Bibliography

Middle-Low Latitude Neutral Composition and Temperature Responses to the 20 and 21 November 2003 Superstorm From GUVI Dayside Limb Measurements

TIMED/Global Ultraviolet Imager (GUVI) limb measurements of far-ultraviolet airglow emission have been used to investigate middle-low latitude thermospheric composition and neutral temperature responses to the 20 and 21 November 2003 (day of year [DOY] 324 and 325) superstorm. Altitude profiles of O, N2 number densities and temperature, as well as O/N2 column density ratio (∑O/N2), on the storm days along the GUVI limb tracks are compared with those on DOY 323 (quiet time). The storm-time composition and temperature responses were global and evolved continuously as the storm progressed. Specially, N2 and temperature increased almost globally at all altitudes during the storm and their perturbation structures were similar. The magnitudes of their enhancements both increased with altitude and latitude. The storm-induced O perturbations decreased in the lower thermosphere but increased in the upper thermosphere. Transition heights of O perturbations from decrease to increase changed with latitude and time. During the storm main and recovery phases, the storm-induced ∑O/N2 decreases were mostly related to the O depletion in the low-middle thermosphere, whereas ∑O/N2 increases during the storm were primarily caused by N2 depletion. There was a remarkable hemispheric asymmetry in composition responses as they have different morphologies and lifetime, especially during the storm recovery phase.

Yu, Tingting; Wang, Wenbin; Ren, Zhipeng; Yue, Jia; Yue, Xinan; He, Maosheng;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2021     DOI: 10.1029/2020JA028427

neutral composition; altitude profile; hemispheric asymmetry in composition responses; neutral temperature; superstorm; transition heights of O responses

Variations of the neutral temperature and sodium density between 80 and 107 km above Troms\o during the winter of 2010-2011 by a new solid-state sodium lidar

A new solid-state sodium lidar installed at Ramfjordmoen, Troms\o (69.6\textdegreeN, 19.2\textdegreeE), started observations of neutral temperature together with sodium density in the mesosphere-lower thermosphere (MLT) region on 1 October 2010. The new lidar provided temperature data with a time resolution of 10 min and with good quality between \~80 and \~105 km from October 2010 to March 2011. This paper aims at introducing the new lidar with its observational results obtained over the first 6 months of observations. We succeeded in obtaining neutral temperature and sodium density data of \~255.5 h in total. In order to evaluate our observations, we compared (1) the sodium density with that published in the literature, (2) average temperature and column sodium density data with those obtained with Arctic Lidar Observatory for Middle Atmosphere Research Weber sodium lidar, and (3) the neutral temperature data with those obtained by Sounding of the Atmosphere with Broadband Emission Radiometry/Thermosphere Ionosphere Mesosphere Energetics and Dynamics satellite. For the night of 5 October 2010, we succeeded in conducting simultaneous observations of the new lidar and the European Incoherent Scatter UHF radar with the tristatic Common Program 1 (CP-1) mode. Comparisons of neutral and ion temperatures showed a good agreement at 104 km between 0050 and 0230 UT on 6 October 2010 when the electric field strength was smaller, while significant deviations (up to \~25 K) are found at 107 km. We evaluated contributions of Joule heating and electron-ion heat exchange, but derived values seem to be underestimated.

Nozawa, S.; Kawahara, T.; Saito, N.; Hall, C.; Tsuda, T.; Kawabata, T.; Wada, S.; Brekke, A.; Takahashi, T.; Fujiwara, H.; Ogawa, Y.; Fujii, R.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 01/2014

YEAR: 2014     DOI: 10.1002/2013JA019520

Joule heating; neutral temperature; polar MLT; sodium lidar