This module computes the moisture tendencies of water vapor, cloud droplets, rain, cloud ice (pristine), snow, and graupel. Prior to WRFv2.2 this code was based on Reisner et al (1998), but few of those pieces remain. A complete description is now found in Thompson, G., P. R. Field, R. M. Rasmussen, and W. D. Hall, 2008: Explicit Forecasts of winter precipitation using an improved bulk microphysics scheme. Part II: Implementation of a new snow parameterization. Mon. Wea. Rev., 136, 5095-5115. More...

Functions/Subroutines
subroutine	thompson_finalize ()

subroutine	qr_acr_qg
	Rain collecting graupel (and inverse). Explicit CE integration.

subroutine	qr_acr_qs
	Rain collecting snow (and inverse). Explicit CE integration.

subroutine	freezeh2o (threads)
	This is a literal adaptation of Bigg (1954) probability of drops of a particular volume freezing. Given this probability, simply freeze the proportion of drops summing their masses.

subroutine	qi_aut_qs
	Cloud ice converting to snow since portion greater than min snow size. Given cloud ice content (kg/m3), number concentration (#/m3) and gamma shape parameter, mu_i, break the distrib into bins and figure out the mass/number of ice with sizes larger than D0s. Also, compute incomplete gamma function for the integration of ice depositional growth from diameter=0 to D0s. Amount of ice depositional growth is this portion of distrib while larger diameters contribute to snow growth (as in Harrington et al. 1995).

subroutine	table_efrw
	Variable collision efficiency for rain collecting cloud water using method of Beard and Grover, 1974 if a/A less than 0.25; otherwise uses polynomials to get close match of Pruppacher & Klett Fig 14-9.

subroutine	table_efsw
	Variable collision efficiency for snow collecting cloud water using method of Wang and Ji, 2000 except equate melted snow diameter to their "effective collision cross-section.".

real function	eff_aero (d, da, visc, rhoa, temp, species)
	Function to compute collision efficiency of collector species (rain, snow, graupel) of aerosols. Follows Wang et al, 2010, ACP, which follows Slinn (1983).

subroutine	table_dropevap
	Integrate rain size distribution from zero to D-star to compute the number of drops smaller than D-star that evaporate in a single timestep. Drops larger than D-star dont evaporate entirely so do not affect number concentration.

subroutine	table_ccnact (errmess, errflag)
	Fill the table of CCN activation data created from parcel model run by Trude Eidhammer with inputs of aerosol number concentration, vertical velocity, temperature, lognormal mean aerosol radius, and hygroscopicity, kappa. The data are read from external file and contain activated fraction of CCN for given conditions.

real function	activ_ncloud (tt, ww, nccn, lsm_in)
	Retrieve fraction of CCN that gets activated given the model temp, vertical velocity, and available CCN concentration. The lookup table (read from external file) has CCN concentration varying the quickest, then updraft, then temperature, then mean aerosol radius, and finally hygroscopicity, kappa.

subroutine	gcf (gammcf, a, x, gln)
	Returns the incomplete gamma function q(a,x) evaluated by its continued fraction representation as gammcf.

subroutine	gser (gamser, a, x, gln)
	Returns the incomplete gamma function p(a,x) evaluated by its series representation as gamser.

real function	gammln (xx)
	Returns the value ln(gamma(xx)) for xx > 0.

real function	gammp (a, x)

real function	wgamma (y)

real function	rslf (p, t)
	THIS FUNCTION CALCULATES THE LIQUID SATURATION VAPOR MIXING RATIO AS A FUNCTION OF TEMPERATURE AND PRESSURE.

real function	rsif (p, t)
	THIS FUNCTION CALCULATES THE ICE SATURATION VAPOR MIXING RATIO AS A FUNCTION OF TEMPERATURE AND PRESSURE.

real function	icedemott (tempc, qv, qvs, qvsi, rho, nifa)

real function	icekoop (temp, qv, qvs, naero, dt)
	Newer research since Koop et al (2001) suggests that the freezing rate should be lower than original paper, so J_rate is reduced by two orders of magnitude.

