j unit vector in the y-direction 



K ratio of setup slope to beach slope 



L 



k wave number (-7—) 



k deepwater wave number (~ — ) 



o 

 L wavelength 



L deepwater wavelength 



L rip current spacing 



1 mixing length (Prandtl's hypothesis) 



M Mach stem 



m the corrected beach slope including wave setup 



N a dimensionless , turbulent closure coefficient for lateral 



wave mixing proposed by Longuet-Higgins (1970) to be of 

 the order N < 0.016 



N^ lateral viscosity coefficient 



n wave celerity ratio, C /C 



P Longuet-Higgins (1970) parameter showing relative importance 



of mixing and bed shear 



P a parameter (= T//gd^) in which the magnitude of the longshore 



current depends, James (1974a) 



P* dimensionless mixing parameter 



p pressure at any distance below fluid surface; gage pressure 



. .. ^,. .-3, 

 P 



1- % 

 (=Npg^(tan 6) '^) from Longuet-Higgins (1970) 



p a dimensionless parameter found from wave orbital velocity 



experiments relating to wave velocity at the bottom to that 

 at the reference elevation 



p discharge per unit width at any d, y, and t 



p (uh) voliometric flow rates per unit width 



Q, the probability that at a given point a wave height is 



associated with a breaking or broken wave 



q constant from Longuet-Higgins (1970) (=(l/TT)pC^g ^Y(tan 6)^) 



q discharge per unit width at any x, y, and t 



q (=vh) , volumetric flow rate per unit width 



15 



