Parameters adjusted to the height specified by z_wanted. Adjustment assumes the modified log-profile is valid at both the observation (ref_ht_wind) and the wanted height (z_wanted), provided that the variable CONVECT is set to zero.

Input Parameters:

Lists input parameters and tables explaining options.
ParameterTypeDescription UnitsArgument Number
dyn_in_prmintDynamic input parameter index none1
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). Altnernatively, this value can be a vector component of the wind (or other such inputs). It should be a vector component in the direction of wave propagation. In a future release, I plan on allowing this to be the u-compoent,. see below2
dyn_in_val2floatDynamic input value 2. This value is usually zero because magnitude of the wind is often entered in dyn_in_val. If a vector component is entered in dyn_in_val, then dyn_in_val is the other vector component. see below2
CONVECTfloatConvective parameter. Recommended value between 0.7 and 1.25. For details see TOGA NOTES #4 none4
CONV_CRITfloatConvergence criterion fraction5
pressurefloatAtmospheric surface pressure. Note that the 2nd most common error in data entry is to enter this value with the wrong units; don't use mb or hPa. Pa6
air_moist_prmintAtmospheric moisture parameter index none7
air_moist_valfloatValue of the parameter corresponding to the above index see below8
sfc_moist_prmintSurface moisture parameter index none9
sfc_moist_valfloatValue of the parameter corresponding to the above index see below10
salinityfloatSalinity. Enter as a fraction (e.g., 0.0349) rather than parts per thousand none11
ss_prmintSeastate parameter index none12
ss_valfloatValue of the parameter corresponding to the above index see below13
t_airfloatAir temperature at the reference height of the thermometer and humidity sensor C14
SST_prmfloatDisignates the surface temperature as a skin temperature or a bulk temperature. Currently this variable is not used in the code. non15
t_skinfloatSkin temperature of the water. C16
ref_ht_windfloatHeight of the wind observations m17
ref_ht_tqfloatHeight of the temperature observations. Note: in the current version of the code this must equal to height of the humidity observations. m18
z_wantedfloatThe height to which the wind speed, potential temperature, and specific humidity are adjusted. Note that the variable CONVECT should be set to zero for proper height adjustment. m19
astabintAtmospheric stability option none20
eqv_neut_prmintEquivalent Neutral Winds Parameter. Do not confuse this variable with astab (for neutral or non-neutral winds). This variable is for adjusting in situ winds to satellite winds, which are termed equivalent neutral winds. none21
QnetintNet energy flux density through the air/sea interface Wm-222
warnfloatSet to zero for no warming written to the screen. Set to one for warning written to the screen. none23
flux_modelintSet to <0 to not use this option. It sets the options for roughness lengths and stability parameterizations to match published flux models as well as modifications to these models. This optionsn is ideal for users unfamilair with the technical details of models and for users that simply want to replicate a published model. Click on the link to a list of the preset options. Alternatively, set this value to <0 and selection options using z0_mom_prm, z0_TQ_prm, and stable_prm. none24
z0_mom_prmintMomentum roughness length parameterization. To use this input, flux_model must have a value less than zero. none25
z0_TQ_prmintPotential temperature and moisture roughness length parameterization. To use this input, flux_model must have a value less than zero. none26
stable_prmintStability parameterization. If astab=0 (neutral stability) then this setting has no influence. Furthermore, flux_model must have a value less than zero. none27
A_oilfloatFraction of surface covered by oil. Normally the input value for this parameter is zero. Larger value will suppress capillary waves and mimic the supression of shorter gravity waves. none28

Output Variables:

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 UnitsArgument Number
shffloatsensible heat flux (positive upward) W m-228
lhffloatlatent heat flux (positive upward) W m-229
tauvector floatstress vector. There are more details on the conversion to zonal and meridional components. N m-230
u_starvector floatfriction velocity (u*) m s-131
t_starfloatscaling term for potential temperature (T*) C32
q_starfloatscaling parameter for moisture (q*) none33
z_over_Lfloatdimensionless Monin-Obhukov scale length none34
wave_agefloatwave age, cp/u* none35
dom_phs_spdfloatdominant phase speed of gravity waves m s-136
h_sigfloatsignificant wave height m37
ww_stabfloatwind-wave evolution parameter none38
zo_mvector floatmomentum roughness length m39
u_at_zfloatwind speed at the specified height m s-140
t_at_zfloatpotential temperature at the specified height oC41
q_at_zfloatspecific humidity at the specified height kg kg-142

