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Of particular importance for these calculations is the issue of data quality. Some data had to culled from the SHEBA data set because the twisting of the ship in the ice floe caused the MFRSR to become misaligned. Calibration of the MFRSR was checked using Langley regressions supplemented by a comparison between calculated broadband fluxes and measured broadband fluxes. The calculated broadband fluxes were obtained from the radiative transfer model SBDART (Ricchiazzi et al., 1998) using MFRSR data (aerosol optical depths) and MWR data (LWP) as input. MWR data had to be screened to eliminate data contaminated by the presence of water on the MWR window.
Once the data quality issues had been resolved, optical depths and effective radius were calculated at the two sites and compared. Some differences are evident that are significant for radiative transfer calculations in climate and numerical weather prediction models. It appears that SHEBA had a greater incidence of clouds and that their optical depths were greater; while the effective drop radii at SHEBA were smaller than at Barrow.
Min, Q. and L. Harrison, 1996: Cloud properties derived from surface MFRSR measurements and comparison with GOES results at the ARM SGP site. Geophys. Res. Lett., 23, 1641-1644.
Ricchiazzi, P., Shiren Yang, and Catherine Gautier, 1998: SBDART. Bulletin of the American Meteorological Society.
Long, C. N. and T. P. Ackerman, 2000: Identification of Clear Skies from Broadband Pyranometer Measurements and Calculation of Downwelling Shortwave Cloud Effects, JGR, 105, No. D12, 15609-15626.
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