Using Sub-Grid Scale Method to Quantify Atmospheric Deposition of Sulfur in East China

Abstract

Atmospheric sulfur deposition in East China was studied using the Regional Acid Deposition Modeling System (RegADMS) with a horizontal resolution of 75 km. A one-year run was performed for the year 2000. As a result, the annually averaged Vd for SO2 and SO42- are 0.34 and 0.27 cm s-1, respectively. The calculated Vd for SO2 and SO42- at Yingtan agreed well with the semi-measurements. And the modeled Vd over different land-use types were generally in agreement with those reported from the references. The sub-grid scale (25 × 25 km) method (SSM) was proven to better describe the dry deposition process and save computational time when estimating dry deposition velocity (Vd) than the coarse grid scale (75 × 75 km) method. The estimated total deposition of sulfur in East China is 2.22 × 106 ton yr-1 . Dry deposition accounts for almost 55% of the total deposition and more than 90% of sulfur was deposited on the soil-plant ecosystem. There was evident regional distribution of sulfur depositions in the provinces of the studied area, with most values more than 3 ~ 5 g m-2 yr-1.

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