Enhancing Numerical Simulation Accuracy for Extreme Heat Events in Metro Manila

Abstract

This study aims to evaluate the impact of lateral boundary conditions, land surface model schemes, and soil conditions on the simulations during extreme heat events in Metro Manila, Philippines. Extreme heat events are simulated using a numerical model representing urban land use and anthropogenic heat flux and compared with observation data. The simulations of near-surface temperature are more sensitive to the land surface model used than initial and boundary conditions. Increasing soil temperature by a factor of 1.10 showed improvements in nighttime temperatures, but overestimated temperature with higher factors. Default temperature simulations are typically underestimated, but soil temperature modifications helped improve bias and error, particularly benefiting Noah-MP simulations at night. The contrast between daytime and nighttime urban heat island intensity was more pronounced in FNL simulations compared to ERA5. This study highlights the value of accurate temperature simulations in understanding and planning for urban heat island effects in Metro Manila.