Data Products:

Optical depths (total or aerosol+cloud) at 3-minute intervals. Total optical depths are calculated using the standard Beer's Law approach, (ln(V0) - ln(V))/airmass. Rayleigh and ozone optical depths are subtracted from total optical depths to give aerosol optical depths. V0 for each wavelength and requested date is determined from a time series of Langley-generated voltage intercepts for morning periods. The Langley method is described in Harrison and Michalsky (1994).

Total optical depths from Langley analyses for each morning and/or afternoon on which a successful analysis was obtained. Each value is the slope of a regression of ln(voltage) on airmass, as described in Harrison and Michalsky (1994). Time periods included in the analyses are limited to specific airmass ranges which vary by wavelength: 1.5-3.0 for 332 and 368nm; 2.0-6.0 for 415-860nm. Since these values represent averages over time periods of varying length (1.5 to 3.5 hours) they should be used with caution. The Instantaneous Optical Depths option provides more detailed information.

Daily column ozone determined from UV-MFRSR measurements by the direct-Sun method described in Gao et al. (2001).

Synthetic Spectra determined by application of a non linear estimation method to the UV MFRSR measurements using the method of Min and Harrison (1998). Spectral values are presented at a resolution on 1nm from 297 to 369 nm inclusive. For details, see Min and Harrison(1998).

Plots summarizing the results of Langley analyses (Harrison and Michalsky, 1994) for one morning or afternoon period.