Analysis of Surface Albedo to improve Upper-Ocean Heat Budget Calculations

Over 90% of the Earth’s energy imbalance is stored in the oceans, so it is important to understand the ocean-atmosphere heat transfer. Of the total net heat flux, close to half is due to shortwave radiation, but the upward shortwave still has large errors. In order to properly understand air-sea heat transfer, upward shortwave must be better characterized. The Ocean Climate Stations group (OCS) at the Pacific Marine Environmental Laboratory maintains two moored surface buoys in the North Pacific (PAPA and KEO), both of which measure downwelling shortwave radiation (SW_down). Satellite-derived calculated surface fluxes give upward shortwave radiation, so that OCS can calculate the net shortwave (SW_net) going into the ocean.

This project developed a CERES-based albedo product for derivation of SW_net to decrease error from the currently used ISCCP-based albedo. The high-resolution surface fluxes from CERES are more frequently updated than those from ISCCP. There was a greater change between ISCCP and CERES albedo during wintertime than during summer. There was a greater change at Station PAPA in the northeastern sub-Arctic Pacific, than at Station KEO in the northwestern subtropical Pacific. The difference between the two albedo estimates is caused by many physical differences in the models used to derive surface fluxes. The rate of temperature change of the mixed-layer is shown to increase based on the new source of albedo data, .08 and .5 C/year at KEO and PAPA, respectively.