The correct option is 1 only
Explanation
The velocity and direction of wind are determined by the combined effects of the Pressure Gradient Force, the Coriolis Force, and Frictional Force. Frictional force acts as a retarding force, opposing the motion of the air and reducing wind velocity.
Statement 1 is Correct:
Frictional force arises from the drag exerted by the Earth's surface features. It is greatest at the surface where the air is in direct contact with the ground, vegetation, and physical structures.
Statement 2 is Incorrect:
The influence of surface friction is generally confined to the lower atmosphere, specifically the planetary boundary layer. This effect typically extends up to an elevation of 1 to 3 km. Above this height, the effect of friction is negligible, and winds move freely under the influence of pressure gradients and the Coriolis force (approximating geostrophic flow). An elevation of 10-15 km represents the upper troposphere, far beyond the reach of surface friction.
Statement 3 is Incorrect:
The magnitude of friction depends on the roughness of the surface. The sea surface is relatively smooth compared to land surfaces characterized by uneven terrain, forests, and buildings. Consequently, friction is minimal over the oceans and maximum over rugged land terrain.
Key Takeaway:
Frictional force is a surface phenomenon that significantly impacts wind speed and direction only within the lowest 1-3 km of the atmosphere and is much weaker over water bodies than over land.