Observing Surface Meteorology and Air-Sea Fluxes

The focus of this chapter is on unattended observations of surface meteorology made from surface buoys. Also discussed is the computation of the air-sea fluxes of heat, freshwater, and momentum from the surface meteorological data obtained from surface buoys. The computation of these fluxes requires measurements of wind speed and direction, air temperature and humidity, barometric pressure, incoming shortwave radiation, incoming longwave radiation, sea surface temperature and salinity, and surface currents. Progress has been made in recent years in developing low power, robust, and accurate instrumentation. The present state of the sensors and related hardware is summarized. Typical buoy installations are described, and a summary of where these observations have been made is presented. The accuracies of the observations of surface meteorology are discussed. These accuracies are used together with the bulk formulae and intercomparisons to estimate the uncertainties in the flux observations. In many cases, it is now possible to make measurements of the mean net air–sea heat flux to an accuracy of 8 W m⁻². Challenges remain, and these challenges are also discussed.