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.
| Parameter | Type | Description | Units | Argument Number |
| dyn_in_prm | int | Dynamic input parameter index | none | 1 |
| dyn_in_val | float | Dynamic 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). | see below | 2 |
| dyn_in_val2 | float | Dynamic 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 below | 3 |
| sfc_current1 | float | Surface current. If the value for dyn_in_val is entered as a speed, then this should be the current speed. The code will assume that they are moving in the same direction. If the value of dyn_in_val is a vector component, then this should be the parallel vector component of the current. | none | 4 |
| sfc_current2 | float | Surface current second vector component. If the value for dyn_in_val is entered as a speed, then the input current for this vector component should be zero. If dyn_in_val2 is a vector conponent, then this input should be the second vector component for current (parallel the 2nd wind component). | none | 5 |
| convect | float | Convective parameter. Designed to improve heat fluxes at lower wind speeds for models with surface roughness based on an aerodynamically smoother surface and gravity waves. In this implication it should be used with caution because it will adversely impact height adjustment of winds, temperature and humidity. For the assumptions stated above, recommended value between 0.7 and 1.25 (for details see TOGA NOTES #4). For models that include capillary wave also including gustiness would use to different mechanisms to fix systematic errors at low winds speeds, therefore it should not be used. The more advance models with capillary waves utilize gustiness in another manner (blending smooth surfaces with gravity waves and capillary waves (without adversely impacting height adjustment). | none | 6 |
| pressure | float | Atmospheric 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. | Pa | 7 |
| air_moist_prm | int | Atmospheric moisture parameter index | none | 8 |
| air_moist_val | float | Value of the parameter corresponding to the above index | see below | 9 |
| sfc_moist_prm | int | Surface moisture parameter index | none | 10 |
| sfc_moist_val | float | Value of the parameter corresponding to the above index | see below | 11 |
| salinity | float | Salinity. Enter as a fraction (e.g., 0.0349) rather than parts per thousand | none | 12 |
| ss_prm | int | Seastate parameter index | none | 13 |
| ss_val | float | Value of the parameter corresponding to the above index | see below | 14 |
| t_air | float | Air temperature at the reference height of the thermometer and humidity sensor | C | 15 |
| SST_prm | float | Disignates the surface temperature as a skin temperature or a bulk temperature. Currently this variable is not used in the code. | non | 16 |
| t_skin | float | Skin temperature of the water. | C | 17 |
| ref_ht_wind | float | Height of the wind observations | m | 18 |
| ref_ht_tq | float | Height of the temperature observations. Note: in the current version of the code this must equal to height of the humidity observations. | m | 19 |
| z_wanted | float | The 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. | m | 20 |
| astab | int | Atmospheric stability option | none | 21 |
| eqv_neut_prm | int | Equivalent 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. | none | 22 |
| net_heat_flux | int | Net radiative flux density through the air/sea interface. This is used in adjusting a bulk SST to a skin temperature. | Wm-2 | 23 |
| warn | float | Set to zero for no warming written to the screen. Set to one for warning written to the screen. | none | 24 |
| flux_model | int | Set 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_theta_q_prm, and stable_prm. | none | 25 |
| z0_mom_prm | int | Momentum roughness length parameterization. To use this input, flux_model must have a value less than zero. | none | 26 |
| z0_theta_q_prm | int | Potential temperature and moisture roughness length parameterization. To use this input, flux_model must have a value less than zero. | none | 27 |
| stable_prm | int | Stability parameterization. If astab=0 (neutral stability) then this setting has no influence. Furthermore, flux_model must have a value less than zero. | none | 28 |
| oil_area_fract | float | Fraction of surface covered by oil. Normally the input value for this parameter is zero. The maximum value is 1.0. Larger value will suppress capillary waves and mimic the supression of shorter gravity waves. | none | 29 |
| z_over_L | float | The dimensionless Obukhov scale length, were z is the height of the wind observations. This input is used only when the stable_prm is set to allow z/L to be input. | none | 30 |
| zo_m | float | Input momentum roughness length. Used only when zo_mom_prm is set to allow the roughness length to be input. This variable is a two component vector. Currently only the first component is used. The second component is includes in anticipation of code modifications that will work with waves propogating in a direction other than the wind direction. | none | 31 |
| Missing | float | The value to be used for output data when those output data are missing. | none | 32 |
Output fluxes and atmospheric dynamic stability appear to be working well. Wave data output are clearly wrong. The related code will be repaired in a future update.
