Influence of Rough Flow over Sea Surface on Dry Atmospheric Deposition Velocities

  • Author(s): Yan Zhang, Weichun Ma, and Limin Chen
  • DOI: 10.3319/TAO.2013.05.09.01(A)
  • Keywords: Sea surface rough flow, Dry deposition, Deposition resistance, Numerical model



A Meteorological model and a dry deposition module were used to estimate the effects of sea surface rough flow (SSRF) over the sea surface on dry deposition velocities. The dry deposition turbulence resistance, Ra, and sub-layer resistance, Rb, decreased more than 10% and 5% due to SSRF, respectively. For example, for HNO3, the mean dry deposition velocities (Vd) were 0.51 cm s-1 in January, 0.58 in April, 0.65 cm s-1 in July and 0.79 cm s-1 in October with only smooth flow over the sea surface. However, the SSRF increased the Vd of HNO3 by 5 - 20% in the east China seas. These results show that SSRF is an important factor in estimating surface roughness to further improve calculation of the dry deposition velocities over the ocean. Improvements in parameterization of sea roughness length will be a worthwhile effort in related future studies.

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