import numpy as np
import sys
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")
elif ((spd.dtype not in ['float64', 'float32']) or
(T.dtype not in ['float64', 'float32']) or
(SST.dtype not in ['float64', 'float32'])):
sys.exit("input dtype of spd, T and SST should be float")
# 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" or meth == "UA" or
meth == "LY04")):
cskin = 0
elif ((cskin == None) and (meth == "C30" or meth == "C35" or meth == "C40"
or meth == "ERA5")):
cskin = 1
if (np.all(gust == None) and (meth == "C30" or meth == "C35" or meth == "C40")):
gust = [1, 1.2, 600]
elif (np.all(gust == None) and (meth == "UA" or meth == "ERA5")):
gust = [1, 1, 1000]
elif np.all(gust == None):
gust = [1, 1.2, 800]
elif ((np.size(gust) < 3) and (gust == 0)):
gust = [0, 0, 0]
elif (np.size(gust) < 3):
sys.exit("gust input must be a 3x1 array")
if (L not in [None, "S80", "ERA5"]):
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" or
meth == "UA" or meth == "C30" or meth == "C35"
or meth == "C40")):
L = "S80"
elif ((L == None) and (meth == "ERA5")):
L = "ERA5"
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