NOPR Community:

Is electron diffusion at low L shells always weak?

2016-10-26T09:19:25Z

Title: Is electron diffusion at low L shells always weak? Authors: Sazhin, S S Abstract: It is pointed out that different definitions of weak and strong diffusion of electrons in the magnetosphere do not necessarily agree with each other. If we use the concept of weak and strong diffusion introduced by Kennel and Petschek [J Geophys Res (USA), 71 (1966) 1], then we would expect the electron diffusion at L £ 1.5 to be virtually always weak. Page(s): 446

Effect of surface radioactivity on vertical distribution of atmospheric electrical conductivities

2016-10-26T09:17:22Z

Title: Effect of surface radioactivity on vertical distribution of atmospheric electrical conductivities Authors: Muralidas, S; Sampath, S; Sasikumar, V Abstract: A balloon-borne force aspirated Gerdien condenser measurement carried out from Hyderabad, India, has given the conductivity profile from the surface onwards. The conductivity, instead of continuously increasing from the surface, decreases initially up to 2 km and then increases. This is due to the combination of the ionization due to galactic cosmic rays and surface radioactivity / radioactive gases. This feature has been presented and discussed. Page(s): 444-445

Generation of VLF hiss and chorus in Jupiter’s magnetosphere

2016-10-26T09:15:59Z

Title: Generation of VLF hiss and chorus in Jupiter’s magnetosphere Authors: Singh, V Abstract: Using the plasma and field parameters corresponding to L=8, temporal growth rates of VLF waves have been computed for a non-Maxwellian electron distribution leads the generation of VLF chorus just below the one-half of the electron gyrofrequency and the presence of nonthermal drifted Maxwellian tail leads the instability below one-fourth of the electron gyrofrequency. The computed results are in good agreement with those reported by the Voyager 1 and 2 plasma wave experiments. Page(s): 438-443

Transport model calculations of 5577Å and 6300Å OI emissions in proton precipitation

2016-10-26T09:14:22Z

Title: Transport model calculations of 5577Å and 6300Å OI emissions in proton precipitation Authors: Srivastava, V; Singh, Vir Abstract: The OI emissions (5577 Å and 6300 Å) are studied by using transport for proton precipitation. All possible sources of these emissions are considered. Recent experimental cross-sections and the reaction rate coefficients are used in the calculations The volume emission rates and the emission intensities of these emissions are calculated for Maxwellian distribution of precipitating protons and are compared with those obtained from the continuous slowing down approximation (CSDA). The yield of O(¹D) due to the reaction of N(²D) with O₂ is found almost negligible. The intensities of 5577 Å and 6300 Å emissions during the 4 Aug. 1972 polar cap absorption (PCA) event are also computed and a comparison is made with the measurements. The present calculated intensity ratio I (1577) / I(6300) is found in reasonable agreement with the measurements. Page(s): 428-437