Master the Navigation, Seamanship, and Shiphandling (NSS) – Officer of the Deck (OOD) Phase 2 Exam with engaging flashcards and multiple choice questions, complete with hints and explanations. Prepare comprehensively for your test!

Multiple Choice

What is the general flow of air relative to high and low pressure systems?

Air moves from higher pressure to lower pressure at the surface due to the horizontal pressure gradient force. This means the general flow is outward from high-pressure centers and inward toward low-pressure centers. Friction with the land or sea slows the wind and causes it to cross isobars toward the lower pressure, so the surface wind isn’t strictly parallel to pressure lines. The result is a pattern of divergence away from highs and convergence toward lows. The idea that winds flow parallel to isobars mainly applies aloft under geostrophic balance, where friction is negligible, not at the surface.

Air moves from higher pressure to lower pressure at the surface due to the horizontal pressure gradient force. This means the general flow is outward from high-pressure centers and inward toward low-pressure centers. Friction with the land or sea slows the wind and causes it to cross isobars toward the lower pressure, so the surface wind isn’t strictly parallel to pressure lines. The result is a pattern of divergence away from highs and convergence toward lows. The idea that winds flow parallel to isobars mainly applies aloft under geostrophic balance, where friction is negligible, not at the surface.