Statistical Studies of the Variation of Ionospheric Parameters and Their Relationship with Space Weather Events

Abstract

The Scintillation Prediction Observation Research Task (SPORT) international collaborative mission willadvance our understanding of the nature and evolution of ionospheric structures around sunset to improvepredictions of disturbances that affect radio propagation and telecommunication signals. Structure in thecharged particle number density in the equatorial ionosphere can have a profound impact on the fidelity of HF,VHF and UHF radio signals that are used for ground-to-ground and space-to-ground communication andnavigation. The degree to which such systems can be compromised depends in large part on the spatialdistribution of the structured regions in the ionosphere and the background plasma density in which they areembedded. Plasma structures originate in the bottomside of the ionospheric layer known as the F regionwhere they may be resident most of the time during the nighttime. However, if conditions allow the structuredregions to penetrate through the bottomside F region and into and above the peak of the layer, then theplasma structures may be of sufficient magnitude to create significant perturbations in both the propagationpath of radio signals as well as changes in the signal phase and amplitude, known as scintillation. Discoveringthe conditions under which the most detrimental effects on radio wave propagation exist remains a challengeto both our observational capability and our physical understanding. The background ionospheric conditionsare conveniently described by latitudinal profiles of the plasma density at nearly constant altitude, whichdescribe the effects of ExB drifts and neutral winds, while the appearance and growth of plasma structurerequires committed observations from the ground from at least one fixed longitude. These goals will beaccomplished by a unique combination of satellite observations from a nearly circular middle inclination orbitand the extensive operation of ground based observations from South America near the magnetic equator.Our proposed mission will produce a coordinated set of measurements of the F-peak height and density aswell as the vertical plasma motions and plasma density in the local time region from 1500 to 2400 over amagnetic latitude range from +/-30°. The advent of reliable derivation of F-peak density and height fromradio occultation receivers allows these parameters, which are sensitive functions of the vertical plasmamotion, to be specified from an orbiting satellite in a large range in local time and longitude around theequator. Coupled with in-situ measurements of the plasma drifts and plasma density, it is possible to tietogether the local and regional behaviors described by these data sources using well-established physical linksas well as powerful new machine learning techniques. With SPORT we propose to undertake such a studyutilizing a simple cube-sat payload consisting of the following instruments: Langmuir/impedance probe, driftmeter, radio occultation sensor and a magnetometer. The mission will feature a strong collaboration with theNational Aeronautics and Space Administration (NASA), Utah State University (USU), University of Alabama inHuntsville (UAH) and the National Institute for Space Research (INPE). The proposed instruments will behosted on an ITA U-class (6U) platform (based on ITASAT) launched from the ISS. This proposal covers the6U platform and its team, the Physics Laboratory at ITA, and a supporting role for the contributedcomponents from the American contingent of NASA USU, UAH and INPE that includes I&T, mission operations, and data collection/reduction/dissemination. Additionally, use of an extensive ground based ionospheric observational network operated by INPE at different locations in Brazil will be available.