At what angle to the isobars do surface winds blow over the open sea?
Official USCG Answer & Rule Citation
Correct Answer: Option B — About 15°
Surface friction over the open sea causes winds to cross isobars at an angle of approximately 15 degrees toward the low-pressure center. This deviation from the geostrophic wind (which flows parallel to isobars) is a fundamental principle of meteorology described in Bowditch, The American Practical Navigator.
100% Free & Open Access — No daily limits, paywalls, or gated answers on BrightMariner.