John Ariel Rojas
Philippine Atmospheric, Geophysical and Astronomical Services Administration
QUASI-BIENNIAL OSCILLATION AND TROPICAL CYCLONE ACTIVITY IN THE PHILIPPINE AREA OF RESPONSIBILITY
The stratospheric Quasi-Biennial Oscillation (QBO) has been shown to influence tropical cyclone (TC) activity through modulation of tropical deep convection, which, in turn, impacts the areas of tropical cyclogenesis and the tracks. Currently, the Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) uses climatological average in determining the possible tracks of TCs based on the location of genesis for monthly and seasonal TC forecasts. This study will aim to characterize the behavior of TCs in the Philippine Area of Responsibility in each of the QBO phases from 1983 to 2014 as well as compare it to those in North Western Pacific and South China Sea. Analyses of surrounding background flow, outgoing longwave radiation, and vertical wind shear will be done to support the QBO-TC relationship as well as explore the possible link to the North Pacific High. A numerical study using WRF model will also be conducted to analyze the possible mechanism on how tracks of formed TCs are influenced by the downward propagation of the stratospheric zonal winds. The results of this study may be used in short- and long-term statistical TC forecasting in the country. This in turn could be helpful in the preparation against and the mitigation of TC-related disasters.