Identify the correct statement from the following:

Geostrophic wind blows parallel to the isobars

Key Points

Geostrophic Wind:

• In atmospheric science, geostrophic flow is the theoretical wind that would result from an exact balance between the Coriolis force and the pressure gradient force.
• This condition is called geostrophic equilibrium or geostrophic balance (also known as geostrophy).
• The geostrophic wind is directed parallel to isobars (lines of constant pressure at a given height). This balance seldom holds exactly in nature.
• The true wind almost always differs from the geostrophic wind due to other forces such as friction from the ground.

• Thus, the actual wind would equal the geostrophic wind only if there were no friction (e.g. above the atmospheric boundary layer) and the isobars were perfectly straight.
• Despite this, much of the atmosphere outside the tropics is close to geostrophic flow much of the time and it is a valuable first approximation.
• Geostrophic flow in air or water is a zero-frequency inertial wave.