Sensitivity of the California Coastal Jet to synoptic scale flow

Abstract

The California Coastal Jet can have a significant impact on many operations. This study examines the sensitivity of the California Coastal Jet to the synoptic-scale flow by examining the surface reflection of the jet at a particular buoy (buoy 46028) off the Central California coast. Statistical analysis and subjective examination of surface charts were performed to help determine the relationship between the synoptic flow regime and the observed surface winds. The main results of the study are as follows: The magnitude of the California Coastal Jet is sensitive to the geostrophic wind direction. The surface reflection of the California Coastal Jet at buoy 46028 does not exhibit diurnal variation. The day to day variability in the observed winds is much larger than the diurnal variation at buoy 46028. Higher wind speed events at buoy 46028 correspond to periods when the synoptic analyses are not performing adequately (meso-scale effects such as flow blocking and supercritical flow are missed in the model). Lower wind speed events correspond to periods when the synoptic-scale analyses are performing adequately. Recommendations for future study are made