HR: 0800h
AN: SA21A-0282    [Abstracts]
TI: Characteristics of Plasma Depletions Over Indian Region During Solar Maximum
AU: * Rajesh, P
EM: pkrajesh@ss.ncu.edu.tw
AF: Institute of Space Science, National Central University, Chung-Li, 32001 Taiwan
AU: Liu, J
EM: jyliu@ss.ncu.edu.tw
AF: Institute of Space Science, National Central University, Chung-Li, 32001 Taiwan
AU: H. S. S., S
SA21A-0282 AF: Physical Research Laboratory, Navrangpura, Ahmedabad, 380009 India
AU: Banerjee, S B
SA21A-0282 AF: Physical Research Laboratory, Navrangpura, Ahmedabad, 380009 India
AU: Misra, R
SA21A-0282 AF: Physical Research Laboratory, Navrangpura, Ahmedabad, 380009 India
AU: Dutt, N
SA21A-0282 AF: Physical Research Laboratory, Navrangpura, Ahmedabad, 380009 India
AU: Dadhania, M
SA21A-0282 AF: Physical Research Laboratory, Navrangpura, Ahmedabad, 380009 India
AB: The all sky imaging observations from Kavalur (12.56° N, 78.8° E), India during February-April in 2002 showed the occurrence of plasma depletions in several consecutive nights. Depletions were present in 630.0 and 777.4 nm for about 80% of the total nights of observation. Out of this, about 70% of the nights showed depletions in 557.7 nm also. There was no significant geomagentic activity during the period. The h'F variation obtained from Trivandrum (7.6 °N, 76.9°E) showed rapid upward motion of F-layer in the post-sunset hours, with vertical velocity in the range 30-70 m/s, and an average value of 41 m/s. About 37% of the nights of depletions in 630.0 nm showed the midnight/post- midnight generation of irregularities within the field of view. In contrast to 630.0 and 777.4 nm, depletions were seen in 557.7 nm around midnight or in the post-midnight hours. Simulations confirm that during solar maximum the thermsperic component of 557.7 nm emission dominates over its mesospheric counterpart in the post-midnight hours, while in solar minimum, the mesospheric component is higher throughout the night.
DE: 0310 Airglow and aurora
DE: 0355 Thermosphere: composition and chemistry
DE: 2415 Equatorial ionosphere
DE: 2419 Ion chemistry and composition (0335)
DE: 2439 Ionospheric irregularities
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005