def main(self,
tair,
par,
vpd,
wind,
pressure,
Ca,
doy,
hod,
lat,
lon,
lai,
rnet=None):
"""
Parameters:
----------
tair : float
air temperature (deg C)
par : float
Photosynthetically active radiation (umol m-2 s-1)
vpd : float
Vapour pressure deficit (kPa, needs to be in Pa, see conversion
below)
wind : float
wind speed (m s-1)
pressure : float
air pressure (using constant) (Pa)
Ca : float
ambient CO2 concentration
doy : float
day of day
hod : float
hour of day
lat : float
latitude
lon : float
longitude
lai : floar
leaf area index
Returns:
--------
An : float
net leaf assimilation (umol m-2 s-1)
gs : float
stomatal conductance (mol m-2 s-1)
et : float
transpiration (mol H2O m-2 s-1)
"""
F = FarquharC3(theta_J=0.85,
peaked_Jmax=True,
peaked_Vcmax=True,
model_Q10=True,
gs_model=self.gs_model,
gamma=self.gamma,
g0=self.g0,
g1=self.g1,
D0=self.D0,
alpha=self.alpha)
P = PenmanMonteith(self.leaf_width, self.SW_abs)
An = np.zeros(2) # sunlit, shaded
gsc = np.zeros(2) # sunlit, shaded
et = np.zeros(2) # sunlit, shaded
Tcan = np.zeros(2) # sunlit, shaded
lai_leaf = np.zeros(2)
#cos_zenith = calculate_solar_geometry(doy, hod, lat, lon)
cos_zenith = sinbet(doy, lat, hod)
#print(doy, lat, hod, cos_zenith)
zenith_angle = np.rad2deg(np.arccos(cos_zenith))
elevation = 90.0 - zenith_angle
sw_rad = par * c.PAR_2_SW # W m-2
# this matches CABLE's logic ... which means they are halving the
# SW_down that is used to compute the direct/diffuse terms and presumbly
# all other calcs
sw_rad_half = par / 4.6 # W m-2
# get diffuse/beam frac
(diffuse_frac, direct_frac) = spitters(doy, sw_rad_half, cos_zenith)
(apar, lai_leaf,
kb) = calculate_absorbed_radiation(par, cos_zenith, lai, direct_frac,
diffuse_frac, doy, sw_rad_half)
# Calculate scaling term to go from a single leaf to canopy,
# see Wang & Leuning 1998 appendix C
scalex = calc_leaf_to_canopy_scalar(lai, kb)
if lai_leaf[0] < 1.e-3: # to match line 336 of CABLE radiation
scalex[0] = 0.
# Is the sun up?
if elevation > 0.0 and par > 50.:
# sunlit / shaded loop
for ileaf in range(2):
# initialise values of Tleaf, Cs, dleaf at the leaf surface
dleaf = vpd
Cs = Ca
Tleaf = tair
Tleaf_K = Tleaf + c.DEG_2_KELVIN
iter = 0
while True:
if scalex[ileaf] > 0.:
(An[ileaf],
gsc[ileaf]) = F.photosynthesis(Cs=Cs,
Tleaf=Tleaf_K,
Par=apar[ileaf],
Jmax25=self.Jmax25,
Vcmax25=self.Vcmax25,
Q10=self.Q10,
Eaj=self.Eaj,
Eav=self.Eav,
deltaSj=self.deltaSj,
deltaSv=self.deltaSv,
Rd25=self.Rd25,
Hdv=self.Hdv,
Hdj=self.Hdj,
vpd=dleaf,
scalex=scalex[ileaf])
else:
An[ileaf], gsc[ileaf] = 0., 0.
