Example solutions for different behaviors of the ambient medium density. The solid line shows the symmetric solution assuming the uniform density (Wilkin 1996). The two nonaxisymmetric solutions arise from the stratified ambient medium with the density gradient in the direction of the arrow (Wilkin 2000). The density of the medium follows the law ρ = ρ₀(1 + a₁x + a₂x²), for x ≥ 0.