Authors: Melliza Templonuevo Cruz, James Bernard Simpas, Armin Sorooshian, Grace Betito, Maria Obiminda L. Cambaliza, Jarl Tynan Collado, Edwin W. Eloranta, Robert Holz, Xzann Garry Vincent Topacio, Jundy Del Socorro, Gerry Bagtasa
e University of Wisconsin-Madison (Shipley et al., 1983; Eloranta, 2005; Razenkov and Eloranta, 2018) was installed at the Manila Observatory (MO) and provided the first relatively long-term, continuous, high-temporal and vertical resolution measurements of aerosol optical properties in Metro Manila that may be used to estimate the PBLH and provide information on the aerosol vertical structure as well as the aerosol types present. These measurements were part of the Cloud, Aerosol and Monsoon Processes Philippines Experiment (CAMP2Ex), which aims to better understand the complex interactions between aerosols, clouds, and radiation in the region. Recent findings from the campaign highlight the importance of meteorological factors in modulating aerosol concentrations in Metro Manila. For instance, size-resolved aerosol measurements during the southwest monsoon (SWM) season revealed that the bulk of the PM and black carbon mass was within the Greenfield Gap (0.10–1.0 μm) where wet scavenging by rain is not efficient (Cruz et al., 2019). Moreover, aerosol concentrations are influenced not only by local sources but also by long-range aerosol transport facilitated by synoptic circulations such as the SWM and the passage of a typhoon (Braun et al., 2020). Precipitation and wind speeds also potentially influence the weekly cycles of aerosols in Metro Manila (Hilario et al., 2020).
In this paper, a combination of ground-based PM2.5 and meteorological data, Weather Research and Forecasting model with Chemistry (WRF-Chem) simulations, and the extensive HSRL dataset collected from January 2019–June 2020 were used to examine both (1) the influence of PBLH on PM2.5 concentrations and (2) the effects of synoptic and mesoscale winds on PBLH and the temporal evolution of PM2.5 concentrations, aerosol types, and aerosol vertical profile in Metro Manila. Aside from providing insights on the extent to which the PBLH and atmospheric circulations modulate PM2.5 concentrations, outcomes of this research include the first comprehensive characterization of the temporal trends of PBLH in Metro Manila and baseline data on diurnal and seasonal variation of surface PM2.5 concentrations.
Read more: Link to science direct publication.