real function	delta_p (yy, y1, y2, aa, bb)
	Helper routine for Phillips et al (2008) ice nucleation.

subroutine	calc_effectrad (t1d, p1d, qv1d, qc1d, nc1d, qi1d, ni1d, qs1d, re_qc1d, re_qi1d, re_qs1d, lsml, kts, kte)
	Compute radiation effective radii of cloud water, ice, and snow. These are entirely consistent with microphysics assumptions, not constant or otherwise ad hoc as is internal to most radiation schemes. Since only the smallest snowflakes should impact radiation, compute from first portion of complicated Field number distribution, not the second part, which is the larger sizes.

subroutine	calc_refl10cm (qv1d, qc1d, qr1d, nr1d, qs1d, qg1d, t1d, p1d, dbz, rand1, kts, kte, ii, jj, melti, vt_dbz, first_time_step)
	Compute radar reflectivity assuming 10 cm wavelength radar and using Rayleigh approximation. Only complication is melted snow/graupel which we treat as water-coated ice spheres and use Uli Blahak's library of routines. The meltwater fraction is simply the amount of frozen species remaining from what initially existed at the melting level interface.

subroutine	semi_lagrange_sedim (km, dzl, wwl, rql, precip, pfsan, dt, r1)

subroutine	graupel_psd_parameters (kts, kte, rand1, rg, ilamg, n0_g)
	Calculates graupel size distribution parameters.

real function	hail_mass_99th_percentile (kts, kte, qg, temperature, pressure, qv)
	Calculates graupel/hail maximum diameter.


subroutine	thompson_init (is_aerosol_aware_in, merra2_aerosol_aware_in, mpicomm, mpirank, mpiroot, threads, errmsg, errflg)
	This subroutine calculates simplified cloud species equations and create lookup tables in Thomspson scheme.


subroutine	mp_gt_driver (wrf_chem)
	This is a wrapper routine designed to transfer values from 3D to 1D.


subroutine	mp_thompson (wrf_chem)
	This subroutine computes the moisture tendencies of water vapor, cloud droplets, rain, cloud ice (pristine), snow, and graupel. Previously this code was based on Reisner et al (1998), but few of those pieces remain. A complete description is now found in Thompson et al. (2004, 2008)[191] [192].

Variables
logical, parameter, private	iiwarm = .false.

logical, private	is_aerosol_aware = .false.

logical, private	merra2_aerosol_aware = .false.

logical, parameter, private	dustyice = .true.

logical, parameter, private	homogice = .true.

