Database of Storm Time Equatorial Ion Temperatures in Earth's Magnetosphere Calculated From Energetic Neutral Atom Data

Ion temperature is a key parameter that influences dynamics in the magnetosphere, such as particle transport and wave‐particle interactions. Measurements of ion heating and energization yield information about phenomena such as magnetic reconnection, bursty bulk flows, and ion injections. Taking advantage of the global view provided by energetic neutral atom imaging, a database of ion temperature maps during geomagnetic storms occurring throughout the National Aeronautics and Space Administration (NASA) Two Wide‐angle Imaging Neutral atom Spectrometers (TWINS) mission has been created. These ion temperature maps and relevant metadata are publicly available on CDAWeb to facilitate comparison to in situ measurements and model output, for use as boundary conditions for simulations, and for other relevant studies. A preliminary study of average plasma sheet ion temperatures calculated from these maps has revealed a common occurrence of decreasing ion temperature, and a case study for one storm is presented. Plain Language Summary The Sun releases large chunks of energetic particles that can bombard the region of space surrounding Earth, causing an event called a geomagnetic storm. During these storms, particles can become heated and move around. We can measure the temperature of these particles to improve our understanding of what happens during these storms. We have made maps of such temperatures and are sharing them publicly so that others can use them in their own research. We have found some cases where the average temperature of space on the nightside of Earth decreases rapidly and remains low. This could be controlled by the magnetic field embedded in the chunks of energetic particles coming from the Sun, but a more detailed study is needed to find out. Key Points Equatorial ion temperature maps have been calculated from ENA data at 10‐min time cadence for 2009–2017 The database of temperature maps is available on CDAWeb A case study of ion temperature drops in the plasma sheet is presented