Glossary
upper case
$B$ groundwater discharge to streams (L/T)
$D$ soil moisture deficit (L)
$E$ total evaporation (L)
$E_a$ atmospheric demand/potential evaporation (L)
$F_{x}$ fraction of $x$, $[0,1]$
$G$ net groundwater exchange $(\text{recharge}-\text{discharge})$
$K_\text{sat}$ saturated hydraulic conductivity (m/s)
$P_R$ precipitation in the form of rain (L)
$P_S$ precipitation in the form of snow (depth of snow water equivalent—SWE)
$P_M$ snowmelt/drainage from snowpack (L)
$R$ runoff, generated at a particular location
$S$ storage reservoir with known capacity $S_\text{max}$ (L)
$T_a$ temperature of air (°C)
$T_c$ critical air temperature (°C) where precipitation likely falls as snow
$T_n$ minimum daily air temperature (°C)
$T_x$ maximum daily air temperature (°C)
$Y_a$ atmospheric yield, i.e., precipitation in its liquid/mobile form: $Y_a=P_R+P_M$
lower case
$b$ groundwater discharge to streams (L)
$e$ vapour pressure of water in air (Pa)
$e_s$ saturation vapour pressure of water in air (Pa)
$f$ infiltration (L)
$k_\text{in(out)}$ later movement of water into (out of) the model cell (L)
$p_a$ atmospheric pressure (Pa)
$q$ lateral groundwater flux (m²/s)
$r$ relative humidity (-)
$u$ windspeed (m/s)
$x$ saturation excess (L)
$z_\text{ext}$ extinction depth (m): depth where evaporation becomes negligible.
upper case Greek
$\Delta t$ model timestep (s)
lower case Greek
$\alpha_u$ wind direction (degrees CW north)
$\beta$ land surface gradient
$\phi$ porosity (-)
$\theta_\text{fc}$ water content at field capacity (-)
nomenclature
Certain parameter pairs are present typically in upper- and lower-case form. This is mainly used to differentiate data distributed at the regional scale (upper) vs. processed occurring at a point in space (lower), for instance:
\[Y_a \longmapsto y\]meaning atmospheric yield collected within the ORMGP region maps to any particular point in space. Similarly:
\[E \longmapsto a\] \[G \longmapsto g\]