integer, parameter, private	ifdry = 0

real, parameter, private	t_0 = 273.15

real, parameter, private	pi = 3.1415926536

real, parameter, private	rho_w = 1000.0

real, parameter, private	rho_s = 100.0

real, parameter, private	rho_g = 500.0

real, parameter, private	rho_i = 890.0

real, parameter	nt_c_o = 50.E6

real, parameter	nt_c_l = 100.E6

real, parameter, private	nt_c_max = 1999.E6

real, parameter	nain0 = 1.5E6

real, parameter	nain1 = 0.5E6

real, parameter	naccn0 = 300.0E6

real, parameter	naccn1 = 50.0E6

real, parameter, private	mu_r = 0.0

real, parameter, private	mu_g = 0.0

real, parameter, private	mu_i = 0.0

real, private	mu_c_o

real, private	mu_c_l

real, parameter, private	mu_s = 0.6357

real, parameter, private	kap0 = 490.6

real, parameter, private	kap1 = 17.46

real, parameter, private	lam0 = 20.78

real, parameter, private	lam1 = 3.29

real, parameter, private	gonv_min = 1.E2

real, parameter, private	gonv_max = 1.E6

real, parameter, private	am_r = PI*rho_w/6.0

real, parameter, private	bm_r = 3.0

real, parameter, private	am_s = 0.069

real, parameter, private	bm_s = 2.0

real, parameter, private	am_g = PI*rho_g/6.0

real, parameter, private	bm_g = 3.0

real, parameter, private	am_i = PI*rho_i/6.0

real, parameter, private	bm_i = 3.0

real, parameter, private	av_r = 4854.0

real, parameter, private	bv_r = 1.0

real, parameter, private	fv_r = 195.0

real, parameter, private	av_s = 40.0

real, parameter, private	bv_s = 0.55

real, parameter, private	fv_s = 100.0

real, parameter, private	av_g = 442.0

real, parameter, private	bv_g = 0.89

real, parameter, private	bv_i = 1.0

real, parameter, private	av_c = 0.316946E8

real, parameter, private	bv_c = 2.0

real, parameter, private	c_cube = 0.5

real, parameter, private	c_sqrd = 0.15

real, parameter, private	ef_si = 0.05

real, parameter, private	ef_rs = 0.95

real, parameter, private	ef_rg = 0.75

real, parameter, private	ef_ri = 0.95

real, parameter, private	r1 = 1.E-12

real, parameter, private	r2 = 1.E-6

real, parameter	eps = 1.E-15

real, parameter, private	tno = 5.0

real, parameter, private	ato = 0.304

real, parameter, private	rho_not = 101325.0/(287.05*298.0)

real, parameter, private	sc = 0.632

real, private	sc3

real, parameter, private	hgfr = 235.16

real, parameter, private	rv = 461.5

real, parameter, private	orv = 1./Rv

real, parameter, private	r = 287.04

real, parameter, private	cp = 1004.0

real, parameter, private	r_uni = 8.314
	J (mol K)-1.

double precision, parameter, private	k_b = 1.38065E-23
	Boltzmann constant [J/K].

double precision, parameter, private	m_w = 18.01528E-3
	molecular mass of water [kg/mol]

double precision, parameter, private	m_a = 28.96E-3
	molecular mass of air [kg/mol]

double precision, parameter, private	n_avo = 6.022E23
	Avogadro number [1/mol].

double precision, parameter, private	ma_w = M_w / N_avo
	mass of water molecule [kg]

real, parameter, private	ar_volume = 4./3.PI(2.5e-6)**3
	assume radius of 0.025 micrometer, 2.5e-6 cm

