diff --git a/CMakeLists.txt b/CMakeLists.txt
index dfa4f8de7a565ad4cab40c41d0b2cc015319f6a0..6fecda294a6f3ef77af22ad2b2cf122fe26b92c1 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -30,13 +30,13 @@ if(CMAKE_Fortran_COMPILER_ID MATCHES GNU)
   endif()
 endif()
 
-# test_write_eddy
-add_executable(test_write_eddy test_write_eddy.f90)
-target_link_libraries(test_write_eddy PRIVATE Shapelib_03::shapelib_03
+# test_write_null
+add_executable(test_write_null test_write_null.f90)
+target_link_libraries(test_write_null PRIVATE Shapelib_03::shapelib_03
   Contour_531::contour_531 Jumble::jumble)
-set_target_properties(test_write_eddy PROPERTIES Fortran_MODULE_DIRECTORY
+set_target_properties(test_write_null PROPERTIES Fortran_MODULE_DIRECTORY
   ${CMAKE_CURRENT_BINARY_DIR}/${my_target}_modules)
-target_include_directories(test_write_eddy PRIVATE
+target_include_directories(test_write_null PRIVATE
   ${CMAKE_CURRENT_BINARY_DIR}/${my_target}_modules)
 
 add_subdirectory(Inst_eddies)
diff --git a/Common/CMakeLists.txt b/Common/CMakeLists.txt
index 9971726efc68115815babed4b6fbb1a7bfe6dec2..1cb3005180c0973bf5be27c87dadd58182f5d180 100644
--- a/Common/CMakeLists.txt
+++ b/Common/CMakeLists.txt
@@ -13,7 +13,7 @@ target_sources(test_spher_polyline_area PRIVATE spher_polyline_area.f90)
 target_sources(inst_eddies PRIVATE spher_polyline_area.f90
   derived_types.f90 shpc_close.f90 shpc_open.f90
   get_slice_dir.f90 read_field_indices.f90)
-target_sources(test_write_eddy PRIVATE derived_types.f90 shpc_open.f90
+target_sources(test_write_null PRIVATE derived_types.f90 shpc_open.f90
   shpc_close.f90 read_field_indices.f90 get_slice_dir.f90)
 
 if(MPI_Fortran_HAVE_F08_MODULE)
diff --git a/Inst_eddies/CMakeLists.txt b/Inst_eddies/CMakeLists.txt
index 8ef85e081a87fcdb222a22a83151f54588dce0c2..d3808689e87d0b36a45f3e7a01c6a67be99e2d1d 100644
--- a/Inst_eddies/CMakeLists.txt
+++ b/Inst_eddies/CMakeLists.txt
@@ -35,4 +35,4 @@ target_sources(test_local_extrema PRIVATE local_extrema.f90)
 target_sources(test_set_max_speed PRIVATE set_max_speed.f90 good_contour.f90
   max_speed_contour_ssh.f90 mean_speed.f90 inside_4.f90 get_var.f90 config.f90
   input_ssh.f90 shpc_create.f90 ccw_orient.f90 write_eddy.f90)
-target_sources(test_write_eddy PRIVATE shpc_create.f90)
+target_sources(test_write_null PRIVATE shpc_create.f90)
diff --git a/Inst_eddies/Tests/test_output.json b/Inst_eddies/Tests/test_output.json
index 591b771a1cd28a28d5be911cf26a0556f972e5d3..f8517bcb3217aa5020a6f2c8de6c09a6fed5b5fd 100644
--- a/Inst_eddies/Tests/test_output.json
+++ b/Inst_eddies/Tests/test_output.json
@@ -3,38 +3,38 @@
 	"title": "Medium_mix",
 	"description": "Append to medium-sized SHPC, mixing output to the three shapefiles.",
 	"input": "&main_nml /\n",
-	"command" : ["time", "$build_dir/Inst_eddies/Tests/test_write_eddy"],
+	"command" : ["time", "$build_dir/Inst_eddies/Tests/test_write_null"],
 	"copy":	[["$PWD/n_dates_14", "SHPC"]],
-	"stdout": "test_write_eddy_stdout.txt",
-	"exclude_cmp": ["test_write_eddy_stderr.txt"]
+	"stdout": "test_write_null_stdout.txt",
+	"exclude_cmp": ["test_write_null_stderr.txt"]
 