# Calculate new Tleaf, dleaf, Cs
(new_tleaf, et[ileaf], le_et, gbH,
gw) = self.calc_leaf_temp(P,
Tleaf,
tair,
gsc[ileaf],
apar[ileaf],
vpd,
pressure,
wind,
rnet=rnet,
lai=lai_leaf[ileaf])
gbc = gbH * c.GBH_2_GBC
if gbc > 0.0 and An[ileaf] > 0.0:
Cs = Ca - An[ileaf] / gbc # boundary layer of leaf
else:
Cs = Ca
if np.isclose(et[ileaf], 0.0) or np.isclose(gw, 0.0):
dleaf = vpd
else:
dleaf = (et[ileaf] * pressure / gw) * c.PA_2_KPA # kPa
# Check for convergence...?
if math.fabs(Tleaf - new_tleaf) < 0.02:
break
if iter > self.iter_max:
#raise Exception('No convergence: %d' % (iter))
An[ileaf] = 0.0
gsc[ileaf] = 0.0
et[ileaf] = 0.0
break
# Update temperature & do another iteration
Tleaf = new_tleaf
Tleaf_K = Tleaf + c.DEG_2_KELVIN
Tcan[ileaf] = Tleaf
iter += 1
# scale to canopy: sum contributions from beam and diffuse leaves
an_canopy = np.sum(An)
an_cansun = An[c.SUNLIT]
an_cansha = An[c.SHADED]
par_sun = apar[c.SUNLIT]
par_sha = apar[c.SHADED]
gsw_canopy = np.sum(gsc) * c.GSC_2_GSW
et_canopy = np.sum(et)
sun_frac = lai_leaf[c.SUNLIT] / np.sum(lai_leaf)
sha_frac = lai_leaf[c.SHADED] / np.sum(lai_leaf)
tcanopy = (Tcan[c.SUNLIT] * sun_frac) + (Tcan[c.SHADED] * sha_frac)
lai_sun = lai_leaf[c.SUNLIT]
lai_sha = lai_leaf[c.SHADED]
else:
an_canopy = 0.0
an_cansun = 0.0
an_cansha = 0.0
gsw_canopy = 0.0
et_canopy = 0.0
par_sun = 0.0
par_sha = 0.0
tcanopy = tair
lai_sun = 0.0
lai_sha = lai
return (an_canopy, gsw_canopy, et_canopy, tcanopy, an_cansun,
an_cansha, par_sun, par_sha, lai_sun, lai_sha)
def main_fast(self, tair, par, vpd, wind, pressure, Ca):
"""
Version as above but using a solver for Tleaf, rather than iterating
Parameters:
----------
tair : float
air temperature (deg C)
par : float
Photosynthetically active radiation (umol m-2 s-1)
vpd : float
Vapour pressure deficit (kPa, needs to be in Pa, see conversion
below)
wind : float
wind speed (m s-1)
pressure : float
air pressure (using constant) (Pa)
Ca : float
ambient CO2 concentration
Returns:
--------
An : float
net leaf assimilation (umol m-2 s-1)
gs : float
stomatal conductance (mol m-2 s-1)
et : float
transpiration (mol H2O m-2 s-1)
"""
F = FarquharC3(theta_J=0.85,
peaked_Jmax=True,
peaked_Vcmax=True,
model_Q10=True,
gs_model=self.gs_model,
gamma=self.gamma,
g0=self.g0,
g1=self.g1,
D0=self.D0,
alpha=self.alpha)
P = PenmanMonteith(self.leaf_width, self.leaf_absorptance)
# set initialise values
dleaf = vpd
dair = vpd
Cs = Ca
Tleaf = tair
Tleaf_K = Tleaf + c.DEG_2_KELVIN
(An, gsc) = F.calc_photosynthesis(Cs=Cs,
Tleaf=Tleaf_K,
Par=par,
Jmax25=self.Jmax25,
Vcmax25=self.Vcmax25,
Q10=self.Q10,
Eaj=self.Eaj,
Eav=self.Eav,
deltaSj=self.deltaSj,
deltaSv=self.deltaSv,
Rd25=self.Rd25,
Hdv=self.Hdv,
Hdj=self.Hdj,
vpd=dleaf)
# Solve new Tleaf
from scipy import optimize
