Changes in the surface temperature and winds due to the growth of the Metro Manila urban area

Abstract

This study investigates the changes in the surface temperature and wind field due to the possible southward growth of the Metro Manila urban area. Twenty days in April 2002 are simulated using the Fifth-Generation PSU/NCAR Mesoscale Model (MM5). In order to isolate the effects of the growth of the urban area, two cases are considered: a baseline run, which used the present land use map for the Philippines; and an experiment run, which incorporated the changes to the land use category of several municipalities in Cavite and Laguna from rural to urban. The model in both cases produces sea and land breezes as well as an urban heat island. Differences in temperature from the two runs indicate up to a 1.25-degree increase in the modified urban section. Relatively stronger winds are also observed in this area. This may be attributed to the enhancement of the sea breeze from Manila Bay due to the weakening of northeasterly winds as it flowed over the heat island. Validation of the baseline with observations denotes an adequate correlation for temperature over Metro Manila. However, poor correlation of wind speeds requires model adjustments to be made. Further studies include a climatological study of this experiment for different atmospheric conditions.