Space Weather Products from the Extreme Ultraviolet Variability Experiment (EVE)

A majority of the solar flare energy is released in the hard x-ray (HXR), soft x-ray (SXR), and extreme ultraviolet (EUV) ranges, and thus these wavelengths are an important measure of solar activity for myriad of space weather applications and operations. The EUV Variability Experiment (EVE) aboard NASA's Solar Dynamics Observatory (SDO) is observing the solar SXR and EUV irradiance continuously from its GEO orbit with 10 sec and better cadence and with spectral resolution of 0.1 nm over most of the EUV range (6-105 nm). EVE's space weather data products are near realtime with latency less than a minute. While EVE Level 1-3 products are intended to be research quality, the quicklook Level 0C and 0CS products are appropriate for space weather operations. For example, the EVE Level 0CS product includes EVE's EUV SpectroPhometer (ESP) measurement of the 1-7 nm band irradiance that is used as a backup proxy for the GOES X-ray Sensor (XRS) 0.1-0.8 nm flare monitor. The ESP and also EVE's Solar Aspect Monitor (SAM) x-ray imager also provide realtime knowledge of the flare location. The EVE Level 0C product includes EVE's Multiple EUV Grating Spectrographs (MEGS) spectra and a listing of the brighter lines. Of particular interest for this session, the cooler coronal emission lines, e.g. Fe IX - Fe XII in the 17-20 nm range, often have coronal dimming during and after a flare, and the slope and depth of the dimming may be indicative of a coronal mass ejection (CME) velocity and mass. If so, then EVE's realtime monitor of these cooler coronal emissions could become a useful proxy for CME warnings.