ON HANEY-TYPE SURFACE THERMAL-BOUNDARY CONDITIONS FOR OCEAN CIRCULATION MODELS

Haney-type surface thermal boundary conditions linearly connect net do wnward surface heat flux Q to air-sea temperature difference (gradient -type condition) Delta T-1 or to climate/synoptic sea temperature diff erence (restoring-type condition) Delta T-2 by a coupling coefficient kappa. In this study, the authors used the global reanalyzed data (6-h resolution) of Q, surface air temperature T-A, and sea surface temper ature T-o from the National Centers for Environmental Prediction durin g 1 October 1994-31 December 1995 to verify the validity of Haney-type surface thermal boundary conditions. First, daily means of these vari ables were computed to get rid of diurnal variation. Second, the cross -correlation coefficients (CCC) between Q and (Delta T-1, Delta T-2) w ere calculated. The ensemble mean CCC fields show (i) no correlation b etween Q and Delta T-2 anywhere in the world oceans, (ii) no correlati on between Q and Delta T-1 in the equatorial regions, and (c) evident correlation (CCC greater than or equal to 0.7) between Q and Delta T-1 in the middle and high latitudes. Third. the variance analysis was co nducted and a value of 70 W m(-2) K-1 (65 W m(-2) K-1) was suggested f or the coupling coefficient kappa in the northern (southern) middle an d high latitude zone. Thus, the authors find that the restoring-type s urface thermal conditions by no means represent the net air-ocean heat flux anywhere in the world oceans. However, the gradient type surface thermal condition represents the net hear flux quite well for the mid dle and high latitudes. in addition, it is also found that, if the sol ar shortwave component is treated separately, the gradient-type condit ion will have more fidelity for the middle and high latitudes.