Atmospheric fluxes of nutrients onto Singapore Strait

Abstract

In view of recurring forest fires in Southeast Asia (SEA) on a large scale and the abundant rainfall in this tropical region, atmospheric fallout of airborne particles i.e. dry atmospheric deposition (DAD) and wet atmospheric deposition (WAD) of nutrients to the ocean surface are thought to be significant. Currently, limited data sets of atmospheric deposition (AD) exist for tropical ecosystems in the region. Furthermore, there is a lack of reliable experimental data on AD of nitrogen (N) & phosphorus (P) in tropical environments. It is therefore imperative to quantify the AD of macro-nutrients, N and P species in order to estimate their impacts on aquatic and terrestrial ecosystems. In this study, field measurements of nitrite, nitrate, ammonium, total N (TN), phosphate and total P (TP) were made, in both airborne particulate matter and precipitation, from January 2006 to July 2006 in Singapore. These measurements were done to characterize and estimate the difference between DAD and WAD fluxes of N & P to coastal waters. The estimated loadings from DAD and WAD (g/m(2)/year) of TN were 1.011 +/- 0.441 and 7.052 +/- 4.34 and those of TP were 0.187 +/- 0.16 and 0.532 +/- 0.524, respectively. This investigation represents a baseline study to access environmental effects of AD of nutrients on the coastal aquatic ecosystem.

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

“…The initial condition of each state variable was assumed to be constant in the vertical planes of the computational boundaries with computed respective baseline concentration in the entire computational domain. Fluxes of AD of nutrients to the coastal waters were obtained based on field monitoring (Sundarambal et al, 2010b) and laboratory methods of nutrient analysis (as in Sundarambal et al, 2009Sundarambal et al, , 2010b. The open boundaries for the water quality modeling were the boundaries facing South-China Sea, Malacca Strait, and Indonesia waters.…”

“…The concentration of nitrate-nitrogen was taken as 0.02 mg/l in water column (C 0 j ), 0 mg/l at ocean boundaries (B j ) and atmospheric WD (S j WD ) of 8.64 mg/l for hazy days and 1.54 mg/l for non-hazy days ( Table 2, Table 3 and comparable to Sundarambal et al, 2009), respectively. The annual average rainfall (P r ) in the model region was 2136 mm (Singapore Department of Statistics, 2005).…”

Sea Surface Temperature (SST) and Rainfall Trends in the Singapore Strait from 2002 to 2019

“…Figure 1 shows that the Singapore Strait is located at 103° 18'57.24" to 104° 33'26.64" east longitude and 0° 54'16.42" to 1° 32'59.28" north latitude. The strait covers about 10,041.25 km 2 (Sundarambal et al, 2009). Furthermore, a detailed analysis focused on the waters of the Singapore Strait, where the changes in SST are influenced by the confluence between the water mass of the South China Sea and the Malacca Strait.…”

“…The Singapore Strait waters are between the Malacca Strait's water masses and the South China Sea. Furthermore, the rainy and dry seasons are experienced yearly, with maximum and minimum rain occurring in December-January and June-August, respectively (Sun et al, 2017;Sundarambal et al, 2009). The changes in rainfall intensity globally are due to El Nino (Isa et al, 2020), which causes variation in seawater temperature depending on the natural conditions affecting these waters.…”

Real-time control of combined surface water quantity and quality: polder flushing

“…Fluxes of AD nutrients to surface water were obtained as based on field monitoring and laboratory methods of nutrient analysis (see Sundarambal et al 2008bSundarambal et al , 2009 and data from Table 1). The wet deposition flux (F) in the model is calculated by precipitation (P r ) £ surface area £ concentration (S j ) of AD species and the dry deposition (1).…”