Initial Ion Results from the RENU2 Sounding Rocket

RENU2 (Rocket Experiment for Neutral Upwelling 2) is a multiple investigator sounding rocket campaign that was designed to transit the cusp region between 200 and 600 km and study particle processes during a neutral upwelling event. The RENU2 payload dayside observations will be compared with measurements made by the EISCAT Svalbard radars. This project aims to investigate the connection between ion upflows and outflows, and neutral upwelling from the topside ionosphere. Low-earth orbiting satellites are affected by these regions of enhanced neutral densities which decay their orbits due to satellite drag. Three electrostatic analyzers were flown to measure 2D ion distribution functions, providing observations of temperature enhancements, bulk velocity moments, anisotropy and conics. The thermal energy ion detector (HT) sweeps over an energy range of .12 to 22 eV and the medium energy detector (HM) has an energy range from 3.6 to 790 eV. The thermal mass ion detector (BPS) sweeps over the same energy range as the thermal energy detector, but also has a crude mass discriminator separating atomic oxygen from hydrogen. All of the detectors provide two dimensional phase space distributions; the thermal detectors have a cadence of 128 ms while the medium energy detector provides a distribution every 64 ms. These measurements of the upwelling process will be used as input for coupled models or be used as a metric to compare to what the models predict. During initial data analysis, we found nongyrotropy in the medium energy ions, a proton enhancement during an otherwise uneventful region, and three ion upflow events which will be further investigated.