[1] Ionospheric disturbances caused by a missile launched from North Korea on 12 December 2012 were investigated by using the GPS total electron content (TEC). The spatial characteristic of the front edge of V-shaped disturbances produced by missiles and rockets was first determined. Considering the launch direction and the height of estimated ionospheric points at which GPS radio signal pierces the ionosphere, the missile passed through the ionosphere at heights of 391, 425, and 435 km at 0056:30, 0057:00, and 0057:30 UT, respectively. The observed velocities of the missile were 2.8 and 3.2 km/s at that time, which was estimated from the traveling speed of the front edge of V-shaped disturbances. Westward and eastward V-shaped disturbances propagated at 1.8-2.6 km/s. The phase velocities of the westward and eastward V-shaped disturbances were much faster than the speed of acoustic waves reported in previous studies, suggesting that sources other than acoustic waves may have played an important role. Furthermore, the plasma density depletion that is often observed following missile and rocket launches was not found. This suggests that the depletion resulting from the missile's exhaust was not strong enough to be observed in the TEC distribution in the topside ionosphere.

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Measuring electron density (Ne) and temperature (Te) using a DC Langmuir probe in the ionosphere is very often degraded by the electrode contamination. In order to examine the accuracy of DEMETER observations, we compared DEMETER Ne and Te with several other satellites observations and IRI2012 as reference data. DEMETER Ne and Te show well-known dependencies on the solar irradiance except for the range of F10.7 > 100. However, DEMETER Ne are about 70% lower than those of IRI in day time data and its solar irradiance dependency is consistent with the reference data in night time data. It was confirmed that the negative slope appears in deep solar minimum solar cycle 23/24. DEMETER Te are higher than IRI data by 500-1500 K in day time and by 800 K in night time. The relation between Ne and Te is well defined by a negative slope both in DEMETER and IRI during day time, while such a similarity is not recognized in night time data. DEMETER Te is 700 K higher than IRI Te for the same value of Ne. When Ne is less than 10(4) cm(-3) in night time, significant reductions in DEMETER Te are observed, which is close to expected values. Such discrepancies from the reference data and some peculiar behaviors of DEMETER Te and Ne data necessitate a careful attention in using them in consideration of their data alterations. However, their relative variations and averaged behavior in time contain useful information for scientific studies such as dependencies on solar irradiance and wave-4 longitudinal structure under certain conditions (Ne > 10(4) cm(-3) and F10.7 < 100). (C) 2013 COSPAR. Published by Elsevier Ltd. All rights reserved

Abstract. This study is a statistical analysis on energy distribution of precipitating electrons, based on CNA (cosmic noise absorption) data obtained from the 256-element imaging riometer in Poker Flat, Alaska (65.11 • N, 147.42 • W), and optical data measured with an MSP (Meridian Scanning Photometer) over 79 days during the winter periods from 1996 to 1998. On the assumption that energy distributions of precipitating electrons represent Maxwellian distributions, CNA is estimated based on the observation data of auroral 427.8-nm and 630.0-nm emissions, as well as the average atmospheric model, and compared with the actual observation data. Although the observation data have a broad distribution, they show systematically larger CNA than the model estimate. CNA determination using kappa or double Maxwellian distributions, instead of Maxwellian distributions, better explains the distribution of observed CNA data. Kappa distributions represent a typical energy distribution of electrons in the plasma sheet of the magnetosphere, the source region of precipitating electrons. Pure kappas are more likely during quiet times -and quiet times are more likely than active times. This result suggests that the energy distribution of precipitating electrons reflects the energy distribution of electrons in the plasma sheet.

We investigate the forces and atmosphere‐ionosphere coupling that create atmospheric dynamo currents using two rockets launched nearly simultaneously on 4 July 2013 from Wallops Island (USA), during daytime Sq conditions with ΔH of −30 nT. One rocket released a vapor trail observed from an airplane which showed peak velocities of >160 m/s near 108 km and turbulence coincident with strong unstable shear. Electric and magnetic fields and plasma density were measured on a second rocket. The current density peaked near 110 km exhibiting a spiral pattern with altitude that mirrored that of the winds, suggesting the dynamo is driven by tidal forcing. Such stratified currents are obscured in integrated ground measurements. Large electric fields produced a current opposite to that driven by the wind, believed created to minimize the current divergence. Using the observations, we solve the dynamo equation versus altitude, providing a new perspective on the complex nature of the atmospheric dynamo.