JCSDA-internal · shlyaeva · Apr 2, 2026 · Apr 10, 2026 · May 27, 2026 · Jul 1, 2026
diff --git a/src/soca/LinearVariableChange/Balance/Balance.cc b/src/soca/LinearVariableChange/Balance/Balance.cc
@@ -60,28 +60,13 @@ namespace soca {
     soca_balance_mult_f90(keyFtnConfig_, dxa.toFortran(), dxm.toFortran());
   }
   // -----------------------------------------------------------------------------
-  void Balance::multiplyInverse(const Increment & dxm, Increment & dxa) const {
-    // dxa = K^-1 dxm
-    oops::Log::trace() << "soca::Balance::multiplyInverse " << std::endl;
-    util::Timer timer("soca::Balance", "multiplyInverse");
-    soca_balance_multinv_f90(keyFtnConfig_, dxm.toFortran(), dxa.toFortran());
-  }
-  // -----------------------------------------------------------------------------
   void Balance::multiplyAD(const Increment & dxm, Increment & dxa) const {
     // dxa = K^T dxm
     oops::Log::trace() << "soca::Balance::multiplyAD " << std::endl;
     util::Timer timer("soca::Balance", "multiplyAD");
     soca_balance_multad_f90(keyFtnConfig_, dxm.toFortran(), dxa.toFortran());
   }
   // -----------------------------------------------------------------------------
-  void Balance::multiplyInverseAD(const Increment & dxa,
-                                  Increment & dxm) const {
-    // dxm = (K^-1)^T dxa
-    oops::Log::trace() << "soca::Balance::multiplyInverseAD " << std::endl;
-    util::Timer timer("soca::Balance", "multiplyInverseAD");
-    soca_balance_multinvad_f90(keyFtnConfig_, dxa.toFortran(), dxm.toFortran());
-  }
-  // -----------------------------------------------------------------------------
   void Balance::print(std::ostream & os) const {
     os << "SOCA linear change variable: Balance";
   }

diff --git a/src/soca/LinearVariableChange/Balance/Balance.h b/src/soca/LinearVariableChange/Balance/Balance.h
@@ -40,9 +40,7 @@ class Balance: public LinearVariableChangeBase {
 
 /// Perform linear transforms
   void multiply(const Increment &, Increment &) const override;
-  void multiplyInverse(const Increment &, Increment &) const override;
   void multiplyAD(const Increment &, Increment &) const override;
-  void multiplyInverseAD(const Increment &, Increment &) const override;
 
  private:
   void print(std::ostream &) const override;

diff --git a/src/soca/LinearVariableChange/Balance/CMakeLists.txt b/src/soca/LinearVariableChange/Balance/CMakeLists.txt
@@ -2,6 +2,8 @@ soca_target_sources(
   Balance.cc
   Balance.h
   BalanceFortran.h
+  InverseBalance.cc
+  InverseBalance.h
   soca_balance_mod.F90
   soca_balance.interface.F90
   soca_ksshts_mod.F90

