The Optical Mesosphere Thermosphere Imagers (OMTIs) for network measurements of aurora and airglow

Abstract

A new digital all-sky imager experiment for optical auroral studies in conjunction with the Scandinavian twin auroral radar experiment Rev. ABSTRACTThe Optical Mesosphere Thermosphere Imagers (OMTIs) currently consist of eight all-sky cooled-CCD imagers and several interferometers and spectrometers. They are making routine observations of aurora and airglow in Japan, Australia, Indonesia, and Canada. Here we show recent results of OMTIs particularly from the two Canadian stations at Resolute Bay (RSB) and Athabasca (ATH). At RSB, we observe polar-cap plasma patches almost always during southward IMF periods. From two-dimensional cross-correlation analyses, we determine velocity vectors of the patches, which indicates the ionospheric convection vector, showing high correlation with the IMF-By and -Bz variations. At ATH, we often observe isolated proton arcs and Stable Auroral Red (SAR) arcs, which are located equatorward of the auroral oval. The appearance of the isolated proton arcs is highly correlated with the Pc 1 geomagnetic pulsations measured simultaneously at ATH, suggesting interactions between the electromagnetic ion cyclotron (EMIC) waves and protons in the vicinity of the plasmapause and the ring current. Similar interactions without waves are also suggested for the SAR arcs, which appear after the substorm expansion phase even without geomagnetic storms. These observations show promising capability to monitor magnetospheric processes from the ground stations, which would contribute to the future satellite projects, such as THEMIS, ERG, and Scope/Xscale.

Ground-based instruments of the PWING project to investigate dynamics of the inner magnetosphere at subauroral latitudes as a part of the ERG-ground coordinated observation network

“…5a, auroral activity is seen in the northern sky of GAK after clouds disappear at 09:20 UT. A detachment of an arc from this northern aurora is observed at ~ 12 UT, indicating a detached SAR arc from the main auroral oval, as reported by Shiokawa et al (2009b). A similar detachment of the SAR arc is seen at KAP in Fig.…”

Thermospheric wind variations observed by a Fabry–Perot interferometer at Tromsø, Norway, at substorm onsets

“…We selected the intervals of the FPI operation under the clear-sky conditions, which were identified using a collocated all-sky airglow imager of Optical Mesosphere Thermosphere Imagers (OMTIs, http://stdb2 .isee.nagoy a-u. ac.jp/omti/) (Shiokawa et al 2009). As shown in Eq.…”

Rapid Loss of Relativistic Electrons by EMIC Waves in the Outer Radiation Belt Observed by Arase, Van Allen Probes, and the PWING Ground Stations

“…Using optical images at these wavelengths, we can constrain the spatial-temporal variation of EMIC wave activity (e.g., Sakaguchi et al, 2012). The PWING stations are equipped with Optical Mesosphere Thermosphere Imagers (OMTIs; Shiokawa et al, 1999;Shiokawa et al, 2009) to measure these emissions, and we can investigate the spatial extent of EMIC waves using images obtained by OMTI. Figures 3a-3c show keograms in a magnetic north-south meridian at wavelengths of 557.7, 630.0, and 486.1 nm, respectively, derived from the images taken by OMTI at ATH.…”