unfroz_evap

Author:

Dag Lohmann, Greg O'Donnell, Keith Cherkauer

Date:

September 1997

Description:

This routine computes canopy transpiration.

References:

Routines based on the original work by Xu Liang.

Input Variables:

Variable	Type	Units	Description
atmos	atmos_data_struct*	N/A	rad - net radiation [W/m²] vpd - vapor pressure deficit [Pa] air_temp - air temperature [C]
layer	layer_data_struct*	N/A	moist - unfrozen layer moisture [mm] moist_froz - frozen layer moisture [mm] moist_thaw - thawed layer moisture [mm] ice - frozen layer ice [mm] tdepth - layer thaw depth [m] fdepth - layer frost depth [m]
soil_con	soil_con_struct	N/A	elevation - grid cell average elevation [m] depth - soil layer thickness [m] Wcr - critical moisture capacity of soil layer [mm] Wpwp - wilting point moisture capacity of soil layer [mm]
veg_class	int	N/A	Vegetation class number, used to index vegetation library table
evap_temp	double	C	Evaporation temperature, either surface temperature for energy balance model, or air temperature for water balance model.
month	int	N/A	Current month
ra	double	s/m	Aerodynamic resistance
ppt	double	mm	Precipitation
f	double	N/A
dt	double	hr	Model time step
Wdew	double	mm	Intercepted water storage
throughfall	double *	mm	Rainfall that passes through the canopy

Output Variables:

Variable	Type	Units	Description
throughfall	double *	mm	Rainfall that passes through the canopy
layerevap	double *	mm	Transpiration from soil layers

Subroutines Called:

penman.c

Modifications and Limitations:

Page Last Modified on 2/8/98