Tleaf = optimize.brent(self.fx,
brack=(Tleaf - 15, Tleaf + 15),
args=(P, Tleaf, gsc, par, vpd, pressure, wind))
#print(Tleaf)
Tleaf_K = Tleaf + c.DEG_2_KELVIN
(An, gsc) = F.calc_photosynthesis(Cs=Cs,
Tleaf=Tleaf_K,
Par=par,
Jmax25=self.Jmax25,
Vcmax25=self.Vcmax25,
Q10=self.Q10,
Eaj=self.Eaj,
Eav=self.Eav,
deltaSj=self.deltaSj,
deltaSv=self.deltaSv,
Rd25=self.Rd25,
Hdv=self.Hdv,
Hdj=self.Hdj,
vpd=dleaf)
# Clunking, but I can't be arsed to rewrite, need to get other vars
# back
(et, le_et, gbH,
gw) = self.calc_leaf_temp_solved(P, Tleaf, tair, gsc, par, vpd,
pressure, wind)
gbc = gbH * c.GBH_2_GBC
Cs = Ca - An / gbc # boundary layer of leaf
if et == 0.0 or gw == 0.0:
dleaf = dair
else:
dleaf = (et * pressure / gw) * c.PA_2_KPA # kPa
gsw = gsc * c.GSC_2_GSW
return (An, gsw, et, le_et)
def main(self, tair, par, vpd, wind, pressure, Ca, Topt_hack=False):
"""
Parameters:
----------
tair : float
air temperature (deg C)
par : float
Photosynthetically active radiation (umol m-2 s-1)
vpd : float
Vapour pressure deficit (kPa, needs to be in Pa, see conversion
below)
wind : float
wind speed (m s-1)
pressure : float
air pressure (using constant) (Pa)
Ca : float
ambient CO2 concentration
Returns:
--------
An : float
net leaf assimilation (umol m-2 s-1)
gs : float
stomatal conductance (mol m-2 s-1)
et : float
transpiration (mol H2O m-2 s-1)
"""
F = FarquharC3(theta_J=0.85,
peaked_Jmax=True,
peaked_Vcmax=True,
model_Q10=True,
gs_model=self.gs_model,
gamma=self.gamma,
g0=self.g0,
g1=self.g1,
D0=self.D0,
alpha=self.alpha)
P = PenmanMonteith(self.leaf_width, self.leaf_absorptance)
# set initialise values
dleaf = vpd
dair = vpd
Cs = Ca
Tleaf = tair
Tleaf_K = Tleaf + c.DEG_2_KELVIN
#print "Start: %.3f %.3f %.3f" % (Cs, Tleaf, dleaf)
#print
Topt = 35.0
Topt_K = Topt + c.DEG_2_KELVIN
iter = 0
while True:
(An, gsc) = F.calc_photosynthesis(Cs=Cs,
Tleaf=Tleaf_K,
Par=par,
Jmax25=self.Jmax25,
Vcmax25=self.Vcmax25,
Q10=self.Q10,
Eaj=self.Eaj,
Eav=self.Eav,
deltaSj=self.deltaSj,
deltaSv=self.deltaSv,
Rd25=self.Rd25,
Hdv=self.Hdv,
Hdj=self.Hdj,
vpd=dleaf)
if Topt_hack:
if Tleaf > Topt:
(Anx, gsc) = F.calc_photosynthesis(Cs=Cs,
Tleaf=Topt_K,
Par=par,
Jmax25=self.Jmax25,
Vcmax25=self.Vcmax25,
Q10=self.Q10,
Eaj=self.Eaj,
Eav=self.Eav,
deltaSj=self.deltaSj,
deltaSv=self.deltaSv,
Rd25=self.Rd25,
Hdv=self.Hdv,
Hdj=self.Hdj,
vpd=dleaf)
# Calculate new Tleaf, dleaf, Cs
(new_tleaf, et, le_et, gbH,
gw) = self.calc_leaf_temp(P, Tleaf, tair, gsc, par, vpd, pressure,
wind)
gbc = gbH * c.GBH_2_GBC
Cs = Ca - An / gbc # boundary layer of leaf
if et == 0.0 or gw == 0.0:
dleaf = dair
else:
dleaf = (et * pressure / gw) * c.PA_2_KPA # kPa
#print "%f %f %f %f %f %f" % (Cs, Tleaf, dleaf, An*12.*0.000001*86400., gs, et*18*0.001*86400.)
