energyWaterBalanceCheck.f90 File Reference

Checks for energy and water balance closure over modelled area. More...

Functions/Subroutines
subroutine	energywaterbalancecheck (ISTEP, CTVSTP, CTSSTP, CT1STP, CT2STP, CT3STP, WTVSTP, WTSSTP, WTGSTP, FSGV, FLGV, HFSC, HEVC, HMFC, HTCC, FSGS, FLGS, HFSS, HEVS, HMFN, HTCS, FSGG, FLGG, HFSG, HEVG, HMFG, HTC, PCFC, PCLC, QFCF, QFCL, ROFC, WTRC, PCPN, QFN, ROFN, WTRS, PCPG, QFG, QFC, ROF, WTRG, CMAI, RCAN, SCAN, TCAN, SNO, WSNOW, TSNOW, THLIQ, THICE, HCPS, THPOR, DELZW, TBAR, ZPOND, TPOND, DELZ, FCS, FGS, FC, FG, IL1, IL2, ILG, IG, N)

Detailed Description

Checks for energy and water balance closure over modelled area.

Author

D. Verseghy

Function/Subroutine Documentation

energywaterbalancecheck()

subroutine energywaterbalancecheck	(	integer, intent(in)	ISTEP,
		real, dimension(ilg), intent(inout)	CTVSTP,
		real, dimension(ilg), intent(inout)	CTSSTP,
		real, dimension(ilg), intent(inout)	CT1STP,
		real, dimension(ilg), intent(inout)	CT2STP,
		real, dimension(ilg), intent(inout)	CT3STP,
		real, dimension(ilg), intent(inout)	WTVSTP,
		real, dimension(ilg), intent(inout)	WTSSTP,
		real, dimension(ilg), intent(inout)	WTGSTP,
		real, dimension (ilg), intent(in)	FSGV,
		real, dimension (ilg), intent(in)	FLGV,
		real, dimension (ilg), intent(in)	HFSC,
		real, dimension (ilg), intent(in)	HEVC,
		real, dimension (ilg), intent(in)	HMFC,
		real, dimension (ilg), intent(in)	HTCC,
		real, dimension (ilg), intent(in)	FSGS,
		real, dimension (ilg), intent(in)	FLGS,
		real, dimension (ilg), intent(in)	HFSS,
		real, dimension (ilg), intent(in)	HEVS,
		real, dimension (ilg), intent(in)	HMFN,
		real, dimension (ilg), intent(in)	HTCS,
		real, dimension (ilg), intent(in)	FSGG,
		real, dimension (ilg), intent(in)	FLGG,
		real, dimension (ilg), intent(in)	HFSG,
		real, dimension (ilg), intent(in)	HEVG,
		real, dimension (ilg,ig), intent(in)	HMFG,
		real, dimension (ilg,ig), intent(in)	HTC,
		real, dimension (ilg), intent(in)	PCFC,
		real, dimension (ilg), intent(in)	PCLC,
		real, dimension (ilg), intent(in)	QFCF,
		real, dimension (ilg), intent(in)	QFCL,
		real, dimension (ilg), intent(in)	ROFC,
		real, dimension (ilg), intent(in)	WTRC,
		real, dimension (ilg), intent(in)	PCPN,
		real, dimension (ilg), intent(in)	QFN,
		real, dimension (ilg), intent(in)	ROFN,
		real, dimension (ilg), intent(in)	WTRS,
		real, dimension (ilg), intent(in)	PCPG,
		real, dimension (ilg), intent(in)	QFG,
		real, dimension (ilg,ig), intent(in)	QFC,
		real, dimension (ilg), intent(in)	ROF,
		real, dimension (ilg), intent(in)	WTRG,
		real, dimension (ilg), intent(in)	CMAI,
		real, dimension (ilg), intent(in)	RCAN,
		real, dimension (ilg), intent(in)	SCAN,
		real, dimension (ilg), intent(in)	TCAN,
		real, dimension (ilg), intent(in)	SNO,
		real, dimension (ilg), intent(in)	WSNOW,
		real, dimension (ilg), intent(in)	TSNOW,
		real, dimension (ilg,ig), intent(in)	THLIQ,
		real, dimension (ilg,ig), intent(in)	THICE,
		real, dimension (ilg,ig), intent(in)	HCPS,
		real, dimension (ilg,ig), intent(in)	THPOR,
		real, dimension (ilg,ig), intent(in)	DELZW,
		real, dimension (ilg,ig), intent(in)	TBAR,
		real, dimension (ilg), intent(in)	ZPOND,
		real, dimension (ilg), intent(in)	TPOND,
		real, dimension (ig), intent(in)	DELZ,
		real, dimension (ilg), intent(in)	FCS,
		real, dimension (ilg), intent(in)	FGS,
		real, dimension (ilg), intent(in)	FC,
		real, dimension (ilg), intent(in)	FG,
		integer, intent(in)	IL1,
		integer, intent(in)	IL2,
		integer, intent(in)	ILG,
		integer, intent(in)	IG,
		integer, intent(in)	N
	)

