A Large Amplitude (>300 M/S) Neutral Wind "Jet" Observed Near 130 km Altitude and Associated DC Electric Fields, Energetic Electron and Other Measurements Revealed by a Vapor Trail and Dual Sounding Rocket and Ground-Based Instruments in the Auroral Zone Lower Ionosphere

NASA's Auroral Jets investigation was carried out to explore the height dependent coupling processes hypothesized to create localized neutral streams in the upper atmosphere associated with steady ionospheric plasma drifts and auroral arcs occurring in the same location for an extended period of time. To this end, NASA successfully launched two sounding rockets near simultaneously from Poker Flat, Alaska on March 2, 2017 at 05:41:00 UT and 05:42:30 UT achieving apogees of 190 km and 331 km. The rockets were launched over an auroral arc, which was relatively stable for over 30 minutes, yet evolved into auroral "break up" conditions during the mission. Each rocket included plasma and neutral gas probes as well as electric field, magnetic field, and energetic electron detectors. Furthermore, the low flyer rocket released a vapor trail on the upleg and downleg which revealed the detailed motions of the ambient neutral atmosphere, providing definitive evidence of a well-developed neutral jet with peak speeds of over 300 m/s near 125-135 km altitude. In addition, wind profiles were measured in situusing instruments on the rocket payloads which also showed enhanced atmospheric motions within the auroral arc region. DC electric fields were observed to be approximately 75 mV/m on the onset of both rocket trajectories, with reasonably steady, precipitating keV energetic electrons observed during the rocket flights, particularly on their uplegs. The experiment was carried out in conjunction with simultaneous measurements by a ground-based imaging Fabry-Perot system used to determine the large scale neutral winds downrange where the rockets flew. Furthermore, incoherent scatter radar observations of the electric fields, plasma density and temperature, and neutral winds were gathered with the PFISR system to provide a time history of the local auroral ionosphere (particularly before the rocket launches) with good spatial resolution. All-sky camera and magnetometer instruments downrange completed the ground-based observations. The combined, comprehensive data set enables an in-depth study of the fundamental processes associated with the localized response versus altitude of the earth's upper atmosphere motions to the driving DC electric fields and energetic electrons of magnetospheric origin.