Modeling an Urban Heat Island during Extreme Frost in Moscow in January 2017

Abstract

Using the example of an analysis of an extreme lowering of temperature in Moscow in January 2017, the horizontal and vertical extent of the urban heat island against the background of a strong stable stratification of the atmospheric boundary layer is studied. The possibilities of measuring and monitoring the vertical structure of the atmosphere using ground-based remote sensing are investigated. The capabilities of the mesoscale model WRF, adapted for a detailed description of mixing processes in the atmospheric boundary layer, in reproducing the spatial dynamics of the temperature anomaly are demonstrated. The numerical estimates of the amplitude and vertical extent of the urban heat island are compared with the measurement accuracy and the total errors of the numerical predictions. A comparison of measurement data and numerical simulation results on the WRF model, using the example of a winter urban heat island in January 2017, showed that mesoscale synoptic models so far only capture the main features of the urban heat island. However, deviations between model and observed temperature fields can reach 5°C.