USGS Home
Contact USGS
Search USGS

U.S. GEOLOGICAL SURVEY
Scientific Investigations Report 2008–5076

Back to Table of Contents

Table 1. List of symbols used in this report.

[Abbreviations: m, meter; s, second; J, joules; g, gram; °C, degrees Celsius; mb, millibar; W, Watt; kg, kilogram; N, Newton; °K, degrees Kelvin; –, no units]

Symbol	Name	Units
a	Constant in equation for surface drag coefficient	(m s-1)-0.5
B	Production of turbulent kinetic energy by buoyancy	m2 s-3
C	Concentration of scalar variable	arbitrary
C10	10 m wind surface drag coefficient	–
CB	Empirical coefficient	mb °C -1
cp	Specific heat capacity of water at 20°C	J g-1 ºC-1
	Constant used to relate turbulent kinetic energy to rate of turbulent kinetic energy dissipation	–
Dz	Vertical turbulent diffusivity coefficient	m2 s-1
Dh	Horizontal turbulent diffusivity coefficient	m2 s-1
es	Saturation vapor pressure of air at water surface temperature	mb
ea	Vapor pressure of air	mb
f	Coriolis parameter	s-1
g	Gravitational acceleration	m s-2
HB	Back radiation from water surface	W m-2
HE	Evaporative cooling	W m-2
HLW	Incoming longwave radiation	W m-2
HS	Sensible heat loss	W m-2
HSW	Incoming shortwave radiation	W m-2
h	Depth of the water column	m
Kz	Vertical turbulent viscosity coefficient	m2 s-1
Kh	Horizontal turbulent viscosity coefficient	m2 s-1
k	Turbulent kinetic energy	m2 s-2
ke	Extinction coefficient	m-1
Lw	Latent heat of evaporation	J kg-1
l	Length scale of turbulent eddies	–
M	Fraction of the sky covered by clouds	–
P	Production of turbulent kinetic energy by mean shear	m2 s-3
p	Pressure	kg m-1 s-2
pa	Atmospheric pressure	kg m-1 s-2
psl	Atmospheric pressure at sea level	kg m-1 s-2
q	Non-hydrostatic component of pressure	m2 s-2
RSW	Shortwave radiation	W m-2
rB	Bottom friction coefficient	–
rh	Relative humidity	–
rLW	Fraction of incident longwave radiation reflected at the water surface	–
rSW	Fraction of incident shortwave radiation reflected at the water surface	–
SD	Stability function used in calculation of turbulent diffusivity for constituent transport	–
SK	Stability function used in calculation of turbulent diffusivity for momentum transport	–
Ta	Air temperature	°C
Tw	Water temperature	°C
t	Time	s
U,V	Depth-integrated components of velocity in the horizontal plane	m s-1
u,v	Components of velocity in the horizontal plane	m s-1
	Near-bottom velocity	m s-1
	Wind vector at i m above the surface	m s-1
	Current vector at the surface of the water column	m s-1
	Friction velocity	m s-1
w	Veritical component of velocity	m s-1
ws	Settling velocity	m s-1
x,y	Cartesian coordinates in the horizontal plane	m
z	Vertical cartesian coordinate	m
zB	Location of bottom computational grid point	m
z0	Bottom roughness height	m
α0	Proportionality constant	°K-2
	Free surface elevation	m
	Rate of dissipation of turbulent kinetic energy	m2 s-3
	Emmisivity of air	–
	Emmisivity of water	–
κ	von Karman constant	–
ρ	Density of water	kg m-3
ρ΄	Depth-integrated deviation of water density from reference density, normalized by reference density	m
ρ0	Reference density of water; density at 20°C	kg m-3
ρa	Density of air	kg m-3
σ	Stefan-Boltzmann constant	W m-2 °K-4
σk	Turbulent Schmidt number for turbulent kinetic energy	–
σε	Turbulent Schmidt number for dissipation of turbulent kinetic energy	–
	Stress vector at the sediment/water interface	N m-2
	Stress vector at the water surface	N m-2
	Variable of integration	–

Back to Table of Contents