Current and future climate research programs are requiring increased accuracy of air-sea flux estimates. Improved meteorological measurements and aerodynamic bulk formulae have brought net error in short-wave radiation and latent and sensible heat fluxes down to approximately +/- 10 W/ m2. Conservative error estimates for long-wave radiation flux measurements are comparable to short-wave measurements at night, but during the day, they are about +/- 40 W/m2. Thus, downward long-wave irradiance is the source of the largest uncertainty in the air-sea surface energy budget. The PI's propose to 1) design and fabricate a new pyrgeometer; 2) demonstrate its improved characteristics; 3) collect accurate downwelling long-wave observations in conjunction with ongoing and planned field activities; and 4) encourage its use by the air-sea interaction community.
