def mieMonteCarlo(wavelength=450 * 10**-9,
r=300 * 10**-9,
Vs=0.1,
nParticle=1.46,
nMedium=1.36):
"""
Calculate the scattering parameters relevant for monte carlo simulation.
Needs pymiecoated: https://code.google.com/p/pymiecoated/
These are calculate scattering coefficient [1/cm] and anisotropy factor for given:
Args
____
wavelength:
wavelength of the incident light [m]
r:
radius of the particle [m]
Vs:
volume fraction of scattering particles
nParticle:
refractive index of the particle that the light wave is scattered on
(default value is the refractive index of collagen)
nMedium:
refractive index of the surronding medium (default is that of colonic
mucosal tissue)
Returns:
____
{'us', 'g'}:
scattering coefficient us [1/m] and anisotropy factor g
TODO:
_____
Additional input parameter specifying a FWHM for the wavelength to simulate the
scattering for a broad filter
"""
# create derived parameters
sizeParamter = 2 * math.pi * r / wavelength
nRelative = nParticle / nMedium
#%% execute mie and create derived parameters
mie = Mie(x=sizeParamter, m=complex(nRelative,
0.0)) # 0.0 complex for no attenuation
A = math.pi * r**2 # geometrical cross sectional area
cs = mie.qsca() * A # scattering cross section
us = Vs / (4 / 3 * r**3 * math.pi) * cs # scattering coefficient [m⁻1]
return {'us': us, 'g': mie.asy()}
def test_p11():
'''
Test to plot a phase function, and make sure it is normalized properly
'''
alam = 500*u.nm
r = 10*u.micron
x = (2*math.pi * r / alam).to('1').value
num_theta = 1000
theta = hbt.frange(0,math.pi, num_theta)
p11 = np.zeros(num_theta)
phase = math.pi - theta # Theta is scattering angle
nm_refract = complex(1.5, 0.1)
mie = Mie(x=x, m=nm_refract) # This is only for one x value, not an ensemble
qext = mie.qext()
qsca = mie.qsca()
qbak = mie.qb()
for i,theta_i in enumerate(theta):
(S1, S2) = mie.S12(np.cos(theta_i)) # Looking at code, S12 returns tuple (S1, S2). S3, S4 are zero for sphere.
k = 2*pi / alam
sigma = pi * r**2 * qsca # For (S1,S2) -> P11: p. 2 of http://nit.colorado.edu/atoc5560/week8.pdf
# qsca = scattering efficiency. sigma = scattering cross-section
p11[i] = 4 * pi / (k**2 * sigma) * ( (np.abs(S1))**2 + (np.abs(S2))**2) / 2
# Check the normalization of the resulting phase function.
dtheta = theta[1] - theta[0]
norm = np.sum(p11 * np.sin(theta) * dtheta) # This should be 2, as per TPW04 eq. 4
print('Normalized integral = {:.2f}'.format(norm))
plt.plot(phase*hbt.r2d, p11)
plt.yscale('log')
plt.title('X = {:.1f}'.format(x))
plt.xlabel('Phase angle')
plt.ylabel('$P_{11}$')
plt.show()
p = plt.plot([0,10], [0,10])
currentAxis = plt.gca()
currentAxis.add_patch(Rectangle((0.5, 0.5), 0.7, 0.7,alpha=0.1, color='red'))
plt.text(1, 1, 'Danger')
plt.show()
def calc_Q_ext(
x,
m,
type,
y=[],
m2=[],
):
"""
Calculate Q_ext. Can be dry, coated in water, or deliquescent with water
:param x: dry particle size parameter
:param m: complex index of refraction for particle
:param y: wet particle size parameter
:param m2: complex index of refraction for water
:return: Q_ext
:return: calc_type: how was particle treated? (e.g. dry, coated)
"""
from pymiecoated import Mie
import numpy as np
# Coated aerosol (insoluble aerosol that gets coated as it takes on water)
if type == 'coated':
if (y != []) & (m2 != []):
all_particles_coat = [
Mie(x=x[i], m=m, y=y[i], m2=m2) for i in np.arange(len(x))
]
Q = np.array([particle.qext() for particle in all_particles_coat])
else:
raise ValueError("type = coated, but y or m2 is empty []")
# Calc extinction efficiency for dry aerosol (using r_md!!!! NOT r_m)
# if singular, then type == complex, else type == array
elif type == 'dry':
all_particles_dry = [Mie(x=x, m=m) for x_i in x]
Q = np.array([particle.qext() for particle in all_particles_dry])
# deliquescent aerosol (solute disolves as it takes on water)
elif type == 'deliquescent':
all_particles_del = [Mie(x=x[i], m=m[i]) for i in np.arange(len(x))]
Q = np.array([particle.qext() for particle in all_particles_del])
return Q
def mie_analytical(radii,
vacuum_wavelength,
out_param='qsca',
cross_section=False,
**mie_params):
"""Returns the analytical values for the efficiencies using the
`pymiecoated`-package. Pass additional parameters to the `Mie`-class
using the `mie_params`, e.g. by writing `m=1.52` to pass the refractive
index of the sphere. `out_param` can be each method of the `Mie`-class,
e.g. 'qext', 'qsca' or 'qabs'. Use `cross_section=True` to return the
related cross section instead of the efficiency."""
from pymiecoated import Mie
import collections
_is_iter = True
if not isinstance(radii, collections.Iterable):
_is_iter = False
radii = np.array([radii])
out_vals = []
for radius in radii:
x = 2 * np.pi * radius / vacuum_wavelength
mie = Mie(x=x, **mie_params)
out_func = getattr(mie, out_param)
out_val = out_func()
if cross_section:
out_val = np.pi * np.square(radius) * out_val
out_vals.append(out_val)
if not _is_iter:
return out_vals[0]
return np.array(out_vals)
def mieMonteCarlo(wavelength = 450*10**-9, r = 300*10**-9, Vs = 0.1, nParticle = 1.46, nMedium = 1.36):
"""
Calculate the scattering parameters relevant for monte carlo simulation.
Needs pymiecoated: https://code.google.com/p/pymiecoated/
These are calculate scattering coefficient [1/cm] and anisotropy factor for given:
Args
____
wavelength:
wavelength of the incident light [m]
r:
radius of the particle [m]
Vs:
volume fraction of scattering particles
nParticle:
refractive index of the particle that the light wave is scattered on
(default value is the refractive index of collagen)
nMedium:
refractive index of the surronding medium (default is that of colonic
mucosal tissue)
Returns:
____
{'us', 'g'}:
scattering coefficient us [1/m] and anisotropy factor g
TODO:
_____
Additional input parameter specifying a FWHM for the wavelength to simulate the
scattering for a broad filter
"""
# create derived parameters
sizeParamter = 2 * math.pi * r / wavelength
nRelative = nParticle / nMedium
#%% execute mie and create derived parameters
mie = Mie(x=sizeParamter, m=complex(nRelative,0.0)) # 0.0 complex for no attenuation
A = math.pi * r**2 # geometrical cross sectional area
cs = mie.qsca() * A # scattering cross section
us = Vs / (4/3 * r**3 * math.pi) * cs # scattering coefficient [m⁻1]
return {'us': us, 'g': mie.asy()}
def mie(self, a=0.3):
qsca = []
qabs = []
qext = []
mie = Mie()
wl = np.arange(0.21, 1.2, .001)
n_cu, k_cu, n_w, k_w = self.intp_data.intpdata(wl)
for i in range(len(wl)):
mie.x = a * 2 * np.pi / wl[i]
temp_n = n_cu[i] / n_w[i]
temp_k = k_cu[i] + k_w[i]
'print temp_n, temp_k'
mie.m = complex(temp_n, temp_k)
'''
mie.y = 3 * a * 2*np.pi/wl[i];
mie.m2 = complex(n_w[i], k_w[i]);
'''
qsca.append(mie.qsca())
qabs.append(mie.qabs())
qext.append(mie.qb())
return wl, qsca, qabs, qext
def mie(self, a = 0.3):
qsca = [];
qabs = [];
qext = [];
mie = Mie();
wl = np.arange(0.21, 1.2, .001);
n_cu, k_cu, n_w, k_w = self.intp_data.intpdata(wl);
for i in range(len(wl)):
mie.x = a * 2*np.pi/wl[i];
temp_n = n_cu[i]/n_w[i];
temp_k = k_cu[i]+k_w[i];
'print temp_n, temp_k'
mie.m = complex(temp_n, temp_k);
'''
mie.y = 3 * a * 2*np.pi/wl[i];
mie.m2 = complex(n_w[i], k_w[i]);
'''
qsca.append(mie.qsca());
qabs.append(mie.qabs());
qext.append(mie.qb());
return wl, qsca, qabs, qext;
if (1 == 1):
extb = np.zeros((len(sbin) - 1, len(wavmin)))
ssab = np.zeros((len(sbin) - 1, len(wavmin)))
asyb = np.zeros((len(sbin) - 1, len(wavmin)))
for nband in range(len(wavmin)):
specbin = np.linspace(wavmin[nband], wavmax[nband], 50)
for db in range(len(Deff)):
qext = 0.
ssa = 0.
asy = 0.
