Fig. 3.
From: Ballooning modes and their stability in a near-Earth plasma
The field-aligned structure (s—the coordinate along the field line measured from the magnetospheric equator s = 0) of unstable mode in the Voigt model under 
. The parameters of the model used are x
b
= 5R
E
, z
b
= 3R
E
. The plasma density is assumed to be constant. Upper panel: the field-aligned distribution of parameter β; middle panel: transverse plasma displacement ξ1, and the characteristics of plasma compression u = ∇ ∙ ξ; bottom panel: magnetic field compression bǁ = b3, and the transversal component of magnetic disturbance b⊥ = b1.