Three-Dimensional Mean and Turbulence Structure of a Coastal Front Influenced by the Gulf Stream

Abstract The interaction of oceanic fronts in the vicinity of the Gulf Stream with an atmospheric coastal front during the Genesis of Atlantic Lows Experiment (GALE) is examined using aircraft, satellite, and ship data. The nearshore, midshelf, and Gulf Stream oceanic fronts are readily discernible from low-level aircraft radiometer and satellite imagery data. The three-dimensional (3D) structure of the coastal front is extensively mapped by low-level aircraft transects through the frontal boundary. Results confirm the existence of the coastal front as a very shallow (depth less than 200 m), spatially inhomogeneous, undulating material surface. Aircraft observations from 2000 to 2200 UTC (late afternoon local time) show a surface location of the coastal front that is aligned over the Gulf Stream oceanic front under conditions of very weak (2 m s−1) onshore flow, but is observed to migrate shoreward for stronger on-shore flow. Ahead of the front in the warm air, the marine atmospheric boundary layer is cha...