diff --git a/changelog/53.feature.md b/changelog/53.feature.md
new file mode 100644
index 00000000..20ff7148
--- /dev/null
+++ b/changelog/53.feature.md
@@ -0,0 +1 @@
+Add test data for the OHC-NOAA IOMB diagnostic
diff --git a/data/CMIP6/CMIP/CSIRO/ACCESS-ESM1-5/historical/r1i1p1f1/Ofx/volcello/gn/v20191115/volcello_Ofx_ACCESS-ESM1-5_historical_r1i1p1f1_gn.nc b/data/CMIP6/CMIP/CSIRO/ACCESS-ESM1-5/historical/r1i1p1f1/Ofx/volcello/gn/v20191115/volcello_Ofx_ACCESS-ESM1-5_historical_r1i1p1f1_gn.nc
new file mode 100644
index 00000000..49321fb0
Binary files /dev/null and b/data/CMIP6/CMIP/CSIRO/ACCESS-ESM1-5/historical/r1i1p1f1/Ofx/volcello/gn/v20191115/volcello_Ofx_ACCESS-ESM1-5_historical_r1i1p1f1_gn.nc differ
diff --git a/data/CMIP6/CMIP/CSIRO/ACCESS-ESM1-5/historical/r1i1p1f1/Omon/thetao/gn/v20191115/thetao_Omon_ACCESS-ESM1-5_historical_r1i1p1f1_gn_200501-200912.nc b/data/CMIP6/CMIP/CSIRO/ACCESS-ESM1-5/historical/r1i1p1f1/Omon/thetao/gn/v20191115/thetao_Omon_ACCESS-ESM1-5_historical_r1i1p1f1_gn_200501-200912.nc
new file mode 100644
index 00000000..145060d0
Binary files /dev/null and b/data/CMIP6/CMIP/CSIRO/ACCESS-ESM1-5/historical/r1i1p1f1/Omon/thetao/gn/v20191115/thetao_Omon_ACCESS-ESM1-5_historical_r1i1p1f1_gn_200501-200912.nc differ
diff --git a/data/CMIP6/CMIP/CSIRO/ACCESS-ESM1-5/historical/r1i1p1f1/Omon/thetao/gn/v20191115/thetao_Omon_ACCESS-ESM1-5_historical_r1i1p1f1_gn_201001-201412.nc b/data/CMIP6/CMIP/CSIRO/ACCESS-ESM1-5/historical/r1i1p1f1/Omon/thetao/gn/v20191115/thetao_Omon_ACCESS-ESM1-5_historical_r1i1p1f1_gn_201001-201412.nc
new file mode 100644
index 00000000..f6b34370
Binary files /dev/null and b/data/CMIP6/CMIP/CSIRO/ACCESS-ESM1-5/historical/r1i1p1f1/Omon/thetao/gn/v20191115/thetao_Omon_ACCESS-ESM1-5_historical_r1i1p1f1_gn_201001-201412.nc differ
diff --git a/registry.txt b/registry.txt
index 8625edd5..94f6476f 100644
--- a/registry.txt
+++ b/registry.txt
@@ -44,9 +44,12 @@ CMIP6/CMIP/CSIRO/ACCESS-ESM1-5/historical/r1i1p1f1/Lmon/nbp/gn/v20191115/nbp_Lmo
 CMIP6/CMIP/CSIRO/ACCESS-ESM1-5/historical/r1i1p1f1/Lmon/treeFrac/gn/v20191115/treeFrac_Lmon_ACCESS-ESM1-5_historical_r1i1p1f1_gn_201301-201412.nc 14b34644c775101b6ac5fa329d446178521e38cb47ad4022f4c971770398c251
 CMIP6/CMIP/CSIRO/ACCESS-ESM1-5/historical/r1i1p1f1/Ofx/areacello/gn/v20191115/areacello_Ofx_ACCESS-ESM1-5_historical_r1i1p1f1_gn.nc 6c81071e48fdbacb49207cbf09aa94eb3ede265ec95116aad3ff5af425a25b26
 CMIP6/CMIP/CSIRO/ACCESS-ESM1-5/historical/r1i1p1f1/Ofx/sftof/gn/v20191115/sftof_Ofx_ACCESS-ESM1-5_historical_r1i1p1f1_gn.nc 1bdac0745938a5b0cd474d39f4cdce8293fe923b680bcea88fb0dc4d47753684