# Check for convergence...?
if math.fabs(Tleaf - new_tleaf) < 0.02:
break
if iter > self.iter_max:
raise Exception('No convergence: %d' % (iter))
# Update temperature & do another iteration
Tleaf = new_tleaf
Tleaf_K = Tleaf + c.DEG_2_KELVIN
iter += 1
#print(Tleaf)
gsw = gsc * c.GSC_2_GSW
return (An, gsw, et, le_et)
def main(self,
tair,
par,
vpd,
wind,
pressure,
Ca,
doy,
hod,
lai,
rnet=None,
tsoil=None):
"""
Parameters:
----------
tair : float
air temperature (deg C)
par : float
Photosynthetically active radiation (umol m-2 s-1)
vpd : float
Vapour pressure deficit (kPa, needs to be in Pa, see conversion
below)
wind : float
wind speed (m s-1)
pressure : float
air pressure (using constant) (Pa)
Ca : float
ambient CO2 concentration
doy : float
day of day
hod : float
hour of day
lai : floar
leaf area index
Returns:
--------
An : float
net leaf assimilation (umol m-2 s-1)
gs : float
stomatal conductance (mol m-2 s-1)
et : float
transpiration (mol H2O m-2 s-1)
"""
F = FarquharC3(peaked_Jmax=self.peaked_Jmax,
peaked_Vcmax=self.peaked_Vcmax,
model_Q10=self.model_Q10,
gs_model=self.gs_model)
PM = PenmanMonteith()
An = np.zeros(2) # sunlit, shaded
Anc = np.zeros(2) # sunlit, shaded
Anj = np.zeros(2) # sunlit, shaded
gsc = np.zeros(2) # sunlit, shaded
et = np.zeros(2) # sunlit, shaded
Tcan = np.zeros(2) # sunlit, shaded
lai_leaf = np.zeros(2)
sw_rad = np.zeros(2) # VIS, NIR
XX = np.zeros(2)
(cos_zenith, elevation) = calculate_cos_zenith(doy, p.lat, hod)
sw_rad[c.VIS] = 0.5 * (par * c.PAR_2_SW) # W m-2
sw_rad[c.NIR] = 0.5 * (par * c.PAR_2_SW) # W m-2
# get diffuse/beam frac, just use VIS as the answer is the same for NIR
(diffuse_frac, direct_frac) = spitters(doy, sw_rad[0], cos_zenith)
(qcan, apar, lai_leaf, kb,
gradis) = calculate_absorbed_radiation(self.p, par, cos_zenith, lai,
direct_frac, diffuse_frac, doy,
sw_rad, tair, tsoil)
# Calculate scaling term to go from a single leaf to canopy,
# see Wang & Leuning 1998 appendix C
scalex = calc_leaf_to_canopy_scalar(lai, kb=kb, kn=p.kn)
if lai_leaf[0] < 1.e-3: # to match line 336 of CABLE radiation
scalex[0] = 0.
if np.sum(sw_rad) < c.RAD_THRESH:
scalex[0] = 0.0
#scalex[1] = 0.0
# Is the sun up?
#print(doy, hod, elevation, par)
yes = True
if yes:
#if elevation > 0.0 and par > 50.:
# sunlit / shaded loop
for ileaf in range(2):
# initialise values of Tleaf, Cs, dleaf at the leaf surface
dleaf = vpd
Cs = Ca
Tleaf = tair
Tleaf_K = Tleaf + c.DEG_2_KELVIN
iter = 0
while True:
if scalex[ileaf] > 0.:
(An[ileaf],
gsc[ileaf]) = F.photosynthesis(p,
Cs=Cs,
Tleaf=Tleaf_K,
Par=apar[ileaf],
vpd=dleaf,
scalex=scalex[ileaf])
else:
An[ileaf] = 0.0
gsc[ileaf] = 0.0
# Calculate new Tleaf, dleaf, Cs
(new_tleaf, et[ileaf], le_et, gbH,
gw) = self.calc_leaf_temp(p,
PM,
Tleaf,
tair,
gsc[ileaf],
None,
vpd,
pressure,
wind,
rnet=qcan[ileaf],
lai=lai_leaf[ileaf],
gradis=gradis[ileaf])
gbc = gbH * c.GBH_2_GBC
if gbc > 0.0 and An[ileaf] > 0.0:
Cs = Ca - An[ileaf] / gbc # boundary layer of leaf
else:
Cs = Ca
if np.isclose(et[ileaf], 0.0) or np.isclose(gw, 0.0):
dleaf = vpd
else:
dleaf = (et[ileaf] * pressure / gw) * c.PA_2_KPA # kPa
if dleaf < 0.05:
dleaf = 0.05
# Check for convergence...?
if math.fabs(Tleaf - new_tleaf) < 0.02:
Tcan[ileaf] = Tleaf
break
if iter > self.iter_max:
#raise Exception('No convergence: %d' % (iter))
An[ileaf] = 0.0
gsc[ileaf] = 0.0
et[ileaf] = 0.0
break
# Update temperature & do another iteration
Tleaf = new_tleaf
Tleaf_K = Tleaf + c.DEG_2_KELVIN
Tcan[ileaf] = Tleaf
"""
# Update leaf surface vapour pressure deficit:
tetena = 6.106
tetenb = 17.27
tetenc = 237.3
TFRZ = 273.15
Tair_K = tair + c.DEG_2_KELVIN
# d(es)/dT (Pa/K)
a1 = tetena * tetenb * tetenc
a2 = ((Tair_K - TFRZ) + tetenc)**2
a3 = np.exp(tetenb * \
(Tair_K-TFRZ) / ((Tair_K-TFRZ) + tetenc))
dsatdk = 100.0 * a1 / a2 * a3 * c.PA_TO_KPA
dleafx = vpd + dsatdk * (Tleaf_K - Tair_K)
"""
iter += 1
return (An, et, Tcan, apar, lai_leaf)
def main(self, tair, par, vpd, wind, pressure, Ca, rnet=None):
"""
Parameters:
----------
tair : float
air temperature (deg C)
par : float
Photosynthetically active radiation (umol m-2 s-1)
vpd : float
Vapour pressure deficit (kPa, needs to be in Pa, see conversion
below)
wind : float
wind speed (m s-1)
pressure : float
air pressure (using constant) (Pa)
Ca : float
ambient CO2 concentration
Returns:
--------
An : float
net leaf assimilation (umol m-2 s-1)
gs : float
stomatal conductance (mol m-2 s-1)
et : float
transpiration (mol H2O m-2 s-1)
"""
F = FarquharC3(theta_J=0.85, peaked_Jmax=True, peaked_Vcmax=True,
model_Q10=True, gs_model=self.gs_model,
gamma=self.gamma, g0=self.g0,
g1=self.g1, D0=self.D0, alpha=self.alpha)
P = PenmanMonteith(self.leaf_width, self.SW_abs)
# set initialise values
dleaf = vpd
dair = tair
Cs = Ca
Tleaf = tair
Tleaf_K = Tleaf + c.DEG_2_KELVIN
#print "Start: %.3f %.3f %.3f" % (Cs, Tleaf, dleaf)
#print
iter = 0
while True:
(An, gsc, Ci) = F.calc_photosynthesis(Cs=Cs, Tleaf=Tleaf_K, Par=par,
Jmax25=self.Jmax25,
Vcmax25=self.Vcmax25,
Q10=self.Q10, Eaj=self.Eaj,
Eav=self.Eav,
deltaSj=self.deltaSj,
deltaSv=self.deltaSv,
Rd25=self.Rd25, Hdv=self.Hdv,
Hdj=self.Hdj, vpd=dleaf)
# Calculate new Tleaf, dleaf, Cs
(new_tleaf, et,
le_et, gbH, gw) = self.calc_leaf_temp(P, Tleaf, tair, gsc,
par, vpd, pressure, wind,
rnet=rnet)
gbc = gbH * c.GBH_2_GBC
if gbc > 0.0 and An > 0.0:
Cs = Ca - An / gbc # boundary layer of leaf
else:
Cs = Ca
if math.isclose(et, 0.0) or math.isclose(gw, 0.0):
dleaf = dair
else:
