How do winds at 2,000 feet compare with surface winds?

How do winds at 2,000 feet compare with surface winds?

• A. Surface winds veer to right of winds at 2,000 feet and are stronger
• B. Winds at 2,000 feet parallel the isobars; surface winds cross isobars toward lower pressure and are weaker
• C. Winds at 2,000 feet are weaker and cross isobars toward higher pressure
• D. Winds at 2,000 feet and surface winds flow in the same direction and have equal speeds

Answer: (B)

Winds at about 2,000 feet are largely governed by a geostrophic balance, so they tend to blow parallel to the isobars. Near the surface, friction slows the air and reduces the Coriolis effect, causing the surface wind to cross the isobars toward the lower pressure area. Because of this friction, surface winds are weaker than the winds aloft. So the correct relationship is that winds at 2,000 feet run parallel to the isobars, while surface winds cross isobars toward lower pressure and are weaker. The other statements conflict with the friction effect near the surface or with the typical speed and directional changes between aloft and surface winds.

Winds at about 2,000 feet are largely governed by a geostrophic balance, so they tend to blow parallel to the isobars. Near the surface, friction slows the air and reduces the Coriolis effect, causing the surface wind to cross the isobars toward the lower pressure area. Because of this friction, surface winds are weaker than the winds aloft.

So the correct relationship is that winds at 2,000 feet run parallel to the isobars, while surface winds cross isobars toward lower pressure and are weaker. The other statements conflict with the friction effect near the surface or with the typical speed and directional changes between aloft and surface winds.