for wl in range(len(specbin)):
sp = np.pi * Deff[db] / specbin[wl]
k = kint(specbin[wl])
nd = ndint(specbin[wl])
mie = Mie(x=sp, m=complex(nd, k))
qext = qext + mie.qsca() + mie.qabs()
qabs = mie.qabs()
ssa = ssa + mie.qsca() / (mie.qsca() + mie.qabs())
asy = asy + mie.asy()
extb[db, nband] = extb[db, nband] + (qext / len(specbin)) / (
2. / 3. * rhop * Deff[db] * 1E-6)
#cross section in m2/g
ssab[db, nband] = ssab[db, nband] + (ssa / len(specbin))
asyb[db, nband] = asyb[db, nband] + (asy / len(specbin))
if (1 == 2):
#method 2(slower) double integration /more precise prblem mie return nan for extrem coarse particles
# calculate the mie parameter for every diameter of the range, averaged on spectral band
extb = np.zeros((len(sbin) - 1, len(wavmin)))
# n_murk = complex(1.53, 0.007) - this is for 550 nm
# n_store += [n_murk]
# complex indices of refraction (n = n(bar) - ik) at ceilometer wavelength (910 nm) Hesse et al 1998
# n_water, _ = linear_interpolate_n('water', lam)
# calculate size parameter for dry and wet
x_dry = (2.0 * np.pi * r_md) / lam
# x_store += [x_dry]
# calculate swollen index of refraction using MURK
# n_swoll = CIR_Hanel(n_water, n_murk, r_md, r_m)
# Calc extinction efficiency for dry aerosol (using r_md!!!! NOT r_m)
for aer_i, n_i in n_aerosol.iteritems():
all_particles_dry = [Mie(x=x_i, m=n_i) for x_i in x_dry]
Q_dry[aer_i][lam_str] = np.array(
[particle.qext() for particle in all_particles_dry])
# once 905 has been calcualted
for aer_i, value in Q_dry.iteritems():
for lam_str_i in ceil_lambda_str:
Q_diff[aer_i][
lam_str_i] = Q_dry[aer_i][lam_str_i] - Q_dry[aer_i]['905']
Q_ratio[aer_i][
lam_str_i] = Q_dry[aer_i][lam_str_i] / Q_dry[aer_i]['905']
# qsca, qabs are alternatives to qext
# -----------------------------------------------
# Post processing, saving and plotting
def main():
import numpy as np
from pymiecoated import Mie
import matplotlib.pyplot as plt
# -------------------------------------------------------------------
# Setup
# setup
ceil_lambda = [0.905e-06] # [m]
# ceil_lambda = np.arange(0.69e-06, 1.19e-06, 0.05e-06) # [m]
# ceil_lambda = np.arange(0.90e-06, 0.91e-06, 0.05e-08) # [m]
# ceil_lambda = np.array(([0.90e-06, 0.91e-06, 0.92e-06])) # [m]
B = 0.14
RH_crit = 0.38
# directories
savedir = '/home/nerc/Documents/MieScatt/figures/'
datadir = '/home/nerc/Documents/MieScatt/data/'
# aerosol with relative volume - average from the 4 Haywood et al 2008 flights
rel_vol = {
'Ammonium sulphate': 0.295,
'Ammonium nitrate': 0.325,
'Organic carbon': 0.38
}
# all the aerosol types
all_aer_order = [
'Ammonium sulphate', 'Ammonium nitrate', 'Organic carbon', 'Biogenic',
'Generic NaCl', 'Soot', 'MURK'
]
# all_aer = ['ammonium_sulphate', 'ammonium_nitrate', 'organic_carbon', 'biogenic', 'NaCl', 'soot']
all_aer = {
'Ammonium sulphate': 'red',
'Ammonium nitrate': 'orange',
'Organic carbon': [0.05, 0.9, 0.4],
'Biogenic': [0.05, 0.56, 0.85],
'Generic NaCl': 'magenta',
'Soot': 'brown'
}
# all_aer = ['soot']
# create dry size distribution [m]
# r_md_microm = np.arange(0.03, 5.001, 0.001) # .shape() = 4971
# r_md_microm = np.arange(0.000 + step, 1.000 + step, step), when step = 0.005, .shape() = 200
step = 0.005
r_md_microm = np.arange(0.000 + step, 5.000 + step, step)
r_md = r_md_microm * 1.0e-06
# RH array [fraction]
# This gets fixed for each Q iteration (Q needs to be recalculated for each RH used)
RH = 0.8
# densities of MURK constituents # [kg m-3]
# range of densities of org carb is massive (0.625 - 2 g cm-3)
# Haywood et al 2003 use 1.35 g cm-3 but Schkolnik et al., 2006 lit review this and claim 1.1 g cm-3
dens_amm_sulph = 1770
dens_amm_nit = 1720
dens_org_carb = 1100 # NOTE ABOVE
# define array to store Q for each wavelength
Q_dry = []
x_store = []
n_store = []
# save the Q(dry) curve for MURK?
savedata = True
# -----------------------------------------------
# Calculate Q for each lambda
# -----------------------------------------------
# -------------------------------------------------------------------
# Process
# calculate complex index of refraction for MURK species
# output n is complex index of refraction (n + ik)
n_aerosol = calc_n_aerosol(all_aer, ceil_lambda)
# NOTE: Able to use volume in MURK equation instead of mass because, if mass is evenly distributed within a volume
# then taking x of the mass = taking x of the volume.
# after calculating volumes used in MURK, can find relative % and do volume mixing.
# bulk complex index of refraction (CIR) for the MURK species using volume mixing method
n_murk = calc_n_murk(rel_vol, n_aerosol)
n_aerosol['MURK'] = n_murk
all_aer['MURK'] = 'black' # add color for plotting
# n_murk = complex(1.53, 0.007) - this is for 550 nm
n_store += [n_murk]
# complex indices of refraction (n = n(bar) - ik) at ceilometer wavelength (905 nm) Hesse et al 1998
# n_water, _ = linear_interpolate_n('water', lam)
# swell particles using FO method
# rm = np.ma.ones(RH.shape) - (B / np.ma.log(RH_ge_RHcrit))
r_m = 1 - (B / np.log(RH))
r_m2 = np.ma.power(r_m, 1. / 3.)
r_m = np.ma.array(r_md) * r_m2
r_m_microm = r_m * 1.0e06
# calculate size parameter for dry and wet
x_dry = (2.0 * np.pi * r_md) / ceil_lambda
x_store += [x_dry]
x_wet = (2.0 * np.pi * r_m) / ceil_lambda
# calculate swollen index of refraction using MURK
# n_swoll = CIR_Hanel(n_water, n_murk, r_md, r_m)
# Calc extinction efficiency for dry aerosol (using r_md!!!! NOT r_m)
# all_particles_dry = [Mie(x=x_i, m=n_murk) for x_i in x_dry]
# Q_dry += [np.array([particle.qext() for particle in all_particles_dry])]
Q_dry = {}
for key, n_i in n_aerosol.iteritems():
all_particles_dry = [Mie(x=x_i, m=n_i) for x_i in x_dry]
Q_dry[key] = np.array(
[particle.qext() for particle in all_particles_dry])
# qsca, qabs
# -----------------------------------------------
# Post processing, saving and plotting
# -----------------------------------------------
# if running for single 905 nm wavelength, save the calculated Q
if savedata == True:
if type(ceil_lambda) == list:
if ceil_lambda[0] == 0.905e-06:
# save Q curve and radius [m]
np.savetxt(datadir + 'calculated_Q_ext_905nm.csv',
np.transpose(np.vstack((r_md, Q_dry['MURK']))),
delimiter=',',
header='radius,Q_ext')
# plot
fig = plt.figure(figsize=(6, 4))
for aer_i in all_aer_order:
# plot it
plt.semilogx(r_md_microm,
Q_dry[aer_i],
label=aer_i,
color=all_aer[aer_i])
# plt.semilogx(r_md_microm, Q_dry, label='dry murk', color=[0,0,0])
# plt.semilogx(r_m_microm, Q_del, label='deliquescent murk (RH = ' + str(RH) + ')')
# plt.semilogx(r_m_microm, Q_coat, label='coated murk (RH = ' + str(RH) + ')')
# for aer_i, Q_dry_i in Q_dry.iteritems():
#
# # plot it
# plt.semilogx(r_md_microm, Q_dry_i, label=aer_i, color=all_aer[aer_i])
# # plt.semilogx(r_md_microm, Q_dry, label='dry murk', color=[0,0,0])
# # plt.semilogx(r_m_microm, Q_del, label='deliquescent murk (RH = ' + str(RH) + ')')
# # plt.semilogx(r_m_microm, Q_coat, label='coated murk (RH = ' + str(RH) + ')')
# plt.title('lambda = ' + str(ceil_lambda[0]) + 'nm')
plt.xlabel(r'$r_{md} \/\mathrm{[\mu m]}$', labelpad=-10, fontsize=13)
plt.xlim([0.05, 5.0])
plt.ylim([0.0, 5.0])
#plt.xlim([0.01, 0.2])
#plt.ylim([0.0, 0.1])
plt.ylabel(r'$Q_{ext,dry}$', fontsize=13)
plt.legend(fontsize=8, loc='best')
plt.tick_params(axis='both', labelsize=10)
plt.grid(b=True, which='major', color='grey', linestyle='--')
plt.grid(b=True, which='minor', color=[0.85, 0.85, 0.85], linestyle='--')
plt.savefig(savedir + 'Q_ext_manyAer2_' + str(ceil_lambda[0]) + 'nm.png')
print 'data dir is... ' + savedir + 'Q_ext_manyAer_' + str(
ceil_lambda[0]) + 'nm.png'
plt.tight_layout(h_pad=10.0)
plt.close()
# plot the radius
# plot_radius(savedir, r_md, r_m)
print 'END PROGRAM'
