Long-range transport of aerosols from East and Southeast Asia to northern Philippines and its direct radiative forcing effect

Sources and characteristics of size-resolved particulate organic acids and methanesulfonate in a coastal megacity: Manila, Philippines

“…These seasons have also been defined in other works (i.e., Akasaka et al, 2007;Cruz et al, 2013;Matsumoto et al, 2020) and can predominately be separated into two general seasons, wet (SWM) and dry (NEM). Generally, there is a second transitional period in May that transitions between the NEM and SWM (Bagtasa and Yuan, 2020); however, recent studies suggest that the transition is abrupt (Matsumoto et al, 2020). Consequently, the second transitional period was combined with the NEM season.…”

“…The Philippines is an important region to study aerosols due to the wide range of both meteorological conditions and diverse local and regional emissions sources (Alas et al, 2018;Bagtasa and Yuan, 2020;Braun et al, 2020;Hilario et al, 2020a;Kecorius et al, 2017). In addition to aerosol sources from nearby regions (Hilario et al, 2020b), the Philippines also has a significant source of local pollution, largely consisting of vehicular emissions due to high population density (Madueño et al, 2019), the use of outdated vehicles (Biona et al, 2017), ship exhaust from highdensity shipping lanes (Streets et al, 1997(Streets et al, , 2000, and more lenient air regulations leading to significant air pollution due to rapid growth and urbanization (Alas et al, 2018;Kecorius et al, 2017).…”

Measurement report: Long-range transport patterns into the tropical northwest Pacific during the CAMP<sup>2</sup>Ex aircraft campaign: chemical composition, size distributions, and the impact of convection

“…Owing to atmospheric residence times ranging from days to weeks (Balkanski et al, 1993;Kritz and Rancher, 1980) and enabled by the surrounding meteorology, aerosol particles from multiple sources can undergo long-range transport into the TNWP (Lin et al, 2007;Xian et al, 2013). These sources include biomass burning from Indonesia and Malaysia (Hilario et al, 2020a, b;Reid et al, 2015); anthropogenic and dust outflow from China, Korea, and Japan (Bagtasa et al, 2019;Braun et al, 2020;Geng et al, 2019;Tan et al, 2012); emissions from countries such as Vietnam, Laos, and Thailand (Bagtasa et al, 2019;Geng et al, 2019;Huang et al, 2020;Lin et al, 2009;; and marine aerosol particles from the Pacific Ocean.…”

Sources and characteristics of size-resolved particulate organic acids and methanesulfonate in a coastal megacity: Manila, Philippines

“…Furthermore, another class of species contributing to ambient aerosol mass is organosulfur compounds, with methanesulfonate (MSA) being an example species (Bardouki et al, 2003b;Ding et al, 2017;Falkovich et al, 2005;Kerminen et al, 1999;Maudlin et al, 2015;Ziemba et al, 2011). The spatiotemporal and size-resolved mass concentration profiles of organic and sulfonic acids are difficult to characterize and can significantly vary depending on the time of day, season, region, and meteorological profile (Adam et al, 2020;Bagtasa et al, 2019;Kobayashi et al, 2004;Maudlin et al, 2015;Mochida et al, 2003;Reid et al, 2013). It is necessary to quantify their relative abundances, and to understand factors affecting their production and eventual removal to be able to quantify their influence on aerosol hygroscopic and optical properties (Beaver et al, 2008;Cai et al, 2017;Freedman et al, 2009;Marsh et al, 2017;Marsh et al, 2019;Myhre and Nielsen, 2004;Peng et al, 2016;Xue et al, 2009).…”

“…This leads to Metro Manila containing some of the highest black carbon (BC) concentrations in Southeast Asia, and quite possibly the world (Alas et al, 2018;Hopke et al, 2011;Kecorius et al, 2017;Kim Oanh et al, 2006). Past aerosol characterization work for that region has focused mainly on gravimetric analysis for total bulk mass (e.g., PM2.5, PM10) (Bagtasa et al, 2018;Bagtasa et al, 2019;Cohen et al, 2009;Kim Oanh et al, 2006), water-soluble inorganic and organic ion speciation (AzadiAghdam et al, 2019;Braun et al, 2020;Cruz et al, 2019;Kim Oanh et al, 2006;Simpas et al, 2014;Stahl et al, 2020b), and BC analysis (Alas et al, 2018;Bautista et al, 2014;Kecorius et al, 2017;Takahashi et al, 2014). In an analysis of two size-resolved aerosol sets in Manila, a significant portion of the total mass unaccounted for by the water-soluble inorganic, water-soluble organic, and BC components was attributed to (but not limited to) organics and non-water soluble metals (Cruz et al, 2019).…”