Open AccessOzone and sulfur dioxide dry deposition to forests: Observations and model evaluation
Author(s) -
Finkelstein Peter L.,
Ellestad Thomas G.,
Clarke John F.,
Meyers Tilden P.,
Schwede Donna B.,
Hebert Eric O.,
Neal Julie A.
Publication year - 2000
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2000jd900185
Subject(s) - deposition (geology) , atmospheric sciences , flux (metallurgy) , deciduous , daytime , diurnal temperature variation , environmental science , ozone , sulfur dioxide , diurnal cycle , seasonality , meteorology , chemistry , geology , physics , ecology , geomorphology , inorganic chemistry , organic chemistry , sediment , biology
Fluxes and deposition velocities of O 3 and SO 2 were measured over both a deciduous and a mixed coniferous‐deciduous forest for full growing seasons. Fluxes and deposition velocities of O 3 were measured over a coniferous forest for a month. Mean deposition velocities of 0.35 to 0.48 cm/s for O 3 and 0.6 to 0.72 cm/s for SO 2 were observed during the growing seasons of 1997 and 1998. Weekly averages of O 3 deposition velocity ranged from 0.25 cm/s at the beginning and end of the season to 1.25 cm/s in late June. SO 2 had a smaller seasonal variation, from 0.75 to 1.5 cm/s between the beginning and peak of the season. Because O 3 concentrations are higher, the flux of O 3 to forests is considerably greater than the flux of SO 2 . Daytime deposition velocities are very similar at each site, from 0.75 to 0.79 cm/s for O 3 , and from 1.01 to 1.04 cm/s for SO 2 . Diurnal cycles for both gases are discussed, as are the impact of some weather events. The peak time for O 3 deposition velocity is in midmorning, while it is near midday for SO 2 . Surface wetness is usually associated with a small increase in deposition velocity, but for some rain events a major increase was noted. Minimum deposition velocities usually occur at night and increase slowly in the predawn hours before light. Comparisons are made between observations of deposition velocity and predictions made with the Meyers multilayer deposition velocity model. While the model is, on average, unbiased for O 3 , it tends to underpredict the higher deposition velocity values. The model is slightly biased low (underpredicts) for SO 2 deposition velocity. The strengths of the model are noted, as are opportunities for improvement.