d_new = pow1d3(4 / 3 * np.pi / N) * a_eff
#d_new = a_eff / 10
r *= (d_new / d_old)
d_old = d_new
# incident plane wave
Ei = E_inc(E0, kvec, r) # direct incident field at dipoles
alph = polarizability_LDR(d_new, m, kvec) # polarizability of dipoles
A = interaction_A(k, r, alph)
P = scipy.sparse.linalg.gmres(A, Ei)[0]
Cext[ix] = C_ext(k, E0, Ei, P) * (lam / 100)**2 / 100 # Convert to um**2
mie = Mie(x=2 * np.pi * a_eff, m=n)
Cext_mie[ix] = mie.qext() * np.pi * (a_eff / 2)**2 # Convert cross section
del (A)
evlukhin = spec.Spec.loadSpecFromASCII("./reference/sphere_r63nm.txt", ',')
#Cext = numpy.divide(Cext, numpy.max(Cext))
#Cext_mie = numpy.divide(Cext_mie, numpy.max(Cext_mie))
#evlukhin.data = numpy.divide(evlukhin.data, numpy.max(evlukhin.data))
plt.figure(1)
plt.plot(lambda_range, Cext)
plt.plot(evlukhin.wavelengths, evlukhin.data)
plt.plot(lambda_range, Cext_mie)
plt.ylabel("$\sigma_{ext}$, $\mu$m$^2$")
plt.xlabel("wavelength, nm")
def main():
# Read in the mass data for 2016
# Read in RH data for 2016
# convert gases and such into the aerosol particles
# swell the particles based on the CLASSIC scheme stuff
# use Mie code to calculate the backscatter and extinction
# calculate lidar ratio
# plot lidar ratio
# ==============================================================================
# Setup
# ==============================================================================
# which modelled data to read in
model_type = 'UKV'
# directories
maindir = '/home/nerc/Documents/MieScatt/'
datadir = '/home/nerc/Documents/MieScatt/data/'
savedir = maindir + 'figures/LidarRatio/'
# data
wxtdatadir = datadir
massdatadir = datadir
ffoc_gfdir = datadir
# RH data
wxt_inst_site = 'WXT_KSSW'
# data year
year = '2016'
# aerosol particles to calculate (OC = Organic carbon, CBLK = black carbon, both already measured)
# match dictionary keys further down
aer_particles = ['(NH4)2SO4', 'NH4NO3', 'NaCl', 'CORG', 'CBLK']
all_species = ['(NH4)2SO4', 'NH4NO3', 'NaCl', 'CORG', 'CBLK', 'H2O']
# aer names in the complex index of refraction files
aer_names = {
'(NH4)2SO4': 'Ammonium sulphate',
'NH4NO3': 'Ammonium nitrate',
'CORG': 'Organic carbon',
'NaCl': 'Generic NaCl',
'CBLK': 'Soot',
'MURK': 'MURK'
}
# density of molecules [kg m-3]
# CBLK: # Zhang et al., (2016) Measuring the morphology and density of internally mixed black carbon
# with SP2 and VTDMA: New insight into the absorption enhancement of black carbon in the atmosphere
# ORG: Range of densities for organic carbon is mass (0.625 - 2 g cm-3)
# Haywood et al 2003 used 1.35 g cm-3 but Schkolink et al., 2006 claim the average is 1.1 g cm-3 after a lit review
aer_density = {
'(NH4)2SO4': 1770.0,
'NH4NO3': 1720.0,
'NaCl': 2160.0,
'CORG': 1100.0,
'CBLK': 1200.0
}
# Organic carbon growth curve (Assumed to be the same as aged fossil fuel organic carbon
# pure water density
water_density = 1000.0 # kg m-3
# wavelength to aim for
ceil_lambda = [0.905e-06]
# ==============================================================================
# Read data
# ==============================================================================
# read in the complex index of refraction data for the aerosol species (can include water)
n_species = read_n_data(aer_particles, aer_names, ceil_lambda, getH2O=True)
# Read in physical growth factors (GF) for organic carbon (assumed to be the same as aged fossil fuel OC)
gf_ffoc_raw = eu.csv_read(ffoc_gfdir + 'GF_fossilFuelOC_calcS.csv')
gf_ffoc_raw = np.array(gf_ffoc_raw)[1:, :] # skip header
gf_ffoc = {
'RH_frac': np.array(gf_ffoc_raw[:, 0], dtype=float),
'GF': np.array(gf_ffoc_raw[:, 1], dtype=float)
}
# Read in species by mass data
# Units are grams m-3
mass_in = read_mass_data(massdatadir, year)
# Read WXT data
wxtfilepath = wxtdatadir + wxt_inst_site + '_' + year + '_15min.nc'
WXT_in = eu.netCDF_read(wxtfilepath, vars=['RH', 'Tair', 'press', 'time'])
WXT_in['RH_frac'] = WXT_in['RH'] * 0.01
WXT_in['time'] -= dt.timedelta(
minutes=15
) # change time from 'obs end' to 'start of obs', same as the other datasets
# Trim times
# as WXT and mass data are 15 mins and both line up exactly already
# therefore trim WXT to match mass time
mass_in, WXT_in = trim_mass_wxt_times(mass_in, WXT_in)
# Time match so mass and WXT times line up INTERNALLY as well
date_range = eu.date_range(WXT_in['time'][0], WXT_in['time'][-1], 15,
'minutes')
# make sure there are no time stamp gaps in the data so mass and WXT will match up perfectly, timewise.
print 'beginning time matching for WXT...'
WXT = internal_time_completion(WXT_in, date_range)
print 'end time matching for WXT...'
# same but for mass data
print 'beginning time matching for mass...'
mass = internal_time_completion(mass_in, date_range)
print 'end time matching for mass...'
# Create idealised number distribution for now... (dry distribution)
# idealised dist is equal for all particle types for now.
step = 0.005
r_range_um = np.arange(0.000 + step, 5.000 + step, step)
r_range_m = r_range_um * 1.0e-06
r_mean = 0.11e-06
sigma = 0
# ==============================================================================
# Process data
# ==============================================================================
# molecular mass of each molecule
mol_mass_amm_sulp = 132
mol_mass_amm_nit = 80
mol_mass_nh4 = 18
mol_mass_n03 = 62
mol_mass_s04 = 96
# Convert into moles
# calculate number of moles (mass [g] / molar mass)
# 1e-06 converts from micrograms to grams.
moles = {
'SO4': mass['SO4'] / mol_mass_s04,
'NO3': mass['NO3'] / mol_mass_n03,
'NH4': mass['NH4'] / mol_mass_nh4
}
# calculate ammonium sulphate and ammonium nitrate from gases
# adds entries to the existing dictionary
mass = calc_amm_sulph_and_amm_nit_from_gases(moles, mass)
# convert chlorine into sea salt assuming all chlorine is sea salt, and enough sodium is present.
# potentially weak assumption for the chlorine bit due to chlorine depletion!
mass['NaCl'] = mass['CL'] * 1.65
# convert masses from g m-3 to kg kg-1_air for swelling.
# Also creates the air density and is stored in WXT
mass_kg_kg, WXT = convert_mass_to_kg_kg(mass, WXT, aer_particles)
# start with just 0.11 microns as the radius - can make it more fancy later...
r_d_microns = 0.11 # [microns]
r_d_m = r_d_microns * 1.0e-6 # [m]
# calculate the number of particles for each species using radius_m and the mass
# Hopefull not needed!
num_part = {}
for aer_i in aer_particles:
num_part[aer_i] = mass_kg_kg[aer_i] / (
(4.0 / 3.0) * np.pi * (aer_density[aer_i] / WXT['dryair_rho']) *
(r_d_m**3.0))
# calculate dry volume
V_dry_from_mass = {}
for aer_i in aer_particles:
# V_dry[aer_i] = (4.0/3.0) * np.pi * (r_d_m ** 3.0)
V_dry_from_mass[aer_i] = mass_kg_kg[aer_i] / aer_density[aer_i] # [m3]
# if np.nan (i.e. there was no mass therefore no volume) make it 0.0
bin = np.isnan(V_dry_from_mass[aer_i])
V_dry_from_mass[aer_i][bin] = 0.0
# ---------------------------------------------------------
# Swell the particles (r_md,aer_i) [microns]
# set up dictionary
r_md = {}
# calculate the swollen particle size for these three aerosol types
# Follows CLASSIC guidence, based off of Fitzgerald (1975)
for aer_i in ['(NH4)2SO4', 'NH4NO3', 'NaCl']:
r_md[aer_i] = calc_r_md_species(r_d_microns, WXT, aer_i)
# set r_md for black carbon as r_d, assuming black carbon is completely hydrophobic
r_md['CBLK'] = np.empty(len(date_range))
r_md['CBLK'][:] = r_d_microns
# calculate r_md for organic carbon using the MO empirically fitted g(RH) curves
r_md['CORG'] = np.empty(len(date_range))
r_md['CORG'][:] = np.nan
for t, time_t in enumerate(date_range):
_, idx, _ = eu.nearest(gf_ffoc['RH_frac'], WXT['RH_frac'][t])
r_md['CORG'][t] = r_d_microns * gf_ffoc['GF'][idx]
