"Fix" for the increment handler application (#738)

Not really a fix, I just removed the linear variable change from the
increment handler application. The option is not used when cycling and
probably shouldn't anyways.

Co-authored-by: Cory Martin <[email protected]>

test/soca/testinput/incr_handler.yaml

@@ -6,7 +6,7 @@ date: 2018-04-15T09:00:00Z
 
 layers variable: [hocn]
 
-increment variables: [tocn, socn, uocn, vocn, ssh, hocn]
+increment variables: [tocn, socn, uocn, vocn, ssh]
 
 set increment variables to zero: [uocn, vocn, ssh]
 
@@ -32,21 +32,6 @@ soca increment:
 #    ocn_filename: 'ocn.1.nc'
 #    read_from_file: 1
 
-linear variable change:
-  linear variable changes:
-  - linear variable change name: BkgErrFILT
-    ocean_depth_min: 500  # zero where ocean is shallower than 500m
-    rescale_bkgerr: 1.0   # rescale perturbation
-    efold_z: 1500.0       # Apply exponential decay
-  - linear variable change name: BalanceSOCA
-
-trajectory:
-  state variables: [tocn, socn, uocn, vocn, ssh, hocn, layer_depth, mld]
-  date: 2018-04-15T09:00:00Z
-  basename: ./INPUT/
-  ocn_filename: MOM.res.nc
-  read_from_file: 1
-
 output increment:
   datadir: ./
   date: 2018-04-15T09:00:00Z

utils/soca/gdas_incr_handler.h

@@ -59,13 +59,6 @@ namespace gdasapp {
         // Zero out specified fields
         incrWithLayer = postProcIncr.setToZero(incrWithLayer);
 
-        // Apply linear change of variables
-        if ( fullConfig.has("linear variable change") ) {
-          soca::State traj = postProcIncr.getTraj(fullConfig, geom);
-          eckit::LocalConfiguration lvcConfig(fullConfig, "linear variable change");
-          postProcIncr.applyLinVarChange(incrWithLayer, lvcConfig, traj);
-        }
-
         // Save final increment
         result = postProcIncr.save(incrWithLayer, i);
         oops::Log::debug() << "========= after appending layer and after saving:" << std::endl;