diff --git a/src/soca/LinearVariableChange/Balance/InverseBalance.cc b/src/soca/LinearVariableChange/Balance/InverseBalance.cc
@@ -0,0 +1,75 @@
+/*
+ * (C) Copyright 2017-2021  UCAR.
+ *
+ * This software is licensed under the terms of the Apache Licence Version 2.0
+ * which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
+ */
+
+#include <ostream>
+#include <string>
+
+#include "eckit/config/Configuration.h"
+
+#include "oops/util/Logger.h"
+#include "oops/util/Timer.h"
+
+#include "soca/Geometry/Geometry.h"
+#include "soca/Increment/Increment.h"
+#include "soca/State/State.h"
+#include "soca/LinearVariableChange/Balance/InverseBalance.h"
+#include "soca/LinearVariableChange/Balance/BalanceFortran.h"
+
+using oops::Log;
+
+namespace soca {
+
+  // -----------------------------------------------------------------------------
+
+  static LinearVariableChangeMaker<InverseBalance>
+                         makerLinearVariableChangeBalance_("Inverse BalanceSOCA");
+
+  // -----------------------------------------------------------------------------
+  InverseBalance::InverseBalance(const State & bkg,
+                                 const State & traj,
+                                 const Geometry & geom,
+                                 const eckit::Configuration & conf) {
+    oops::Log::trace() << "soca::InverseBalance::setup " << std::endl;
+    util::Timer timer("soca::InverseBalance", "InverseBalance");
+
+    const eckit::Configuration * configc = &conf;
+
+    // Interpolate trajectory to the geom resolution
+    State traj_at_geomres(geom, traj);
+
+    // Compute Jacobians of the balance wrt traj
+    soca_balance_setup_f90(keyFtnConfig_,
+                           &configc,
+                           traj_at_geomres.toFortran(),
+                           geom.toFortran());
+  }
+  // -----------------------------------------------------------------------------
+  InverseBalance::~InverseBalance() {
+    oops::Log::trace() << "soca::InverseBalance::delete " << std::endl;
+    soca_balance_delete_f90(keyFtnConfig_);
+  }
+  // -----------------------------------------------------------------------------
+  void InverseBalance::multiply(const Increment & dxm, Increment & dxa) const {
+    // dxa = K^-1 dxm
+    oops::Log::trace() << "soca::InverseBalance::multiply " << std::endl;
+    util::Timer timer("soca::InverseBalance", "multiply");
+    soca_balance_multinv_f90(keyFtnConfig_, dxm.toFortran(), dxa.toFortran());
+  }
+  // -----------------------------------------------------------------------------
+  void InverseBalance::multiplyAD(const Increment & dxa,
+                           Increment & dxm) const {
+    // dxm = (K^-1)^T dxa
+    oops::Log::trace() << "soca::InverseBalance::multiplyAD " << std::endl;
+    util::Timer timer("soca::InverseBalance", "multiplyAD");
+    soca_balance_multinvad_f90(keyFtnConfig_, dxa.toFortran(), dxm.toFortran());
+  }
+  // -----------------------------------------------------------------------------
+  void InverseBalance::print(std::ostream & os) const {
+    os << "SOCA linear change variable: inverse Balance";
+  }
+  // -----------------------------------------------------------------------------
+}  // namespace soca
diff --git a/src/soca/LinearVariableChange/Balance/InverseBalance.h b/src/soca/LinearVariableChange/Balance/InverseBalance.h
@@ -0,0 +1,51 @@
+/*
+ * (C) Copyright 2017-2021  UCAR.
+ *
+ * This software is licensed under the terms of the Apache Licence Version 2.0
+ * which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
+ */
+
+#pragma once
+
+#include <ostream>
+#include <string>
+
+#include "oops/util/DateTime.h"
+#include "oops/util/Printable.h"
+
+#include "soca/LinearVariableChange/Base/LinearVariableChangeBase.h"
+
+// Forward declarations
+namespace eckit {
+  class Configuration;
+}
+namespace soca {
+  class State;
+  class Increment;
+  class Geometry;
+}
+
+// -----------------------------------------------------------------------------
+
+namespace soca {
+
+/// SOCA balance: inverse
+class InverseBalance: public LinearVariableChangeBase {
+ public:
+  static const std::string classname() {return "soca::Balance";}
+
+  explicit InverseBalance(const State &, const State &,
+                          const Geometry &, const eckit::Configuration &);
+  ~InverseBalance();
+
+/// Perform linear transforms
+  void multiply(const Increment &, Increment &) const override;
+  void multiplyAD(const Increment &, Increment &) const override;
+
+ private:
+  void print(std::ostream &) const override;
+  int keyFtnConfig_;
+};
+// -----------------------------------------------------------------------------
+
+}  // namespace soca
diff --git a/src/soca/LinearVariableChange/Base/LinearVariableChangeBase.h b/src/soca/LinearVariableChange/Base/LinearVariableChangeBase.h
@@ -58,9 +58,7 @@ class LinearVariableChangeBase : public util::Printable,
   LinearVariableChangeBase() {}
   virtual ~LinearVariableChangeBase() {}
   virtual void multiply(const Increment &, Increment &) const = 0;
-  virtual void multiplyInverse(const Increment &, Increment &) const = 0;
   virtual void multiplyAD(const Increment &, Increment &) const = 0;
-  virtual void multiplyInverseAD(const Increment &, Increment &) const = 0;
 