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.
| Parameter | Type | Description | Units | Argument Number |
| count | float | Diagnostic indicating if the algorithm converged on a solution. If count < 1 the algorthm has not converged (meaning that the input data are not consistent with the model physics). This typically happens when the wind speed is near zero or an observation height is outside the modified log-layer. While fluxes are output (and often plausible) this is an indicator of a problem with the output values. | none | 1 |
| shf | float | sensible heat flux (positive upward) | W m-2 | 2 |
| lhf | float | latent heat flux (positive upward) | W m-2 | 3 |
| tau | vector float | stress vector. Directional convention matches that of the input winds. | N m-2 | 4 |
| u_star | vector float | friction velocity (u*). Directional convention matches that of the input winds. | m s-1 | 5 |
| t_star | float | scaling term for potential temperature (T*) | C | 6 |
| q_star | float | scaling parameter for moisture (q*) | none | 7 |
| z_over_L | float | dimensionless Monin-Obhukov scale length | none | 8 |
| wave_age | vector float | wave age, cp/u* | none | 9 |
| dom_phs_spd | float | dominant phase speed of gravity waves | m s-1 | 10 |
| h_sig | float | significant wave height | m | 11 |
| zo_out | vector float | momentum roughness length | m | 12 |
| u_at_z | vector float | wind speed at the specified height. If wind and current are entered as speeds, then the first component of u_at_z is a speed (and the second component is zero). If wind and current are entered as vector compoents, then u_at_z output vector components in the same coordinate system. | m s-1 | 13 |
| t_at_z | float | potential temperature at the specified height | oC | 14 |
| q_at_z | float | specific humidity at the specified height | kg kg-1 | 15 |
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 |
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 and used. | none |
| 2 | The value of z/L passed into the routine is used. This option is unavailable in versions prior to the 2021 version. | none |
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_neut | Description | Units |
| 0 | Height adjustment is not modified, winds are still normal winds. | none |
| 1 | Equivalent 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 |
| 2 | Equivalent 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.
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 from Bourassa et al. (1999) BVW. Set to 1.0 for wind/wave equilibrium. | 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. 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 |
| 2 | Wave age the dominant waves. This is used to modify Charnock's parameter. (cp/u*) | none |
| 3 | Significant 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 |
| 4 | Significant 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 |
| 5 | Period 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_prm | Parameter 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 |
Choose the moisture parameter that is easiest for you to deal
with:
| sfc_moist_prm | Parameter 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 |
| flux_model | Parameter for moisture of air (sfc_moist_val) |
| <0 | The flux_model variable is not used. Instead, the parameterizations are selected using three variables: z0_mom_prm, z0_theta_q_prm, and stable_prm. |
| 0 | Bourassa, Vincent and Wood (1999, JAS) |
| 1 | Smith (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). |
| 2 | BVW (1999) without stability considered in the estimation of wind speed a wave height. |
| 3 | BVW (1999) with Smith (1988) stability parameterization. |
| 4 | BVW (1999) without roughness from capillary waves. |
| 5 | BVW (1999) without surface tension in phase speed parameterizaiton. |
| 6 | BVW (1999) without roughness from capillary waves, and without surface tension in phase speed parameterizaiton. |
| 7 | Taylor and Yelland (2001, JTECH) parameterization (warning - use only with wind waves). |
| 8 | Taylor and Yelland (2001, JTECH) parameterization with additional momentum roughness length due to capillary wavesi (warning - use only with wind waves). |
| 9 | Bourassa (2006) roughness length parameterization and CFC (Clayson, Fairall, and Curry) roughness length parameterization for potential temperature and moisture. |
| 10 | Bourassa (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. |
| 11 | Bourassa (2006) roughness length parameterization and Zilitinkevich et al. roughness length parameterization for potential temperature and moisture. |
| 12 | Bourassa (2006) roughness length parameterization and LKB (Liu, Katsaros, and Businger; 1979; JAS) roughness length parameterization for potential temperature and moisture. |
| 13 | Bourassa (2006) roughness length parameterization and COARE3.0 (ref) roughness length parameterization for potential temperature and moisture. |
| 14 | Bourassa (2006) roughness length parameterization and wall theory roughness length parameterization for potential temperature and moisture. |
| 15 | Bourassa (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. |
This option is applied only if flux_model < 0.
| z0_mom_prm | Parameterizaton for Momentum Roughness Length (z0_mom_prm) |
| 0 | Bourassa, Vincent and Wood (1999, JAS) momentum roughness length parameterization. |
| 1 | Bourassa (2006) momentum roughness length parameterization. |
| 2 | Taylor and Yelland (1999, JTECH) momentum roughness length parameterization with additional roughness from BVW capillary waves. Currently does not work - DO NOT USE |
| 3 | Taylor 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 oil_area_fract = 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. |
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_theta_q_prm | Parameterizaton Type for Potential Temperature and Moisture Roughness Length (z0_theta_q_prm) |
| 0 | Wall theory |
| 1 | CFC (Clayson, Fairall and Curry; 1996, JGR) parameterization. |
| 2 | Zilitinkevich et al. (2001) roughness length parameterization. |
| 3 | LKB (Liu, Katsaros, and Businger; 1979, JAS) parameterization. |
| 4 | COARE3.0 parameterization |
| 5 | Modified (Griffin, M.S. Thesis) CFC (Clayson, Fairall and Curry; 1996, JGR) parameterization. |
This option is applied only if flux_model < 0.
| stable_prm | Parameterizaton 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. 1, 2023
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