dleaf = (et * pressure / gw) * c.PA_2_KPA # kPa
# Check for convergence...?
if math.fabs(Tleaf - new_tleaf) < 0.02:
break
if iter > self.iter_max:
raise Exception('No convergence: %d' % (iter))
# Update temperature & do another iteration
Tleaf = new_tleaf
Tleaf_K = Tleaf + c.DEG_2_KELVIN
iter += 1
gsw = gsc * c.GSC_2_GSW
if et < 0.0:
raise Exception("ET shouldn't be negative, issue in energy balance")
return (An, gsw, et, le_et, Cs, Ci)
def main(self,
tair,
par,
vpd,
wind,
pressure,
Ca,
doy,
hod,
lat,
lon,
LAI,
rnet=None):
"""
Parameters:
----------
tair : float
air temperature (deg C)
par : float
Photosynthetically active radiation (umol m-2 s-1)
vpd : float
Vapour pressure deficit (kPa, needs to be in Pa, see conversion
below)
wind : float
wind speed (m s-1)
pressure : float
air pressure (using constant) (Pa)
Ca : float
ambient CO2 concentration
doy : float
day of day
hod : float
hour of day
lat : float
latitude
lon : float
longitude
lai : floar
leaf area index
Returns:
--------
An : float
net leaf assimilation (umol m-2 s-1)
gs : float
stomatal conductance (mol m-2 s-1)
et : float
transpiration (mol H2O m-2 s-1)
"""
F = FarquharC3(theta_J=0.85,
peaked_Jmax=True,
peaked_Vcmax=True,
model_Q10=True,
gs_model=self.gs_model,
gamma=self.gamma,
g0=self.g0,
g1=self.g1,
D0=self.D0,
alpha=self.alpha)
P = PenmanMonteith(self.leaf_width, self.SW_abs)
# set initial values
dleaf = vpd
Cs = Ca
Tleaf = tair
Tleaf_K = Tleaf + c.DEG_2_KELVIN
cos_zenith = calculate_cos_zenith(doy, lat, hod)
zenith_angle = np.rad2deg(np.arccos(cos_zenith))
elevation = 90.0 - zenith_angle
# Is the sun up?
if elevation > 0.0 and par > 50.0:
iter = 0
while True:
(An, gsc) = F.photosynthesis(Cs=Cs,
Tleaf=Tleaf_K,
Par=par,
Jmax25=self.Jmax25,
Vcmax25=self.Vcmax25,
Q10=self.Q10,
Eaj=self.Eaj,
Eav=self.Eav,
deltaSj=self.deltaSj,
deltaSv=self.deltaSv,
Rd25=self.Rd25,
Hdv=self.Hdv,
Hdj=self.Hdj,
vpd=dleaf)
# Calculate new Tleaf, dleaf, Cs
(new_tleaf, et, le_et, gbH,
gw) = self.calc_leaf_temp(P,
Tleaf,
tair,
gsc,
par,
vpd,
pressure,
wind,
rnet=rnet)
gbc = gbH * c.GBH_2_GBC
if gbc > 0.0 and An > 0.0:
Cs = Ca - An / gbc # boundary layer of leaf
else:
Cs = Ca
if np.isclose(et, 0.0) or np.isclose(gw, 0.0):
dleaf = vpd
else:
dleaf = (et * pressure / gw) * c.PA_2_KPA # kPa
# Check for convergence...?
if math.fabs(Tleaf - new_tleaf) < 0.02:
break
if iter > self.iter_max:
#raise Exception('No convergence: %d' % (iter))
An = 0.0
gsc = 0.0
et = 0.0
break
# Update temperature & do another iteration
Tleaf = new_tleaf
Tleaf_K = Tleaf + c.DEG_2_KELVIN
iter += 1
an_canopy = An * LAI
gsw_canopy = gsc * c.GSC_2_GSW * LAI
et_canopy = et * LAI
tcanopy = Tleaf
else:
an_canopy = 0.0
gsw_canopy = 0.0
et_canopy = 0.0
tcanopy = tair
return (an_canopy, gsw_canopy, et_canopy, tcanopy)
def main(self,
tair,
par,
vpd,
wind,
pressure,
Ca,
doy,
hod,
lai,
rnet=None):
"""
Parameters:
----------
tair : float
air temperature (deg C)
par : float
Photosynthetically active radiation (umol m-2 s-1)
vpd : float
Vapour pressure deficit (kPa, needs to be in Pa, see conversion
below)
wind : float
wind speed (m s-1)
pressure : float
air pressure (using constant) (Pa)
Ca : float
ambient CO2 concentration
doy : float
day of day
hod : float
hour of day
lat : float
latitude
lon : float
longitude
lai : floar
leaf area index
Returns:
--------
An : float
net leaf assimilation (umol m-2 s-1)
gs : float
stomatal conductance (mol m-2 s-1)
et : float
transpiration (mol H2O m-2 s-1)
"""
F = FarquharC3(peaked_Jmax=self.peaked_Jmax,
peaked_Vcmax=self.peaked_Vcmax,
model_Q10=self.model_Q10,
gs_model=self.gs_model)
PM = PenmanMonteith()
# set initial values
dleaf = vpd
Cs = Ca
Tleaf = tair
Tleaf_K = Tleaf + c.DEG_2_KELVIN
(cos_zenith, elevation) = calculate_cos_zenith(doy, p.lat, hod)
# Calculate big-leaf scaling term to go from a single leaf to canopy
fpar = calc_leaf_to_canopy_scalar(lai, k=p.k, big_leaf=True)
# Is the sun up?
if elevation > 0.0 and par > 50.0:
iter = 0
while True:
# Scale fractional PAR absorption at plant projective area level
# (FPAR) to fractional absorption at leaf level (APAR)
# Eqn 4, Haxeltine & Prentice 1996a
apar = par * fpar
(An, gsc) = F.photosynthesis(self.p,
Cs=Cs,
Tleaf=Tleaf_K,
Par=apar,
vpd=dleaf)
# Calculate new Tleaf, dleaf, Cs
(new_tleaf, et, le_et, gbH,
gw) = self.calc_leaf_temp(self.p,
PM,
Tleaf,
tair,
gsc,
par,
vpd,
pressure,
wind,
rnet=rnet)
gbc = gbH * c.GBH_2_GBC
if gbc > 0.0 and An > 0.0:
Cs = Ca - An / gbc # boundary layer of leaf
else:
Cs = Ca
if np.isclose(et, 0.0) or np.isclose(gw, 0.0):
dleaf = vpd
else:
