Which type of fog is most likely to form on a clear, calm night over a recently irrigated field?
Why →
Radiation fog forms when the ground (and moist surface air) radiates heat away overnight, cooling to the dew point. Recently irrigated fields provide abundant surface moisture that accelerates fog formation with minimal temperature drop. Clear skies allow maximum radiative cooling (no cloud blanket to retain heat) and calm winds prevent mixing. This is the classic radiation fog scenario.The trap →
Advection fog requires warm moist air moving over a cold surface. Typical over cold ocean currents (San Francisco Bay, for example). Upslope fog forms when moist air rises and cools over terrain. The irrigated field + clear night + calm wind scenario is unambiguously radiation fog.SOURCE → PHAK Chapter 12, Weather TheoryCHECKED APR 21ACS III.B.K1MED