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Commit de93be2b authored by sbiri's avatar sbiri
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changed to contain only subroutines related to fluxes

parent 723b94fb
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Showing with 11 additions and 343 deletions
flux_subs.py
View file @ de93be2b
import numpy as np
import sys
from VaporPressure import VaporPressure
from util_subs import (CtoK, kappa, gc, visc_air)
CtoK = 273.16 # 273.15
""" Conversion factor for $^\circ\,$C to K """
kappa = 0.4 # NOTE: 0.41
""" von Karman's constant """
# ---------------------------------------------------------------------
......@@ -500,7 +494,8 @@ def psiu_26(zol, meth):
f = np.power(zol, 2)/(1+np.power(zol, 2))
psi = np.where(zol < 0, (1-f)*psik+f*psic, psi)
return psi
# ---------------------------------------------------------------------
#------------------------------------------------------------------------------
def psim_conv(zol, meth):
......@@ -547,137 +542,6 @@ def psim_stab(zol, meth):
# ---------------------------------------------------------------------
def get_init(spd, T, SST, lat, P, Rl, Rs, cskin, gust, L, tol, meth, qmeth):
"""
Checks initial input values and sets defaults if needed
Parameters
----------
spd : float
relative wind speed in m/s (is assumed as magnitude difference
between wind and surface current vectors)
T : float
air temperature in K
SST : float
sea surface temperature in K
lat : float
latitude (deg), default 45deg
P : float
air pressure (hPa), default 1013hPa
Rl : float
downward longwave radiation (W/m^2)
Rs : float
downward shortwave radiation (W/m^2)
cskin : int
0 switch cool skin adjustment off, else 1
default is 1
gust : int
3x1 [x, beta, zi] x=1 to include the effect of gustiness, else 0
beta gustiness parameter, beta=1 for UA, beta=1.2 for COARE
zi PBL height (m) 600 for COARE, 1000 for UA and ERA5, 800 default
default for COARE [1, 1.2, 600]
default for UA, ERA5 [1, 1, 1000]
default else [1, 1.2, 800]
L : int
Monin-Obukhov length definition options
0 : default for S80, S88, LP82, YT96 and LY04
1 : following UA (Zeng et al., 1998), default for UA
2 : following ERA5 (IFS Documentation cy46r1), default for ERA5
3 : COARE3.5 (Edson et al., 2013), default for C30, C35 and C40
tol : float
4x1 or 7x1 [option, lim1-3 or lim1-6]
option : 'flux' to set tolerance limits for fluxes only lim1-3
option : 'ref' to set tolerance limits for height adjustment lim-1-3
option : 'all' to set tolerance limits for both fluxes and height
adjustment lim1-6 ['all', 0.01, 0.01, 5e-05, 0.01, 1, 1]
meth : str
"S80","S88","LP82","YT96","UA","LY04","C30","C35","C40","ERA5"
qmeth : str
is the saturation evaporation method to use amongst
"HylandWexler","Hardy","Preining","Wexler","GoffGratch","CIMO",
"MagnusTetens","Buck","Buck2","WMO","WMO2000","Sonntag","Bolton",
"IAPWS","MurphyKoop"]
default is Buck2
Returns
-------
lat : float
latitude
P : float
air pressure (hPa)
Rl : float
downward longwave radiation (W/m^2)
Rs : float
