xcoare.xcoare35

xcoare.xcoare35(u, zu, t, zt, rh, zq, P, ts, Rs=150, Rl=370, lat=45, zi=600, rain=None, cp=None, sigH=None, jcool=True, qspec=None, albedo=0.055, emissivity=0.97)

Vectorized version of COARE 3 code (Fairall et al, 2003) with modification based on the CLIMODE, MBL and CBLAST experiments (Edson et al., 2012). The cool skin option is retained but warm layer and surface wave options removed.

This version include parameterizations using wave height and wave slope using cp and sigH. If these are set to NaN, then the wind speed depent formulation is used.

An important component of this code is whether the inputed ts represents the skin temperature of a near surface temperature. How this variable is treated is determined by the jcool parameter: set jcool=1 if Ts is bulk ocean temperature (default),

jcool=0 if Ts is true ocean skin temperature.

The code assumes u,t,rh,ts are vectors; sensor heights zu,zt,zl, latitude lat, and PBL height zi are constants; air pressure P and radiation Rs,Rl may be vectors or constants. Default values are assigned for P,Rs,Rl,lat,and zi if these data are not available. Input NaNs to indicate no data. Defaults should be set to representative regional values if possible.

Parameters

  • zu(m) (u = relative wind speed (m/s) at height) –

  • zt(m) (t = bulk air temperature (degC) at height) –

    rh = relative humidity (%) at height zq(m)

    P = surface air pressure (mb) (default = 1015)

    ts = water temperature (degC) see jcool below Rs = downward shortwave radiation (W/m^2) (default = 150) Rl = downward longwave radiation (W/m^2) (default = 370)

    lat = latitude (default = +45 N)

    zi = PBL height (m) (default = 600m)

    rain = rain rate (mm/hr)

    cp = phase speed of dominant waves (m/s)

    sigH = significant wave height (m)

qspec = specific humidity at zq (kg/kg) The user controls the output. This is currently set as:

A=[usr tau hsb hlb hbb hsbb tsr qsr zot zoq Cd Ch Ce L zet dter dqer tkt Urf Trf Qrf RHrf UrfN Rnl Le rhoa UN U10 U10N Cdn_10 Chn_10 Cen_10];

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30

where

usr = friction velocity that includes gustiness (m/s) tau = wind stress (N/m^2) hsb = sensible heat flux into ocean (W/m^2) hlb = latent heat flux into ocean (W/m^2) hbb = buoyany flux into ocean (W/m^2) hsbb = “sonic” buoyancy flux measured directly by sonic anemometer hlWebb= Webb correction for latent heat flux, add this to directly measured eddy covariance latent heat flux using water vapor mass concentration sensors. tsr = temperature scaling parameter (K) qsr = specific humidity scaling parameter (g/Kg) zot = thermal roughness len (m) zoq = moisture roughness len (m) Cd = wind stress transfer (drag) coefficient at height zu Ch = sensible heat transfer coefficient (Stanton number) at height zu Ce = latent heat transfer coefficient (Dalton number) at height zu

L = Obukhov len scale (m)

zet = Monin-Obukhov stability parameter zu/L

dter = cool-skin temperature depression (degC) dqer = cool-skin humidity depression (degC)

tkt = cool-skin thickness (m) Urf = wind speed at reference height (user can select height below) Tfr = temperature at reference height Qfr = specific humidity at reference height

RHfr = relative humidity at reference height UrfN = neutral value of wind speed at reference height

Rnl = Upwelling IR radiation computed by COARE

Le = latent heat of vaporization

rhoa = density of air

UN = neutral value of wind speed at zu

U10 = wind speed adjusted to 10 m

UN10 = neutral value of wind speed at 10m Cdn_10 = neutral value of drag coefficient at 10m Chn_10 = neutral value of Stanton number at 10m Cen_10 = neutral value of Dalton number at 10m

Notes

  1. u is the relative wind speed, i.e., the magnitude of the

difference between the wind (at zu) and ocean surface current vectors.

  1. Set jcool=0 in code if ts is true surface skin temperature,

otherwise ts is assumed the bulk temperature and jcool=1.

  1. Set P=NaN to assign default value if no air pressure data

available.

  1. Set Rs=NaN, Rl=NaN if no radiation data available. This assigns

default values to Rs, Rl so that cool skin option can be applied.

  1. Set lat=NaN and/or zi=NaN to assign default values if latitude

and/or PBL height not given.

  1. The code to compute the heat flux caused by precipitation is

included if rain data is available (default is no rain).

  1. Code updates the cool-skin temperature depression dter and thickness

tkt during iteration loop for consistency.

  1. Number of iterations set to nits = 6.

References

Fairall, C.W., E.F. Bradley, J.E. Hare, A.A. Grachev, and J.B. Edson (2003), Bulk parameterization of air sea fluxes: updates and verification for the COARE algorithm, J. Climate, 16, 571-590.

Welcome to xcoare’s documentation!