Concept:Geostrophic wind is a horizontal wind found above the friction layer (typically above 600 m) where the pressure gradient force and the Coriolis force are exactly balanced, causing the wind to blow parallel to the isobars.
Explanation:Isobars are lines on a weather map that join places with equal atmospheric pressure.
At heights greater than about 600 metres, the frictional effect of the Earth’s surface becomes negligible.
In such conditions, when the isobars are straight and parallel, the pressure gradient force (directed from high to low pressure) is exactly balanced by the Coriolis force (which deflects moving air due to Earth's rotation).
This balance forces the wind to blow horizontally and parallel to the isobars, not across them.
Statement I correctly describes this phenomenon: geostrophic wind blows above 600 m parallel to isobars.
Statement II correctly defines geostrophic wind as the horizontal wind velocity where the Coriolis force balances the horizontal pressure force.
Since the balance of forces is the very reason why geostrophic wind remains parallel to isobars, Statement II serves as the correct explanation for Statement I.
Answer:Option A: Both statements are individually true and Statement II is the correct explanation of Statement I.