Probing Ionosphere-Magnetosphere coupling with the combination of in-situ and ground based measurements: the GREECE mission

Marilia Samara1, Robert Michell1,2, Guy Alan Grubbs II3, Donald L Hampton4, John W Bonnell5 and Keiichi Ogasawara3, (1)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (2)University of Maryland, College Park, MD, United States, (3)Southwest Research Institute, San Antonio, United States, (4)University of Alaska Fairbanks, Fairbanks, AK, United States, (5)University of California Berkeley, Berkeley, CA, United States

Contact First Author: Marilia Samara; marilia.samara@nasa.gov

Previously Published Material: The specific findings were not reported but an overview of the GREECE mission was given at the Fall AGU in San Francisco, December 2014.

Abstract ID#: 34701

 

English Abstract:
The Ground-to-Rocket Electrodynamics-Electrons Correlative Experiment (GREECE) sounding rocket successfully launched from Poker Flat, Alaska on 03 March 2014 reaching an apogee of 335 km. GREECE launched into a dynamic post-midnight auroral arc event—rich in particle and wave signatures—that occurred directly over the downrange imaging site of Venetie, AK. The onboard electron detectors measured the precipitating electrons, which were then compared to the optical auroral structures that they were responsible for. The ground-based auroral imaging consisted of 6 different imagers with a total of 3 separate fields of view, providing information about the aurora on both the large-scale (>10 km) and the small scale (~100 m). This yielded multi-emission line intensities of the auroral brightness at the magnetic footprint of the rocket critical for our main goal of exploring the correlation of the sheer flows—often observed in high resolution imagery during aurora—and the in situ signatures of precipitating particles and waves. The emission line brightness data correlate well with electron characteristics taken by the Acute Precipitating Electron Spectrometer (APES). The ultimate goal is to characterize the auroral emissions produced from a known precipitating electron distribution, such that we can more accurately use ground-based imaging and photometry to infer the characteristics of the precipitating electrons. These techniques can then be applied over larger scales and longer times, when only multi-spectral imaging data are available with no corresponding in situ data. Moreover, using both electron detectors and the electric field instrument on board GREECE we were able to determine that the auroral flows are not caused by large-amplitude electric fields in the low altitude (<400 km) ionosphere. The nature of the electron precipitation reveals that the flow structure is caused by motions of the electron source region, occurring much farther out in the near-Earth space environment.
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