def absolutehumidityfromRH(Ta, RH):
# convert to masked arrays
RH, WasND = SeriestoMA(RH)
Ta, dummy = SeriestoMA(Ta)
# do the job
VPsat = es(Ta)
vp = RH * VPsat / float(100)
ah = float(1000000) * vp / ((Ta + 273.15) * c.Rv)
# convert back to ndarray if input is not a masked array
if WasND: ah, _ = MAtoSeries(ah)
return ah
def RHfromdewpoint(Td, Ta):
# Relative humidity from dew point temperature
# Ta is the air temperature, C
# Td is the dew point temperature, C
# RH is the relative humidity, %
# convert to masked arrays
Td, WasND = SeriestoMA(Td)
Ta, dummy = SeriestoMA(Ta)
# do the job
RH = 100 * 10**(7.591386 * (Td / (Td + 240.7263) - Ta / (Ta + 240.7263)))
# convert back to ndarray if input is not a masked array
if WasND: RH, _ = MAtoSeries(RH)
return RH
def RHfromspecifichumidity(q, Ta, ps):
# Relative humidity from specific humidity
# q is the specific humidity, kg/kg
# Ta is the air temperature, C
# ps is the pressure, kPa
# RH is the relative humidity, %
# convert to masked arrays
q, WasND = SeriestoMA(q)
Ta, dummy = SeriestoMA(Ta)
# do the job
VPsat = es(Ta)
RH = float(100) * q * (c.Md / c.Mv) * ps / VPsat
# convert back to ndarray if input is not a masked array
if WasND: RH, _ = MAtoSeries(RH)
return RH
def RHfromabsolutehumidity(Ah, Ta):
# Relative humidity from absolute humidity
# Ta is the air temperature, C
# Ah is the absolute humidity, g/m3
# RH is the relative humidity, %
# convert to masked arrays
Ah, WasND = SeriestoMA(Ah)
Ta, dummy = SeriestoMA(Ta)
# do the job
VPsat = es(Ta)
#vp = Ah * ((Ta+273.15)*c.Rv)/float(1000000)
vp = vapourpressure(Ah, Ta)
RH = float(100) * vp / VPsat
# convert back to ndarray if input is not a masked array
if WasND: RH, _ = MAtoSeries(RH)
return RH
def Fc_umolpm2psfrommgCO2pm2ps(Fc_mgpm2ps):
"""
Convert Fc in units of mg/m2/s to units of umol/m2/s
Usage:
Fc_umolpm2ps = Fc_umolpm2psfrommgCO2pm2ps(Fc_mgpm2ps)
where:
Fc_mgpm2ps (input) - CO2 flux in units of mg/m2/s
Returns the CO2 flux in units of umol/m2/s
"""
# convert to masked array
Fc_mgpm2ps, WasND = SeriestoMA(Fc_mgpm2ps)
# do the job
Fc_umolpm2ps = Fc_mgpm2ps / c.Mco2
# convert back to ndarray if input is not a masked array
if WasND: Fc_umolpm2ps, _ = MAtoSeries(Fc_umolpm2ps)
return Fc_umolpm2ps
def h2o_gpm3frommmolpmol(h_mmpm, T, p):
"""
Convert H2O concentration units of mmol/mol to g/m3.
Usage:
H2O_gpm3 = h2o_gpm3frommmolpmol(H2O_mmolpmol, T, p)
where
H2O_mmolpmol (input) - H2O concentration, mmol/mol
T (input) - air temperature, C
p (input) - air pressure, kPa
Returns the H2O concentration in g/m3.
"""
# convert to masked arrays
h_mmpm, WasND = SeriestoMA(h_mmpm)
T, dummy = SeriestoMA(T)
p, dummy = SeriestoMA(p)
# do the job
h_gpm3 = (c.Mv * h_mmpm * p * 1000) / (c.R * (T + 273.15))
# convert to ndarray if input is not a masked array
if WasND: h_gpm3, _ = MAtoSeries(h_gpm3)
return h_gpm3
def h2o_mmolpmolfromgpm3(h_gpm3, T, p):
"""
Convert H2O concentration units of g/m3 to mmol/mol.
Usage:
H2O_mmolpmol = h2o_mmolpmolfromgpm3(H2O_gpm3, T, p)
where
H2O_gpm3 (input) - H2O concentration, g/m3
T (input) - air temperature, C
p (input) - air pressure, kPa
Returns the H2O concentration in mmol/mol.
"""
# convert to masked arrays
h_gpm3, WasND = SeriestoMA(h_gpm3)
T, dummy = SeriestoMA(T)
p, dummy = SeriestoMA(p)
# do the job
h_mmpm = (h_gpm3 / c.Mv) * c.R * (T + 273.15) / (p * 1000)
# convert to ndarray if input is not a masked array
if WasND: h_mmpm, _ = MAtoSeries(h_mmpm)
return h_mmpm
def co2_umolpm3fromppm(c_ppm, T, p):
"""
Convert CO2 concentration units of umol/mol (ppm) to umol/m3
Usage:
CO2_umolpm3 = co2_umolpm3fromppm(CO2_ppm, T, p)
where
CO2_ppm (input) - CO2 concentration, umol/mol
T (input) - air temperature, C
p (input) - air pressure, kPa
Returns the CO2 concentration in umol/m3.
"""
# convert to masked array if required
c_ppm, WasND = SeriestoMA(c_ppm)
T, dummy = SeriestoMA(T)
T = T + 273.15 # temperature in K
p, dummy = SeriestoMA(p)
p = p * float(1000) # pressure in Pa
# do the job
c_umolpm3 = c_ppm * p / (c.R * T)
# convert back to ndarray if input is not a masked array
if WasND: c_umolpm3, _ = MAtoSeries(c_umolpm3)
return c_umolpm3
def co2_ppmfrommgCO2pm3(c_mgpm3, T, p):
"""
Convert CO2 concentration units of mgCO2/m3 to umol/mol (ppm)
Usage:
CO2_ppm = co2_ppmfrommgCO2pm3(CO2_mgpm3, T, p)
where
CO2_mgpm3 (input) - CO2 concentration, mgCO2/m3
T (input) - air temperature, C
p (input) - air pressure, kPa
Returns the CO2 concentration in ppm.
"""
# convert to masked array if required
c_mgpm3, WasND = SeriestoMA(c_mgpm3)
T, dummy = SeriestoMA(T)
T = T + 273.15 # temperature in K
p, dummy = SeriestoMA(p)
p = p * float(1000) # pressure in Pa
# do the job
c_ppm = (c_mgpm3 / c.Mco2) * c.R * T / p
# convert back to ndarray if input is not a masked array
if WasND: c_ppm, _ = MAtoSeries(c_ppm)
return c_ppm
