The Ground Imaging to Rocket investigation of Auroral Fast Features (GIRAFF) sounding rocket mission

Abstract:

We describe the Ground Imaging to Rocket investigation of Auroral Fast Features (GIRAFF) mission, which is a recently selected sounding rocket mission to study auroral electrodynamics. The main science goal of the mission is to evaluate the processes responsible for creating flickering and fast pulsating aurora. These types of aurora contain the fastest observed optical auroral features, which allow for investigation into the actual wave-particle interactions that are responsible for scattering and accelerating the precipitating electrons. The main objective is to quantify the electron precipitation, with high-time resolution, inside a region of flickering aurora and inside a region of fast pulsating aurora, enabling the determination of the electron modulation mechanisms. We will focus on three scientific objectives: 1) To determine the mechanisms causing the electron modulation responsible for flickering and fast pulsating aurora; 2) To determine the altitudes where the electromagnetic wave–particle interactions are occurring; 3) To investigate the relationship between the spatial scale sizes and temporal frequencies within these auroral features. The mission will be implemented by using two instrumented sounding rocket payloads launched into the auroral ionosphere (350 km apogee) from Poker Flat, AK. We will make in situ measurements of the precipitating electrons and the magnetic field. We will also use ground-based, common-volume, high-resolution imaging observations of the auroral structures conjugate to the rocket near apogee, to identify and quantify the spatial scale sizes and temporal frequencies of the auroral structures traversed by the payload. The two rocket payloads will be identical and equipped with 2 electron spectrometers. One spectrometer will provide high-time resolution (1 ms cadence) measurements of the precipitating electron spectra. The second electron spectrometer will be a standard top-hat type electro-static analyzer that will provide pitch-angle information about the precipitating electrons. The vector magnetic field (DC to low frequency) will be measured with a fluxgate magnetometer. One payload will be used to target flickering aurora and one will be used to target fast pulsating aurora.