A pilot heat and momentum flux study for the North Atlantic - base climatology

A base set of climatological heat and momentum flux fields has been calculated for the North Atlantic as part of a pilot study for a global climatology. The fields are qualitatively reasonable. Comparison with the fields of lsemer and Hasse (1987), which have been adjusted to match oceanographic constraints, indicates that the net heat loss in the base climatology is too low by between 10-30 Wfm2 over most of the North Atlantic basin if the constraints are representative of the long-term mean ocean heat transport. The deficit arises mainly as a result of differences between the latent heat flux fields, the shortwave fields are in very good agreement. The implied ocean heat transport at 24°N is 0.29 PW less that the lower limit on the hydrographic estimate (Bryden, 1993). Possible reasons for this discrepancy are discussed and at present it is not clear whether the problem lies in the calculation of the fluxes or inappropriate use of the hydrographic estimates as constraints.