Month-long simulations using the fifth-generation Pennsylvania State University–National Center for Atmospheric
Research Mesoscale Model (MM5) with a horizontal resolution of 9 km have been used to investigate
perturbations of topographically forced wind stress and wind stress curl during upwelling-favorable winds along
the California and Baja California coasts during June 1999. The dominant spatial inhomogeneity of the wind
stress and wind stress curl is near the coast. Wind and wind stress maxima are found in the lees of major capes
near the coastline. Positive wind stress curl occurs in a narrow band near the coast, while the region farther
offshore is characterized by a broad band of weak negative curl. Curvature of the coastline, such as along the
Southern California Bight, forces the northerly flow toward the east and generates positive wind stress curl even
if the magnitude of the stress is constant. The largest wind stress curl is simulated in the lees of Point Conception
and the Santa Barbara Channel. The Baja California wind stress is upwelling favorable. Although the winds
and wind stress exhibit great spatial variability in response to synoptic forcing, the wind stress curl has relatively
small variation. The narrow band of positive wind stress curl along the coast adds about 5% to the coastal
upwelling generated by adjustment to the coastal boundary condition. The larger area of positive wind stress
curl in the lee of Point Conception may be of first-order importance to circulation in the Santa Barbara Channel
and the Southern California Bight