CONTENTS—Continued 



Page 

 APPENDIXES 



A Field Observations — Longshore Currents 235 



B Laboratory Observations — Longshore Currents 239 



C Longshore Current Formulas 241 



D Longshore Current Profile Theory Equations 242 



TABLES 



1 Proposed mechanisms for rip current generation and primary 



investigators since 1969 47 



2 Idealized environment for longshore current theory 79 



3 Longshore current theories since 1969 based on radiation stress 



theory 90 



4 Lateral turbulent eddy viscosity formulations and characteristic 



reference velocity and length scales 101 



5 Surf zone similarity parameter versus wave characteristics 108 



6 Two dimensional numerical models of surf zone hydrodynamics 124 



7 Summary of the preliminary laboratory data of Mizuguchi, Oshima, 



and Horikawa ( 1978) 180 



8 Summary of bed friction and eddy viscosity coefficients 186 



9 Estimates of eddy viscosity across the surf zone from laboratory 



and field experiments 191 



10 Comparison of four surf zone theories for mean eddy viscosity 



across the surf zone 191 



11 Three domains of the near shore current system 201 



FIGURES 



1 Nearshore current system at La Jolla Beach, California, 



December 1948 25 



2 Rip current and nearshore currents at Seagrove, Florida, July 1968.... 26 



3 Velocity profile in a rip current at Seagrove, Florida, July 1968 28 



4 Longshore component current time histories at three elevations in 



the surf zone of eastern Lake Michigan 29 



