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Measured and Modeled Radiometric Fluxes in the Arctic During FIRE-ACE |
Scripps Institution of Oceanography
spope@ucsd.edu
Radiative flux measurements made during the FIRE Arctic Clouds Experiment are compared to model calculations. The data were collected by radiometers on board the NCAR C-130 aircraft which flew in the vicinity of the SHEBA ship, located in the Arctic Ocean, in sky conditions ranging from clear to cloudy.
Upwelling and downwelling solar broadband irradiances measured as the aircraft flew at altitudes above and below cloud layers are combined to yield reflectance, transmittance, and absorptance of the layer. These observations show good agreement with preliminary models which use input from sondes launched from the SHEBA ship.
Measurements made at different altitudes on a relatively clear day (May 24, 1998) are combined to give a profile of irradiances from the surface up to 4 km altitude. Observations of the upwelling and downwelling solar broadband and visible (400 to 700 nm) irradiances can be matched by a model with a surface of snow and an overhead cloud of optical depth 0.13. Model results for a cloudy day (May 18, 1998) will also be presented.
