SDO-EVE Science Product Changes

The Solar Dynamics Observatory (SDO) Extreme ultraviolet (EUV) Variability Experiment (EVE) version 7 science data products contain changes that better reflect our improved understanding of the instrument initial calibration and long-term degradation. Re-analysis of suborbital rocket flight measurements of the prototype instrument and calibration of the prototype at NIST were used to produce improved reference spectra for near solar minimum, near solar maximum and intermediate conditions. The long-term trend corrections applied to the SDO-EVE Multiple EUV Grating Spectrograph-B (MEGS-B) have been improved through validations involving multiple proxy models calculated for each spectral wavelength. A new Level 2b product with a 1-minute cadence is created spanning the entire mission providing a continuing data product after the increased exposure time for MEGS-B. Degradation trends are extrapolated linearly for future times. An additional Level 4 model spectrum product for 0.1 nm to 106 nm is being created to replace MEGS-A spectral coverage, and this Level 4 model is derived using the ESP 0.1-7 nm band as the proxy for daily variability and flare 1-minute variability. Science data products are publicly available in accordance with the NASA open data policy.