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SORCE-SOLSTICE TAV (TSIS1 Adjusted Values)

This data product uses the temporal overlap of the Solar Radiation and Climate Experiment (SORCE) SOlar Stellar Irradiance Comparison Experiment (SOLSTICE) and Total and Spectral Solar Irradiance Sensor (TSIS1) Spectral Irradiance Monitor (SIM) instruments to create an alternate SORCESOLSTICE irradiance calibration, known as SOLSTICR (SORCE-SOLSTICE to TSIS-SIM Irradiance Calibration Ratio). This update to the SORCE SOLSTICE irradiances is an improvement in the 200nm to 310nm range due to the better accuracy of the TSIS-1 SIM irradiances (Richard et al., 2024) as compared to the SORCE SOLSTICE which depends primarily on its pre-flight calibration accuracy and in-flight stability from 2003 to 2018 (Snow et al., 2022). This new SOLSTICR calibration is applied to the publicly released SOLSTICE data products to produce the corresponding SOLSTICE TSIS1 Adjusted Values (SOLTAV). This is SOLTAV version 2 (V02), using the SORCE-SOLSTICE V18 and TSIS-SIM V13 data releases.

This re-calibration is based solely upon the temporal overlap of TSIS1 and SORCE-SOLSTICE, without any additional corrections for instrument degradations. This corresponds to an absolute calibration performed on the SOLSTICE data to align with the TSIS-1 SIM data during the overlap period. The common wavelength band of the two instruments range from 200.0nm to 310.0nm and corresponds to a portion of the SOLSTICE-MUV detector data only. The SOLTAV irradiance values at the end of the SORCE-SOLSTICE mission agree with TSIS1-SIM, but this may not be true for earlier in the SORCE mission due to uncorrected SOLSTICE degradation trend or instrumental issues.

The SOLTAV re-calibration is achieved by multiplying the SORCE-SOLSTICE V18 irradiances by V02 of the SOLSTICR, which is contained in a separate data product. Two versions of SOLSTICR and SOLTAV are provided corresponding to the SOLSTICE Level3 high resolution (0.1nm resolution with a 0.025nm sampling) and the low resolution (1.0nm sampling) data products. The DOI for V02 of the SOLSTICR is https://doi.org/10.25810/8wsf-jz39 .

In simple terms:

SOLTAV V02 (irradiance) = SOLSTICE V18 (irradiance) * SOLSTICR V02

SOLTAV V02 differs from V01 in that version 13 instead of version 12 of TSIS1-SIM data was used in creating the V02 of SOLSTICR calibration data. Two SOLTAV data products are available corresponding to the nominal 1.0 nm sampling and the high resolution product sampled at 0.025 nm. The NASA DAAC short-name for these products are SOR3SOLS_TAV_TXT and SOR3SOLS_TAV_HIGH_NC, and they appear in ASCII and netCDF format respectively at these locations:

  1. LASP SORCE website (https://lasp.colorado.edu/home/sorce/data/)
  2. LASP LISIRD website (https://lasp.colorado.edu/lisird/)
  3. NASA DAAC:
    • SOR3SOLS_TAV_TXT = https://doi.org/10.5067/LS9OSSL4YL22
    • SOR3SOLS_TAV_HIGH_NC = https://doi.org/10.5067/P1N63D4CTF4I

 

The SOLTAV V02 data product is also available as an IDL SAVE file from the LASP website
(https://lasp.colorado.edu/home/sorce/data/).

An IDL file reader (https://lasp.colorado.edu/data/sorce/file_readers/read_lasp_ascii_file.pro) is available which will read the SOLTAV ASCII file and return an array of structures whose field names and types are defined in Section 2 of the Release Notes. A SOLTAV IDL SAVE file is available on the LASP SORCE website which contains all the information in the ASCII file. The IDL SAVE file is described in Section 3 of the Release Notes.

Further details on the SORCE-SOLSTICE V18 can be found by locating the release notes on the LASP website at https://lasp.colorado.edu/home/sorce/data/. Further details, release notes and SOLSTICR V02.0 data can be found at https://doi.org/10.25810/8wsf-jz39.2 TSIS1-SIM data and release notes can be obtained from https://lasp.colorado.edu/home/tsis/data/.