Speaker
Description
Besides the detrimental effects on the environment, according to a general consensus of the literature, climate change may cause to amplify duration and magnitude of heatwaves. Moreover, cities are more vulnerable to the heatwaves due to alteration of natural surfaces with urban structures, which have high heat retention, leading to the phenomenon of urban heat island (UHI) effect. The aim of this modeling study is to examine the UHI effect with present status and under climate change conditions. Istanbul, one of the densely populated cities in the world, was chosen for the analysis. In this paper, the Weather Research and Forecasting (WRF) model was used to dynamically downscale global climate model simulation from the CMIP5 project for 1990, 2004 and 2050. All WRF simulations were conducted at high spatial resolution with three nested domains and physical parameters were arranged for mesoscale urban study. The WRF model was used to simulate weather during July 1990 and 2004 (current conditions) and 2050 (climate change conditions) forced with the Representative Concentration Pathway 8.5 scenario. The satellite-derived land surface temperatures were compared to the simulation-derived skin surface temperature, in order to evaluate the model performance. The research further investigates within-day and monthly dispersal of temperature over the study area and attributes regarding UHI. The outcomes of this study confirm that the increasing temperature influences the generation of the urban heat island. The results show that the average monthly 2 m air temperature in July is projected to increase by 1.5 degrees with the climate change conditions forced by Representative Concentration Pathway 8.5 scenario in 2050. Based on the evidence from this research, it is recommended that prior to making decisions to mitigate climate change, the urban heat island effect should be considered.