real, parameter, private	lsub = 2.834E6

real, parameter, private	lvap0 = 2.5E6

real, parameter, private	lfus = lsub - lvap0

real, parameter, private	olfus = 1./lfus

real, parameter, private	xm0i = 1.E-12

real, parameter, private	d0c = 1.E-6

real, parameter, private	d0r = 50.E-6

real, parameter, private	d0s = 300.E-6

real, parameter, private	d0g = 350.E-6

real, private	d0i

real, private	xm0s

real, private	xm0g

real, parameter	re_qc_min = 2.50E-6

real, parameter	re_qc_max = 50.0E-6

real, parameter	re_qi_min = 2.50E-6

real, parameter	re_qi_max = 125.0E-6

real, parameter	re_qs_min = 5.00E-6

real, parameter	re_qs_max = 999.0E-6

integer, parameter, private	nbins = 100

integer, parameter, private	nbc = nbins

integer, parameter, private	nbi = nbins

integer, parameter, private	nbr = nbins

integer, parameter, private	nbs = nbins

integer, parameter, private	nbg = nbins

integer, parameter, private	ntb_c = 37

integer, parameter, private	ntb_i = 64

integer, parameter, private	ntb_r = 37

integer, parameter, private	ntb_s = 28

integer, parameter, private	ntb_g = 28

integer, parameter, private	ntb_g1 = 37

integer, parameter, private	ntb_r1 = 37

integer, parameter, private	ntb_i1 = 55

integer, parameter, private	ntb_t = 9

integer, private	nic1

integer, private	nic2

integer, private	nii2

integer, private	nii3

integer, private	nir2

integer, private	nir3

integer, private	nis2

integer, private	nig2

integer, private	nig3

integer, parameter, private	ntb_arc = 7

integer, parameter, private	ntb_arw = 9

integer, parameter, private	ntb_art = 7

integer, parameter, private	ntb_arr = 5

integer, parameter, private	ntb_ark = 4

integer, parameter, private	ntb_in = 55

integer, private	niin2

double precision, dimension(nbins+1)	xdx

double precision, dimension(nbc)	dc

double precision, dimension(nbc)	dtc

double precision, dimension(nbi)	di

double precision, dimension(nbi)	dti

double precision, dimension(nbr)	dr

double precision, dimension(nbr)	dtr

double precision, dimension(nbs)	ds

double precision, dimension(nbs)	dts

double precision, dimension(nbg)	dg

double precision, dimension(nbg)	dtg

double precision, dimension(nbc)	t_nc

real, dimension(ntb_c), parameter, private	r_c = (/1.e-6,2.e-6,3.e-6,4.e-6,5.e-6,6.e-6,7.e-6,8.e-6,9.e-6, 1.e-5,2.e-5,3.e-5,4.e-5,5.e-5,6.e-5,7.e-5,8.e-5,9.e-5, 1.e-4,2.e-4,3.e-4,4.e-4,5.e-4,6.e-4,7.e-4,8.e-4,9.e-4, 1.e-3,2.e-3,3.e-3,4.e-3,5.e-3,6.e-3,7.e-3,8.e-3,9.e-3, 1.e-2/)
	Lookup tables for cloud water content (kg/m**3).

real, dimension(ntb_i), parameter, private	r_i = (/1.e-10,2.e-10,3.e-10,4.e-10, 5.e-10,6.e-10,7.e-10,8.e-10,9.e-10, 1.e-9,2.e-9,3.e-9,4.e-9,5.e-9,6.e-9,7.e-9,8.e-9,9.e-9, 1.e-8,2.e-8,3.e-8,4.e-8,5.e-8,6.e-8,7.e-8,8.e-8,9.e-8, 1.e-7,2.e-7,3.e-7,4.e-7,5.e-7,6.e-7,7.e-7,8.e-7,9.e-7, 1.e-6,2.e-6,3.e-6,4.e-6,5.e-6,6.e-6,7.e-6,8.e-6,9.e-6, 1.e-5,2.e-5,3.e-5,4.e-5,5.e-5,6.e-5,7.e-5,8.e-5,9.e-5, 1.e-4,2.e-4,3.e-4,4.e-4,5.e-4,6.e-4,7.e-4,8.e-4,9.e-4, 1.e-3/)
	Lookup tables for cloud ice content (kg/m**3).

real, dimension(ntb_r), parameter, private	r_r = (/1.e-6,2.e-6,3.e-6,4.e-6,5.e-6,6.e-6,7.e-6,8.e-6,9.e-6, 1.e-5,2.e-5,3.e-5,4.e-5,5.e-5,6.e-5,7.e-5,8.e-5,9.e-5, 1.e-4,2.e-4,3.e-4,4.e-4,5.e-4,6.e-4,7.e-4,8.e-4,9.e-4, 1.e-3,2.e-3,3.e-3,4.e-3,5.e-3,6.e-3,7.e-3,8.e-3,9.e-3, 1.e-2/)
	Lookup tables for rain content (kg/m**3).

real, dimension(ntb_g), parameter, private	r_g = (/1.e-5,2.e-5,3.e-5,4.e-5,5.e-5,6.e-5,7.e-5,8.e-5,9.e-5, 1.e-4,2.e-4,3.e-4,4.e-4,5.e-4,6.e-4,7.e-4,8.e-4,9.e-4, 1.e-3,2.e-3,3.e-3,4.e-3,5.e-3,6.e-3,7.e-3,8.e-3,9.e-3, 1.e-2/)
	Lookup tables for graupel content (kg/m**3).