     },
     {
 	"title": "Small_mix",
 	"description": "Append to small SHPC, mixing output to the three shapefiles.",
 	"input": "&main_nml /\n",
-	"command" : ["time", "$build_dir/Inst_eddies/Tests/test_write_eddy"],
+	"command" : ["time", "$build_dir/Inst_eddies/Tests/test_write_null"],
 	"copy":	[["$PWD/n_dates_1", "SHPC"]],
-	"stdout": "test_write_eddy_stdout.txt",
-	"exclude_cmp": ["test_write_eddy_stderr.txt"]
+	"stdout": "test_write_null_stdout.txt",
+	"exclude_cmp": ["test_write_null_stderr.txt"]
     },
     {
 	"title": "Medium_sep",
 	"description": "Append to medium-sized SHPC, separating output to the three shapefiles.",
 	"input": "&main_nml mixed = f/\n",
-	"command" : ["time", "$build_dir/Inst_eddies/Tests/test_write_eddy"],
+	"command" : ["time", "$build_dir/Inst_eddies/Tests/test_write_null"],
 	"copy":	[["$PWD/n_dates_14", "SHPC"]],
-	"stdout": "test_write_eddy_stdout.txt",
-	"exclude_cmp": ["test_write_eddy_stderr.txt"]
+	"stdout": "test_write_null_stdout.txt",
+	"exclude_cmp": ["test_write_null_stderr.txt"]
     },
     {
 	"title": "Small_sep",
 	"description": "Append to small SHPC, separating output to the three shapefiles.",
 	"input": "&main_nml mixed = f/\n",
-	"command" : ["time", "$build_dir/Inst_eddies/Tests/test_write_eddy"],
+	"command" : ["time", "$build_dir/Inst_eddies/Tests/test_write_null"],
 	"copy":	[["$PWD/n_dates_1", "SHPC"]],
-	"stdout": "test_write_eddy_stdout.txt",
-	"exclude_cmp": ["test_write_eddy_stderr.txt"]
+	"stdout": "test_write_null_stdout.txt",
+	"exclude_cmp": ["test_write_null_stderr.txt"]
     },
     {
 	"title": "Create_mix",
@@ -43,10 +43,10 @@
 	"commands" :
 	[
 	    ["mkdir", "-p", "SHPC/Slice_0/Cyclones"],
-	    ["time", "$build_dir/Inst_eddies/Tests/test_write_eddy"]
+	    ["time", "$build_dir/Inst_eddies/Tests/test_write_null"]
 	],
-	"stdout": "test_write_eddy_stdout.txt",
-	"exclude_cmp": ["test_write_eddy_stderr.txt"]
+	"stdout": "test_write_null_stdout.txt",
+	"exclude_cmp": ["test_write_null_stderr.txt"]
     },
     {
 	"title": "Create_sep",
@@ -55,27 +55,27 @@
 	"commands" :
 	[
 	    ["mkdir", "-p", "SHPC/Slice_0/Cyclones"],
-	    ["time", "$build_dir/Inst_eddies/Tests/test_write_eddy"]
+	    ["time", "$build_dir/Inst_eddies/Tests/test_write_null"]
 	],
-	"stdout": "test_write_eddy_stdout.txt",
-	"exclude_cmp": ["test_write_eddy_stderr.txt"]
+	"stdout": "test_write_null_stdout.txt",
+	"exclude_cmp": ["test_write_null_stderr.txt"]
     },
     {
 	"title": "Big_mix",
 	"description": "Append to big SHPC, mixing output to the three shapefiles.",
 	"input": "&main_nml /\n",
-	"command" : ["time", "$build_dir/Inst_eddies/Tests/test_write_eddy"],
+	"command" : ["time", "$build_dir/Inst_eddies/Tests/test_write_null"],
 	"copy":	["$PWD/Inst_eddies_9/SHPC"],
-	"stdout": "test_write_eddy_stdout.txt",
-	"exclude_cmp": ["test_write_eddy_stderr.txt"]
+	"stdout": "test_write_null_stdout.txt",
+	"exclude_cmp": ["test_write_null_stderr.txt"]
     },
     {
 	"title": "Big_sep",
 	"description": "Append to big SHPC, separating output to the three shapefiles.",
 	"input": "&main_nml mixed = f/\n",
-	"command" : ["time", "$build_dir/Inst_eddies/Tests/test_write_eddy"],
+	"command" : ["time", "$build_dir/Inst_eddies/Tests/test_write_null"],
 	"copy":	["$PWD/Inst_eddies_9/SHPC"],
-	"stdout": "test_write_eddy_stdout.txt",
-	"exclude_cmp": ["test_write_eddy_stderr.txt"]
+	"stdout": "test_write_null_stdout.txt",
+	"exclude_cmp": ["test_write_null_stderr.txt"]
     }
 ]
diff --git a/test_write_eddy.f90 b/test_write_null.f90
similarity index 100%
rename from test_write_eddy.f90
rename to test_write_null.f90