OMI Solar Proxy Index Data
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Matthew DeLand and Sergey Marchenko

Contact:  matthew.deland@ssaihq.com

Last revision:  3 February 2021


This file gives a basic description of the solar proxy index data that we have
produced from Aura OMI solar measurements.  Detailed discussion can be found in
the paper "The solar chromospheric Ca and Mg indices from Aura OMI" by M. DeLand
and S. Marchenko (2013), J. Geophys. Res. Atmos., 118, 3415-3423, 
doi:10.1002/jgrd.50310.

The most recent update of the OMI proxy index data are available in the text 
file 'solar_indices_OMI_alternative_20210125.txt'.  The term '_alternative' in 
this file name indicates the use of data processing improvements that provide 
increased sampling compared to the standard L1B processing.  The first 
measurement date is 1 October 2004, and the last date included in the current 
data file is 25 January 2021.

There are 9 columns with the following contents.

Column 1:  Year of measurement.

Column 2:  Month of measurement.

Column 3:  Day of measurement.

Column 4:  Hour of measurement [UT].

Column 5:  Minute of measurement [UT].

Column 6:  Daily average Mg II proxy index (280 nm).

Column 7:  Daily average Mg I proxy index (285 nm).

Column 8:  Daily average Ca II K proxy index (393.4 nm).

Column 9:  Daily average Ca II H proxy index (396.8 nm).

Missing data are represented by -9.0 as a fill value.

NOTE:  The Mg II and Mg I index values are reported as derived from the OMI 
irradiance measurements.  The Ca II K and Ca II H index values have been scaled 
to the scale of the National Solar Observatory ISS 1 A bandpass data sets.