# -----------------------------------------------------------
# calculate abs volume of wetted particles (V_abs,wet,aer_i)
# use the growth factors calculated based on r_d to calc V_wet from V_dry(mass, density)
# calculate the physical growth factor, wetted particle density, wetted particle volume, ...
# and water volume (V_wet - Vdry)
GF = {}
# aer_wet_density = {}
V_wet_from_mass = {}
V_water_i = {}
for aer_i in aer_particles: # aer_particles:
# physical growth factor
GF[aer_i] = r_md[aer_i] / r_d_microns
# # wet aerosol density
# aer_wet_density[aer_i] = (aer_density[aer_i] / (GF[aer_i]**3.0)) + \
# (water_density * (1.0 - (1.0 / (GF[aer_i]**3.0))))
# wet volume, using the growth rate from r_d to r_md
# if np.nan (i.e. there was no mass therefore no volume) make it 0.0
V_wet_from_mass[aer_i] = V_dry_from_mass[aer_i] * (GF[aer_i]**3.0)
bin = np.isnan(V_wet_from_mass[aer_i])
V_wet_from_mass[aer_i][bin] = 0.0
# water volume contribution from just this aer_i
V_water_i[aer_i] = V_wet_from_mass[aer_i] - V_dry_from_mass[aer_i]
# ---------------------------
# Calculate relative volume of all aerosol AND WATER (to help calculate n_mixed)
# calculate total water volume
V_water_2d = np.array(V_water_i.values(
)) # turn into a 2D array (does not matter column order)
V_water_tot = np.nansum(V_water_2d, axis=0)
# combine volumes of the DRY aerosol and the water into a single 2d array shape=(time, substance)
# V_abs = np.transpose(np.vstack([np.array(V_dry_from_mass.values()),V_water_tot]))
# shape = (time, species)
V_abs = np.transpose(
np.vstack([
np.array([V_dry_from_mass[i] for i in aer_particles]), V_water_tot
]))
# now calculate the relative volume of each of these (V_rel)
# scale absolute volume to find relative volume of each (such that sum(all substances for time t = 1))
vol_sum = np.nansum(V_abs, axis=1)
vol_sum[vol_sum == 0.0] = np.nan
scaler = 1.0 / (vol_sum) # a value for each time step
# if there is no mass data for time t, and therefore no volume data, then set scaler to np.nan
bin = np.isinf(scaler)
scaler[bin] = np.nan
# Relative volumes
V_rel = {'H2O': scaler * V_water_tot}
for aer_i in aer_particles:
V_rel[aer_i] = scaler * V_dry_from_mass[aer_i]
# --------------------------------------------------------------
# Calculate relative volume of the swollen aerosol (to weight and calculate r_md)
# V_wet_from_mass
V_abs_aer_only = np.transpose(
np.array([V_wet_from_mass[aer_i] for aer_i in aer_particles]))
# now calculate the relative volume of each of these (V_rel_Aer_only)
# scale absolute volume to find relative volume of each (such that sum(all substances for time t = 1))
vol_sum_aer_only = np.nansum(V_abs_aer_only, axis=1)
vol_sum_aer_only[vol_sum_aer_only == 0.0] = np.nan
scaler = 1.0 / (vol_sum_aer_only) # a value for each time step
# if there is no mass data for time t, and therefore no volume data, then set scaler to np.nan
bin = np.isinf(scaler)
scaler[bin] = np.nan
# Relative volumes
V_rel_aer_only = {}
for aer_i in aer_particles:
V_rel_aer_only[aer_i] = scaler * V_wet_from_mass[aer_i]
# for aer_i in aer_particles:
# print aer_i
# print V_rel[aer_i][-1]
# --------------------------------------------------------------
# calculate n_mixed using volume mixing method
# volume mixing for CIR (eq. 12, Liu and Daum 2008)
n_mixed = np.array([V_rel[i] * n_species[i] for i in V_rel.iterkeys()])
n_mixed = np.sum(n_mixed, axis=0)
# calculate volume mean radii from r_md,aer_i (weighted by V_rel,wet,aer_i)
r_md_avg = np.array(
[V_rel_aer_only[aer_i] * r_md[aer_i] for aer_i in aer_particles])
r_md_avg = np.nansum(r_md_avg, axis=0)
r_md_avg[r_md_avg == 0.0] = np.nan
# convert from microns to m
r_md_avg_m = r_md_avg * 1e-6
# calculate the size parameter for the average aerosol size
x_wet_mixed = (2.0 * np.pi * r_md_avg_m) / ceil_lambda[0]
# --------------------------
# calculate Q_back and Q_ext from the avergae r_md and n_mixed
S = np.empty(len(date_range))
S[:] = np.nan
for t, time_t in enumerate(date_range):
x_i = x_wet_mixed[t] # size parameter_i
n_i = n_mixed[t] # complex index of refraction i
if t in np.arange(0, 35000, 500):
print t
if np.logical_and(~np.isnan(x_i), ~np.isnan(n_i)):
particle = Mie(x=x_i, m=n_i)
Q_ext = particle.qext()
Q_back = particle.qb()
# calculate the lidar ratio
S_t = Q_ext / Q_back
S[t] = Q_ext / Q_back
# ---------------------
# simple plot of S
fig, ax = plt.subplots(1, 1, figsize=(6, 6))
plt.plot_date(date_range, S)
plt.savefig(savedir + 'quickplot.png')
plt.close(fig)
# --------------------------
# Testing lidar ratio computation
# read in Franco's computation of the lidar ratio CIR=1.47 + 0.099i, lambda=905nm
lr_f = eu.netCDF_read(
'/home/nerc/Documents/MieScatt/testing/lr_1.47_0.099_0.905.nc',
['DIAMETER', 'LIDAR_RATIO'])
step = 0.005
r_range_um = np.arange(0.000 + step, 10.000 + step, step)
r_range_m = r_range_um * 1.0e-06
x_range = (2.0 * np.pi * r_range_m) / ceil_lambda[0]
# calculate Q_back and Q_ext from the avergae r_md and n_mixed
#S_r = lidar ratio
S_r = np.empty(len(r_range_m))
S_r[:] = np.nan
for r_idx, r_i in enumerate(r_range_m):
x_i = x_range[r_idx] # size parameter_i
n_i = complex(1.47 + 0.099j) # fixed complex index of refraction i
# print loop progress
if r_idx in np.arange(0, 2100, 100):
print r_idx
particle = Mie(x=x_i, m=n_i)
Q_ext = particle.qext()
Q_back = particle.qb()
Q_back_alt = Q_back / (4.0 * np.pi)
# #Q_back = particle.qb()
# S12 = particle.S12(-1)
# S11 = S12[0].imag
# S22 = S12[1].imag
# Q_back_fancy = ((np.abs(S11)**2) + (np.abs(S22)**2))/(2 * np.pi * (x_i**2))
# calculate the lidar ratio
# S_t = Q_ext / Q_back
S_r[r_idx] = Q_ext / Q_back_alt
# simple plot of S
fig, ax = plt.subplots(1, 1, figsize=(6, 5))
plt.loglog(r_range_um * 2, S_r, label='mine') # diameter [microns]
plt.loglog(lr_f['DIAMETER'], lr_f['LIDAR_RATIO'], label='Franco' 's')
plt.xlim([0.01, 100.0])
plt.ylim([1.0, 10.0e7])
plt.ylabel('Lidar Ratio')
plt.xlabel('Diameter [microns]')
plt.legend()
plt.tight_layout()
plt.savefig(savedir + 'quickplot_S_vs_r.png')
plt.close(fig)
# -----------------------------------------------
d_test = 0.001e-06
r_test = d_test / 2.0
r_test_microns = r_test * 1.0e6
x_i = (2.0 * np.pi * r_test) / ceil_lambda[0] # size parameter_i
n_i = complex(1.47 + 0.099j) # fixed complex index of refraction i
particle = Mie(x=x_i, m=n_i)
Q_ext = particle.qext()
Q_back = particle.qb()
Q_back_alt = Q_back / (4.0 * np.pi)
# calculate extinction and scattering cross section
C_ext = Q_ext * np.pi * (r_test_microns**2.0)
C_back = Q_back * np.pi * (r_test_microns**2.0)
C_back_alt = Q_back_alt * np.pi * (r_test_microns**2.0)
S12 = particle.S12(-1)
S11 = S12[0].imag
S22 = S12[1].imag
Q_back_fancy = ((np.abs(S11)**2) + (np.abs(S22)**2)) / (2 * np.pi *
(x_i**2))
# calculate the lidar ratio
S_t = Q_ext / Q_back
S_test = Q_ext / Q_back_alt
S_c_test = C_ext / C_back
S_c_alt = C_ext / C_back_alt
return
def test_lidar_computation(ceil_lambda, r_md_m):
"""
Test my computation of the lidar ratio against Franco's. Done for a monodisperse, soot(like?) aerosol
:param ceil_lambda:
:param r_md_m:
:return:
"""
import ellUtils as eu
# Testing lidar ratio computation
# read in Franco's computation of the lidar ratio CIR=1.47 + 0.099i, lambda=905nm
lr_f = eu.netCDF_read(
'/home/nerc/Documents/MieScatt/testing/lr_1.47_0.099_0.905.nc',
['DIAMETER', 'LIDAR_RATIO'])
step = 0.005
r_range_um = np.arange(0.000 + step, 10.000 + step, step)
r_range_m = r_range_um * 1.0e-06
x_range = (2.0 * np.pi * r_range_m) / ceil_lambda[0]
# calculate Q_back and Q_ext from the avergae r_md and n_mixed
#S_r = lidar ratio
S_r = np.empty(len(r_range_m))
S_r[:] = np.nan
for r_idx, r_i in enumerate(r_range_m):
