NOTATION 
xz Horizontal coordinate. 
z Vertical coordinate, positive upward from 
undisturbed sea surface. 
t Time. 
p Pressure. 
p Density of water (1.025 g/cm’). 
p’ Density of air (1.251073 g/cm). 
u Horizontal component of particle velocity. 
w Vertical component of particle velocity. 
u’ Mass transport veiocity. 
U Wind velocity at about 8m above sea 
surface. 
OC Velocity of progress of wave (phase 
velocity). 
V’ Group velocity. 
V Velocity of energy flow associated with 
wave motion. 
L Wave length. 
2a 
t L 
T Wave period. 
2a 
er 
a Wave amplitude. 
H Wave height (from crest to trough). 
h Depth of water. 
n Elevation of sea surface relative to undis- 
turbed level. 
u Viscosity of water (0.018 at 0° C.). 
7 Stress of wind at sea surface. 
E, Mean potential energy of wave per unit 
area. 
EF, Mean kinetic energy of wave per unit area. 
E Mean total energy of wave per unit area. 
Ry Mean rate of energy transfer to wave due to 
normal wind pressure. 
R, Mean rate of energy transfer to wave due to 
tangential wind stress. 
Ry Rate at which wind energy is dissipated 
below level to which wind velocity is 
referred. 
Ryu Mean rate of energy dissipation due to vis- 
cosity. 
Ry Mean rate at which energy is used to change 
wave height. 
Re Mean rate at which energy is used to change 
wave velocity. 
- Ry +R, 
Ru 
F Length of fetch. 
D Distance of decay. 
g Acceleration of gravity (980 cm/sec ”). 
r Coefficient of energy partition (0.580). 
s Sheltering coefficient (0.013). 
B C/U (Wave age). 
6 H/L (Wave steepness). 
y? Resistance coefficient applicable to wind 
(y?=2.6 107% for wind velocities >5 m. 
per sec). 
s 
a 2? (2.50). 
A 27’ p’/p (6.351075). 
Subscripts: 
F refers to value at end of the fetch. 
D refers to values at end of distance of decay. 
For all numerical computation, c. g. 8. units are 
employed. 
