Initial ocean whitecap results from WAGES

Oceanic whitecaps are the surface manifestation of bubble plumes entrained into the ocean surface by breaking waves. Below the surface the bubbles are thought to be an important mediator of gas exchange for weakly soluble gases, such as carbon dioxide, while at the surface bursting bubbles generate sea-spray aerosol particles. There have been many studies relating whitecap fraction to the near surface wind, but historically most of these have utilized a relatively small number of images; only with the advent of digital cameras and the application of automated image processing approaches to identifying whitecaps within the images has it been possible to work with very large numbers of individual images.

As part of the Waves Aerosol and Gas Exchange Study (WAGES) project, images of the sea surface have been obtained from RRS James Clark Ross on a near continuous basis since September 2010. Here we present some initial results, including measurements from both the Southern Ocean and a transect from the UK to the Falkland Islands. The Southern Ocean measurements provide a rare cold-water data set – almost all previous studies have taken place in the Northern hemisphere, and in temperate climes.