Solar Doppler Velocity Results from the SDO EVE Level 4 Lines Data Product

NASA's Solar Dynamics Observatory (SDO) Extreme-ultraviolet Variability Experiment (EVE) observes solar full-disk extreme ultraviolet (EUV) spectral measurements over the spectral range of 6 nm to 106 nm with 0.1 nm spectral resolution. A new EVE data product called the EVE Level 4 Lines data product provides line profile-fit results for intensity, wavelength shift, and line width for 70 emission features. These emission features are from the chromosphere, transition region, and corona. While EVE's Multiple EUV Grating Spectrographs (MEGS) were not specifically designed to measure intrinsic solar wavelength shifts (Doppler velocities), the high stability of solar pointing by the SDO spacecraft and the very stable thermal environment for SDO in a geosynchronous Earth orbit (GEO) enable detection of solar flare Doppler velocities with MEGS spectra at its modest 0.1-nm resolution. These Doppler velocity results are more accurate after making corrections for MEGS optical wavelength shifts based on wavelength and flare location relative to the MEGS optical center. These Doppler velocity results are most interesting for studying the plasma dynamical behavior during a flare's impulsive phase and gradual phase. In particular for eruptive flares, there are often wavelength red shifts (downflows) for the transition region emissions with Doppler velocities of about 30 km/s and wavelength blue shifts (upflows) for the corona emissions with Doppler velocities of about - 80 km/s. The Doppler velocity maxima during flare events almost always occur during the impulsive phase of the flares.