x_i = x_range[r_idx] # size parameter_i
n_i = complex(1.47 + 0.0j) # fixed complex index of refraction i
# n_i = complex(1.47 + 0.099j) # fixed complex index of refraction i for soot
# print loop progress
if r_idx in np.arange(0, 2100, 100):
print r_idx
particle = Mie(x=x_i, m=n_i)
Q_ext = particle.qext()
Q_back = particle.qb()
Q_back_alt = Q_back / (4.0 * np.pi)
# #Q_back = particle.qb()
# S12 = particle.S12(-1)
# S11 = S12[0].imag
# S22 = S12[1].imag
# Q_back_fancy = ((np.abs(S11)**2) + (np.abs(S22)**2))/(2 * np.pi * (x_i**2))
# calculate the lidar ratio
# S_t = Q_ext / Q_back
S_r[r_idx] = Q_ext / Q_back_alt
# simple plot of S
fig, ax = plt.subplots(1, 1, figsize=(8, 7))
plt.loglog(r_range_um * 2, S_r, label='mine') # diameter [microns]
plt.loglog(lr_f['DIAMETER'], lr_f['LIDAR_RATIO'], label='Franco' 's')
for aer_i, r_md_m_aer_i in r_md_m.iteritems():
for r_i in r_md_m_aer_i:
plt.vlines(r_i, 1, 1e6, linestyle='--', alpha=0.5)
plt.xlim([0.01, 100.0])
plt.ylim([1.0, 10.0e7])
plt.ylabel('Lidar Ratio')
plt.xlabel('Diameter [microns]')
plt.legend()
plt.tight_layout()
plt.savefig(maindir + 'figures/LidarRatio/' +
'quickplot_S_vs_r_with_rbin_lines.png')
plt.close(fig)
return
S_r[aer_i] = np.empty(len(r_range_m))
S_r[aer_i][:] = np.nan
# n_i = complex(1.47 + 0.099j) # fixed complex index of refraction i
n_i = n_species[aer_i]
for r_idx, r_i in enumerate(r_range_m):
x_i = x_range[r_idx] # size parameter_i
# print loop progress
if r_idx in np.arange(0, 2100, 100):
print r_idx
# calculate Q_back and Q_ext efficiency for current size parameter and complex index of refraction
particle = Mie(x=x_i, m=n_i)
Q_ext = particle.qext()
Q_back = particle.qb()
Q_back_alt = Q_back / (4.0 * np.pi)
# calculate the lidar ratio
S_r[aer_i][r_idx] = Q_ext / Q_back_alt
# simple plot of S
fig, ax = plt.subplots(1, 1, figsize=(7, 4))
for key, data in S_r.iteritems():
plt.loglog(r_range_um * 2.0, data,
label=aer_labels[key]) # diameter [microns]
# plt.xlim([0.01, 100.0])
plt.ylim([1.0, 10.0e5])
plt.xlim([0.01, 20])
# create excitation
polarisation = np.array([1,0,0])
direction = np.array([0,0,1])
import mnpbempp.simulation.planewave.excitation
exc = mnpbempp.simulation.planewave.excitation.exc( polarisation, direction)
# loop over energies
for j in range(0,n):
j
# solve with given excitation and wavelength
sig = bem.solve( enei[j], exc( p, enei[j] ) )
# compute extinction
ext[j] = exc.ext( sig )
## plot solution and compare with mie solution
from pymiecoated import Mie
#radius of sphere
R = 75
xs = 2*np.pi*R/enei
ext_mie = np.array(ene, float)
for imie in range(n):
mie = Mie(x=xs[imie],eps=epstab[1](enei[imie]))
ext_mie[imie]=mie.qext()
#from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
#%matplotlib qt
#plt.plot( ene, ext,'ro', ene, ext_mie , 'b' )
plt.plot(ene,ext/(1239.8*8*np.pi),'ro',ene,ext_mie,'b')
def main():
import numpy as np
from pymiecoated import Mie
import matplotlib.pyplot as plt
# -------------------------------------------------------------------
# Setup
# setup
ceil_lambda = [0.91e-06] # [m]
# ceil_lambda = np.arange(0.69e-06, 1.19e-06, 0.05e-06) # [m]
# directories
savedir = '/home/nerc/Documents/MieScatt/figures/'
datadir = '/home/nerc/Documents/MieScatt/data/'
# aerosol with relative volume - average from the 4 Haywood et al 2008 flights
rel_vol = {'ammonium_sulphate': 0.295,
'ammonium_nitrate': 0.325,
'organic_carbon': 0.38}
# create dry size distribution [m]
# r_md_microm = np.arange(0.03, 5.001, 0.001) # .shape() = 4971
# r_md_microm = np.arange(0.000 + step, 1.000 + step, step), when step = 0.005, .shape() = 200
step = 0.0005
r_md_microm = np.arange(0.000 + step, 2.000 + step, step)
r_md = r_md_microm * 1.0e-06
# RH array [fraction]
# This gets fixed for each Q iteration (Q needs to be recalculated for each RH used)
RH = 0.8
# densities of MURK constituents # [kg m-3]
# range of densities of org carb is massive (0.625 - 2 g cm-3)
# Haywood et al 2003 use 1.35 g cm-3 but Schkolnik et al., 2006 lit review this and claim 1.1 g cm-3
dens_amm_sulph = 1770
dens_amm_nit = 1720
dens_org_carb = 1100 # NOTE ABOVE
# define array to store Q for each wavelength
Q_dry = []
x_store =[]
n_store=[]
# -----------------------------------------------
# Calculate Q for each lambda
# -----------------------------------------------
for lam in ceil_lambda:
# -------------------------------------------------------------------
# Process
# calculate complex index of refraction for MURK species
# output n is complex index of refraction (n + ik)
n_aerosol = calc_n_aerosol(rel_vol, lam)
# NOTE: Able to use volume in MURK equation instead of mass because, if mass is evenly distributed within a volume
# then taking x of the mass = taking x of the volume.
# after calculating volumes used in MURK, can find relative % and do volume mixing.
# bulk complex index of refraction (CIR) for the MURK species using volume mixing method
n_murk = calc_n_murk(rel_vol, n_aerosol)
# n_murk = complex(1.53, 0.007) - makes no sense as this is for 550 nm
# n_store += [n_murk]
# complex indices of refraction (n = n(bar) - ik) at ceilometer wavelength (910 nm) Hesse et al 1998
# n_water, _ = linear_interpolate_n('water', lam)
# swell particles using FO method
# rm = np.ma.ones(RH.shape) - (B / np.ma.log(RH_ge_RHcrit))
# r_m = 1 - (B / np.log(RH))
# r_m2 = np.ma.power(r_m, 1. / 3.)
# r_m = np.ma.array(r_md) * r_m2
# r_m_microm = r_m * 1.0e06
# calculate size parameter for dry and wet
x_dry = (2.0 * np.pi * r_md)/lam
x_store += [x_dry]
# x_wet = (2.0 * np.pi * r_m)/lam
# calculate swollen index of refraction using MURK
# n_swoll = CIR_Hanel(n_water, n_murk, r_md, r_m)
# Calc extinction efficiency for dry aerosol (using r_md!!!! NOT r_m)
all_particles_dry = [Mie(x=x_i, m=n_murk) for x_i in x_dry]
Q_dry += [np.array([particle.qext() for particle in all_particles_dry])]
# -----------------------------------------------
# Post processing, saving and plotting
# -----------------------------------------------
# if running for single 910 nm wavelength, save the calculated Q
if type(ceil_lambda) == list:
if ceil_lambda[0] == 9.1e-07:
# save Q curve and radius [m]
np.savetxt(datadir + 'calculated_Q_ext_910nm.csv', np.transpose(np.vstack((r_md, Q_dry))), delimiter=',', header='radius,Q_ext')
# plot
fig = plt.figure(figsize=(7, 4.5))
for Q_i, lam in zip(Q_dry, ceil_lambda):
# plot it
plt.semilogx(r_md_microm, Q_i, label=str(lam) + 'm')
# plt.semilogx(r_md_microm, Q_dry, label='dry murk', color=[0,0,0])
# plt.semilogx(r_m_microm, Q_del, label='deliquescent murk (RH = ' + str(RH) + ')')
# plt.semilogx(r_m_microm, Q_coat, label='coated murk (RH = ' + str(RH) + ')')
# # average Q_dry if multiple Q_drys were calculated
# if Q_dry.__len__() != 1:
# q = np.array(Q_dry)
# Q_dry_avg = np.mean(q, axis=0)
# ax = plt.semilogx(r_md_microm, Q_dry_avg, label='average', color='black', linewidth=2)
plt.title('lambda = ' + str(ceil_lambda[0]) + '-' + str(ceil_lambda[-1]) + 'm, n = murk')
plt.xlabel('radius [micrometer]', labelpad=-5)
plt.xlim([0.05, 5.0])
plt.ylim([0.0, 5.0])
#plt.xlim([0.01, 0.2])
#plt.ylim([0.0, 0.1])
plt.ylabel('Q_ext')
plt.legend(fontsize=8, loc='best')
plt.grid(b=True, which='major', color='grey', linestyle='--')
plt.grid(b=True, which='minor', color=[0.85, 0.85, 0.85], linestyle='--')
plt.savefig(savedir + 'Q_ext_murk_' + str(ceil_lambda[0]) + '-' + str(ceil_lambda[-1]) + 'lam.png')
plt.tight_layout()
plt.close()
# plot the radius
# plot_radius(savedir, r_md, r_m)
print 'END PROGRAM'
def scatter_mie_ensemble(nm_refract, n, r, ang_phase, alam, do_plot=False):
"""
Return the Mie scattering properties of an ensemble of particles.
