Bisoi, Susanta Kumar ; Janardhan, P. ; Ingale, M. ; Subramanian, P. ; Ananthakrishnan, S. ; Tokumaru, M. ; Fujiki, K. (2014) A STUDY OF DENSITY MODULATION INDEX IN THE INNER HELIOSPHERIC SOLAR WIND DURING SOLAR CYCLE 23 The Astrophysical Journal, 795 (1). p. 69. ISSN 1538-4357
![]() |
PDF
3MB |
Official URL: http://doi.org/10.1088/0004-637X/795/1/69
Related URL: http://dx.doi.org/10.1088/0004-637X/795/1/69
Abstract
The ratio of the rms electron density fluctuations to the background density in the solar wind (density modulation index, epsilon N ≡ ΔN/N) is of vital importance for understanding several problems in heliospheric physics related to solar wind turbulence. In this paper, we have investigated the behavior of epsilon N in the inner heliosphere from 0.26 to 0.82 AU. The density fluctuations ΔN have been deduced using extensive ground-based observations of interplanetary scintillation at 327 MHz, which probe spatial scales of a few hundred kilometers. The background densities (N) have been derived using near-Earth observations from the Advanced Composition Explorer. Our analysis reveals that 0.001 <~ epsilon N <~ 0.02 and does not vary appreciably with heliocentric distance. We also find that epsilon N declines by 8% from 1998 to 2008. We discuss the impact of these findings on problems ranging from our understanding of Forbush decreases to the behavior of the solar wind dynamic pressure over the recent peculiar solar minimum at the end of cycle 23.
Item Type: | Article |
---|---|
Source: | Copyright of this article belongs to arXiv |
Keywords: | interplanetary medium; solar wind; turbulence; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
ID Code: | 130497 |
Deposited On: | 30 Nov 2022 11:33 |
Last Modified: | 30 Nov 2022 11:33 |
Repository Staff Only: item control page