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_inDescription Units
0Wind speed, relative to the surface current m/s
1Friction velocity (magnitude) m/s
2Surface wind stress (magnitude) N/m^2
3Equivalent 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.

astabDescription Units
0Atmospheric stability is assumed to be neutral none
1Stability is calculatedi and used. none
2The value of z/L passed into the routine is used. This option is unavailable in versions prior to the 2021 version. none

Options for outputting (or not outputting) equivalent neutral winds:

This parameter can modifies how the height adjusted wind speed (u_at_z) is calculated. Note that the various forms of nuetral equivalent values have some dependency on the stability parameterization.

eqv_neutDescription Units
0Height adjustment is not modified, winds are still normal winds. none
1Equivalent neutral winds are calculated and output in the u_at_z variable. This version of equivalent neutral winds (Ross et al., 1985; Liu and Tang, 1996; Kara et al., 2008) treats the friction velocity and roughness length as identical to the observed winds and stability, and uses those values to calculate a height adjusted wind for neutral conditions. Optimized for preserving stress: the correct stress can be calculated from this equivalent neutral wind speed by using air density and a neutral drag coefficient. none
2Equivalent neutral winds are calculated and output in t he u_at_z variable. This version of equivalent neutral winds (Geernaert and Katsaros, 1986) preserves the roughness length for momentum, but does not preserve the friction velocity. Optimized for a neutral CD. none

Geernaert, G. L., and K. B. Katsaros (1986), Incorporation of stratification effects on the oceanic roughness length in the derivation of the neutral drag coefficient, J. Phys. Oceanogr., 16, 1580-1584.

Kara, A. B., Wallcraft, A. J., & Bourassa, M. A. (2008). Air-Sea Stability Effects on the 10m Winds Over the Global Ocean: Evaluations of Air-Sea Flux Algorithms. J. Geophys. Res., 113, C04009. doi:10.1029/2007JC004324

Liu, W. T., and W. Tang (1996), Equivalent neutral wind, JPL Publ., 96-17, 8 pp.

Ross, D. B., V. J. Cardone, J. Overland, R. D. McPherson, W. J. Pierson Jr., and T. Yu (1985), Oceanic surface winds, Adv. Geophys., 27, 101-138.

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_prmParameter treated as known (ss_val) Units
0Wind-wave stability parameter from Bourassa et al. (1999) BVW. Set to 1.0 for wind/wave equilibrium. none
1Phase 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. If no other wave data are input this phase speed will be used in Toba's relation, which is better suited for wind waves than swell. m/s
2Wave age the dominant waves. This is used to modify Charnock's parameter. (cp/u*) none
3Significant wave height. if no other wave data are input this phase speed will be used in Toba's relation, which is better suited for wind waves than swell. (Hs) m
4Significant slope. If no other wave data are input this phase speed will be used in Toba's relation, which is better suited for wind waves than swell. (Hs/l) none
5Period of the dominant waves. If no other wave data are input this phase speed will be used in Toba's relation, which is better suited for wind waves than swell. (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
0Specific humidity at the reference height of the thermometer and humidity sensor g vapor / g air
1Relative humidity fraction
2Dew point temperature C
3Wet 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
0Specific humidity 'at' (near) the surface g vapor / g air
1Relative humidity fraction
2Dew point temperature C
3Wet bulb temperature C

