Thermospheric and ionospheric dynamics in the auroral region

Shinagawa, Hiroyuki; Oyama, Shin‐ichiro; Nozawa, S.; Buchert, Stephan; Fujii, Ryoichi; Ishii, Mamoru

doi:10.1016/s0273-1177(02)00792-5

Cited by 12 publications

(17 citation statements)

References 17 publications

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“…However, their study showed only a few snapshots of the velocity near an arc, which might not be a typical or steady feature. In this study, the interaction between a local heat source and a background horizontal flow was investigated in more detail than Shinagawa et al (2003). It is found that for large horizontal flow larger than 300 m/s, this picture agrees qualitatively to the model calculations obtained in this study.…”

Section: Discussionsupporting

confidence: 82%

“…Smith (2000) suggested that waves of vertical winds can be generated in the downstream region associated with auroral heating. Shinagawa et al (2003) studied the dynamics near a moving auroral arc, using a two-dimensional thermospheric model. They found that wave-like signature tends to be formed in the downstream region of the moving heat source.…”

Section: Discussionmentioning

confidence: 99%

“…Therefore, we employ a two-dimensional nonhydrostatic compressible atmospheric model to study the behavior of vertical winds associated with a local heat source in a background flow. The modeling method is basically the same as previous nonhydrostatic thermospheric models Walterscheid and Lyons, 1992;Sun et al, 1995;Shinagawa et al, 2003).…”

Section: Simulation Modelmentioning

confidence: 99%

“…However, strong vertical motion, especially downward motion has not been reproduced by those models. Shinagawa et al (2003) studied the dynamics near a moving auroral arc, using a two-dimensional thermospheric model. They found that wave-like signature tends to be formed in the downstream region of the moving heat source.…”

Section: Introductionmentioning

confidence: 99%

“…In this study, we examine whether or not and how significant vertical oscillation suggested by Smith (2000) and by Shinagawa et al (2003) is generated as a result of interaction of local heating and background horizontal wind field. To solve the fluid equations for the neutral atmosphere, a relatively new numerical technique, Cubic-Interpolated Pseudo-particle (CIP) method, is appllied, and the basic procedure is briefly described in Appendix.…”

Section: Introductionmentioning

confidence: 99%

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A two-dimensional simulation of thermospheric vertical winds in the vicinity of an auroral arc

Shinagawa

Oyama

2006

Earth Planet Sp

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The observations made by Fabry-Perot interferometers (FPIs), radars, and satellites have indicated that large vertical motion in the polar region is occasionally generated in the thermosphere associated with auroral activities. However, the behavior of the vertical wind is often very complicated, and the cause of the vertical wind has not been explained by auroral heating or by ion-neutral drag alone. It has been pointed out that a background horizontal flow is likely to significantly alter the dynamics of the neutral atmosphere near an auroral arc. Recent observations have also suggested that strong downward motion is generated in the vicinity of an auroral arc. To study the thermospheric dynamics near a local heating region embedded in a large-scale horizontal flow, a twodimensional numerical simulation of the thermospheric dynamics has been performed. It is found that interaction of local heating and strong horizontal flow could play an important role in generating vertical motion near an auroral arc. The simulation results indicate that for a horizontal wind speed larger than about 300 m/s, a steady wave-like structure of the neutral wind is formed within and downstream of the heated region. For a horizontal wind speed less than about 300 m/s, on the other hand, no significant vertical motion is generated outside the heated region. This process might account for at least some of the observed features of vertical motion within and outside an auroral arc.

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Section: Discussionsupporting

confidence: 82%

Section: Discussionmentioning

confidence: 99%