Parameters

[in]	istep	Flag indicating position at beginning or end of time step
[in,out]	ctvstp	Change in internal energy of vegetation over current time step \([W m^{-2}] \)
[in,out]	ctsstp	Change in internal energy of snow pack over current time step \([W m^{-2}] \)
[in,out]	ct1stp	Change in internal energy of first soil layer over current time step \([W m^{-2}] \)
[in,out]	ct2stp	Change in internal energy of second soil layer over current time step \([W m^{-2}] \)
[in,out]	ct3stp	Change in internal energy of third soil layer over current time step \([W m^{-2}] \)
[in,out]	wtvstp	Change in vegetation mass over current time step \([kg m^{-2}]\)
[in,out]	wtsstp	Change in snow mass over current time step \([kg m^{-2}]\)
[in,out]	wtgstp	Change in soil water storage over current time step \([kg m^{-2}]\)
[in]	fsgv	Diagnosed net shortwave radiation on vegetation canopy \([W m^{-2}] (K_{*,c})\)
[in]	flgv	Diagnosed net longwave radiation on vegetation canopy \([W m^{-2}] (L_{*,c})\)
[in]	hfsc	Diagnosed sensible heat flux on vegetation canopy \([W m^{-2}] (Q_{H,c})\)
[in]	hevc	Diagnosed latent heat flux on vegetation canopy \([W m^{-2}] (Q_{E,c})\)
[in]	hmfc	Diagnosed energy associated with phase change of water on vegetation \([W m^{-2}] (Q_{M,c})\)
[in]	htcc	Diagnosed internal energy change of vegetation canopy due to conduction and/or change in mass \([W m^{-2}] (Q_{I,c})\)
[in]	fsgs	Diagnosed net shortwave radiation at snow surface \([W m^{-2}] (K_{*,s})\)
[in]	flgs	Diagnosed net longwave radiation at snow surface \([W m^{-2}] (L_{*,s})\)
[in]	hfss	Diagnosed sensible heat flux at snow surface \([W m^{-2}] (Q_{H,s})\)
[in]	hevs	Diagnosed latent heat flux at snow surface \([W m^{-2}] (Q_{E,s})\)
[in]	hmfn	Diagnosed energy associated with phase change of water in snow pack \([W m^{-2}] (Q_{M,s})\)
[in]	htcs	Diagnosed internal energy change of snow pack due to conduction and/or change in mass \([W m^{-2}] (Q_{I,s})\)
[in]	fsgg	Diagnosed net shortwave radiation at soil surface \([W m^{-2}] (K_{*,g})\)
[in]	flgg	Diagnosed net longwave radiation at soil surface \([W m^{-2}] (L_{*,g})\)
[in]	hfsg	Diagnosed sensible heat flux at soil surface \([W m^{-2}] (Q_{H,g})\)
[in]	hevg	Diagnosed latent heat flux at soil surface \([W m^{-2}] (Q_{E,g})\)
[in]	hmfg	Diagnosed energy associated with phase change of water in soil layers \([W m^{-2}] (Q_{M,g})\)
[in]	htc	Diagnosed internal energy change of soil layer due to conduction and/or change in mass \([W m^{-2}] (Q_{I,g})\)
[in]	pcfc	Diagnosed frozen precipitation intercepted by vegetation \([kg m^{-2} s^{-1}] (P_{f,c})\)
[in]	pclc	Diagnosed liquid precipitation intercepted by vegetation \([kg m^{-2} s^{-1}] (P_{l,c})\)
[in]	qfcf	Diagnosed vapour flux from frozen water on vegetation \([kg m^{-2} s^{-1}] (E_{f,c})\)
[in]	qfcl	Diagnosed vapour flux from liquid water on vegetation \([kg m^{-2} s^{-1}] (E_{l,c})\)
[in]	rofc	Liquid/frozen water runoff from vegetation \([kg m^{-2} s^{-1}] (R_c)\)
[in]	wtrc	Diagnosed water transferred off the vegetation canopy \([kg m^{-2} s^{-1}] (A_c)\)
[in]	pcpn	Diagnosed precipitation incident on snow pack \([kg m^{-2} s^{-1}] (P_s)\)
[in]	qfn	Diagnosed water vapour flux from snow pack \([kg m^{-2} s^{-1}] (E_s)\)
[in]	rofn	Liquid water runoff from snow pack \([kg m^{-2} s^{-1}] (R_s)\)
[in]	wtrs	Diagnosed water transferred into or out of the snow pack \([kg m^{-2} s^{-1}] (A_s)\)
[in]	pcpg	Diagnosed precipitation incident on ground \([kg m^{-2} s^{-1}] (P_g)\)
[in]	qfg	Diagnosed water vapour flux from ground surface \([kg m^{-2} s^{-1}] (E_g)\)
[in]	qfc	Diagnosed vapour flux from transpiration over modelled area \([W m^{-2}] (E_c)\)
[in]	rof	Total runoff from soil \([kg m^{-2} s^{-1}] (R_g)\)
[in]	wtrg	Diagnosed water transferred into or out of the soil \([kg m^{-2} s^{-1}] (A_g)\)
[in]	cmai	Current mass of vegetation canopy \([kg m^{-2}] (W_c)\)
[in]	rcan	Intercepted liquid water stored on canopy \([kg m^{-2}] (W_{l,c})\)
[in]	scan	Intercepted frozen water stored on canopy \([kg m^{-2}] (W_{f,c})\)
[in]	tcan	Vegetation canopy temperature \([K] (T_c)\)
[in]	sno	Mass of snow pack \([kg m^{-2}] (W_s)\)
[in]	wsnow	Liquid water content of snow pack \([kg m^{-2}] (W_{l,s})\)
[in]	tsnow	Snowpack temperature \([K] (T_s)\)
[in]	thliq	Volumetric liquid water content of soil layers \([m^3 m^{-3}] (\theta_l)\)
[in]	thice	Volumetric frozen water content of soil layers \([m^3 m^{-3}] (\theta_f)\)
[in]	hcps	Volumetric heat capacity of soil particles \([J m^{-3}] (C_g)\)
[in]	thpor	Pore volume in soil layer \([m^3 m^{-3}]\)
[in]	delzw	Permeable thickness of soil layer \([m] (\Delta_zw)\)
[in]	delz	Total thickness of soil layer \([m] (\Delta_z)\)
[in]	tbar	Temperature of soil layers \([K] (T_g)\)
[in]	zpond	Depth of ponded water on surface \([m] (z_p)\)
[in]	tpond	Total thickness of soil layer \([m] (\Delta_z)\)
[in]	fcs	Fractional coverage of vegetation over snow on modelled area [ ]
[in]	fgs	Fractional coverage of snow over bare ground on modelled area [ ]
[in]	fc	Fractional coverage of vegetation over bare ground on modelled area [ ]
[in]	fg	Fractional coverage of bare ground on modelled area [ ]