  private:
   virtual void print(std::ostream &) const = 0;

diff --git a/src/soca/LinearVariableChange/LinearModel2GeoVaLs/LinearModel2GeoVaLs.cc b/src/soca/LinearVariableChange/LinearModel2GeoVaLs/LinearModel2GeoVaLs.cc
@@ -69,14 +69,6 @@ void LinearModel2GeoVaLs::multiply(const Increment &dxin,
 
 // -----------------------------------------------------------------------------
 
-void LinearModel2GeoVaLs::multiplyInverse(const Increment &dxin,
-                                                Increment &dxout) const {
-  util::Timer timer("soca::LinearModel2GeoVaLs", "multiplyInverse");
-  multiply(dxin, dxout);
-}
-
-// -----------------------------------------------------------------------------
-
 void LinearModel2GeoVaLs::multiplyAD(const Increment &dxin,
                                            Increment &dxout) const {
   util::Timer timer("soca::LinearModel2GeoVaLs", "multiplyAD");
@@ -106,14 +98,6 @@ void LinearModel2GeoVaLs::multiplyAD(const Increment &dxin,
 
 // -----------------------------------------------------------------------------
 
-void LinearModel2GeoVaLs::multiplyInverseAD(const Increment &dxin,
-                                                  Increment &dxout) const {
-  util::Timer timer("soca::LinearModel2GeoVaLs", "multiplyInverseAD");
-  multiplyAD(dxin, dxout);
-}
-
-// -----------------------------------------------------------------------------
-
 void LinearModel2GeoVaLs::print(std::ostream & os) const {
   os << "SOCA linear change variable: LinearModel2GeoVaLs";
 }

diff --git a/src/soca/LinearVariableChange/LinearModel2GeoVaLs/LinearModel2GeoVaLs.h b/src/soca/LinearVariableChange/LinearModel2GeoVaLs/LinearModel2GeoVaLs.h
@@ -33,9 +33,7 @@ class LinearModel2GeoVaLs: public LinearVariableChangeBase {
   ~LinearModel2GeoVaLs();
 
   void multiply(const Increment &, Increment &) const;
-  void multiplyInverse(const Increment &, Increment &) const;
   void multiplyAD(const Increment &, Increment &) const;
-  void multiplyInverseAD(const Increment &, Increment &) const;
 
  private:
   const Geometry & geom_;

diff --git a/src/soca/LinearVariableChange/LinearVariableChange.cc b/src/soca/LinearVariableChange/LinearVariableChange.cc
@@ -109,27 +109,6 @@ void LinearVariableChange::changeVarTL(Increment & dx,
 
 // -----------------------------------------------------------------------------
 
-void LinearVariableChange::changeVarInverseTL(Increment & dx,
-                                              const oops::Variables & vars) const {
-  Log::trace() << "LinearVariableChange::multiplyInverse starting"
-               << vars << std::endl;
-
-  // Create output state
-  Increment dxout(dx.geometry(), vars, dx.validTime());
-
-  // Call variable change(s)
-  for (ircst_ it = linVarChas_.rbegin(); it != linVarChas_.rend(); ++it) {
-    dxout.zero();
-    it->multiplyInverse(dx, dxout);
-    dx.updateFields(vars);
-    dx = dxout;
-  }
-
-  Log::trace() << "LinearVariableChange::multiplyInverse done" << std::endl;
-}
-
-// -----------------------------------------------------------------------------
-
 void LinearVariableChange::changeVarAD(Increment & dx,
                                        const oops::Variables & vars) const {
   Log::trace() << "LinearVariableChange::multiplyAD starting" << std::endl;
@@ -148,27 +127,6 @@ void LinearVariableChange::changeVarAD(Increment & dx,
 