Options for selecting parameterizations to match published flux models:

flux_modelParameter for moisture of air (sfc_moist_val)
<0The flux_model variable is not used. Instead, the parameterizations are selected using three variables: z0_mom_prm, z0_TQ_prm, and stable_prm.
0Bourassa, Vincent and Wood (1999, JAS)
1Smith (1988, JGR) version based on a momentum roughness length being a sum of roughesses for a smooth surface and gravity waves (Charnock's constant = 0.011).
2BVW (1999) without stability considered in the estimation of wind speed a wave height.
3BVW (1999) with Smith (1988) stability parameterization.
4BVW (1999) without roughness from capillary waves.
5BVW (1999) without surface tension in phase speed parameterizaiton.
6BVW (1999) without roughness from capillary waves, and without surface tension in phase speed parameterizaiton.
7Taylor and Yelland (2001, JTECH) parameterization (warning - use only with wind waves).
8Taylor and Yelland (2001, JTECH) parameterization with additional momentum roughness length due to capillary wavesi (warning - use only with wind waves).
9Bourassa (2006) roughness length parameterization and CFC (Clayson, Fairall, and Curry) roughness length parameterization for potential temperature and moisture.
10Bourassa (2006) roughness length parameterization and CFC (Clayson, Fairall, and Curry) roughness length parameterization for potential temperature and moisture, and a displacement height of 80% of the significant wave height. This assumption about displacement height works for wind driven waves; however, a displacement height of zero is a better assumption for swell.
11Bourassa (2006) roughness length parameterization and Zilitinkevich et al. roughness length parameterization for potential temperature and moisture.
12Bourassa (2006) roughness length parameterization and LKB (Liu, Katsaros, and Businger; 1979; JAS) roughness length parameterization for potential temperature and moisture.
13Bourassa (2006) roughness length parameterization and COARE3.0 (ref) roughness length parameterization for potential temperature and moisture.
14Bourassa (2006) roughness length parameterization and wall theory roughness length parameterization for potential temperature and moisture.
15Bourassa (2006) roughness length parameterization and CFC (Clayson, Fairall, and Curry) roughness length parameterization for potential temperature and moisture. The surface is also considered to be covered with oil modeled after the DWH spill.

Roughness Length Options for Momentum:

This option is applied only if flux_model < 0.

z0_mom_prmParameterizaton for Momentum Roughness Length (z0_mom_prm)
0Bourassa, Vincent and Wood (1999, JAS) momentum roughness length parameterization.
1 Bourassa (2006) momentum roughness length parameterization.
2Taylor and Yelland (1999, JTECH) momentum roughness length parameterization with additional roughness from BVW capillary waves. Currently does not work - DO NOT USE
3Taylor and Yelland (1999, JTECH) momentum roughness length parameterization. Currently does not work - DO NOT USE
4 Bourassa (2006) momentum roughness length parameterization modified for an oil slick modeled after the DWH slick.
5 Aerodynamically smooth surface.
6 2020 version of the oil slick code. Use with A_oil = 0.0 to have a more realistic open ocean mean roughness length while near the capillary cutoff. Uses a fixed value of Charnock's constant of 0.018. Not available prior to the 2021 update.
7 Uses a constant input value of momentum Roughness length. Not available prior to the 2021 update.

Roughness Length Options for Potential Temperature and Moisture:

This option is applied only if flux_model < 0. Note that the potential temperature and moisture roughness lengths are calculated separately; however, the type of parameterization comes from the same source.

z0_TQ_prmParameterizaton Type for Potential Temperature and Moisture Roughness Length (z0_TQ_prm)
0Wall theory
1CFC (Clayson, Fairall and Curry; 1996, JGR) parameterization.
2 Zilitinkevich et al. (2001) roughness length parameterization.
3LKB (Liu, Katsaros, and Businger; 1979, JAS) parameterization.
4COARE3.0 parameterization
5Modified (Griffin, M.S. Thesis) CFC (Clayson, Fairall and Curry; 1996, JGR) parameterization.

Boundary-Layer Stability Options:

This option is applied only if flux_model < 0.

stable_prmParameterizaton Type for Boundary-Layer Stability (stable_prm)
0 Bourassa, Vincent and Wood (1999) selection of parameterizations: Businger-Dyer parameterizations as applied for unstable by Benoit (1977; with updated fitting parameters), stable parameterizations from Beljaars and Holstag (1991)
1 Smith (1988; JGR) selection of parameterizations: Dyer (1974) with original fitting parameters.
2 COAWST parameterizations (not available prior to 2021 version): Dyer (1974) for unstable conditions and Hicks parameterization for stable conditions.
3 Paulson (1970) parameterizations (not available prior to 2021 version). The difference from the Dyer parameterizations is that z0/L is not assumed to be zero.

Last update: Sept. 22, 2012


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