dleaf = (et * pressure / gw) * c.PA_2_KPA # kPa
# Check for convergence...?
if math.fabs(Tleaf - new_tleaf) < 0.02:
break
if iter > self.iter_max:
#raise Exception('No convergence: %d' % (iter))
An = 0.0
gsc = 0.0
et = 0.0
break
# Update temperature & do another iteration
Tleaf = new_tleaf
Tleaf_K = Tleaf + c.DEG_2_KELVIN
iter += 1
an_canopy = An
gsw_canopy = gsc * c.GSC_2_GSW
et_canopy = et
tcanopy = Tleaf
else:
an_canopy = 0.0
gsw_canopy = 0.0
et_canopy = 0.0
tcanopy = tair
return (an_canopy, gsw_canopy, et_canopy, tcanopy)
def main(self,
tair,
par,
vpd,
wind,
pressure,
Ca,
doy,
hod,
lat,
lon,
lai,
rnet=None):
"""
Parameters:
----------
tair : float
air temperature (deg C)
par : float
Photosynthetically active radiation (umol m-2 s-1)
vpd : float
Vapour pressure deficit (kPa, needs to be in Pa, see conversion
below)
wind : float
wind speed (m s-1)
pressure : float
air pressure (using constant) (Pa)
Ca : float
ambient CO2 concentration
doy : float
day of day
hod : float
hour of day
lat : float
latitude
lon : float
longitude
lai : floar
leaf area index
Returns:
--------
An : float
net leaf assimilation (umol m-2 s-1)
gs : float
stomatal conductance (mol m-2 s-1)
et : float
transpiration (mol H2O m-2 s-1)
"""
F = FarquharC3(theta_J=0.85,
peaked_Jmax=True,
peaked_Vcmax=True,
model_Q10=True,
gs_model=self.gs_model,
gamma=self.gamma,
g0=self.g0,
g1=self.g1,
D0=self.D0,
alpha=self.alpha)
P = PenmanMonteith(self.leaf_width, self.SW_abs)
An = np.zeros(2) # sunlit, shaded
gsc = np.zeros(2) # sunlit, shaded
et = np.zeros(2) # sunlit, shaded
Tcan = np.zeros(2) # sunlit, shaded
cos_zenith = calculate_solar_geometry(doy, hod, lat, lon)
zenith_angle = np.rad2deg(np.arccos(cos_zenith))
elevation = 90.0 - zenith_angle
sw_rad = par * c.PAR_2_SW # W m-2
# get diffuse/beam frac
(diffuse_frac, direct_frac) = spitters(doy, sw_rad, cos_zenith)
# Is the sun up?
if elevation > 0.0 and par > 50.0:
(apar, lai_leaf, kb) = calculate_absorbed_radiation_big_leaf(
par, cos_zenith, lai, direct_frac, diffuse_frac)
# Calculate scaling term to go from a single leaf to canopy,
# see Wang & Leuning 1998 appendix C
scalex = calc_leaf_to_canopy_scalar(lai, kb)
# initialise values of Tleaf, Cs, dleaf at the leaf surface
dleaf = vpd
Cs = Ca
Tleaf = tair
Tleaf_K = Tleaf + c.DEG_2_KELVIN
iter = 0
while True:
(An, gsc) = F.photosynthesis(Cs=Cs,
Tleaf=Tleaf_K,
Par=apar,
Jmax25=self.Jmax25,
Vcmax25=self.Vcmax25,
Q10=self.Q10,
Eaj=self.Eaj,
Eav=self.Eav,
deltaSj=self.deltaSj,
deltaSv=self.deltaSv,
Rd25=self.Rd25,
Hdv=self.Hdv,
Hdj=self.Hdj,
vpd=dleaf,
scalex=scalex)
# Calculate new Tleaf, dleaf, Cs
(new_tleaf, et, le_et, gbH,
gw) = self.calc_leaf_temp(P,
Tleaf,
tair,
gsc,
apar,
vpd,
pressure,
wind,
rnet=rnet,
lai=lai)
gbc = gbH * c.GBH_2_GBC
if gbc > 0.0 and An > 0.0:
Cs = Ca - An / gbc # boundary layer of leaf
else:
Cs = Ca
if math.isclose(et, 0.0) or math.isclose(gw, 0.0):
dleaf = vpd
else:
dleaf = (et * pressure / gw) * c.PA_2_KPA # kPa
# Check for convergence...?
if math.fabs(Tleaf - new_tleaf) < 0.02:
break
if iter > self.iter_max:
raise Exception('No convergence: %d' % (iter))
# Update temperature & do another iteration
Tleaf = new_tleaf
Tleaf_K = Tleaf + c.DEG_2_KELVIN
Tcan = Tleaf
iter += 1
# scale to canopy: sum contributions from beam and diffuse leaves
an_canopy = An
gsw_canopy = gsc * c.GSC_2_GSW
et_canopy = et
tcanopy = Tleaf
else:
an_canopy = 0.0
gsw_canopy = 0.0
et_canopy = 0.0
tcanopy = tair
return (an_canopy, gsw_canopy, et_canopy, tcanopy)