A. Content of Namelist

The following are lists and explanations of the EnKF namelist variables. Users can also check file params.f90 for the details.
Section nam_enkf
Variable Name Description Data Type Default
datein Analysis date in YYYYMMDDHH integer 0
datapath path to data directory (include trailing slash) Character (len=500) “”
iassim_order = 0 for the order they are read in, =1 for random order = 2 for order of predicted posterior variance reduction (based on prior) integer 0
covinflatemax maximum inflation real(r_single) 1.e30
covinflatemin minimum inflation real(r_single) 1.0
deterministic if true, use EnSRF w/o perturbed obs. if false, use perturbed obs EnKF. logical true
sortinc if false, re-order obs to minimize regression errors as described in Anderson (2003). logical true
corrlengthnh length for horizontal localization (in km) in north hemisphere real(r_single) 2800
corrlengthtr length for horizontal localization (in km) in tropic real(r_single) 2800
corrlengthsh length for horizontal localization (in km) in south hemisphere real(r_single) 2800


Variable Name Description Data Type Default
varqc Turn on varqc logical false
huber use huber norm instead of “flat-tail” logical fales
nlons number of lons integer 0
nlats Number of lats integer 0
smoothparm smoothing parameter for inflation (-1 for no smoothing) real(r_single) -1
readin_localization If true, read in localization length scales from an external file logical false
zhuberleft Parameter for “huber norm” QC real(r_single) 1.e30
zhuberright Parameter for “huber norm” QC real(r_single) 1.e30
obtimelnh observation time localization in hours over north hemisphere real(r_single) 25.925
obtimeltr observation time localization in hours over tropic real(r_single) 25.925
obtimelsh observation time localization in hours over south hemisphere real(r_single) 25.925
reducedgrid Smooth in a reduced grid with variable number of longitudes per latitude. Number of longitudes chosen so that zonal grid spacing is approx the same as at the equator logical false  
lnsigcutoffnh length for vertical localization in ln(p) over north hemisphere for conventional observation real(r_single) 2.0
lnsigcutofftr length for vertical localization in ln(p) over tropic conventional observation real(r_single) 2.0
lnsigcutoffsh length for vertical localization in ln(p) over south hemisphere for conventional observation real(r_single) 2.0
lnsigcutoffsatnh length for vertical localization in ln(p) over north hemisphere for satellite radiance observation real(r_single) -999.0
lnsigcutoffsattr length for vertical localization in ln(p) over tropic satellite radiance observation real(r_single) -999.0
lnsigcutoffsatsh length for vertical localization in ln(p)over south hemisphere for satellite radiance observation real(r_single) -999.0
lnsigcutoffpsnh length for vertical localization in ln(p) over north hemisphere for surface pressure observation real(r_single) -999.0
lnsigcutoffpstr length for vertical localization in ln(p) over tropic surface pressure observation real(r_single) -999.0
lnsigcutoffpssh length for vertical localization in ln(p) over south hemisphere for surface pressure observation real(r_single) -999.0


Variable Name Description Data Type Default
analpertwtnh adaptive posterior inflation parameter over north hemisphere: 1 means inflate all the way back to prior spread real(r_single) 0.0
analpertwtsh adaptive posterior inflation parameter over tropic: 1 means inflate all the way back to prior spread real(r_single) 0.0
analpertwttr adaptive posterior inflation parameter over south hemisphere: 1 means inflate all the way back to prior spread real(r_single) 0.0
sprd_tol tolerance for background check: observations are not used if they are more than sqrt(S+R) from mean, S is ensemble variance, R is observation error variance. real(r_single) 9.9e31
nlevs total number of levels integer 0
nanals number of ensemble members integer 0
nvars number of 3d variables to update. For hydrostatic models, typically 5 (u,v,T,q,ozone). integer 5
saterrfact factor to multiply sat radiance errors real(r_single) 1.0
univaroz If true, ozone observations only affect ozone logical true
regional If true, analysis is for regional logical false
use_gfs_nemsio If true, GFS background is in NEMS format logical false
paoverpb_thresh if obs space posterior variance divided by prior variance less than this value, observation is skipped during serial processing. 1.0 = don’t skip any obs (r_single) 1.0
latbound definition of tropics and mid-latitudes (for inflation). real(r_single) 25.0
delat width of transition zone real(r_single) 10.0
pseudo_rh use ’pseudo-rh’ analysis variable, as in GSI logical false
numiter number of times to iterate state/bias correction update. (only relevant when satellite radiances assimilated, i.e. nobs_sat>0) integer 1.0


Variable Name Description Data Type Default
biasvar background error variance for rad bias coeffs (used in radbias.f90). Default is (old) GSI value. if negative, bias coeff error
variace is set to - biasvar/N, where N is number of obs per instrument/channel. if newpc4pred is .true., biasvar is not used -
the estimated analysis error variance from the previous cycle is used instead (same as in the GSI). real(r_single) 0.1
lupd_satbiasc if performing satellite bias correction update logical true
cliptracers if true, tracers are clipped to zero when read in, and just before they are written out. logical true
simple_partition partition obs for enkf using Graham’s rule logical true
adp_anglebc turn off or on the variational radiance angle bias correction logical false
angord order of polynomial for angle bias correction Integer 0
newpc4pred controls preconditioning due to sat-bias correction term logical  
nmmb If true, ensemble forecast is NMMB logical false
iau logical false
nhr_anal background forecast time for analysis integer 6
letkf_flag If true, do LETKF logical false
boxsize Observation box size for LETKF (deg) real(r_single) 90.0
massbal_adjust mass balance adjustment for GFS logical false
use_edges logical to use data on scan edges (.true.=to use) logical true
emiss_bc If true, turn on emissivity bias correction logical false

Section nam_wrf

Variable Name Description Data Type Default
arw regional dynamical core ARW logical false
nmm regional dynamical core NMM logical true
doubly_periodic   logical true

Section satobs_enkf

Variable Name Description Data Type Default
sattypes_rad strings describing the satellite data type (which form part of the diag* filename). character(len=20) array (nsatmax_rad) ’”“
dsis strings corresponding to sattypes_rad which correspond to the names in the NCEP global_satinfo file. character(len=20) array (nsatmax_rad) “”

Section ozobs_enkf

Variable Name Description Data Type Default
sattypes_oz strings describing the ozone satellite data type (which form part of the diag* filename) character(len=20) array (nsatmax_oz) “”