We use an automated procedure to identify periods of enhanced dayside reconnection followed by enhanced nightside reconnection in measurements of the polar cap size by the Active Magnetosphere and Planetary Electrodynamics Response Experiment between January 2010 and December 2012; we find 490 such events. We investigate the dynamics of the spatial distributions of the total electron content (TEC) and phase scintillations of Global Positioning System (GPS) signals across the northern polar region and here report three important findings: (1) While a TEC enhancement (due to polar cap patches) propagates across the polar cap during these events, this enhancement is not associated with significant GPS phase scintillations. (2) Instead, a significant impact on GPS signal quality is first found when the TEC enhancements cross the nightside auroral boundary. (3) In combination with upward field‐aligned currents, these TEC enhancements cause the strongest GPS phase scintillations. We conclude that polar cap patches are not, as previously thought, a space weather threat inside the polar cap but instead reveal their biggest impact once they reach the nightside auroral oval, in particular when combined with upward field‐aligned currents.

Atomic samarium has been injected into the neutral atmosphere for production of electron clouds that modify the ionosphere. These electron clouds may be used as high‐frequency radio wave reflectors or for control of the electrodynamics of the F region. A self‐consistent model for the photochemical reactions of Samarium vapor cloud released into the upper atmosphere has been developed and compared with the Metal Oxide Space Cloud (MOSC) experimental observations. The release initially produces a dense plasma cloud that that is rapidly reduced by dissociative recombination and diffusive expansion. The spectral emissions from the release cover the ultraviolet to the near infrared band with contributions from solar fluorescence of the atomic, molecular, and ionized components of the artificial density cloud. Barium releases in sunlight are more efficient than Samarium releases in sunlight for production of dense ionization clouds. Samarium may be of interest for nighttime releases but the artificial electron cloud is limited by recombination with the samarium oxide ion.

[1] Ground based optical instruments are invaluable tools for studies of processes associated with the cusps and auroral morphology. In this work we present a method for obtaining the magnetic latitude of the open/closed field line boundary (OCB) from the cusp 6300 Å[OI] auroral red line using a meridian scanning photometer. The method which is based on a pre-defined reference cusp aurora produced by the GLOW model is examined with respect to uncertainties, and we describe how a set of equations describing the error is constructed. The method is applicable to data from optical instruments located at high latitude observation sites such as Svalbard and Antarctica. Equations describing both errors and the mapping altitude for transforming the OCB from instrument centered coordinates to magnetic latitude for instrumentation located in Svalbard (Longyearbyen) are presented. Further, by applying the GLOW model we present results illustrating the great variability in the altitude profile of the atomic oxygen 6300 Å[OI] red line emission in the cusp. A simple calculation showing how a poleward neutral wind will change the latitudinal shape of the cusp aurora is also performed.

Two rocket‐borne releases of samarium vapor in the upper atmosphere occurred in May 2013, as part of the Metal Oxide Space Clouds experiment. The releases were characterized by a combination of optical and RF diagnostic instruments located at the Roi‐Namur launch site and surrounding islands and atolls. The evolution of the optical spectrum of the solar‐illuminated cloud was recorded with a spectrograph covering a 400–800 nm spectral range. The spectra exhibit two distinct spectral regions centered at 496 and 636 nm within which the relative intensities change insignificantly. The ratio between the integrated intensities within these regions, however, changes with time, suggesting that they are associated with different species. With the help of an equilibrium plasma spectral model we attribute the region centered at 496 nm to neutral samarium atoms (Sm I radiance) and features peaking at 649 nm to a molecular species. No evidence for structure due to Sm+ (Sm II) is identified. The persistence of the Sm I radiance suggests a high dissociative recombination rate for the chemi‐ionization product, SmO+. A one‐dimensional plasma chemical kinetic model of the evolution of the density ratio NSmO/NSm(t) demonstrates that the molecular feature peaking at 649 nm can be attributed to SmO radiance. SmO+ radiance is not identified. By adjusting the Sm vapor mass of the chemical kinetic model input to match the evolution of the total electron density determined by ionosonde data, we conclude that less than 5% of the payload samarium was vaporized.

Using the narrowband all‐sky imager mode of the Long Wavelength Array (LWA1), we have now detected 30 transients at 25.6 MHz, 1 at 34 MHz, and 93 at 38.0 MHz. While we have only optically confirmed that 37 of these events are radio afterglows from meteors, evidence suggests that most, if not all, are. Using the beam‐forming mode of the LWA1, we have also captured the broadband spectra between 22.0 and 55.0 MHz of four events. We compare the smooth, spectral components of these four events and fit the frequency‐dependent flux density to a power law, and find that the spectral index is time variable, with the spectrum steepening over time for each meteor afterglow. Using these spectral indices along with the narrowband flux density measurements of the 123 events at 25.6 and 38 MHz, we predict the expected flux densities and rates for meteor afterglows potentially observable by other low‐frequency radio telescopes.