 // -----------------------------------------------------------------------------
 
-void LinearVariableChange::changeVarInverseAD(Increment & dx,
-                                              const oops::Variables & vars) const {
-  Log::trace() << "LinearVariableChange::multiplyInverseAD starting"
-               << std::endl;
-
-  // Create output state
-  Increment dxout(dx.geometry(), vars, dx.validTime());
-
-  // Call variable change(s)
-  for (icst_ it = linVarChas_.begin(); it != linVarChas_.end(); ++it) {
-    dxout.zero();
-    it->multiplyInverseAD(dx, dxout);
-    dx.updateFields(vars);
-    dx = dxout;
-  }
-
-  Log::trace() << "LinearVariableChange::multiplyInverseAD done" << std::endl;
-}
-
-// -----------------------------------------------------------------------------
-
 void LinearVariableChange::print(std::ostream & os) const {
   for (icst_ it = linVarChas_.begin(); it != linVarChas_.end(); ++it) {
     os << *it;

diff --git a/src/soca/LinearVariableChange/LinearVariableChange.h b/src/soca/LinearVariableChange/LinearVariableChange.h
@@ -59,9 +59,7 @@ class LinearVariableChange : public util::Printable {
   void changeVarTraj(const State &, const oops::Variables &);
 
   void changeVarTL(Increment &, const oops::Variables &) const;
-  void changeVarInverseTL(Increment &, const oops::Variables &) const;
   void changeVarAD(Increment &, const oops::Variables &) const;
-  void changeVarInverseAD(Increment &, const oops::Variables &) const;
 
  private:
   void print(std::ostream &) const override;

diff --git a/src/soca/VariableChange/Base/VariableChangeBase.h b/src/soca/VariableChange/Base/VariableChangeBase.h
@@ -56,7 +56,6 @@ class VariableChangeBase : public util::Printable, private boost::noncopyable {
   virtual ~VariableChangeBase() {}
 
   virtual void changeVar(const State &, State &) const = 0;
-  virtual void changeVarInverse(const State &, State &) const = 0;
 
   virtual const std::string classname() = 0;
 

diff --git a/src/soca/VariableChange/Model2Ana/Model2Ana.cc b/src/soca/VariableChange/Model2Ana/Model2Ana.cc
@@ -54,7 +54,6 @@ void Model2Ana::changeVar(const State & xm,
                         std::endl;
   util::Timer timer("soca::Model2Ana", "changeVar");
 
-  util::DateTime * vtime = &xa.validTime();
   xa = xm;
 
   // Rotate from the logical grid to meridional/zonal
@@ -81,7 +80,6 @@ void Model2Ana::changeVarInverse(const State & xa,
                         std::endl;
   util::Timer timer("soca::Model2Ana", "changeVarInverse");
 
-  util::DateTime * vtime = &xm.validTime();
   xm = xa;
 
   // Rotate from meridional/zonal to the logical grid

diff --git a/src/soca/VariableChange/Model2Ana/Model2Ana.h b/src/soca/VariableChange/Model2Ana/Model2Ana.h
@@ -37,7 +37,7 @@ class Model2Ana: public VariableChangeBase {
   ~Model2Ana();
 
   void changeVar(const State &, State &) const override;
-  void changeVarInverse(const State &, State &) const override;
+  void changeVarInverse(const State &, State &) const;
 
   std::vector<std::string> initRotate(const eckit::Configuration & conf,
                                       const std::string & uv) const

diff --git a/src/soca/VariableChange/Model2GeoVaLs/Model2GeoVaLs.cc b/src/soca/VariableChange/Model2GeoVaLs/Model2GeoVaLs.cc
@@ -46,10 +46,4 @@ void Model2GeoVaLs::changeVar(const State & xin, State & xout) const {
 
