BVW Routines for IDL Users

The algorithms for the 1999 version of the Bourassa-Vincent-Wood (BVW) flux model can be downloaded through this web site or taken from our public FTP site (anonymous FTP to coaps.fsu.edu, change directories to pub/bourasssa/bvw).

The following files are needed to call the BVW library from IDL.

bvw99.c: the library of algorithms,

bvw99.h: header file with function prototypes,

bvw99.pro: IDL subroutine used to call shell for bvw 'C' code,

call_bvw99.c: 'C' shell used to call bvw 'C' code from the IDL subroutine (bvw99.pro),

ht_adj99.pro: IDL subroutine used to call shell for bvw 'C' code,

call_ht_adj99.c: 'C' shell used to call bvw 'C' code from the IDL subroutine (bvw99.pro),

test_bvw99.pro: example and test program for 'IDL',

test_ht_adj99.pro: example and test program for 'IDL',

testdata99.dat: input and output data for the test program.

How to Compile BVW (Flux and sea state) Code

cc -c -KPIC call_bvw99.c

ld -shared -o call_bvw99.so call_bvw97.o

The file call_bvw99.so can be called from the IDL routine.

How to Compile Height Adjustment Code

cc -c -KPIC call_ht_adj99.c

ld -shared -o call_ht_adj99.so call_ht_adj99.o

The file call_ht_adj99.so can be called from the IDL routine.

Use of the Test Routine

The test program can be used to check for compiler related changes in output. The test code also demonstrates how to call the main bvw routine. The test program reads in data from the file testdata99.dat, and outputs to the screen. This output should match the second table in the file testdata99.dat

Example Variable Declaration and Calls

It is a lot easier to program if you have examples, and even better if you can cut and paste. These examples are taken from the test codes.

pmix

lhf = 0.0
shf = 0.0
tau = FLTARR(2)
tau = [0.0, 0.0]
u_star = FLTARR(2)
u_star = [0.0, 0.0]
t_star = 0.0
q_star = 0.0
z_over_L = 0.0
wave_age = 0.0
dom_phs_spd = 0.0
h_sig = 0.0
ww_stab = 0.0
zo_m = [0.0, 0.0]

CONV_CRIT = 0.00005 ; convergence critereon (fractional change) [] */
CONVECT = 1.25 ; convective parameter */
warn = 1L ; warning are given */

; read in test data
READF, test_data, dyn_in_prm, dyn_in_val, rel_wind_ang, $
ss_prm, ss_val, air_moist_prm, air_moist_val, sfc_moist_prm, $
sfc_moist_val, t_skin, t_air, ref_ht_wind, ref_ht_tq, $
press_sfc, salinity, CONVECT, astab

ss_prm = LONG( ss_prm )
air_moist_prm = LONG( air_moist_prm )
sfc_moist_prm = LONG( sfc_moist_prm )
astab = LONG( astab )
dyn_in_prm = LONG( dyn_in_prm )

; run the flux code
result = bvw99( dyn_in_prm, dyn_in_val, rel_wind_ang, CONVECT, conv_crit, $
press_sfc, air_moist_prm, air_moist_val, sfc_moist_prm, sfc_moist_val, $
salinity, ss_prm, ss_val, t_air, t_skin, ref_ht_wind, ref_ht_tq, $
astab, warn, shf, lhf, tau, u_star, t_star, q_star, z_over_L, $
wave_age, dom_phs_spd, h_sig, ww_stab, zo_m )

ht_adj

z_wind_ref = 6.0
wind_spd = 6.0
theta_ang_dum = 0.0
CON_P = 0.0
conv_crit = 0.005
press = 101300.0
air_moist_prm = 0L
air_moist_val = 0.020
sfc_moist_prm = 0L
sfc_moist_val = 0.023
salinity = 0.0349
ss_prm = 0L
ss_val = 1.0
astab = 1L
warn = 1L
z_temp_ref = 10.0
lhf = 0.0
shf = 0.0
tau = [0.0, 0.0]
u_star = [0.0, 0.0]
t_star = 0.0
q_star = 0.0
z_over_L = 0.0
wave_age = 0.0
dom_phs_spd = 0.0
h_sig = 0.0
ww_stab = 0.0
zo_m = [0.0, 0.0]
eqv_neut = LONG(false)
u_at_z = miss
t_at_z = miss
q_at_z = miss

flag = ht_adj99( dyn_in_prm, wind_spd, theta_ang_dum, CON_P, $
conv_crit, press, air_moist_prm, air_moist_val, sfc_moist_prm, $
sfc_moist_val, salinity, ss_prm, ss_val, tair, twater, $
z_wind_ref, z_temp_ref, astab, warn, shf, lhf, tau, u_star, $
t_star, q_star, z_over_L, wave_age, dom_phs_spd, h_sig, $
ww_stab, zo_m, eqv_neut, z_wanted, u_at_z, t_at_z, q_at_z )

Additional Information

The flux and seastate model is programmed in 'C'. The bulk of the documentation is in the subroutine pmix. Wrappers for calling the programs from IDL and FORTRAN have been developed for the '99 version of the code.

Status: tested and working, except for a bug at very low wind speeds U10 < 0.6 m/s) when the sea state is set to local equilibrium.

Warnings:

1) There are very few checks on the range of input parameters: unbelievable input will result in unbelievable output.

2) The influence of a difference in the directions of wind velocity and mean wave propagation is underestimated. This model is an improvement over models with only one horizontal dimension; however, several problems remain to be resolved.

Last update: 18 January 1999