SORCE-SIM Spectral Solar Irradiance Level 3 ENIGMA (L3E)

Abstract

The SORCE-SIM Solar Spectral Irradiance (SSI) data products are provided on a fixed wavelength scale which varies in spectral resolution from 1-34 nm over the entire spectral range. Irradiances are reported at a mean solar distance of 1 AU and zero relative line-of-sight velocity with respect to the Sun. The SORCE-SIM Level3 ENIGMA (L3E) Version 1 data product is the result of the NASA Solar Irradiance Science Team (SIST) ENIGMA project. It incorporates updated solar exposure records and degradation corrections based on the delay between solar observations when compared to the NNLSSI proxy model. A new absolute calibration was applied to the IRRADIANCES, based on the TSIS-1 SIM measurememnts during the overlap period of the two missions. The details of this effort are included in the release notes available with the dataset here and at https://lasp.colorado.edu/ SORCE-SIM Solar Spectral Irradiance (SSI) Measurement Summary. &nbsp; &nbsp;Measuring Instrument &nbsp; &nbsp; &nbsp; SIM (Spectral Irradiance Monitor) &nbsp; &nbsp;Temporal Cadence &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Daily &nbsp; &nbsp;Detector &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Radiometer (ESR) and Photodiodes (UV, VIS, &amp; IR) &nbsp; &nbsp;Instrument Modes &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 31 (ESR), 41 (VIS), 43 (UV), 44 (IR) &nbsp; &nbsp;Spectral Range &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 210.04-2401.40 nm &nbsp; &nbsp;Spectral Resolution &nbsp; &nbsp; &nbsp; &nbsp;variable (1-34 nm) &nbsp; &nbsp;Accuracy &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 2% &nbsp; &nbsp;Long-Term Repeatability &nbsp; &nbsp;&lt; 0.1%/yr The dataset is provided in netCDF4 and IDL Savefile formats. Each include a descriptive header of the content. Each data record contains the nominal date in YYYYMMDD.D and Julian Day Number (JDN), the wavelength of the irradiance measurement (repeated in the MIN_WAVELENGTH and MAX_WAVELENGTH fields), the INSTRUMENT_MODE, DATA_VERSION, spectral IRRADIANCE, IRRADIANCE_UNCERTAINTY, and data QUALITY flag. Additional data files and IDL code are included in the SORCE_SIM_L3E_ANCILLARY folder. These include the uncorrected irradiances for the four detectors on Channel-A and Channel-B (8 total). Also included are the mean spectral degradation signatures for these detectors, the solar exposure record from the instrument telemetry and the updated Solar exposure from this work. &nbsp;The SORCE to TSIS Irradiance Correction Ratio (STICR) data file, which brings to SORCE-SIM calibartion to the TSIS-1SIM, is also included. &nbsp;These are provided in the IDL Savefile format. A seperate sub-folder (level3Smoothing) contains the list of jump corrections that were applied to each detector data as a function of time and wavelength. The IDL code developed specifically for this research is included in the folder SORCE_SIM_L3E_CODE. &nbsp;</p