downward shortwave radiation (W/m^2)
cskin : int
cool skin adjustment switch
gust : int
gustiness switch
tol : float
tolerance limits
L : int
MO length switch
"""
if ((type(spd) != np.ndarray) or (type(T) != np.ndarray) or
(type(SST) != np.ndarray)):
sys.exit("input type of spd, T and SST should be numpy.ndarray")
# if input values are nan break
if meth not in ["S80", "S88", "LP82", "YT96", "UA", "LY04", "C30", "C35",
"C40","ERA5"]:
sys.exit("unknown method")
if qmeth not in ["HylandWexler", "Hardy", "Preining", "Wexler", "CIMO",
"GoffGratch", "MagnusTetens", "Buck", "Buck2", "WMO",
"WMO2000", "Sonntag", "Bolton", "IAPWS", "MurphyKoop"]:
sys.exit("unknown q-method")
if (np.all(np.isnan(spd)) or np.all(np.isnan(T)) or np.all(np.isnan(SST))):
sys.exit("input wind, T or SST is empty")
if (np.all(lat == None)): # set latitude to 45deg if empty
lat = 45*np.ones(spd.shape)
elif ((np.all(lat != None)) and (np.size(lat) == 1)):
lat = np.ones(spd.shape)*np.copy(lat)
if ((np.all(P == None)) or np.all(np.isnan(P))):
P = np.ones(spd.shape)*1013
elif (((np.all(P != None)) or np.all(~np.isnan(P))) and np.size(P) == 1):
P = np.ones(spd.shape)*np.copy(P)
if (np.all(Rl == None) or np.all(np.isnan(Rl))):
Rl = np.ones(spd.shape)*370 # set to default for COARE3.5
if (np.all(Rs == None) or np.all(np.isnan(Rs))):
Rs = np.ones(spd.shape)*150 # set to default for COARE3.5
if ((cskin == None) and (meth == "S80" or meth == "S88" or meth == "LP82"
or meth == "YT96")):
cskin = 0
elif ((cskin == None) and (meth == "UA" or meth == "LY04" or meth == "C30"
or meth == "C35" or meth == "C40"
or meth == "ERA5")):
cskin = 1
if ((gust == None) and (meth == "C30" or meth == "C35" or meth == "C40")):
gust = [1, 1.2, 600]
elif ((gust == None) and (meth == "UA" or meth == "ERA5")):
gust = [1, 1, 1000]
elif (gust == None):
gust = [1, 1.2, 800]
elif (np.size(gust) < 3):
sys.exit("gust input must be a 3x1 array")
if (L not in [None, 0, 1, 2, 3]):
sys.exit("L input must be either None, 0, 1, 2 or 3")
if ((L == None) and (meth == "S80" or meth == "S88" or meth == "LP82"
or meth == "YT96" or meth == "LY04")):
L = 0
elif ((L == None) and (meth == "UA")):
L = 1
elif ((L == None) and (meth == "ERA5")):
L = 2
elif ((L == None) and (meth == "C30" or meth == "C35" or meth == "C40")):
L = 3
if (tol == None):
tol = ['flux', 0.01, 1, 1]
elif (tol[0] not in ['flux', 'ref', 'all']):
sys.exit("unknown tolerance input")
return lat, P, Rl, Rs, cskin, gust, tol, L
# ---------------------------------------------------------------------
def get_skin(sst, qsea, rho, Rl, Rs, Rnl, cp, lv, tkt, usr, tsr, qsr, lat):
""" Computes cool skin
......@@ -779,7 +643,7 @@ def get_gust(beta, Ta, usr, tsrv, zi, lat):
def get_L(L, lat, usr, tsr, qsr, t10n, tv10n, qair, h_in, T, Ta, th, tv, sst,
dt, dq, wind, monob, meth):
dt, dtv, dq, zo, wind, monob, meth):
"""
calculates Monin-Obukhov length and virtual star temperature
......@@ -843,8 +707,13 @@ def get_L(L, lat, usr, tsr, qsr, t10n, tv10n, qair, h_in, T, Ta, th, tv, sst,
monob = ((tv10n*np.power(usr, 2))/(g*kappa*tsrv))
