Multivariate Regression Analysis on Multiangle Imaging Spectroradiometer (MISR) Fractional Aerosol Optical Depth for the Identification of Primary Aerosol Components in the Manila Observatory (14.635 N, 121.078 E)

IRWIN ANGELO AMAGO^1*, HANZ VLADIMIR CABANES¹ and NOFEL LAGROSAS^1,2

¹Physics Department, Ateneo de Manila University, Loyola Heights, Quezon City, Philippines

²Manila Observatory, Ateneo de Manila University, Loyola Heights, Quezon City, Philippines

irwinamago320@gmail.com

MISR fractional aerosol optical depth data were explored for the purpose of identifying aerosol components. MISR data over Manila Observatory were downloaded from January to December of 2011. The goal of the paper is to show the utility of the MISR data set and the possibility of using satellite remote-sensed data as surrogates for ground based data. A multivariate regression approach with the fractional data as input data yields an error of 17.4%, which is lower than literature, when computing the corresponding ground-measured PM_2.5 data. In this method, the relationship between ground measured to computed (from the multivariate regression) PM_2.5 concentration is governed by the equation PM_2.5c=0.9676PM_2.5m, where PM_2.5c and PM_2.5m are the computed and ground measured PM_2.5 concentrations. [2]. Moreover, using the MISR fractional AOD data, one can identify the primary aerosol constituents and their percentage contribution [2]. Using this method, the highest contributor to the particulate matter concentration was carbon-based aerosols that compose 65.65% of the total aerosol optical depth. The other two contributors were sulfates and nitrates (13.64%) and dust (20.71%). These numbers are consistent with the results of urban air quality measurements in several Asian cities [1] and at the Manila Observatory. Previous source apportionment studies yield more than 50% of PM_2.5 comes from traffic, which is characteristic of black carbon while around 30% comes from sulfates. In terms of coarse mode aerosols, around 70% come from soil, which would account for the dust contribution for the west season. For the dry season, around 40% comes from traffic and sulfates while around 70% of coarse mode aerosols are still contributed by the soil. (http://www.observatory.ph/downloads/381b698b8ec5c2d0/MO_poster_052.jpg)

References

[1]     Kim Oanh, N.T., et al., “Particulate air pollution in six Asian cities: Spatial and temporal distributions and associated sources,” Atmospheric Environment, 40. Pp3367-3380.

[2]     Yang L., et al., “Estimating Fine Particulate Matter Component Concentrations and Size Distributions Using Satellite-Retrieved Fractional Aerosol Optical Depth: Part 1—Method Development,” Air and Waste Management, 57. Pp1351, 1360.