Global Ozone Monitoring Experiment-2 (GOME-2) Level 3 Daily Magnesium II Index Data

In the last step, the step-two ozone estimation is modified to correct for wavelength dependent effects (tropospheric aerosol and sun glint) and local upper level profile shape effects. The algorithm writes out all the retrieval variables and corresponding geo-referenced information to PMF at the end of each scan process. The weights scale as the reciprocal of the relative path lengths (one divided by the sum of the secant of view angle plus secant of solar zenith angle) for each observation.

The Magnesium II information is extracted daily from the GOME-2 1B granules, as soon as new solar radiance measurements are available. The product includes a 61-wavelength subset of the daily solar spectrum and a Mg II core-to-wing ratio for the spectrum. Our Mg II Index value is a simple ratio of the average of the irradiance measurements near three core wavelengths to the average of the irradiance measurements near four wavelengths at the wings, two at each wing.

Each irradiance value is computed by interpolation of the pair of values for GOME-2 surrounding the following positions: 276.82, 276.97, 279.78, 279.92, 280.07, 283.03, and 283.17 nm. The daily gridded total ozone and Magnesium II products are available in ASCII format.