Ozone deposition velocity by ship-based eddy correlation flux measurements

Because ozone is an important constituent of the earth's atmosphere, it is important to have a good comprehension of its production, transport and destruction. A significant term in the global ozone atmospheric budget is the deposition to the oceans, but direct observations are quite rare. To assess this process, measurements aboard the R/V Ronald H. Brown have been made during 2006 over the Gulf of Mexico (TexAQS) and in the Pacific Ocean (STRATUS). The ozone concentration has been measured by a newly developed fast-response instrument using the chemiluminescence principle. From these data, classical eddy correlation air/sea fluxes have been computed, and ozone deposition velocity has been evaluated. For the TexAQS cruise, we found a value of ~ 0.09 cm/s which includes both ocean and land footprints. On the other hand, the STRATUS cruise was far from the shore, and the deposition velocity calculated is ~ 0.03 cm/s. This is in concordance with the literature values which range from 0.01 to 0.12 cm s-1 for ocean water.