monob = np.where(np.fabs(monob) < 1, np.where(monob < 0, -1, 1), monob)
elif (L == 1):
Rb = g*h_in[0]*dtv/(tv*np.power(wind, 2))
zol = np.where(Rb >= 0, Rb*np.log(h_in[0]/zo) /
(1-5*np.where(Rb < 0.19, Rb, 0.19)),
Rb*np.log(h_in[0]/zo))
monob = h_in[0]/zol
tsrv = tsr*(1.+0.61*qair)+0.61*th*qsr
monob = ((tv*np.power(usr, 2))/(kappa*g*tsrv))
# monob = ((tv*np.power(usr, 2))/(kappa*g*tsrv))
elif (L == 2):
tsrv = tsr+0.61*t10n*qsr
Rb = ((g*h_in[0]*((2*dt)/(Ta+sst-g*h_in[0])+0.61*dq)) /
......@@ -867,64 +736,6 @@ def get_L(L, lat, usr, tsr, qsr, t10n, tv10n, qair, h_in, T, Ta, th, tv, sst,
#------------------------------------------------------------------------------
def get_hum(hum, T, sst, P, qmeth):
"""
Get specific humidity output
Parameters
----------
hum : array
humidity input switch 2x1 [x, values] default is relative humidity
x='rh' : relative humidity in %
x='q' : specific humidity (g/kg)
x='Td' : dew point temperature (K)
T : float
air temperature in K
sst : float
sea surface temperature in K
P : float
air pressure at sea level in hPa
qmeth : str
method to calculate specific humidity from vapor pressure
Returns
-------
qair : float
specific humidity of air
qsea : float
specific humidity over sea surface
"""
if (hum == None):
RH = np.ones(sst.shape)*80
qsea = qsat_sea(sst, P, qmeth)/1000 # surface water q (g/kg)
qair = qsat_air(T, P, RH, qmeth)/1000 # q of air (g/kg)
elif (hum[0] not in ['rh', 'q', 'Td']):
sys.exit("unknown humidity input")
qair, qsea = np.nan, np.nan
elif (hum[0] == 'rh'):
RH = hum[1]
if (np.all(RH < 1)):
sys.exit("input relative humidity units should be \%")
qair, qsea = np.nan, np.nan
qsea = qsat_sea(sst, P, qmeth)/1000 # surface water q (g/kg)
qair = qsat_air(T, P, RH, qmeth)/1000 # q of air (g/kg)
elif (hum[0] == 'q'):
qair = hum[1]
qsea = qsat_sea(sst, P, qmeth)/1000 # surface water q (g/kg)
elif (hum[0] == 'Td'):
Td = hum[1] # dew point temperature (K)
Td = np.where(Td < 200, np.copy(Td)+CtoK, np.copy(Td))
T = np.where(T < 200, np.copy(T)+CtoK, np.copy(T))
esd = 611.21*np.exp(17.502*((Td-273.16)/(Td-32.19)))
es = 611.21*np.exp(17.502*((T-273.16)/(T-32.19)))
RH = 100*esd/es
qair = qsat_air(T, P, RH, qmeth)/1000 # q of air (g/kg)
qsea = qsat_sea(sst, P, qmeth)/1000 # surface water q (g/kg)
return qair, qsea
#-------------------------------------------------------------------------
def get_strs(h_in, monob, wind, zo, zot, zoq, dt, dq, dter, dqer, ct, cq,
cskin, meth):
"""
......@@ -951,7 +762,7 @@ def get_strs(h_in, monob, wind, zo, zot, zoq, dt, dq, dter, dqer, ct, cq,
dter : float
cskin temperature adjustment (K)
dqer : float
cskin q adjustment (q/kg)
cskin q adjustment (g/kg)
ct : float
temperature exchange coefficient
cq : float
......@@ -1033,147 +844,4 @@ def get_strs(h_in, monob, wind, zo, zot, zoq, dt, dq, dter, dqer, ct, cq,
tsr = ct*wind*(dt+dter*cskin)/usr
qsr = cq*wind*(dq+dqer*cskin)/usr
return usr, tsr, qsr
#------------------------------------------------------------------------------
def get_heights(h, dim_len):
