Propagation characteristics of gravity waves observed by airglow imaging At Syowa Station(69S,39E), Antarctica

第3回極域科学シンポジウム　横断セッション「中層大気・熱圏」 11月26日（月）、27日（火） 国立極地研究所 ２階ラウン

Characteristics of equatorial gravity waves derived from mesospheric airglow imaging observations

We present the characteristics of small-scale (<100 km) gravity waves in the equatorial mesopause region derived from OH airglow imaging observations at Kototabang (100.3° E, 0.2° S), Indonesia, from 2002 to 2005. We adopted a method that could automatically detect gravity waves in the airglow images using two-dimensional cross power spectra of gravity waves. The propagation directions of the waves were likely controlled by zonal filtering due to stratospheric mean winds that show a quasi-biennial oscillation (QBO) and the presence of many wave sources in the troposphere

Excitation Functions for 3He-induced Reactions on Silver

開始ページ、終了ページ: 冊子体のページ付

Pressure-driven instability in auroral images to create auroral patches

第3回極域科学シンポジウム/第36回極域宙空圏シンポジウム 11月27日（火） 国立極地研究所 2階大会議

Stoner gap in the superconducting ferromagnet UGe2

We report the temperature ($T$) dependence of ferromagnetic Bragg peak intensities and dc magnetization of the superconducting ferromagnet UGe2 under pressure ($P$). We have found that the low-$T$ behavior of the uniform magnetization can be explained by a conventional Stoner model. A functional analysis of the data produces the following results: The ferromagnetic state below a critical pressure can be understood as the perfectly polarized state, in which heavy quasiparticles occupy only majority spin bands. A Stoner gap $\Delta(P)$ decreases monotonically with increasing pressure and increases linearly with magnetic field. We show that the present analysis based on the Stoner model is justified by a consistency check, i.e., comparison of density of states at the Fermi energy deduced from the analysis with observed electronic specific heat coeffieients. We also argue the influence of the ferromagnetism on the superconductivity.Comment: 5 pages, 4 figures. to be published in Phys. Rev.

Relationship between propagation direction of gravity waves in OH and OI airglow images and VHF radar echo occurrence during the SEEK-2 campaign

We report simultaneous observations of atmospheric gravity waves (AGW) in OI (557.7nm) and OH airglow images and VHF radar backscatter from field-aligned irregularities (FAI) in the <i>E</i>-region during the SEEK-2 (Sporadic-<i>E</i> Experiment over Kyushu 2) campaign period from 29 July to 9 August 2002. An all-sky imager was operated at Nishino-Omote (30.5 N, 130.1 E), Japan. On 14 nights, 17 AGW events were detected in OI and OH airglow images. AGW propagated mostly toward the northeast or southeast. From comparison with the <i>E</i>-region FAI occurrence, which is detected by a nearby VHF radar (31.57MHz), we found that AGW tended to propagate southeastward during FAI events. This result suggests that the interaction between AGW and <i>E</i>-region plasma plays an important role in generating FAI. Furthermore, polarization electric fields generated directly by AGW may contribute to the FAI generation.<br><br> <b>Keywords.</b> Atmospheric composition and structure (Airglow and aurora), Ionosphere (Ionospheric irregularities, Mid-latitude ionosphere