real, dimension(ntb_s), parameter, private	r_s = (/1.e-5,2.e-5,3.e-5,4.e-5,5.e-5,6.e-5,7.e-5,8.e-5,9.e-5, 1.e-4,2.e-4,3.e-4,4.e-4,5.e-4,6.e-4,7.e-4,8.e-4,9.e-4, 1.e-3,2.e-3,3.e-3,4.e-3,5.e-3,6.e-3,7.e-3,8.e-3,9.e-3, 1.e-2/)
	Lookup tables for snow content (kg/m**3).

real, dimension(ntb_r1), parameter, private	n0r_exp = (/1.e6,2.e6,3.e6,4.e6,5.e6,6.e6,7.e6,8.e6,9.e6, 1.e7,2.e7,3.e7,4.e7,5.e7,6.e7,7.e7,8.e7,9.e7, 1.e8,2.e8,3.e8,4.e8,5.e8,6.e8,7.e8,8.e8,9.e8, 1.e9,2.e9,3.e9,4.e9,5.e9,6.e9,7.e9,8.e9,9.e9, 1.e10/)
	Lookup tables for rain y-intercept parameter (/m**4).

real, dimension(ntb_g1), parameter, private	n0g_exp = (/1.e2,2.e2,3.e2,4.e2,5.e2,6.e2,7.e2,8.e2,9.e2, 1.e3,2.e3,3.e3,4.e3,5.e3,6.e3,7.e3,8.e3,9.e3, 1.e4,2.e4,3.e4,4.e4,5.e4,6.e4,7.e4,8.e4,9.e4, 1.e5,2.e5,3.e5,4.e5,5.e5,6.e5,7.e5,8.e5,9.e5, 1.e6/)
	Lookup tables for graupel y-intercept parameter (/m**4).

real, dimension(ntb_i1), parameter, private	nt_i = (/1.0,2.0,3.0,4.0,5.0,6.0,7.0,8.0,9.0, 1.e1,2.e1,3.e1,4.e1,5.e1,6.e1,7.e1,8.e1,9.e1, 1.e2,2.e2,3.e2,4.e2,5.e2,6.e2,7.e2,8.e2,9.e2, 1.e3,2.e3,3.e3,4.e3,5.e3,6.e3,7.e3,8.e3,9.e3, 1.e4,2.e4,3.e4,4.e4,5.e4,6.e4,7.e4,8.e4,9.e4, 1.e5,2.e5,3.e5,4.e5,5.e5,6.e5,7.e5,8.e5,9.e5, 1.e6/)
	Lookup tables for ice number concentration (/m**3).

real, dimension(ntb_arc), parameter, private	ta_na = (/10.0, 31.6, 100.0, 316.0, 1000.0, 3160.0, 10000.0/)

real, dimension(ntb_arw), parameter, private	ta_ww = (/0.01, 0.0316, 0.1, 0.316, 1.0, 3.16, 10.0, 31.6, 100.0/)

real, dimension(ntb_art), parameter, private	ta_tk = (/243.15, 253.15, 263.15, 273.15, 283.15, 293.15, 303.15/)

real, dimension(ntb_arr), parameter, private	ta_ra = (/0.01, 0.02, 0.04, 0.08, 0.16/)

real, dimension(ntb_ark), parameter, private	ta_ka = (/0.2, 0.4, 0.6, 0.8/)

real, dimension(ntb_in), parameter, private	nt_in = (/1.0,2.0,3.0,4.0,5.0,6.0,7.0,8.0,9.0, 1.e1,2.e1,3.e1,4.e1,5.e1,6.e1,7.e1,8.e1,9.e1, 1.e2,2.e2,3.e2,4.e2,5.e2,6.e2,7.e2,8.e2,9.e2, 1.e3,2.e3,3.e3,4.e3,5.e3,6.e3,7.e3,8.e3,9.e3, 1.e4,2.e4,3.e4,4.e4,5.e4,6.e4,7.e4,8.e4,9.e4, 1.e5,2.e5,3.e5,4.e5,5.e5,6.e5,7.e5,8.e5,9.e5, 1.e6/)
	Lookup tables for IN concentration (/m**3) from 0.001 to 1000/Liter.

