Answer:
σ = 1.52 10⁻¹² 1 /Ω m
Explanation:
The current density is linear in the atmosphere, so it complies with Ohm's law
J = σ E
Where J is the current density, sigma is the electrical inductance and E is the electric field
σ = J / E
σ = 7.3 10⁻¹³ / 48
σ = 1.52 10⁻¹² A / V 1 / m
σ = 1.52 10⁻¹² 1 /Ω m