Impact of biomass burning on ocean water quality in Southeast Asia through atmospheric deposition: eutrophication modeling

Abstract

Abstract. Atmospheric deposition of nutrients (N and P species) can intensify anthropogenic eutrophication of coastal waters. It was found that the atmospheric wet and dry depositions of nutrients was remarkable in the Southeast Asian region during the course of smoke haze events, as discussed in a companion paper on field observations (Sundarambal et al., 2010b). The importance of atmospheric deposition of nutrients in terms of their biological responses in the coastal waters of the Singapore region was investigated during hazy days in relation to non-hazy days. The influence of atmospherically-derived, bio-available nutrients (both inorganic and organic nitrogen and phosphorus species) on the coastal water quality between hazy and non-hazy days was studied. A numerical modeling approach was employed to provide qualitative and quantitative understanding of the relative importance of atmospheric and ocean nutrient fluxes in this region. A 3-D eutrophication model, NEUTRO, was used with enhanced features to simulate the spatial distribution and temporal variations of nutrients, plankton and dissolved oxygen due to atmospheric nutrient loadings. The percentage increase of the concentration of coastal water nutrients relative to the baseline due to atmospheric deposition was estimated between hazy and non-hazy days. Model computations showed that atmospheric deposition fluxes of nutrients might account for up to 17 to 88% and 4 to 24% of total mass of nitrite + nitrate-nitrogen in the water column, during hazy days and non-hazy days, respectively. The results obtained from the modeling study could be used for a Correspondence to: R. Balasubramanian (eserbala@nus.edu) better understanding of the energy flow in the coastal zone system, exploring various possible scenarios concerning the atmospheric deposition of nutrients onto the coastal zone and studying their impacts on water quality.

Deforestation of watersheds of Panama: nutrient retention and export to streams

“…This effect could follow, as reported for elsewhere in the tropics (Sigha-Nkamdjou et al 2003;Baker et al 2006;Sundarambal et al 2010;Chen et al 2010), from the incidence of burning during the dry season (mainly done during March). Alternately, the seasonal difference could be by dilution owing to larger volume of more frequent rain during the wet season; we found, however, no relationship of concentrations and previous rain events (data not shown).…”

A Decadal Climatology of Chemical, Physical, and Optical Properties of Ambient Smoke in the Western and Southeastern United States

“…The U.S. National Emissions Inventory created by the U.S. Environmental Protection Agency estimates that these fires contribute 34% of the total primary PM 2.5 (particulate matter with aerodynamic diameters smaller than 2.5 μm) emitted in the United States (NEI, 2014). Fire-emitted particles are harmful to human health (Cascio, 2018;Crouse et al, 2012;Gan et al, 2017;Johnston et al, 2012;Liu et al, 2015;Reid et al, 2016;Yao et al, 2018), visibility (Bond et al, 2013;Brewer & Moore, 2009;Ford et al, 2018), and ecosystems (Abram et al, 2003;Sundarambal et al, 2010). Due to climatic and socioeconomic changes, wildfire activities, including the number of large wildfires, total burned areas of large wildfires, wildfire durations, and wildfire seasons, have increased in recent decades (Dennison et al, 2014;Westerling et al, 2006).…”

Enhanced Primary Production in the Oligotrophic South China Sea Related to Southeast Asian Forest Fires

“…In contrast, the new productivity was estimated to be 1.733 ± 1.681 mg C·m −2 ·hr −1 over the SCS in 2009, representing a more typical summer. Although we have shown the potential effects of Indonesian forest fire-derived atmospheric wet AND to the marine ecosystem, the nonuniform spatial-temporal distribution of wet deposition, and nonnegligible deposition of other nutrients (e.g., P or Fe) and dry AND probably largely account for the new productivity (Hsu et al, 2014;Sundarambal, Tkalich, et al, 2010). Atmospheric deposition is also a potential mechanism for increasing Fe or P in the surface seawaters, thereby enhancing new productivity or nitrogen (N 2 ) fixation (Abram et al, 2003;Ponettegonzález et al, 2016;Wu et al, 2000).…”