In this subroutine, checks are carried out to ensure that the change in energy storage in each of the components of the modelled area (canopy, snow and soil) is equal to the sum of the energy fluxes into and out of them; and that the change in moisture storage in each of the components is equal to the sum of the water fluxes into and out of them. The subroutine is called twice, once at the beginning (ISTEP=0) and once at the end (ISTEP=1) of each time step. At the beginning, the instantaneous energy and moisture storage terms are evaluated, and at the end the differences over the time step are calculated:

Change in canopy energy storage = \(\Delta [(c_c W_c + c_w W_{l,c} + c_i W_{f,c} )T_c ] / \Delta t\)

Change in snow energy storage = \(\Delta [(C_i W_s /\rho_i + C_w W_{l,s} / \rho_w)T_s ]/ \Delta t \)

Change in soil layer energy storage = \(\Delta {[(C_w \theta_l + C_i \theta_f + C_g \theta_g) \Delta z_w + C_b (\Delta z – \Delta z_w)]T_j }/ \Delta t\) (For the first soil layer, the numerator contains the additional term \(C_w z_p T_p\).)

Change in canopy moisture storage = \(\Delta[W_{l,c} + W_{f,c}]\)

Change in snow moisture storage = \(\Delta[W_s + W_{l,s}]\)

Change in soil moisture storage = \(\Delta [(\theta_l \rho_w + \theta_f \rho_i) \Delta z_w + z_p \rho_w ]\)

The net energy and moisture fluxes are also evaluated at the end of the time step:

Net energy flux for canopy = \(K_{*,c} + L_{*,c} – Q_{H,c} – Q_{E,c} – Q_{M,c} + Q_{I,c}\)

Net energy flux for snow = \(K_{*,s} + L_{*,s} – Q_{H,s} – Q_{E,s} – Q_{M,s} + Q_{I,s}\)

Net energy flux for first soil layer = \(K_{*,g} + L_{*,g} – Q_{H,g} – Q_{E,g} – Q_{M,1} + Q_{I,1}\)

Net energy flux for other soil layers = \(- Q_{M,j} + Q_{I,j}\)

Net moisture flux for canopy = \(P_{l,c} + P_{f,c} – E_{l,c} – E_{f,c} – R_c + A_c\)

Net moisture flux for snow = \(P_s – E_s – R_s + A_s\)

Net moisture flux for soil = \(P_g – E_g – R_g + A_g - E_c\)

In these equations the \(K_*\) terms refer to net shortwave radiation, the \(L_*\) terms to net longwave radiation, the \(Q_H\) terms to sensible heat flux, the \(Q_E\) terms to latent heat flux, the \(Q_M\) terms to heat associated with melting or freezing of water, and the \(Q_I\) terms to changes in heat storage caused by conduction or redistribution of water. The P terms refer to precipitation, the E terms to evaporation, the R terms to runoff and the A terms to water transferred between different components of the landscape. The subscript 1 refers to the first soil layer, and j to a generalized other layer.

Finally, each change in energy or moisture storage is compared in turn with the corresponding net flux of energy or moisture, and if the difference is greater than a selected threshold value, an error message is printed out and the run is stopped.