initialize_atmos

Author:

Keith Cherkauer

Date:

February 3, 1997

Description:

This subroutine initializes atmospheric variables. It computes snow versus rain, gauge undercatch, missing incoming radiation, vapor pressure, etc. from surface airways or SHAW model meteorological input files.

References

Bras, R, "Hydrology: An Introduction to Hydrologic Science," 1989: incoming long and shortwave calculations.
Handbook of Hydrology: Saturated Vapor Pressure (4.7)
Handbook of Hydrology: Atmospheric Density (4.5)

Input Variables:

Variable	Type	Units	Description
temp	atmos_data_struct *	N/A	Structure of atmospheric data values per time step double air_temp (C) double prec (mm) double wind (mm) double rel_humid (%) double pressure (Pa)
dmy	dmy_struct *	N/A	Structure of date parameters for each time step
theta_l	double	degrees	Longitude of the observer meridian
theta_s	double	degrees	Longitude of the standard meridian (center of local time zone)
phi	double	degrees	Local latitude
nrecs	int	N/A	Number of records over which model will be run

Output Variables:

Variable	Type	Units	Description
temp	atmos_data_struct *	N/A	Structure of atmospheric data values per time step double prec (mm) - if CORRPREC double rainonly (mm) double melt (mm) double vp (Pa) double rel_humid (fraction) double spec_humid (fraction) double density (kg/m^3) double tmax (C) double tmin (C) double shortwave (W/m^2) - if not provided double tskc (fraction) - if not provided double longwave (W/m^2) - if not provided

Subroutines Called:

Modifications and Limitations

Incoming longwave predictions appear to be slightly high, but can be compensated for by using the longwave correction factor in user.h. In the future perhaps a better equation can be used.

VIC Home Page

VIC Code Page

Page Last Modified on 9/3/97