The size distribution may be any arbitrary n(r).
The returned phase function is properly normalized s.t. \\int(0 .. pi) {P sin(alpha) d_alpha} = 2.
Calculated using pymiecoated library. That library supports coated grains, but my functions do not.
Parameters
------
nm_refract:
Index of refraction. Complex. Imaginary component is typically positive, not negative.
n:
Particle number distribution.
r:
Particle size distribution. Astropy units.
ang_phase:
Scattering phase angle (array).
alam:
Wavelength. Astropy units.
Return values
----
phase:
Summed phase curve -- ie, P11 * n * pi * r^2 * qsca, summed. Array [num_angles]
qsca:
Scattering matrix. Array [num_radii]. Usually not needed.
p11_out:
Phase curve. Not summed. Array [num_angles, num_radii]. Usually not needed.
"""
num_r = len(n)
num_ang = len(ang_phase)
pi = math.pi
k = 2*pi / alam
qmie = np.zeros(num_r)
qsca = np.zeros(num_r)
qext = np.zeros(num_r)
qbak = np.zeros(num_r)
qabs = np.zeros(num_r)
p11_mie = np.zeros((num_r, num_ang))
# Calc Q_ext *or* Q_sca, based on whether it's reflected or transmitted light
x = (2*pi * r/alam).to('1').value
print('Doing Mie code')
# Mie code doesn't compute the phase function unless we ask it to, by passing dqv.
for i,x_i in enumerate(x):
mie = Mie(x=x_i, m=nm_refract) # This is only for one x value, not an ensemble
qext[i] = mie.qext()
qsca[i] = mie.qsca()
qbak[i] = mie.qb()
for j, ang_j in enumerate(ang_phase):
(S1, S2) = mie.S12(np.cos(pi*u.rad - ang_j)) # Looking at code, S12 returns tuple (S1, S2).
# For a sphere, S3 and S4 are zero.
# Argument to S12() is scattering angle theta, not phase
sigma = pi * r[i]**2 * qsca[i]
# Now convert from S1 and S2, to P11: Use p. 2 of http://nit.colorado.edu/atoc5560/week8.pdf
p11_mie[i, j] = 4 * pi / (k**2 * sigma) * ( (np.abs(S1))**2 + (np.abs(S2))**2) / 2
if (do_plot):
for i, x_i in enumerate(x):
plt.plot(ang_phase.to('deg'), p11_mie[i, :], label = 'X = {:.1f}'.format(x_i))
plt.title("P11, nm = {}".format(nm_refract))
plt.yscale('log')
# plt.legend(loc='upper left')
plt.xlabel('Phase Angle [deg]')
plt.title('P11')
plt.show()
for i, x_i in enumerate(x):
plt.plot(ang_phase.to('deg'), p11_mie[i, :] * n[i] * r[i]**2, label = 'X = {:.1f}'.format(x_i))
plt.title("P11 * n(r) * r^2, nm = {}".format(nm_refract))
plt.yscale('log')
# plt.legend(loc='upper left')
plt.xlabel('Phase Angle [deg]')
plt.show()
# Multiply by the size dist, and flatten the array and return just showing the angular dependence.
# I(theta) = n(r) pi r^2 Q_sca P_11(theta)
terms = np.transpose(np.tile(pi * n * r**2 * qsca, (num_ang,1)))
phase_out = np.sum(p11_mie * terms, axis=0)
# Remove any units from this
phase_out = phase_out.value
# Now normalize it. We want \int (0 .. pi) {P(alpha) sin(alpha) d_alpha} = 2
# The accuracy of the normalized result will depend on how many angular bins are used.
# This normalization is
d_ang = ang_phase - np.roll(ang_phase,1)
d_ang[0] = 0
tot = np.sum(phase_out * np.sin(ang_phase) * d_ang.value)
phase_out = phase_out * 2 / tot
# Return everything
return(phase_out, p11_mie, qsca)
def main():
# -------------------------------------------------------------------
# Setup
# setup
# ceil_lambda = [0.91e-06] # [m]
# ceil_lambda = np.arange(0.69e-06, 1.19e-06, 0.05e-06) # [m]
# ceil_lambda = np.arange(8.95e-07, 9.16e-07, 1.0e-09) # [m]
ceil_lambda = np.array([905e-09, 1064e-09])
ceil_lambda_str = ['%d' % i for i in ceil_lambda * 1.0e9]
# extra =''
extra = '_largelam'
# directories
savedir = '/home/nerc/Documents/MieScatt/figures/'
datadir = '/home/nerc/Documents/MieScatt/data/'
# aerosol with relative volume - average from the 4 Haywood et al 2008 flights
rel_vol = {
'ammonium_sulphate': 0.295,
'ammonium_nitrate': 0.325,
'organic_carbon': 0.38
}
# all the aerosol types
# all_aer = ['ammonium_sulphate', 'ammonium_nitrate', 'organic_carbon', 'oceanic', 'biogenic', 'NaCl', 'soot']
aer_names = {
'ammonium_sulphate': 'Ammonium sulphate',
'ammonium_nitrate': 'Ammonium nitrate',
'organic_carbon': 'Organic carbon',
'NaCl': 'Generic NaCl',
'soot': 'Soot',
'MURK': 'MURK'
}
# all_aer = {'ammonium_sulphate': 'red', 'ammonium_nitrate':'orange', 'organic_carbon': 'green',
# 'biogenic': 'cyan', 'NaCl': 'magenta', 'soot': 'brown'}
all_aer = {
'ammonium_sulphate': 'red',
'ammonium_nitrate': 'orange',
'organic_carbon': 'green',
'NaCl': 'magenta',
'soot': 'brown',
'MURK': 'black'
}
all_aer_constits = [
'ammonium_sulphate', 'ammonium_nitrate', 'organic_carbon', 'NaCl',
'soot'
]
# create dry size distribution [m]
# r_md_microm = np.arange(0.03, 5.001, 0.001) # .shape() = 4971
# r_md_microm = np.arange(0.000 + step, 1.000 + step, step), when step = 0.005, .shape() = 200
step = 0.005
r_md_microm = np.arange(0.000 + step, 10.000 + step, step)
r_md = r_md_microm * 1.0e-06
# define array to store Q for each wavelength
Q_dry = {}
Q_diff = {}
Q_ratio = {}
# make each, first level key (i.e. Q_dry[firstkey]) the aerosol type, followed later by the wavelength [nm].
for aer_i in all_aer.iterkeys():
Q_dry[aer_i] = {}
Q_diff[aer_i] = {}
Q_ratio[aer_i] = {}
for lam_i in ceil_lambda_str:
Q_dry[aer_i][lam_i] = []
Q_diff[aer_i][lam_i] = []
Q_ratio[aer_i][lam_i] = []
# save the Q(dry) curve for MURK?
savedata = False
# -----------------------------------------------
# Calculate Q for each lambda
# -----------------------------------------------
for lam, lam_str in zip(ceil_lambda, ceil_lambda_str):
print '\n lam_i = ' + lam_str + ' nm'
# -------------------------------------------------------------------
# Process
# calculate complex index of refraction for MURK species
# output n is complex index of refraction (n + ik)
n_aerosol = calc_n_aerosol(all_aer_constits, lam)
