A detectable urbanization effect in observed surface air temperature data series in Pyongyang region, Democratic People's Republic of Korea

Abstract

A significant urbanization effect in the observed surface air temperature (SAT) data series have been found in developing regions. Here we analyzed the possible impact of urbanization on long-term SAT trends in the Pyongyang region of the Democratic People's Republic of Korea by using data of SAT, wind data and Landsat TM images. Results show that the annual mean urbanization effect in the SAT series was about 0.051 °C/decade for Pyongyang station, 0.031 °C/decade for stations of medium-size cities, and 0.019 °C/decade for stations of small cities and towns, over the period 1969–2019. The annual mean urbanization contributions to the overall warming ranged from 5.3% to 13.1% for different city stations during the study periods, with Pyongyang station witnessing the largest urbanization contribution. Seasonally, the urbanization effect was the largest during wintertime. Urbanization contributions to trend of extreme temperature events are more evident in cold weather indices than warm indices, which reached nearly one-quarter or one-fifth and even 30%. Compared to China's mainland and Japan, the urbanization effect on the regional SAT trend in the Pyongyang region is smaller, but it is detectable.