real, dimension(10), parameter, private	sa = (/ 5.065339, -0.062659, -3.032362, 0.029469, -0.000285, 0.31255, 0.000204, 0.003199, 0.0, -0.015952/)
	For snow moments conversions (from Field et al. 2005)

real, dimension(10), parameter, private	sb = (/ 0.476221, -0.015896, 0.165977, 0.007468, -0.000141, 0.060366, 0.000079, 0.000594, 0.0, -0.003577/)

real, dimension(ntb_t), parameter, private	tc = (/-0.01, -5., -10., -15., -20., -25., -30., -35., -40./)
	Temperatures (5 C interval 0 to -40) used in lookup tables.

character(len= *), parameter	thomp_table_file = 'thompson_tables_precomp_v2.sl'

character(len= *), parameter	qr_acr_qg_file = 'qr_acr_qgV2.dat'

character(len= *), parameter	qr_acr_qs_file = 'qr_acr_qsV2.dat'

character(len= *), parameter	freeze_h2o_file = 'freezeH2O.dat'

integer, parameter, private	r8size = 8

integer, parameter, private	r4size = 4

real(kind=r8size), dimension(:,:,:,:), allocatable	tcg_racg

real(kind=r8size), dimension(:,:,:,:), allocatable	tmr_racg

real(kind=r8size), dimension(:,:,:,:), allocatable	tcr_gacr

real(kind=r8size), dimension(:,:,:,:), allocatable	tmg_gacr

real(kind=r8size), dimension(:,:,:,:), allocatable	tnr_racg

real(kind=r8size), dimension(:,:,:,:), allocatable	tnr_gacr

real(kind=r8size), dimension(:,:,:,:), allocatable	tcs_racs1

real(kind=r8size), dimension(:,:,:,:), allocatable	tmr_racs1

real(kind=r8size), dimension(:,:,:,:), allocatable	tcs_racs2

real(kind=r8size), dimension(:,:,:,:), allocatable	tmr_racs2

real(kind=r8size), dimension(:,:,:,:), allocatable	tcr_sacr1

real(kind=r8size), dimension(:,:,:,:), allocatable	tms_sacr1

real(kind=r8size), dimension(:,:,:,:), allocatable	tcr_sacr2

real(kind=r8size), dimension(:,:,:,:), allocatable	tms_sacr2

real(kind=r8size), dimension(:,:,:,:), allocatable	tnr_racs1

real(kind=r8size), dimension(:,:,:,:), allocatable	tnr_racs2

real(kind=r8size), dimension(:,:,:,:), allocatable	tnr_sacr1

real(kind=r8size), dimension(:,:,:,:), allocatable	tnr_sacr2

real(kind=r8size), dimension(:,:,:,:), allocatable	tpi_qcfz

real(kind=r8size), dimension(:,:,:,:), allocatable	tni_qcfz

real(kind=r8size), dimension(:,:,:,:), allocatable	tpi_qrfz

real(kind=r8size), dimension(:,:,:,:), allocatable	tpg_qrfz

real(kind=r8size), dimension(:,:,:,:), allocatable	tni_qrfz

real(kind=r8size), dimension(:,:,:,:), allocatable	tnr_qrfz

real(kind=r8size), dimension(:,:), allocatable	tps_iaus

real(kind=r8size), dimension(:,:), allocatable	tni_iaus

real(kind=r8size), dimension(:,:), allocatable	tpi_ide

real(kind=r8size), dimension(:,:), allocatable	t_efrw

real(kind=r8size), dimension(:,:), allocatable	t_efsw

real(kind=r8size), dimension(:,:,:), allocatable	tnr_rev

real(kind=r8size), dimension(:,:,:), allocatable	tpc_wev

real(kind=r8size), dimension(:,:,:), allocatable	tnc_wev

real(kind=r4size), dimension(:,:,:,:,:), allocatable	tnccn_act

real, dimension(5, 15), private	cce

real, dimension(5, 15), private	ccg

real, dimension(15), private	ocg1

real, dimension(15), private	ocg2

real, dimension(7), private	cie

real, dimension(7), private	cig

real, private	oig1

real, private	oig2

real, private	obmi

real, dimension(13), private	cre

real, dimension(13), private	crg

real, private	ore1

real, private	org1

