Observations of a progressive warm-fresh oceanic front and a cool-moist atmospheric front at Duck, North Carolina

This paper presents a unique set of observations of nearly coincident and p rogressive oceanic and marine atmospheric boundary-layer (MABL) fronts in a coastal zone. The event was observed during the afternoon of 12 May 1996 a t the United States Army Corps of Engineers, Coastal Engineering Research C enter, Field Research Facility pier at Duck, North Carolina. The oceanic fr ont was warm and fresh. Current variability accompanied the oceanic front. A marked MABL front preceded the oceanic front by several minutes and had c haracteristics of a sea-breeze front. This MABL front separated warmer and dryer pre-frontal air from cooler and moister post-frontal air. Wind direct ion and wind speed variability accompanied the MABL front. The sea-surface roughness signatures of both fronts were detected by an X-band pulsed Doppl er radar. Supporting data are used to identify each front detected by the r adar and to calculate each front's velocity. In an attempt to explain the s ea-surface roughness variations associated with each front, the radar data are compared to corresponding variations in wind speed, wind direction, and air-sea temperature difference.