Which condition is likely to increase the effective strength of the friction layer?

The effective strength of the friction layer in the atmosphere is influenced by the stability of the atmosphere. A stable atmosphere is characterized by a temperature profile that does not allow significant vertical mixing or turbulence. In this state, the air layers are stratified, which enhances the resistance to vertical motion and allows the surface friction to exert a stronger influence on wind flow.

In stable conditions, the air near the surface remains relatively undisturbed, promoting a more laminar flow close to the ground. This enhances the effectiveness of the friction layer, as the wind speed varies with height in a more consistent manner. Stability ensures that the wind does not mix excessively with the layers above it, allowing the frictional forces acting at the surface to be more pronounced and thus increasing the effective strength of that layer.

In contrast, conditions such as high turbulence or low humidity tend to disrupt this stability and can lead to a weaker influence of the friction layer. High altitude also generally results in reduced friction effects due to thinner air and changes in the boundary layer dynamics.