FAA Flight Instructor Airplane (FIA)Weather and Weather ServicesEasy
At a coastal airport on a clear summer afternoon, surface winds blow steadily from the ocean toward the land. A student pilot asks what causes this pattern. Which explanation is correct?
- AThe land heats faster than the water, creating lower pressure over land that draws air in from the sea
- BA cold front is passing through the coastal area
- CThe water heats faster than the land, creating lower pressure over the water
- DCoriolis force deflects offshore winds back toward the coast during the day
Show answer & explanationAnswer & explanation
Correct answer: A. The land heats faster than the water, creating lower pressure over land that draws air in from the sea
During the day, land heats faster than water due to differences in specific heat, creating a local low pressure area over land. Cooler, denser air over the water flows inland to replace the rising warm air, producing a sea breeze.
Why the other options are wrong
- B. A cold front passage is unrelated to this daily thermal circulation pattern.
- C. Water actually heats more slowly than land during the day, the opposite of this statement.
- D. Coriolis force does not create the pressure differential that drives sea breezes.
Sea Breeze
A local wind that blows from sea to land during the day due to differential heating between land and water surfaces.
- Land heats faster than water during the day, lowering pressure over land
- Reverses at night as land cools faster than water (land breeze)
- Most pronounced on clear, calm days with strong sun heating
Memory trick: Day: Sea to land (land is hot); Night: Land to sea (land is cold)