SOILW VARIABLES

PARAMETERS:

  WD = 1000	Density of water [kg/m^3]
  GR = 9.8      Gravity [m/s^2]
  WM = 0.018    Molecular weight of water [kg/mole]
  R  = 8.31     Gas constant [J/(K mole)]
  DV = 2.4e-5	Water vapor diffusivity [m^2/s]
  VD = 0.017	Water vapor density [kg/m^3]
  HA = 0.5 	Humidity of air

SOURCE(JZSFC1):	Water source at soil surface [mm/s = kg/(m^2 s)]

TPRECP:		Precipitation transmitted to soil surface [mm/s]

WPOND(IHR):	Water ponded on surface during timestep IHR [mm]

DT:		Timestep [s]

EVSOIL:		Soil evaporation rate [mg/(m^2 s)] corresponding to initial
		soil surface relative humidity estimate, RHSFC(2)

RHEV:		Slope of evap vs relative humidity function at soil surface
		[mg/(m^2 s)] (Estimated in profl2)

RHSOIL:		Current estimate of relative humidity at soil surface in
		N-R iteration loop.

RHSFC(2):	Initial soil surface relative humidity estimate	

SOURMX:		Maximum rate at which water can infiltrate into the
		soil surface [mm/s = kg/(m^2 s)]

AKS(JZS):	Saturated hydraulic conductivity at soil node JZS [kg s/m^3]

ROOTUP(JZ):	Rate at which water is taken up by roots at layer JZ [mm/s]

EN(IHR,JZ):	Vapor pressure at layer JZ during timestep IHR [mbar]

EREF:		Vapor pressure at soil surface [mbar]

PN(IHR,JZ):	Soil water potential at layer JZ during timestep IHR [J/kg]

TN(IHR,JZ):	Temperature at layer JZ during timestep IHR [C]

AKL(JZ):	Soil hydraulic conductivity in lower half of layer
		JZ [kg s/m^3]

AKU(JZ):	Soil hydraulic conductivity in upper half of layer
		JZ [kg s/m^3]

AKV(JZ):	Vapor conductivity in layer JZ [kg s/m^3]

FL(JZ):		Flux of liquid water through node JZ [kg/m^2 s]

FV(JZ):		Flux of water vapor through node JZ [kg/m^2 s]

DKDPU(JZ):	d(AKU)/d(PN) - differential change in soil hydraulic
		conductivity with soil water potential in upper half of
		layer JZ 

DKDPL(JZ):	d(AKL)/d(PN) - differential change in soil hydraulic
		conductivity with soil water potential in lower half of
		layer JZ 

CPL(JZ):        Capillary water capacity of soil divided by layer thickness 
                for upper half of layer [kg s/m^4]
                
CPU(JZ):        Capillary water capacity of soil divided by layer thickness 
                for lower half of layer [kg s/m^4]

WNL(IHR,JZ):	Volumetric water content in lower half of layer JZ
		during timestep IHR.

WNU(IHR,JZ):	Volumetric water content in upper half of layer JZ
		during timestep IHR.

V(JZ):		"Volume" associated with node JZ [m]

Z(JZ):		Depth of node JZ [m]		

DZ(JZ):		Thickness of layer JZ [m]

SE:		Sum of mass imbalance over all nodes

PE(JZS):	Air entry potential at soil node JZS [J/kg]

WS(JZS):	Saturated water content at soil node JZS (volumetric)

AN(JZS):	Exponent in conductivity-matric potential relation:
		AN(JZS)=2+3/BX(JZS)

BX(JZS):	Exponent in soil moisture release curve [unitless]

PHIL(JZ):	Matric flux potential in lower half of layer JZ 

DWDP:		d(theta)/d(phi) - differential change in water content 
		with matric flux potential.

H(JZ):		Relative humidity in layer JZ		

LAYID(JZ1):	ID for layer at soil node JZS (discontinuities in IDs indicate
		discontinuities in soil hydraulic properties).

PHIU(JZ):	Matric flux potential in upper half of layer JZ 

WT(IHR,JZ):	Volumetric water content in layer JZ during timestep IHR

AKBAR(JZ):	A representative conductivity associated with layer JZ,
		computed through matric flux potential considerations
		(AKBAR ~ d(PHI)/d(PN))	

A(JZ):		DF(JZ)/D(PN(JZ-1)) coefficient in Jacobean

C(JZ):		DF(JZ)/D(PN(JZ+1)) coefficient in Jacobean

B(JZ):		DF(JZ)/D(PN(JZ)) coefficient in Jacobean

F(JZ):		Mass balance at node JZ

TREF:		Temperature at soil surface (C)

DP(JZ):		Increment in soil water potential computed by N-R loop for
		layer JZ [  ]
		
DPLIM:		Limit to increment DP in any given iteration loop.

DELD:		Maximum flux imbalance tolerated in Newton-Raphson

CW(JZ):         Capillary water capacity of soil divided by layer thickness 
                for layer JZ [kg s/m^4]

AK:		Average hydraulic conductivity in layer JZ [  ]

AKW(JZ):        Capillary conductivity of a layer in soil 
                divided by layer thickness [kg s/m^4]

WGRAV(JZ):	Gravitationally-induced flux through layer JZ [mm/s]

WCPYS:		Soil surface evaporation calculated from  soil water flux 
		equations [W/m^2]

FILT:		Infiltration into top of profile during this timestep [mm]

DRAIN:		Drainage out of bottom of profile during this timestep [mm]

DRAIN5:		Drainage of of layer JZBOT-5 during this timestep [mm]	

DRGRAV:		Drainage out of bottom of profile due to gravity during
		this timestep [mm]

ETMM:		Total ET in mm

ECOND(2):	Total ET in W/m^2

SW:		Total water stored in soil profile this timestep [mm]

WSTOR(JZ):	Total water stored in layer JZ this timestep [mm]

SWLAST:		Total water stored in soil profile during previous
                timestep [mm]

CPYTR:		Canopy transpiration during this timestep [mm]