real, private	org2

real, private	org3

real, private	obmr

real, dimension(18), private	cse

real, dimension(18), private	csg

real, private	oams

real, private	obms

real, private	ocms

real, dimension(12), private	cge

real, dimension(12), private	cgg

real, private	oge1

real, private	ogg1

real, private	ogg2

real, private	ogg3

real, private	oamg

real, private	obmg

real, private	ocmg

real	t1_qr_qc

real	t1_qr_qi

real	t2_qr_qi

real	t1_qg_qc

real	t1_qs_qc

real	t1_qs_qi

real	t1_qr_ev

real	t2_qr_ev

real	t1_qs_sd

real	t2_qs_sd

real	t1_qg_sd

real	t2_qg_sd

real	t1_qs_me

real	t2_qs_me

real	t1_qg_me

real	t2_qg_me

type(mpi_comm)	mpi_communicator

logical	thompson_table_writer

Detailed Description

Prior to WRFv3.1, this code was single-moment rain prediction as described in the reference above, but in v3.1 and higher, the scheme is two-moment rain (predicted rain number concentration).

Beginning with WRFv3.6, this is also the "aerosol-aware" scheme as described in Thompson, G. and T. Eidhammer, 2014: A study of aerosol impacts on clouds and precipitation development in a large winter cyclone. J. Atmos. Sci., 71, 3636-3658. Setting WRF namelist option mp_physics=8 utilizes the older one-moment cloud water with constant droplet concentration set as Nt_c (found below) while mp_physics=28 uses double-moment cloud droplet number concentration, which is not permitted to exceed Nt_c_max below.

Most importantly, users may wish to modify the prescribed number of cloud droplets (Nt_c; see guidelines mentioned below). Otherwise, users may alter the rain and graupel size distribution parameters to use exponential (Marshal-Palmer) or generalized gamma shape. The snow field assumes a combination of two gamma functions (from Field et al. 2005) and would require significant modifications throughout the entire code to alter its shape as well as accretion rates. Users may also alter the constants used for density of rain, graupel, ice, and snow, but the latter is not constant when using Paul Field's snow distribution and moments methods. Other values users can modify include the constants for mass and/or velocity power law relations and assumed capacitances used in deposition/ sublimation/evaporation/melting. Remaining values should probably be left alone.

Author: Greg Thompson, NCAR-RAL, gthom.nosp@m.psn@.nosp@m.ucar..nosp@m.edu, 303-497-2805

Last modified: 24 Jan 2018 Aerosol additions to v3.5.1 code 9/2013 Cloud fraction additions 11/2014 part of pre-v3.7
Imported in CCPP by: Dom Heinzeller, NOAA/ESRL/GSD, dom.h.nosp@m.einz.nosp@m.eller.nosp@m.@noa.nosp@m.a.gov
Last modified: 6 Aug 2018 Update of initial import to WRFV4.0
Last modified: 13 Mar 2020 Add logic to turtn on/off the calculation of melting layer in radar reflectivity routine
Last modified: 2 Jun 2020 Add option to rollback to version 3.8.1 used in RAPv5/HRRRv4, include stochastic physics perturbations to the graupel intercept parameter, the cloud water shape parameter, and the number concentration of nucleated aerosols.
Last modified: 12 Feb 2021 G. Thompson updated to align more closely with his WRF version, including bug fixes and designed changes.

Functions/Subroutines

Variables

Detailed Description