Investigation of diffusivity and viscosity in solar plasma

Abstract

For diffusive and viscous plasma, the dispersion relation ω2 = k 2 [v 2 − iω(ν + η)] + νηk 4 is applied for the North Polar Coronal Hole, where we have assumed the angular frequency ω to be a real quantity and the wave number k as a complex quantity. For ω = 2π/τ, we have chosen three values 10−2, 10−3 and 10−4 s for τ. For each value of τ, we have considered three situations: (i) where ν = 0 (no viscosity), (ii) where η = 0 (no magnetic diffusivity) and (iii) where both the diffusivity η and viscosity ν are present. For the cases (i) and (ii), we have obtained two solutions, ±(k r + i k i ). But, for the case (iii), we have obtained two pairs of solutions, ±(k r1 + i k i1) and ±(k r2 + i k i2). These two pairs correspond to the fast-mode and slow-mode waves.