Buoyancy flux

The buoyancy flux out of the ocean is computed by the formula (e.g., Schmitt et al. 1989)

where is the water density at the surface, and and are the thermal expansion and haline coefficients:

In eq. (32) is the normalized heat flux, with being the net heat flux into the ocean:

The flux of salt due to loss of fresh water at the surface is given by:

The components of net heat flux () and the evaporation and precipitation rate estimates are computed from COADS individual observations as described above and adjusted using the constraints discussed in section 9. Sea surface salinity, , however, is not part of standard ship synoptic weather reports. As salinity enters the above equation primarily as a coefficient, and as the interannual variability of salinity is only a few percent of its climatological value, we use the Levitus et al. (1994) monthly climatological surface salinity values in the above formula.