# NOTE: Able to use volume in MURK equation instead of mass because, if mass is evenly distributed within a volume
# then taking x of the mass = taking x of the volume.
# after calculating volumes used in MURK, can find relative % and do volume mixing.
# bulk complex index of refraction (CIR) for the MURK species using volume mixing method
n_murk = calc_n_murk(rel_vol, n_aerosol)
n_aerosol['MURK'] = n_murk
# n_murk = complex(1.53, 0.007) - this is for 550 nm
# n_store += [n_murk]
# complex indices of refraction (n = n(bar) - ik) at ceilometer wavelength (910 nm) Hesse et al 1998
# n_water, _ = linear_interpolate_n('water', lam)
# calculate size parameter for dry and wet
x_dry = (2.0 * np.pi * r_md) / lam
# x_store += [x_dry]
# calculate swollen index of refraction using MURK
# n_swoll = CIR_Hanel(n_water, n_murk, r_md, r_m)
# Calc extinction efficiency for dry aerosol (using r_md!!!! NOT r_m)
for aer_i, n_i in n_aerosol.iteritems():
all_particles_dry = [Mie(x=x_i, m=n_i) for x_i in x_dry]
Q_dry[aer_i][lam_str] = np.array(
[particle.qext() for particle in all_particles_dry])
# once 910 has been calcualted
for aer_i, value in Q_dry.iteritems():
for lam_str_i in ceil_lambda_str:
Q_diff[aer_i][
lam_str_i] = Q_dry[aer_i][lam_str_i] - Q_dry[aer_i]['905']
Q_ratio[aer_i][
lam_str_i] = Q_dry[aer_i][lam_str_i] / Q_dry[aer_i]['905']
# qsca, qabs are alternatives to qext
# -----------------------------------------------
# Post processing, saving and plotting
# -----------------------------------------------
# plot
# plot_one_aer_i
plot_absolute(r_md_microm, Q_dry, ceil_lambda, ceil_lambda_str,
all_aer_constits, aer_names, savedir, extra)
plot_diff(r_md_microm, Q_diff, ceil_lambda, ceil_lambda_str,
all_aer_constits, aer_names, savedir, extra)
plot_ratio(r_md_microm, Q_ratio, ceil_lambda, ceil_lambda_str,
all_aer_constits, aer_names, savedir, extra)
# plot the radius
# plot_radius(savedir, r_md, r_m)
print 'END PROGRAM'
frac_lambert = 1 - frac_mie
# Calc Q_ext *or* Q_sca, based on whether it's reflected or transmitted light
n_refract = 1.33
m_refract = -0.001
nm_refract = complex(n_refract,m_refract)
x = (2*pi * r/alam).to('1').value
print('Doing Mie code')
# Mie code doesn't compute the phase function unless we ask it to, by passing dqv.
if DO_MIE:
for i,x_i in enumerate(x): # Loop over particle size X, and get Q and P_11 for each size
mie = Mie(x=x_i, m=nm_refract) # This is only for one x value, not an ensemble
qext[i] = mie.qext()
qsca[i] = mie.qsca()
qbak[i] = mie.qb()
(S1, S2) = mie.S12(np.cos(pi*u.rad - phase)) # Looking at code, S12 returns tuple (S1, S2).
# For a sphere, S3 and S4 are zero.
# Argument to S12() is scattering angle theta, not phase
k = 2*pi / alam
sigma = pi * r[i]**2 * qsca[i] # Just a guess here
# Now convert from S1 and S2, to P11: Use p. 2 of http://nit.colorado.edu/atoc5560/week8.pdf
p11_mie[i] = 4 * pi / (k**2 * sigma) * ( (np.abs(S1))**2 + (np.abs(S2))**2) / 2
def main():
"""
Carry out a sensitivity analysis on the Mie scattering code
:return: plots Mie scattering curve of murk, deliquecent and coated spheres at 80 % RH.
"""
import numpy as np
from pymiecoated import Mie
import matplotlib.pyplot as plt
# -------------------------------------------------------------------
# Setup
# setup
ceil_lambda = 0.91e-06 # [m]
B = 0.14
RH_crit = 0.38
# directories
savedir = '/home/nerc/Documents/MieScatt/figures/sensitivity/'
# aerosol with relative volume - varying manually - first one is average from haywood et al., 2008
rel_vol = {
'ammonium_sulphate': [0.295, 0.80, 0.10, 0.10],
'ammonium_nitrate': [0.325, 0.10, 0.80, 0.10],
'organic_carbon': [0.38, 0.10, 0.10, 0.80]
}
# create dry size distribution [m]
r_md_microm = np.arange(0.03, 5.001, 0.001)
r_md = r_md_microm * 1.0e-06
# RH array [fraction]
# This gets fixed for each Q iteration (Q needs to be recalculated for each RH used)
RH = 0.8
# densities of MURK constituents # [kg m-3]
# range of densities of org carb is massive (0.625 - 2 g cm-3)
# Haywood et al 2003 use 1.35 g cm-3 but Schkolnik et al., 2006 lit review this and claim 1.1 g cm-3
dens_amm_sulph = 1770
dens_amm_nit = 1720
dens_org_carb = 1100 # NOTE ABOVE
# -------------------------------------------------------------------
# Process
# calculate complex index of refraction for each particle
# output n is complex index of refraction (n + ik)
n_aerosol = calc_n_aerosol(rel_vol, ceil_lambda)
# NOTE: Able to use volume in MURK equation instead of mass because, if mass is evenly distributed within a volume
# then taking x of the mass = taking x of the volume.
# after calculating volumes used in MURK, can find relative % and do volume mixing.
n_mixed = []
for i in range(len(rel_vol['ammonium_sulphate'])):
# extract out just this one set of relative amounts
rel_vol_i = {}
for key in rel_vol.keys():
rel_vol_i[key] = rel_vol[key][i]
# uses relative amounts in the MURK equation!
n_mixed += [calc_n_murk(rel_vol_i, n_aerosol)]
# complex indices of refraction (n = n(bar) - ik) at ceilometer wavelength (910 nm) Hesse et al 1998
n_water, _ = linear_interpolate_n('water', ceil_lambda)
# swell particles using FO method
# rm = np.ma.ones(RH.shape) - (B / np.ma.log(RH_ge_RHcrit))
r_m = 1 - (B / np.log(RH))
r_m2 = np.ma.power(r_m, 1. / 3.)
r_m = np.ma.array(r_md) * r_m2
r_m_microm = r_m * 1.0e06
# calculate size parameter for dry and wet
x_dry = (2.0 * np.pi * r_md) / ceil_lambda
x_wet = (2.0 * np.pi * r_m) / ceil_lambda
# # calculate swollen index of refraction using MURK
# n_swoll = CIR_Hanel(n_water, n_murk, r_md, r_m)
for j in range(len(n_mixed)):
# Calc extinction efficiency for dry aerosol (using r_md!!!! NOT r_m)
all_particles_dry = [Mie(x=x_i, m=n_mixed[j]) for x_i in x_dry]
Q_dry = np.array([particle.qext() for particle in all_particles_dry])
# use proportions of each to scale the colours on the plot
colours = [
rel_vol['ammonium_sulphate'][j], rel_vol['ammonium_nitrate'][j],
rel_vol['organic_carbon'][j]
]
lab = 'AS=' + str(rel_vol['ammonium_sulphate'][j]) + '; ' +\
'AN=' + str(rel_vol['ammonium_nitrate'][j]) + '; ' +\
'OC=' + str(rel_vol['organic_carbon'][j])
# plot it
plt.semilogx(r_md_microm, Q_dry, color=colours, label=lab)
plt.title('lambda = interpolated to ' + str(ceil_lambda) + 'm')
plt.xlabel('radius [micrometer]')
plt.xlim([0.03, 5.0])
plt.ylim([0.0, 5.0])
plt.ylabel('Q')
plt.legend(fontsize=9)
plt.savefig(savedir + 'Q_ext_murk_sensitivity_' + str(ceil_lambda) +
'lam.png')
# plt.close()
print 'END PROGRAM'
def get_optical_properties(rhop, filename):
# user defined parameter
#define the number (or mass) distribution (e.g from Kok et al).
#diameter micron
D = np.arange(0.001, 20, 0.005)
if (1 == 2):
D = np.arange(0.01, 65, 0.05)
if (1 == 1):
cN = 0.9539
Ds = 3.4
sigs = 3.0
lamb = 12
A = np.log(D / Ds) / (np.sqrt(2) * np.log(sigs))
#care dND/dD or dND/d(lnD) !!
dND = (1 / D) * (1 /
(cN * D * D)) * (1 + erf(A)) * np.exp(-1. *
(D / lamb)**3)
#dND = (D/12.62) * (1 + erf(A)) * np.exp(-1.*(D/lamb)**3)
# here use a 3 log distribution
# e.g. alfaro Gomez
if (1 == 2):
sig = [1.75, 1.75, 1.75]
Dm = [0.64, 3.45, 8.67]
Nf = [0.74, 0.20, 0.06]
dND = ddlogn(D, Dm, sig, Nf)
if (1 == 1):
#define 2 size bins for each SOA category
sbin = np.array([0.001, 0.03, 0.70])
if (1 == 2):
#define the 12 new size bin cut of diam from LISA optimised distribution
#you can take also one big bin encompassing the whole distrib (that 's what
#we do for BC/OC, in this case it is equivalent to integrate over the full
#distrib mode).
#here is LISA optimal distrib for dust
sbin = np.array([0.09,0.18, 0.6, 1.55, 2.50, 3.75, 4.70, 5.70, 7.50,\
14.50, 26.0, 41.0, 63.0])
#sbin = [0.01 ,1.,2.5,5.,20. ]
#sbin =[0.98,1.2,2.5,5.,20.]
