@@ -97,6 +97,12 @@ namespace gdasapp {
9797 ensMembers.push_back (postProcIncr.read (i));
9898 }
9999
100+ // Check if we need to recenter the increment around the deterministic
101+ bool addRecenterIncr (false );
102+ if ( fullConfig.has (" add recentering increment"
103+ fullConfig.get (" add recentering increment"
104+ }
105+
100106 // Compute ensemble moments
101107 soca::Increment ensMean (geom, postProcIncr.socaIncrVar_ , postProcIncr.dt_ );
102108 soca::Increment ensStd (geom, postProcIncr.socaIncrVar_ , postProcIncr.dt_ );
@@ -120,24 +126,25 @@ namespace gdasapp {
120126 fullConfig.get (" steric height"
121127 oops::Log::info () << " steric config 0000: "
122128
123- // Initialize trajectories
129+ // Initialize the trajectories used in the linear variable changes
124130 const eckit::LocalConfiguration trajConfig (fullConfig, " trajectory"
125- soca::State cycleTraj (geom, trajConfig); // trajectory of the cycle
126- soca::State meanTraj (cycleTraj); // trajectory defined as the ens. mean
127- meanTraj.zero ();
128- meanTraj += ensMean;
129-
130- // Compute the error between the ensemble mean and the deterministic
131- soca::Increment deterministicError (geom, postProcIncr.socaIncrVar_ , postProcIncr.dt_ );
132- deterministicError.diff (cycleTraj, meanTraj);
131+ soca::State determTraj (geom, trajConfig); // deterministic trajectory
132+ soca::State ensMeanTraj (determTraj); // trajectory defined as the ens. mean
133+ ensMeanTraj.zero ();
134+ ensMeanTraj += ensMean;
135+
136+ // Compute the recentering increment as the difference between
137+ // the ensemble mean and the deterministic
138+ soca::Increment recenteringIncr (geom, postProcIncr.socaIncrVar_ , postProcIncr.dt_ );
139+ recenteringIncr.diff (determTraj, ensMeanTraj);
133140 eckit::LocalConfiguration sshRecErrOutputConfig (fullConfig, " ssh output.recentering error"
134- deterministicError = postProcIncr.setToZero (deterministicError );
141+ recenteringIncr = postProcIncr.setToZero (recenteringIncr );
135142 oops::Log::info () << " steric config : "
136- postProcIncr.applyLinVarChange (deterministicError , stericVarChangeConfig, cycleTraj );
137- oops::Log::info () << " ensemble mean: " meanTraj << std::endl;
138- oops::Log::info () << " deterministic: " cycleTraj << std::endl;
139- oops::Log::info () << " error: " deterministicError << std::endl;
140- deterministicError .write (sshRecErrOutputConfig);
143+ postProcIncr.applyLinVarChange (recenteringIncr , stericVarChangeConfig, determTraj );
144+ oops::Log::info () << " ensemble mean: " ensMeanTraj << std::endl;
145+ oops::Log::info () << " deterministic: " determTraj << std::endl;
146+ oops::Log::info () << " error: " recenteringIncr << std::endl;
147+ recenteringIncr .write (sshRecErrOutputConfig);
141148
142149 // Re-process the ensemble of perturbations
143150 int result = 0 ;
@@ -165,7 +172,7 @@ namespace gdasapp {
165172
166173 // Compute the original steric height perturbation from T and S
167174 eckit::LocalConfiguration stericConfig (fullConfig, " steric height"
168- postProcIncr.applyLinVarChange (incr, stericConfig, meanTraj );
175+ postProcIncr.applyLinVarChange (incr, stericConfig, ensMeanTraj );
169176 ssh_tmp = incr;
170177 sshSteric.push_back (ssh_tmp);
171178
@@ -183,10 +190,10 @@ namespace gdasapp {
183190 incr = postProcIncr.setToZero (incr);
184191
185192 // Filter ensemble member and recompute steric ssh, recentering around
186- // the cycle's trajectory
193+ // the deterministic trajectory
187194 if ( fullConfig.has (" linear variable change"
188195 eckit::LocalConfiguration lvcConfig (fullConfig, " linear variable change"
189- postProcIncr.applyLinVarChange (incr, lvcConfig, cycleTraj );
196+ postProcIncr.applyLinVarChange (incr, lvcConfig, determTraj );
190197 }
191198
192199 // Add the unbalanced ssh to the recentered perturbation
@@ -200,12 +207,23 @@ namespace gdasapp {
200207 incr.fromFieldSet (incrFs);
201208 oops::Log::debug () << " &&&&& after adding ssh_u "
202209
203- // Save final perturbation, used in the offline EnVAR
210+ // Save final perturbation, used in the EnVAR or to initialize the ensemble forecast
211+ if (addRecenterIncr) {
212+ // Add the recentering increment to the increment ensemble members.
213+ // This is generally used to recenter the ensemble fcst around the
214+ // deterministic
215+ incr += recenteringIncr;
216+ }
204217 result = postProcIncr.save (incr, i+1 );
205218
206219 // Update ensemble
207220 ensMembers[i] = incr;
208- }
221+ }
222+
223+ // Exit early if only recentering around the deterministic
224+ if (addRecenterIncr) {
225+ return 0 ;
226+ }
209227
210228 // Compute ensemble moments for total ssh
211229 soca::Increment sshMean (geom, socaSshVar, postProcIncr.dt_ );
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