 // -----------------------------------------------------------------------------
 
-void Model2GeoVaLs::changeVarInverse(const State &, State &) const {
-  util::abor1_cpp("Model2GeoVaLs::changeVarInverse not implemented");
-}
-
-// -----------------------------------------------------------------------------
-
 }  // namespace soca
diff --git a/src/soca/VariableChange/Model2GeoVaLs/Model2GeoVaLs.h b/src/soca/VariableChange/Model2GeoVaLs/Model2GeoVaLs.h
@@ -22,7 +22,6 @@ class Model2GeoVaLs: public VariableChangeBase {
   ~Model2GeoVaLs();
 
   void changeVar(const State &, State &) const override;
-  void changeVarInverse(const State &, State &) const override;
 
  private:
   const Geometry & geom_;

diff --git a/src/soca/VariableChange/Soca2Cice/Soca2Cice.cc b/src/soca/VariableChange/Soca2Cice/Soca2Cice.cc
@@ -70,10 +70,4 @@ void Soca2Cice::changeVar(const State & xin, State & xout) const
 
 // -----------------------------------------------------------------------------
 
-void Soca2Cice::changeVarInverse(const State &, State &) const {
-  util::Timer timer("soca::Soca2Cice", "changeVarInverse");
-}
-
-// -----------------------------------------------------------------------------
-
 }  // namespace soca
diff --git a/src/soca/VariableChange/Soca2Cice/Soca2Cice.h b/src/soca/VariableChange/Soca2Cice/Soca2Cice.h
@@ -104,7 +104,6 @@ class Soca2Cice: public VariableChangeBase {
   ~Soca2Cice();
 
   void changeVar(const State &, State &) const override;
-  void changeVarInverse(const State &, State &) const override;
 
  private:
   const Geometry & geom_;

diff --git a/src/soca/VariableChange/Soca2Cice/soca_soca2cice_mod.F90 b/src/soca/VariableChange/Soca2Cice/soca_soca2cice_mod.F90
@@ -33,9 +33,6 @@ module soca_soca2cice_mod
 !!
 !! - forward: deaggregates a 2D analysis of sea-ice and inserts
 !!            analysis in CICE restarts
-!! - inverse: TODO(G), aggregates seaice variables along CICE sea-ice
-!!            categories, save the aggregated variables in a file
-!!            readable by soca
 
 type, public :: soca_soca2cice_params
    real(kind=kind_real) :: seaice_edge

diff --git a/src/soca/VariableChange/VariableChange.cc b/src/soca/VariableChange/VariableChange.cc
@@ -125,14 +125,6 @@ void VariableChange::changeVar(State & x, const oops::Variables & vars) const {
 
 // -----------------------------------------------------------------------------
 
-void VariableChange::changeVarInverse(State & x,
-                                      const oops::Variables & vars) const {
-  util::Timer timer("soca::VariableChange", "changeVarInverse");
-  changeVar(x, vars);
-}
-
-// -----------------------------------------------------------------------------
-
 void VariableChange::print(std::ostream & os) const {
   os << *variableChange_;
 }

diff --git a/src/soca/VariableChange/VariableChange.h b/src/soca/VariableChange/VariableChange.h
@@ -48,7 +48,6 @@ class VariableChange : public util::Printable {
   ~VariableChange();
 
   void changeVar(State &, const oops::Variables &) const;
-  void changeVarInverse(State &, const oops::Variables &) const;
 
  private:
   void print(std::ostream &) const override;