Simulation of Dry Deposition Rates of Acidic Pollutants--An Assessment of Deposition Pathways in Hiroshima, Japan

• Published in: Water, air, and soil pollution Vol. 130; no. 1-4; pp. 583 - 588
• Main Authors: Sinogaya, Jonnifer R, Sakugawa, Hiroshi
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Nature B.V 01.08.2001
• Subjects: Acid deposition; Air pollution; Computer simulation; Deposition; Dispersions; Dry deposition; Drying; Emissions; Environmental monitoring; Mathematical models; Nitrogen; Pathways; Photochemical; Photochemicals; Pollutant deposition; Pollutants; Pollution dispersion; Seasonal variations; Simulation; Sulfur; Transport; Wet deposition; Japan, Hiroshima; Japan; Japan, Honshu, Hiroshima Prefect
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1023/A:1013803200594

A eulerian grid photochemical transport and dispersion model was used to simulate the dry deposition rates of nitrogen (as HNO sub(3)) and sulfur (as SO sub(2)) in Hiroshima, west Japan. Seasonal patterns of predicted dry deposition fluxes reveal that HNO sub(3) is most prevalent at more remote locations while SO sub(2) is deposited near to and slightly downwind from the major emission sources. The predicted dry deposition rates of HNO sub(3) and SO sub(2) were compared to the values measured at Mt. Gokurakuji (located in Hatsukaichi) and in Hiroshima City. The simulation results show that the model under-predicted (about 44% and 80%, respectively) both nitrogen and sulfur deposition rates at Mt. Gokurakuji and in Hiroshima City, indicating that the acid deposition in Hiroshima prefecture is possibly affected by long-range transboundary transport of acidic pollutants. Comparison of wet to dry deposition ratios (4.5 and 8.7 for nitrogen and 4.6 and 7.0 for sulfur) from the two observation sites above indicates that wet deposition maybe the most important acid deposition pathway in Hiroshima, Japan.