## Uncomment the following line for testing
# rhop, ndbib, wbib, kbib = return_test_variables()
wbib, ndbib, kbib = np.loadtxt(soa_ri_path + filename,
skiprows=0,
unpack=True)
#kbib = [0.04, 0.027866667, 0.020111111, 0.014933333, 0.001, 0.001, 0.001, 0.001, 0.003177778, 0.003033333, 0.003011111, 0.002911111, 0.003111111, 0.003111111, 0.003066667 , 0.0028,0.0025,0.002, 0.00195, 0.0019]
#with this function we can simply interpolate kbib for every value of wavelenght !
kint = interp1d(wbib, kbib, kind='linear')
ndint = interp1d(wbib, ndbib, kind='linear')
#########
# define the spectral band ( wavmin and wavemax) of the radiation model
# here from radiation RegCM standard regcm code
wavmin = [
0.2000, 0.2450, 0.2650, 0.2750, 0.2850, 0.2950, 0.3050, 0.3500, 0.6400,
0.7000, 0.7010, 0.7010, 0.7010, 0.7010, 0.7020, 0.7020, 2.6300, 4.1600,
4.1600
]
wavmax = [
0.2450, 0.2650, 0.2750, 0.2850, 0.2950, 0.3050, 0.3500, 0.6400, 0.7000,
5.0000, 5.0000, 5.0000, 5.0000, 5.0000, 5.0000, 5.0000, 2.8600, 4.5500,
4.5500
]
#num = 7 for visible band standard scheme
num = 7
## si RRTM set 1 == 1 to overwrite
#if(1==2):
# # RRTM Shortwave spectral band limits (wavenumbers)
# #wavenum are in cm-1 / take the inverse for wavelenght
# wavenum1 = np.array([2600., 3250., 4000., 4650., 5150., 6150., 7700., \
# 8050.,12850.,16000.,22650.,29000.,38000., 820.])
# wavenum2 = np.array([3250., 4000., 4650., 5150., 6150., 7700., 8050., \
# 12850.,16000.,22650.,29000.,38000.,50000., 2600.])
#
## Longwave spectral band limits (wavenumbers)
# if(1==2):
# wavenum1 = np.array([ 10., 350., 500., 630., 700., 820., \
# 980. ,1080. ,1180. ,1390. ,1480. ,1800. , \
# 2080. ,2250. ,2380. ,2600. ])
# wavenum2 = np.array([350. , 500. , 630. , 700. , 820. , 980. , \
# 1080. ,1180. ,1390. ,1480. ,1800. ,2080. , \
# 2250. ,2380. ,2600. ,3250. ])
## determined from indica marc for the longwave
# wbib= [3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 20, 30, 1100]
# kbib = [7.54E-2, 5.14E-2, 5.94E-2, 1.41E-1, 1.46E-1, 2.18E-1, \
# 5.35E-1, 3.70E-1, 1.18E-1, 2.28E-1, 2.79E-1, 6.12E-1,\
# 4.95E-1, 6.50E-1 ]
# nbib = [1.49, 1.51, 1.58, 1.45, 1.46, 1.19, 1.86, 1.84, 1.78, \
# 1.65, 1.55, 2.25, 2.40, 2. ]
# kint = interp1d(wbib,kbib,kind='linear')
# ndint = interp1d(wbib,nbib,kind='linear')
# #convert to wavelenght in micron
# # visible is index
# wavmin = np.power(wavenum2*1.E-4,-1.)
# wavmax = np.power(wavenum1*1.E-4,-1.)
#
# if (1==1):
# num = 7 # for visible band standard scheme
# if (1==2):
# num = 9 # for vis RRTM
#print num
#print wavmin
#print wavmax
# end of user deined parameter
##################################################################
####################################################################3
# 1) calculate the effective radius of each bin (used in regcm )
Sv = np.zeros(len(sbin) - 1)
Ss = np.zeros(len(sbin) - 1)
normb = np.zeros(len(sbin) - 1)
for b in range(len(sbin) - 1):
for dd in range(len(D)):
if (D[dd] >= sbin[b] and D[dd] < sbin[b + 1]):
Sv[b] = Sv[b] + D[dd]**3 * dND[dd]
Ss[b] = Ss[b] + D[dd]**2 * dND[dd]
normb[b] = normb[b] + dND[dd]
Deff = Sv / Ss
print Deff
## visu
#
#fig = plt.figure()
#ax = fig.add_subplot(1,3,1)
##here plot dN/d(logD) !!
#ax.plot(D,dND *D , color='blue')
#ax.set_yscale('log')
#ax.set_xscale('log')
#ax.set_xlim([0.08, 65])
#ax.set_ylim([1.E-4, 1])
#ax.set_title("distribution and bins, dot= Deff")
#ax.set_xlabel('D in micrometer')
#plot also bin end effrad
#for x in sbin:
# ax.plot([x, x],[1.E-4, 1], color='black')
#for x in Deff:
# ax.scatter(x,2E-4, color='green')
#
#
##visu also the ref index spectral variation interp + values
#ax2 = fig.add_subplot(1,3,2)
##xx = np.linspace(0.2,13,500)
#xx = np.linspace(3,40,500)
#ax2.plot(xx, ndint(xx), color='green')
##ax2.scatter(wbib,kbib)
#ax2.set_title(" im ref index, dot = data, line = interp used for oppt calc. ")
#ax2.set_xlabel('wavelenght in micrometer')
#2 mie calculation
######################################
#calculate optical properties per bin
#######################################3
# methode 1 considering only bin effective diam calculated before
if (1 == 1):
extb = np.zeros((len(sbin) - 1, len(wavmin)))
ssab = np.zeros((len(sbin) - 1, len(wavmin)))
asyb = np.zeros((len(sbin) - 1, len(wavmin)))
for nband in range(len(wavmin)):
specbin = np.linspace(wavmin[nband], wavmax[nband], 50)
for db in range(len(Deff)):
qext = 0.
ssa = 0.
asy = 0.
for wl in range(len(specbin)):
sp = np.pi * Deff[db] / specbin[wl]
k = kint(specbin[wl])
nd = ndint(specbin[wl])
mie = Mie(x=sp, m=complex(nd, k))
qext = qext + mie.qsca() + mie.qabs()
qabs = mie.qabs()
ssa = ssa + mie.qsca() / (mie.qsca() + mie.qabs())
asy = asy + mie.asy()
extb[db, nband] = extb[db, nband] + (qext / len(specbin)) / (
2. / 3. * rhop * Deff[db] * 1E-6)
#cross section in m2/g
ssab[db, nband] = ssab[db, nband] + (ssa / len(specbin))
asyb[db, nband] = asyb[db, nband] + (asy / len(specbin))
if (1 == 2):
#method 2(slower) double integration /more precise prblem mie return nan for extrem coarse particles
# calculate the mie parameter for every diameter of the range, averaged on spectral band
extb = np.zeros((len(sbin) - 1, len(wavmin)))
ssab = np.zeros((len(sbin) - 1, len(wavmin)))
asyb = np.zeros((len(sbin) - 1, len(wavmin)))
for nband in range(len(wavmin)):
specbin = np.linspace(wavmin[nband], wavmax[nband], 10)
extd = np.zeros(len(D))
ssad = np.zeros(len(D))
asyd = np.zeros(len(D))
for db in range(len(D)):
qext = 0.
ssa = 0.
asy = 0.
for wl in range(len(specbin)):
sp = np.pi * D[db] / specbin[wl]
k = kint(specbin[wl])
nd = ndint(specbin[wl])
mie = Mie(x=sp, m=complex(nd, k))
qext = qext + mie.qsca() + mie.qabs()
ssa = ssa + mie.qsca() / (mie.qsca() + mie.qabs())
asy = asy + mie.asy()
extd[db] = qext / len(specbin) / (2. / 3. * rhop * D[db] *
1E-6)
ssad[db] = ssa / len(specbin)
asyd[db] = asy / len(specbin)
# perform the bin wighting av according to distibution
for b in range(len(sbin) - 1):
if (D[db] >= sbin[b] and D[db] < sbin[b + 1]):
extb[b,
nband] = extb[b,
nband] + extd[db] * dND[db] / normb[b]
ssab[b,
nband] = ssab[b,
nband] + ssad[db] * dND[db] / normb[b]
asyb[b,
nband] = asyb[b,
nband] + asyd[db] * dND[db] / normb[b]
# 3 nan out for the big bin which can have nan values ....
# the kext is set very low which means that the bin won't matter much in the rad
extb[np.isnan(extb)] = 1.E-20
asyb[np.isnan(asyb)] = 0.99
ssab[np.isnan(ssab)] = 0.5
print "extb vis", extb[:, num]
print "ssab vis", ssab[:, num]
print "asyb vis", asyb[:, num]
#print "absb vis", extb[:,num] * ssab[:,num]
##4 visu oppt / bin
#
#ax3 = fig.add_subplot(1,3,3)
#xx = np.linspace(0.2,4,500)
#ax3.set_xlim([0.08,65 ])
#ax3.set_ylim([0, 5])
#for n in range(len(sbin)-1):
# ax3.plot([sbin[n], sbin[n+1]],[extb[n,num],extb[n,num]], color='black')
# ax3.plot([sbin[n], sbin[n+1]],[ssab[n,num],ssab[n,num]], color='blue')
# ax3.plot([sbin[n], sbin[n+1]],[asyb[n,num],asyb[n,num]], color='red')
#
#ax3.set_title(" bin oppt vis: blk:kext, blue:ssa, red:asy ")
#ax3.set_xscale('log')
#ax3.set_xlabel('D in micrometer')
# finally save in afile in a format close to mod_rad_aerosol block data
# will just need copy paste + a few edit for fortan
# file = open("aeroppt_blocl.txt", "w")
compound = os.path.splitext(os.path.basename(filename))[0]
np.savetxt(compound + '_Deff.txt', Deff, fmt='%7.5E', delimiter=', ')
np.savetxt(compound + '_extb.txt', extb, fmt='%7.5E', delimiter=', ')
np.savetxt(compound + '_ssab.txt', ssab, fmt='%7.5E', delimiter=', ')
np.savetxt(compound + '_asyb.txt', asyb, fmt='%7.5E', delimiter=', ')