Three-Dimensional View of a Gulf Stream Meander between Savannah, Georgia and Cape Hatteras, North Carolina,

Synoptic views of large regions of the ocean are difficult to obtain. Conventional shipboard techniques require such long periods of time for data collection and ship travel that severe temporal aliasing can adversely affect a data set. This is the case with measurements made in the Gulf Stream along the southeastern United States, because the Stream has significant variations with periods ranging from a few days to many weeks. Recent synoptic observations of the sea-surface temperature field, made possible through the advent of satellite-borne thermal infrared sensors, indicate that the dominant mesoscale fluctuations in the Gulf Stream in that area are wavelike meanders. They have alongshore wavelengths of about 150 km and progress in the northeastward, or downstream direction at about 40 km day Legeckis, 1979. These properties of the surface thermal variability compare well with Websters 1961 analysis of subsurface temperature data collected during 1 month off Onslow Bay, N.C. He showed the two dominant meander periods to be near 7 days and 4 days. The consistencies between these two sets of observations make a three-dimensional, synoptic picture of the Gulf Stream quite desirable.