Amplitude and Horizontal Structure of a Large Diurnal Sea Surface Warming Event during the Coastal Ocean Dynamics Experiment

Intense diurnal warming of the ocean surface was observed in April 1982 off California, using a combination of mooring, hydrographic, and satellite infrared and satellite pigment measurements. The event corresponded to a spatial and temooral minimum of the wind stress. The diurnal surface temperature amplitude exceeded 6.6°C locally despite a 490-nm optical depth of 20 m, suggesting that phytoplankton was not responsible for the shallow heat trapping. Coherent horizontal temperature streaks at least 50 km long and 4-8 km wide formedduring the subsequent erosion of the shallow warm layers. It is hypothesized that thcfr scale was set by planetary boundary-layer circulations.