Adjustment of the Summer Marine Boundary Layer around Point Sur, California

Abstract

An instrumented C-130 aircraft flew over water around Point Sur, California, on 17 June 1996 under strong northwest wind conditions and a strong marine inversion. Patterns were flown from 30-to 1200-m elevation and up to 120 km offshore. Nearshore, marine air accelerated past Point Sur, reaching a surface maximum of 17 m s 1 in the lee. Winds measured over water in and above the marine layer were alongshore with no significant cross-shore flow. Sea level pressure, 10-m air temperature, and air temperature inversion base generally decreased toward the coast and were an absolute minimum just downcoast of the wind speed maximum. The sea surface temperature also decreased toward the coast, but was an absolute minimum directly off Point Sur. The nearcoast, air temperature inversion base height was 400 m north of Point Sur, decreased to a minimum of 50 m in the lee of Point Sur, then increased farther to the south. Wind speeds were at a maximum centered along the air temperature inversion base; the fastest was 27 m s 1 in the lee of Point Sur.