APPENDIX V 



Coastal Circulation 



By B. H. Ketchum and D. F. Bumpus 

 Woods Hole Oceanographic Institution 

 Woods Hole, Massachusetts 



The general features of the non-tidal circulation adjacent 

 to the east coast of the United States are fairly well known and have 

 been reiterated in the recent NAS-1©C Publication 55l« This present 

 memorandum m.lL consequently be very brief. 



Our knowledge of the circulation in these waters results 

 from the studies of Bigelow, 1927j Redfield and Walford, 19$!; Ket- 

 chum, Redfield and Ayres, 195lj Miller, 1952 j Bumpus, 1955 and Day, 

 in press. These studies were based on the distribution of tempera- 

 ture and salinity in the sea, direct current measiirements at light- 

 ships, the returns from drift bottles broadcast throughout the area 

 and more recently the observed drift of telemetering buoys in a limi- 

 ted area. 



In the offings of estuaries we may expect a seaward flow of 

 river effluent and a landward flow of sea vjater necessary to maintain 

 the distribution of salinity in the brackish part of the estuary. 

 Where there is a vertical density discontinuity, the inflow of sea 

 water will be at the bottom. At times of vertical uniformity of den- 

 sity, the inflow of sea water may be horizontally separated from the 

 outflow and will generally He on the right side facing the estuary. 

 During the seasons of the year when there is no pycnocline we might 

 expect the non-tidal motions at depth to be quite comparable to those 

 at the surface. During the time when the pycnocline is well developed 

 the shear may be quite prono\inced and motions at depth quite dissimilar 

 to those at the surface. 



