TY - JOUR
T1 - On stabilizing role of parallel inhomogeneous flow on low-frequency space fluctuations
AU - Sen, S.
PY - 2003
Y1 - 2003
N2 - A fundamental reality throughout the space plasma is the existence of magnetic field-aligned flows. It is usually believed that the spatial transverse shear in the parallel flow destabilizes many low frequency oscillations and this may be the origin of low frequency oscillations in the ionosphere (V. V. Gavrishchaka et al., 1998, Phys. Rev. Lett., 80, 728 and Phys. Rev. Lett.: 2000, 85, 4285). Here we show that this notion of destabilizing influence of the shear in the parallel flow can be changed altogether if one takes the effect of the flow curvature (second spatial derivative) into account. The transverse curvature in the parallel flow can overcome the destabilizing influence of the shear and can render the low frequency modes stable. It is shown that unlike flow shear the effect of flow curvature is sign- and mode-dependent.
AB - A fundamental reality throughout the space plasma is the existence of magnetic field-aligned flows. It is usually believed that the spatial transverse shear in the parallel flow destabilizes many low frequency oscillations and this may be the origin of low frequency oscillations in the ionosphere (V. V. Gavrishchaka et al., 1998, Phys. Rev. Lett., 80, 728 and Phys. Rev. Lett.: 2000, 85, 4285). Here we show that this notion of destabilizing influence of the shear in the parallel flow can be changed altogether if one takes the effect of the flow curvature (second spatial derivative) into account. The transverse curvature in the parallel flow can overcome the destabilizing influence of the shear and can render the low frequency modes stable. It is shown that unlike flow shear the effect of flow curvature is sign- and mode-dependent.
KW - Ballooning mode
KW - Flow profile
KW - PVS instability
KW - RT instability
UR - http://www.scopus.com/inward/record.url?scp=0142059537&partnerID=8YFLogxK
U2 - 10.1023/A:1025593721677
DO - 10.1023/A:1025593721677
M3 - Article
SN - 0038-6308
VL - 107
SP - 373
EP - 381
JO - Space Science Reviews
JF - Space Science Reviews
IS - 1-2
ER -