Influence of rain on air-sea gas exchange: Lessons from a model ocean

LDEO Publication: 
Publication Type  Journal Article
Year of Publication  2004
Authors  Ho, D. T.; Zappa, C. J.; McGillis, W. R.; Bliven, L. F.; Ward, B.; Dacey, J. W. H.; Schlosser, P.; Hendricks, M. B.
Journal Title  Journal of Geophysical Research-Oceans
Volume  109
Issue  C8
Pages  -
Journal Date  Jul 1
ISBN Number  0148-0227
Accession Number  ISI:000222781400001
LDEO Publication Number  6523
Key Words  gas exchange; rain; sf6; turbulence; stratification; microscale wave breaking; thermal-boundary layer; total heat flow; surface temperature; wind-speed; capillary waves; water; skin; lake; dissipation

Rain has been shown to significantly enhance the rate of air-water gas exchange in fresh water environments, and the mechanism behind this enhancement has been studied in laboratory experiments. In the ocean, the effects of rain are complicated by the potential influence of density stratification at the water surface. Since it is difficult to perform controlled rain-induced gas exchange experiments in the open ocean, an SF6 evasion experiment was conducted in the artificial ocean at Biosphere 2. The measurements show a rapid depletion of SF6 in the surface layer due to rain enhancement of air-sea gas exchange, and the gas transfer velocity was similar to that predicted from the relationship established from freshwater laboratory experiments. However, because vertical mixing is reduced by stratification, the overall gas flux is lower than that found during freshwater experiments. Physical measurements of various properties of the ocean during the rain events further elucidate the mechanisms behind the observed response. The findings suggest that short, intense rain events accelerate gas exchange in oceanic environments.


839JYTimes Cited:7Cited References Count:61

URL  <Go to ISI>://000222781400001
DOI  Doi 10.1029/2003jc001806