Ozone deposition to coastal waters

The air-sea exchange rate of ozone to a coastal region on the North Sea was measured using the eddy correlation technique at the UK Weybourne Atmospheric Observatory. The average measured surface resistance to ozone uptake, rs[O3], was found to be 950 ± 70 s m-1. This exchange rate for coastal waters is very close to that recommended for open ocean conditions by Galbally and Roy of 1000 s m-1. The results are discussed in the light of currently accepted exchange rates and the rather small micrometeorological measurement database available for trace gas exchange to sea surfaces. Although more data are needed to confirm the observations, a tentative dependence on the surface uptake with friction speed, u*, was found, given by rs[O3] ≈ -574 ln(u*) + 282 s m-1, possibly explaining the variation in previous measurements presented in the literature which were mostly obtained using chamber techniques.