Routine pmix in BVW Flux and Sea State Model

Input Parameters:

Lists input parameters and tables explaining options.
ParameterTypeDescription Units
Argument Number
astabintAtmospheric stability option none
18
CONVECTfloatConvective parameter. Recommended value between 0.7 and 1.25. For details see TOGA NOTES #4 none
4
CONV_CRITfloatConvergence criterion fraction
5
air_moist_prmintAtmospheric moisture parameter index none
7
air_moist_valfloatValue of the parameter corresponding to the above index see below
8
dyn_in_prmintDynamic input parameter index none
1
dyn_in_valfloatDynamic input value. Usually the mean wind speed at the height (zref) of the anemometer. Other input options are friction velocity (magnitude), wind stress (magnitude), and equivalent neutral wind speed (scatterometer wind speed). see below
2
pressurefloatAtmospheric surface pressure Pa
6
ref_ht_windfloatHeight of the wind observations m
16
ref_ht_tqfloatHeight of the temperature observations. Note: in the current version of the code this must equal to height of the humidity observations. m
17
rel_wind_angfloat Angle of the mean wind relative to the direction that the dominant waves propagate. The positive direction is counter-clockwise when looking down on the surface. degrees
3
salinityfloatSalinity none
11
sfc_moist_prmintSurface moisture parameter index none
9
sfc_moist_valfloatValue of the parameter corresponding to the above index see below
10
ss_prmintSeastate parameter index none
12
ss_valfloatValue of the parameter corresponding to the above index see below
13
t_airfloatAir temperature at the reference height of the thermometer and humidity sensor C
14
t_skinfloatSkin temperature of the water. C
15
warnintWarning level: 0 warnings, 1 no warnings. none
19

Options for dynamic input:

Typically wind speed is used as an input to boundary-layer models. However, scatterometers are now producing 'observations' of friction velocity and equivelent neutral wind speed.
dyn_in
Description Units
0
Wind speed, relative to the surface current m/s
1
Friction velocity (magnitude) m/s
2
Surface wind stress (magnitude) N/m^2
3
Equivalent neutral wind speed (relative to the surface current) m/s

Options for atmospheric stability condition:

The atmospheric stability in the boundary-layer can be assumed to neutral, or it can be calculated input parameters.
astab
Description Units
0
Atmospheric stability is assumed to be neutral none
1
Stability is calculated none

Options for seastate parameterizations:

There are six possible seastate assumptions: any one of the following can be treated as known: wind-wave stability parameter (set to 1.0 for local equilibrium), phase speed, wave age, significant wave height, significant slope, and the period of the dominant waves. Caution: in many cases, these wave characteristics will correspond to swell rather than the phase speed of locally wind induced waves.
ss_prm
Parameter treated as known (ss_val) Units
0
Wind-wave stability parameter none
1
Phase speed of the dominant waves. Note: in many cases, this phase speed will correspond to the swell rather than the phase speed of locally wind induced waves. Use of the wrong phase speed can lead to large overestimations of fluxes. m/s
2
Wave age the dominant waves (cp/u*) none
3
Significant wave height (Hs) m
4
Significant slope (Hs/l) none
5
Period of the dominant waves (Tp) s

Options for atmospheric moisture input:

Choose the moisture parameter that is easiest for you to deal with:
air_moist_prmParameter for moisture of air (air_moist_val) Units
0
Specific humidity at the reference height of the thermometer and humidity sensor g vapor / g air
1
Relative humidity fraction
2
Dew point temperature C
3
Wet bulb temperature C

Options for surface moisture input:

Choose the moisture parameter that is easiest for you to deal with:
sfc_moist_prmParameter for moisture of air (sfc_moist_val) Units
0
Specific humidity 'at' (near) the surface g vapor / g air
1
Relative humidity fraction
2
Dew point temperature C
3
Wet bulb temperature C


Model Output:

Vector components are calculated parallel and perpendicular to the direction in which the dominant waves are propagating. The first component is parallel the direction of wave propagation, and the second component is perpendicular to the first (while looking down it is 90 counter-clockwise from the first component; i.e., in a right handed coordinate system with the positive vertical axis pointing upward). For most applications there will be insufficient wave information, requiring the assumption of local wind-wave equilibrium. This assumption implies that the wind and the waves are moving in the same direction; which results in the first component of the vectors being parallel to the wind direction, and the second component being zero.

All output is single precision floating point.

The routine returns a integer value (i.e., a warning flag). Positive values indicate a lack of specific problems. If there are problems with missing input, non-convergence within the algorithm, or if the modeled physics obviously fails to apply, then the output is set to -1. For example, if the thickness of the boundary layer is too small (i.e., the absolute value of the Obhukov scale length less than or equal to 1 m) then the warning flag is set at -1.

ParameterTypeDescription Units
Argument Number
shffloatsensible heat flux W m-2
20
lhffloatlatent heat fluxW m-2
21
tauvector floatstress vector. There are more details on the conversion to zonal and meridional components. N m-2
22
u_starvector floatfriction velocity (u*) m s-1
23
t_starfloatscaling term for potential temperature (T*) C
24
q_starfloatscaling parameter for moisture (q*) none
25
z_over_Lfloatdimensionless Monin-Obhukov scale length none
26
wave_agefloatwave age, cp/u* none
27
dom_phs_spdfloatphase speed of dominant gravity waves m s-1
28
h_sigfloatsignificant wave height m
29
ww_stabfloatwind-wave evolution parameter none
30
zo_mvector floatmomentum roughness length m
31


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Last update: July 28, 1998