From 3209bea5f089986a4c1656c20cec36c61cc7619e Mon Sep 17 00:00:00 2001 From: CatherineThomas-NOAA <59020064+CatherineThomas-NOAA@users.noreply.github.com> Date: Fri, 15 Nov 2024 17:37:39 -0500 Subject: [PATCH] Enable tapering of atm ens perts at the model top (#3097) This commit turns on the tapering of atmospheric ensemble perturbations at the model top in the EnKF to reduce the upper layer ensemble spread. Resolves #3096 --------- Co-authored-by: Rahul Mahajan --- parm/config/gfs/config.eupd | 2 +- scripts/exgdas_enkf_update.sh | 3 ++- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/parm/config/gfs/config.eupd b/parm/config/gfs/config.eupd index 2ff48240ae..7b0c8994c2 100644 --- a/parm/config/gfs/config.eupd +++ b/parm/config/gfs/config.eupd @@ -28,7 +28,7 @@ export lnsigcutoff=2.75 # ignored if modelspace_vloc=.true. export lobsdiag_forenkf=".true." # use jacobian. must be .true. if modelspace_vloc=".true." # need to specify .true. setting since config.anal sets to .false. - +export taperanalperts=".true." export NAM_ENKF="smoothparm=35," echo "END: config.eupd" diff --git a/scripts/exgdas_enkf_update.sh b/scripts/exgdas_enkf_update.sh index e924274d39..752cb07a6b 100755 --- a/scripts/exgdas_enkf_update.sh +++ b/scripts/exgdas_enkf_update.sh @@ -77,6 +77,7 @@ write_spread_diag=${write_spread_diag:-".false."} cnvw_option=${cnvw_option:-".false."} netcdf_diag=${netcdf_diag:-".true."} modelspace_vloc=${modelspace_vloc:-".false."} # if true, 'vlocal_eig.dat' is needed +taperanalperts=${taperanalperts:-".false."} IAUFHRS_ENKF=${IAUFHRS_ENKF:-6} NMEM_ENS_MAX=${NMEM_ENS:-80} if [ "${RUN}" = "enkfgfs" ]; then @@ -287,7 +288,7 @@ cat > enkf.nml << EOFnml univaroz=.false.,adp_anglebc=.true.,angord=4,use_edges=.false.,emiss_bc=.true., letkf_flag=${letkf_flag},nobsl_max=${nobsl_max},denkf=${denkf},getkf=${getkf}., nhr_anal=${IAUFHRS_ENKF},nhr_state=${IAUFHRS_ENKF}, - lobsdiag_forenkf=$lobsdiag_forenkf, + lobsdiag_forenkf=${lobsdiag_forenkf},taperanalperts=${taperanalperts}, write_spread_diag=$write_spread_diag, modelspace_vloc=$modelspace_vloc, use_correlated_oberrs=${use_correlated_oberrs},