""" Reads input heights for velocity, temperature and humidity
Parameters
----------
h : float
input heights (m)
dim_len : int
length dimension
Returns
-------
hh : array
"""
hh = np.zeros((3, dim_len))
if (type(h) == float or type(h) == int):
hh[0, :], hh[1, :], hh[2, :] = h, h, h
elif (len(h) == 2 and np.ndim(h) == 1):
hh[0, :], hh[1, :], hh[2, :] = h[0], h[1], h[1]
elif (len(h) == 3 and np.ndim(h) == 1):
hh[0, :], hh[1, :], hh[2, :] = h[0], h[1], h[2]
elif (len(h) == 1 and np.ndim(h) == 2):
hh = np.zeros((3, h.shape[1]))
hh[0, :], hh[1, :], hh[2, :] = h[0, :], h[0, :], h[0, :]
elif (len(h) == 2 and np.ndim(h) == 2):
hh = np.zeros((3, h.shape[1]))
hh[0, :], hh[1, :], hh[2, :] = h[0, :], h[1, :], h[1, :]
elif (len(h) == 3 and np.ndim(h) == 2):
hh = np.zeros((3, h.shape[1]))
hh = np.copy(h)
return hh
# ---------------------------------------------------------------------
def qsat_sea(T, P, qmeth):
""" Computes surface saturation specific humidity (g/kg)
Parameters
----------
T : float
temperature ($^\\circ$\\,C)
P : float
pressure (mb)
qmeth : str
method to calculate vapor pressure
Returns
-------
qs : float
"""
T = np.asarray(T)
if (np.nanmin(T) > 200): # if Ta in Kelvin convert to Celsius
T = T-CtoK
ex = VaporPressure(T, P, 'liquid', qmeth)
es = 0.98*ex # reduction at sea surface
qs = 622*es/(P-0.378*es)
return qs
# ------------------------------------------------------------------------------
def qsat_air(T, P, rh, qmeth):
""" Computes saturation specific humidity (g/kg) as in C35
Parameters
----------
T : float
temperature ($^\circ$\,C)
P : float
pressure (mb)
rh : float
relative humidity (%)
qmeth : str
method to calculate vapor pressure
Returns
-------
q : float
em : float
"""
T = np.asarray(T)
if (np.nanmin(T) > 200): # if Ta in Kelvin convert to Celsius
T = T-CtoK
es = VaporPressure(T, P, 'liquid', qmeth)
em = 0.01*rh*es
q = 622*em/(P-0.378*em)
return q
# ---------------------------------------------------------------------
def gc(lat, lon=None):
""" Computes gravity relative to latitude
Parameters
----------
lat : float
latitude ($^\circ$)
lon : float
longitude ($^\circ$, optional)
Returns
-------
gc : float
gravity constant (m/s^2)
"""
gamma = 9.7803267715
c1 = 0.0052790414
c2 = 0.0000232718
c3 = 0.0000001262
c4 = 0.0000000007
if lon is not None:
lon_m, lat_m = np.meshgrid(lon, lat)
else:
lat_m = lat
phi = lat_m*np.pi/180.
xx = np.sin(phi)
gc = (gamma*(1+c1*np.power(xx, 2)+c2*np.power(xx, 4)+c3*np.power(xx, 6) +
c4*np.power(xx, 8)))
return gc
# ---------------------------------------------------------------------
def visc_air(T):
""" Computes the kinematic viscosity of dry air as a function of air temp.
following Andreas (1989), CRREL Report 89-11.
Parameters
----------
Ta : float
air temperature ($^\circ$\,C)
Returns
-------
visa : float
kinematic viscosity (m^2/s)
"""
T = np.asarray(T)
if (np.nanmin(T) > 200): # if Ta in Kelvin convert to Celsius
T = T-273.16
visa = 1.326e-5*(1+6.542e-3*T+8.301e-6*np.power(T, 2) -
4.84e-9*np.power(T, 3))
return visa
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