moved the Forcing to its own IO

components/omega/configs/Default.yml

@@ -125,6 +125,19 @@ Omega:
       Contents:
         - State
         - Base
+    # Forcing is the external forcing in standalone mode.
+    # It contains the surface stress, surface fluxes
+    # and the surface restoring target files (if appl.).
+    Forcing:
+      UsePointerFile: false
+      Filename: forcing.nc
+      Mode: read
+      Precision: double
+      Freq: 1
+      FreqUnits: OnStartup
+      UseStartEnd: false
+      Contents:
+        - Forcing
     # Restarts are used to initialize for all job submissions after the very
     # first startup job. We use UseStartEnd with a start time just after the
     # simulation start time so that omega does not attempt to use a restart

components/omega/src/ocn/Forcing.cpp

@@ -11,6 +11,7 @@
 
 #include "Forcing.h"
 #include "Field.h"
+#include "IOStream.h"
 #include "Logging.h"
 #include "Pacer.h"
 
@@ -58,6 +59,7 @@ Forcing *Forcing::create(const std::string &Name, const HorzMesh *Mesh,
 }
 
 // Initialize the default forcing instance and read configuration.
+// Reads the forcing fields from streams at startup (for now).
 void Forcing::init() {
    if (DefaultForcing != nullptr) {
       return;
@@ -78,6 +80,10 @@ void Forcing::init() {
 
    Config *OmegaConfig = Config::getOmegaConfig();
    DefaultForcing->readConfigOptions(OmegaConfig);
+   // for now, forcing fields are read at start-up only.
+   // to be extended to include switch from standalone to coupled.
+   // to be moved to a Forcing->prepareForStep(SimTime) method later.
+   DefaultForcing->readStreamIntoArrays();
 }
 
 // Return the default forcing instance.
@@ -159,4 +165,32 @@ I4 Forcing::exchangeHalo() const {
    return Err;
 }
 
+// Read forcing fields from input stream.
+// To be extended with time indexing later.
+void Forcing::readStreamIntoArrays() {
+   Error Err;
+
+   Real FillValueReal = -999._Real;
+   deepCopy(SfcStressForcing.ZonalStressCell, FillValueReal);
+   deepCopy(SfcStressForcing.MeridStressCell, FillValueReal);
+
+   std::string StreamName = "Forcing";
+
+   // Attempt to read stream; if unavailable, log and fall back to zero forcing.
+   Err = IOStream::read(StreamName);
+   if (Err.isFail()) {
+      LOG_INFO("Forcing: Error while reading {} stream, using zero forcing",
+               StreamName);
+      deepCopy(SfcStressForcing.ZonalStressCell, 0._Real);
+      deepCopy(SfcStressForcing.MeridStressCell, 0._Real);
+   }
+
+   I4 HaloErr = exchangeHalo();
+   if (HaloErr != 0) {
+      ABORT_ERROR("Forcing: Error exchanging halo for startup forcing fields");
+   }
+
+   computeAll();
+}
+
 } // namespace OMEGA

components/omega/src/ocn/Forcing.h

@@ -66,6 +66,9 @@ class Forcing {
    /// Unregister surface stress fields from IO streams
    void unregisterFields() const;
 
+   /// Read forcing fields from input stream at startup
+   void readStreamIntoArrays();
+
    /// Compute all forcing variables
    void computeAll() const;
 

components/omega/src/ocn/OceanRun.cpp

@@ -44,8 +44,8 @@ int ocnRun(TimeInstant &CurrTime ///< [inout] current sim time
       // track step count
       ++IStep;
 
-      // call forcing routines, anything needed pre-timestep
-      DefForcing->computeAll();
+      // placeholder: call needed pre-timestep compute here
+      // (e.g. forcing routine)
 
       // do forward time step
       // first call to doStep can sometimes take very long

components/omega/test/infra/IOStreamTest.cpp

@@ -114,6 +114,10 @@ void initIOStreamTest(Clock *&ModelClock // Model clock
    // Initialize Tracers
    Tracers::init();
 
+   // IOStream::validateAll() depends on Forcing::init() so Forcing fields
+   // are registered before stream validation.
+   Forcing::init();
+
    // Initialize Aux State
    AuxiliaryState::init();
 

components/omega/test/ocn/ForcingTest.cpp

@@ -62,13 +62,15 @@ struct TestSetupSphere {
 };
 
 #ifdef FORCING_TEST_PLANE
-constexpr Geometry Geom          = Geometry::Planar;
-constexpr char DefaultMeshFile[] = "OmegaPlanarMesh.nc";
-using TestSetup                  = TestSetupPlane;
+constexpr Geometry Geom             = Geometry::Planar;
+constexpr char DefaultMeshFile[]    = "OmegaPlanarMesh.nc";
+constexpr char DefaultForcingFile[] = "forcingPlanar.nc";
+using TestSetup                     = TestSetupPlane;
 #else
-constexpr Geometry Geom          = Geometry::Spherical;
-constexpr char DefaultMeshFile[] = "OmegaSphereMesh.nc";
-using TestSetup                  = TestSetupSphere;
+constexpr Geometry Geom             = Geometry::Spherical;
+constexpr char DefaultMeshFile[]    = "OmegaSphereMesh.nc";
+constexpr char DefaultForcingFile[] = "forcingSphere.nc";
+using TestSetup                     = TestSetupSphere;
 #endif
 
 int testSfcStressForcingVars(Real RTol) {
@@ -144,6 +146,10 @@ int initForcingTest(const std::string &MeshFile) {
    Field::init(ModelClock);
    IOStream::init(ModelClock);
 
+   // Select the case-specific forcing file before Forcing::init() performs
+   // startup stream reads.
+   IOStream::changeFilename("Forcing", DefaultForcingFile);
+
    Err = Halo::init();
    if (Err != 0) {
       ABORT_ERROR("ForcingTest: error initializing default halo");

components/omega/test/ocn/StateTest.cpp

@@ -15,6 +15,7 @@
 #include "Dimension.h"
 #include "Error.h"
 #include "Field.h"
+#include "Forcing.h"
 #include "Halo.h"
 #include "HorzMesh.h"
 #include "IO.h"
@@ -89,6 +90,10 @@ void initStateTest() {
    // Initialize tracers
    Tracers::init();
 
+   // IOStream::validateAll() depends on Forcing::init() so Forcing fields
+   // are registered before stream validation.
+   Forcing::init();
+
    // Initialize Aux State variables
    AuxiliaryState::init();
 
@@ -406,6 +411,7 @@ int main(int argc, char *argv[]) {
       // Finalize Omega objects
       OceanState::clear();
       Tracers::clear();
+      Forcing::clear();
       AuxiliaryState::clear();
       PressureGrad::clear();
       Tendencies::clear();