, and it is constantly increasing at 0.06

Results

Discussion

Conclusion