Urban heat effect
: focusing on relative humidity
A numerical model is a computer-based simulation process that involves solving a series of phenomena using mathematical equations. Numerical models can be broadly categorized into Numerical Weather Prediction Models (NWP) for weather forecasting and Computational Fluid Dynamics Models (CFD) for analyzing irregular turbulent flows, depending on the specific analysis objectives.
NWP models quantitatively predict the current and future atmospheric conditions by numerically integrating the governing equations of atmospheric dynamics and physical principles. Among the widely used models are MM5 (Mesoscale Meteorological Model version 5), jointly developed by Pennsylvania State University and the United States National Weather Service in the early 1970s, and WRF (Weather Research and Forecasting), a medium-scale model developed and operated by the National Center for Atmospheric Research (NCAR) in the United States, which builds upon and complements MM5.
The WRF model, designed to support weather forecasting and atmospheric research, offers various dynamical cores, a 3DVAR (Three-dimensional Variational Assimilation) data assimilation system, and parallel computing considerations. Being open-source and non-commercially developed, it is user-friendly, providing high prediction accuracy through two-way nesting, starting from large-scale domains and extending to areas of interest. Therefore, for our analysis, we utilized a medium-scale model like WRF that can account for the interaction between large-scale and small-scale meteorological phenomena.
