検索画面に戻る Go Research

	(288KB)

C-1.3.3 Studies on Evaluation of Dry Deposition Velocity of Aerosol Particles

[Contact Person]

Hiroshi Hara
Senior Research Scientist
Department of Community Environmental Sciences
National Institute of Public Health, Japan
Ministry of Health and Welfare
Shirokanedai 4-6-1, Minato-ku, Tokyo 108-8683
Tel: +81-3-3441-7111, Fax: +81-3-3446-4319

Total Budget for FY 1996-1998

8,911,000 Yen (FY 1998 2,920,000 Yen)

Abstract

Dry deposition to forests plays an important role to discuss forest declines in a quantitative manner. This study focuses on the field measurement of concentration profiles for sulfate as well as sulfur dioxide in forests and a corn field in order to evaluate deposition velocity. Sulfur dioxide concentration showed a concentration profile that concentration decreased with decreasing height. Sulfate concentrations, however, were rather homogeneous irrespective of the height: the concentration did not decrease even near the surface. In the case of a coniferous (red pine) forest, the sulfate concentration decreased over the canopy top to yield negative deposition velocities for sulfate particles. The emission velocity, defined as a negative deposition-velocity, showed a high correlation with deposition velocity of ozone that was also measured in this collaboration work. This fact strongly suggested that sulfate was formed on the particles generated by the reaction between ozone and terpenes emitted from the leaves of red-pine into the atmosphere. The deposition velocity of sulfate

[Key Words]

Dry Deposition, Aerosol, Sulfate, Concentration Profile, Forest