H and O ENA observations of the 22 July 2009 storm as observed by the TWINS mission

The moderate storm of 22 July 2009 (Dst of ~-80 nT) was accompanied by a sudden increase of the strength of the interplanetary magnetic field (IMF), multiple rotations of the IMF clock angle during the storm, and rapid changes in the proton density. During this storm the Two Wide-angle Imaging Neutral-atom Spectrometer (TWINS) mission continuously imaged the inner magnetosphere, with periods of stereoscopic imaging, using Energetic Neutral Atoms (ENAs). TWINS measures the incident flux and velocity of ENAs, and can also determine the fraction of the incident flux that is due to hydrogen (H) and oxygen (O) ENAs. This study presents mass-separated ENA maps from 22 July 2009 as they vary with the solar wind drivers. For the time periods when good stereoscopic viewing is available we will also be showing the first stereoscopic mass-separated ENA images of the inner magnetosphere.