Why do some regions have dry seasons?
Show answer & explanation
Answer: Shifting atmospheric pressure
Distance from oceans — Wrong. Distance affects moisture availability, but seasonal wet/dry patterns come from shifting pressure zones and wind patterns.
Shifting atmospheric pressure ✓ — Correct! Tropical regions have wet/dry seasons from shifting atmospheric circulation. The ITCZ (Intertropical Convergence Zone—rising air, heavy rain) migrates north/south following the sun. When ITCZ is overhead, wet season; when shifted away, high-pressure descending air brings dry season. Monsoon regions experience this dramatically!
Reduced sunlight in winter — Wrong. Sunlight changes cause temperate seasons, but tropical wet/dry seasons result from shifting pressure zones (ITCZ migration), not reduced sunlight.