NAM_ELEC

It contains the different parameters used by the electrical scheme. They are included in the declarative module MODD_ELEC_DESCRn.

NAM_ELEC content

Fortran name	Fortran type	Default value
LOCG	LOGICAL	.FALSE.
LELEC_FIELD	LOGICAL	.TRUE.
LFLASH_GEOM	LOGICAL	.TRUE.
LFW_HELFA	LOGICAL	.FALSE.
LCOSMIC_APPROX	LOGICAL	.FALSE.
LION_ATTACH	LOGICAL	.TRUE.
CDRIFT	CHARACTER(LEN=3)	‘PPM’
LRELAX2FW_ION	LOGICAL	.FALSE.
LINDUCTIVE	LOGICAL	.FALSE.
LSAVE_COORD	LOGICAL	.FALSE.
LLNOX_EXPLICIT	LOGICAL	.FALSE.
LSERIES_ELEC	LOGICAL	.FALSE.
NTSAVE_SERIES	INTEGER	60
NFLASH_WRITE	INTEGER	100
CNI_CHARGING	CHARACTER(LEN=5)	‘TAKAH’
XQTC	REAL	263.0
XLIM_NI_IS	REAL	10.E-15
XLIM_NI_IG	REAL	30.E-15
XLIM_NI_SG	REAL	100.E-15
CLSOL	CHARACTER(LEN=5)	‘RICHA’
NLAPITR_ELEC	INTEGER	4
XRELAX_ELEC	REAL	1
XETRIG	REAL	200.E3
XEBALANCE	REAL	0.1
XEPROP	REAL	15.E3
XQEXCES	REAL	2.E-10
XQNEUT	REAL	1.E-10
XDFRAC_ECLAIR	REAL	2.3
XDFRAC_L	REAL	1500.0
XWANG_A	REAL	0.34E21
XWANG_B	REAL	1.3E16

• LOCG :

  • .TRUE. : only the cloud electrification is computed.

  • .FALSE. : lightning flashes can be produced.

• LELEC_FIELD :

  • .TRUE. : the electric field is computed.

  • .FALSE. : the electric field is not computed.

• LFLASH_GEOM : when .TRUE., the lightning flash branches are produced randomly. (only one lightning scheme implemented, then must be set to .TRUE.)

• LFW_HELFA : when .TRUE., Helsdon-Farley Fair Weather field

• LCOSMIC_APPROX : when .TRUE., neglecting height variations of fair ion weather ion current in calculating ion source from cosmic rays

• LION_ATTACH : when .TRUE., ion attachment to hydrometeors is considered

• CDRIFT : ion drift

  • ‘PPM’ : PPM advection scheme

  • ‘DIV’ : divergence form

• LRELAX2FW_ION : when .TRUE., relaxation to fair weather concentration in rim zone and top absorbing layer

• LINDUCTIVE : when .TRUE., the inductive charging mechanism is taken into account.

• LSAVE_COORD : when .TRUE., the flash coordinates are written in an ascii file.

• LSERIES_ELEC : when .TRUE., some dynamical and microphysical parameters are computed and saved in an ascii file

• NTSAVE_SERIES : time interval (s) at which data from series_cloud_elec are written in an ascii file

• NFLASH_WRITE : number of flashes to be saved before writing the diag and/or coordinates in ascii files

• LLNOX_EXPLICIT : when .TRUE., nitrogen oxides are produced along the lightning path (not yet implemented)

• CNI_CHARGING : non-inductive charging parameterization

  • ‘HELFA’ : based on Helsdon and Farley (1987)

  • ‘TAKAH’ : based on Takahashi (1978)

  • ‘SAUN1’ : based on Saunders et al. (1991), but does not take into account the marginal positive and negative regions at low liquid water content

  • ‘SAUN2’ : based on Saunders et al. (1991)

  • ‘SAP98’ : based on Saunders and Peck (1998)

  • ‘GARDI’ : based on Gardiner et al. (1985)

• XQTC : temperature charge reversal (K), only if CNI_CHARGING = ‘HELFA’

• XLIM_NI_IS : max magnitude of dq for I-S non-inductive charging (C)

• XLIM_NI_IG : max magnitude of dq for I-G non-inductive charging (C)

• XLIM_NI_SG : max magnitude of dq for S-G non-inductive charging (C)

• CLSOL : Laplace equation solver for the electric field

• NLAPITR_ELEC : number of iterations for the electric field solver

• XRELAX_ELEC : relaxation factor for the electric field solver

• XETRIG : electric field threshold (V \(m^{-1}\)) for lightning flash triggering

• XEBALANCE : (1-XEBALANCE) is the proportion of XETRIG over which a lightning can be triggerred to take into account the subgrid scale variability

• XEPROP : electric field threshold (V \(m^{-1}\)) for the bidirectional leader propagation

• XQEXCES : charge density threshold (C \(m^{-3}\)) for neutralization

• XDFRAC_ECLAIR : fractal dimension of lightning flashes

• XDFRAC_L : linear coefficient for the branch number

• XWANG_A : a parameter of the Wang et al. (1998) formula for LNOx production (not yet implemented)

• XWANG_B : b parameter of the Wang et al. (1998) formula for LNOx production (not yet implemented)