Exemplo n.º 1
0
    def __call__(self, atmosphere):
        if self._lapse_cache is not None:
            return self._lapse_cache

        T = atmosphere['T'][0, :]
        p = atmosphere['plev'][:]
        phlev = atmosphere['phlev'][:]

        # Use short formula symbols for physical constants.
        g = constants.earth_standard_gravity
        L = constants.heat_of_vaporization
        Rd = constants.specific_gas_constant_dry_air
        Rv = constants.specific_gas_constant_water_vapor
        Cp = constants.isobaric_mass_heat_capacity_dry_air

        gamma_d = g / Cp  # dry lapse rate

        w_saturated = vmr2mixing_ratio(saturation_pressure(T) / p)

        gamma_m = (gamma_d * ((1 + (L * w_saturated) / (Rd * T)) /
                              (1 + (L**2 * w_saturated) / (Cp * Rv * T**2))
                              )
                   )
        lapse = interp1d(np.log(p), gamma_m, fill_value='extrapolate')(
            np.log(phlev[:-1]))

        if self.fixed:
            self._lapse_cache = lapse

        return lapse
Exemplo n.º 2
0
    def entrain(self, T_con_adiabat, atmosphere):
        # Physical constants.
        L = constants.heat_of_vaporization
        Rv = constants.specific_gas_constant_water_vapor
        Cp = constants.isobaric_mass_heat_capacity_dry_air

        # Abbreviated variables references.
        T_rad = atmosphere["T"][0, :]
        p = atmosphere["plev"][:]
        phlev = atmosphere["phlev"][:]

        # Zero-buoyancy plume entrainment.
        k_ttl = np.max(np.where(T_con_adiabat >= T_rad))
        r_saturated = np.ones_like(p) * 0.0
        r_saturated[: k_ttl + 1] = vmr2mixing_ratio(
            saturation_pressure(T_con_adiabat[: k_ttl + 1]) / p[: k_ttl + 1]
        )
        q_saturated = r_saturated / (1 + r_saturated)
        q_saturated_hlev = interp1d(np.log(p), q_saturated, fill_value="extrapolate")(
            np.log(phlev[:-1])
        )

        z = atmosphere["z"][0, :]
        zhlev = interp1d(np.log(p), z, fill_value="extrapolate")(np.log(phlev[:-1]))
        dz_lapse = np.hstack((np.array([z[0] - zhlev[0]]), np.diff(z)))

        RH = vmr2relative_humidity(atmosphere["H2O"][0, :], p, atmosphere["T"][0, :])
        RH = np.where(RH > 1, 1, RH)

        RH_hlev = interp1d(np.log(p), RH, fill_value="extrapolate")(np.log(phlev[:-1]))

        entr = self.entr
        deltaT = np.ones_like(p) * 0.0
        k_cb = np.max(np.where(p >= 96000.0))

        # First calculate temperature deviation based on Eq. (4) in Singh&O'Gorman (2013)
        deltaT[k_cb:] = (
            1
            / (1 + L / (Rv * T_con_adiabat[k_cb:] ** 2) * L * q_saturated[k_cb:] / Cp)
            * np.cumsum(
                entr
                / zhlev[k_cb:]
                * (1 - RH_hlev[k_cb:])
                * L
                / Cp
                * q_saturated_hlev[k_cb:]
                * dz_lapse[k_cb:]
            )
        )
        # Second weight deltaT obtained from above by a height-dependent coefficient,
        # as described in Eq. (4) in Bao et al. (submitted).
        if np.any(T_con_adiabat > T_rad):
            k_ttl = np.max(np.where(T_con_adiabat > T_rad))
            z_ttl = z[k_ttl]
            z_cb = z[k_cb]

            f = lambda x: x ** (2.0 / 3.0)
            weight = f((z[k_cb : k_ttl + 1] - z_ttl) / (z_cb - z_ttl))
            deltaT[k_cb : k_ttl + 1] = deltaT[k_cb : k_ttl + 1] * weight
            deltaT[k_ttl + 1 :] = 0

        self.create_variable(
            name="entrainment_cooling",
            dims=("time", "plev"),
            data=deltaT.reshape(1, -1),
        )

        return T_con_adiabat - deltaT
Exemplo n.º 3
0
 def test_vmr2mixing_ratio(self):
     """Test conversion of VMR to mass mixing ratio."""
     w = physics.vmr2mixing_ratio(0.04)
     assert np.isclose(w, 0.025915747437955664)
#%% PIC 2140

# PIC, it seems HC is actially calculating the specific humidity with his calculation (instead of mixing ratio as he thinks), HOWEVER, it does not make a difference
dfPIC2m10min=pd.read_csv('/Volumes/gfi_snowiso/Vapour/2018/processed_data_combined/EG18_level180cm.txt',index_col=0,parse_dates=True,na_values=['NAN'])
dfPIC2m10min=dfPIC2m10min.loc[pd.to_datetime('2018-06-11 12:00'):pd.to_datetime('2018-07-01 21:00'),:] #only use specific period where the new 2140 was measuring at 2m only
dfPIC2m10min.loc[:,'shum']=dfPIC2m10min.H2O*1e-6*B #you could also use deltatogas function, dfPIC2m.mr is g/kg air --> specific humidity


#interpolate to 1h mean
dfPIC2m=dfPIC2m10min.resample('1h').mean()



# CHECK what typhon does --> Conclusion: What I have done is pretty close to what typhon would do, so no need to change my code again
# see what typhon makes from the volume mixing ratio (ppmv) 
dfPIC2m.loc[:,'ty_mr']=ty.vmr2mixing_ratio(dfPIC2m.H2O*1e-6)*1e3 # to get g/kg

dfPIC2m.loc[:,'ty_mr_from_mr']=ty.specific_humidity2mixing_ratio(dfPIC2m.shum/1000)*1000  #assume HC formula is actually for spec humidity and not for mr
dfPIC2m.loc[:,'ty_spechum']=ty.vmr2specific_humidity(dfPIC2m.H2O*1e-6)*1e3

# combine to get rid of nan
dfcombiPIC=pd.concat([dfPIC2m.shum,geus_h.spechum],axis=1).dropna() # dfcombiPIC dfPIC2m.shum in g/kg and dfgeus.spechum in g/kg 


#%% calibration of Picarro 2140 EASTGRIP 2019

plt.figure()
plt.plot(dfPIC2m10min.shum,label='PIC original',Marker='s',LineStyle='-',color='darkred',MarkerSize=2)
plt.plot(dfPIC2m.shum,label='PIC resampled',Marker='*',LineStyle=':',color='blue',MarkerSize=2)
plt.plot(geus_h.spechum,label='geus',Marker='s',LineStyle='--',color='orange',MarkerSize=2)
plt.legend()