+CMIP6/CMIP/CSIRO/ACCESS-ESM1-5/historical/r1i1p1f1/Ofx/volcello/gn/v20191115/volcello_Ofx_ACCESS-ESM1-5_historical_r1i1p1f1_gn.nc fde4d035bfda71245de3fe0f5baaf8d20083cf97c6edc410f8f828ca1beb6a19
 CMIP6/CMIP/CSIRO/ACCESS-ESM1-5/historical/r1i1p1f1/Omon/msftmz/gn/v20191115/msftmz_Omon_ACCESS-ESM1-5_historical_r1i1p1f1_gn_200001-200912.nc 8701fb7ec96033fb2f85dfd91db4529a95234f14e05defb27fc664e6f1b1e635
 CMIP6/CMIP/CSIRO/ACCESS-ESM1-5/historical/r1i1p1f1/Omon/msftmz/gn/v20191115/msftmz_Omon_ACCESS-ESM1-5_historical_r1i1p1f1_gn_201001-201412.nc e90376384addcc6fecb680ff9385c2f30728ce74a9784af5c43fc8241b97db58
 CMIP6/CMIP/CSIRO/ACCESS-ESM1-5/historical/r1i1p1f1/Omon/sos/gn/v20191115/sos_Omon_ACCESS-ESM1-5_historical_r1i1p1f1_gn_200001-201412.nc 86346e7b8fc0b0d41a9a0bf504c48646e26614628adcc814e558922b846facde
+CMIP6/CMIP/CSIRO/ACCESS-ESM1-5/historical/r1i1p1f1/Omon/thetao/gn/v20191115/thetao_Omon_ACCESS-ESM1-5_historical_r1i1p1f1_gn_200501-200912.nc 24218ff453181ab003892cad38f191ae75c94a82e12ee640cebfdecbf10dcd12
+CMIP6/CMIP/CSIRO/ACCESS-ESM1-5/historical/r1i1p1f1/Omon/thetao/gn/v20191115/thetao_Omon_ACCESS-ESM1-5_historical_r1i1p1f1_gn_201001-201412.nc 84e8f9b8033ec663afd52a4df13e3d75be702788e65184408444f42b8248bc5a
 CMIP6/CMIP/CSIRO/ACCESS-ESM1-5/historical/r1i1p1f1/Omon/tos/gn/v20191115/tos_Omon_ACCESS-ESM1-5_historical_r1i1p1f1_gn_185001-201412.nc b0e020688297c13f17725b081f2ad46d9bab68e7dad7dbca69577fba7435473f
 CMIP6/CMIP/CSIRO/ACCESS-ESM1-5/historical/r1i1p1f1/SImon/siconc/gn/v20200817/siconc_SImon_ACCESS-ESM1-5_historical_r1i1p1f1_gn_197901-201412.nc d62a0a84d634b7695c94d49c75efd4b69f56ee7fa1870dfda2d73d63f2b4b7cd
 CMIP6/CMIP/CSIRO/ACCESS-ESM1-5/historical/r1i1p1f1/fx/areacella/gn/v20191115/areacella_fx_ACCESS-ESM1-5_historical_r1i1p1f1_gn.nc 97418f230390c28d897e31c1f0f15709677b08ad4ae52a5e88d32c3ddc22a9ca
diff --git a/scripts/fetch_test_data.py b/scripts/fetch_test_data.py
index e8879a4c..ba6883d1 100755
--- a/scripts/fetch_test_data.py
+++ b/scripts/fetch_test_data.py
@@ -472,6 +472,29 @@ def process_sample_data_request(
         remove_ensembles=True,
         time_span=("2000", "2025"),
     ),
+    CMIP6Request(
+        id="iomb-data-3",
+        facets=dict(
+            source_id="ACCESS-ESM1-5",
+            frequency=["mon"],
+            variable_id=["thetao"],
+            experiment_id=["historical"],
+        ),
+        remove_ensembles=True,
+        time_span=("2005", "2025"),
+    ),
+    # separate request as ACCESS has volcello as monthly and fixed
+    CMIP6Request(
+        id="iomb-data-4",
+        facets=dict(
+            source_id="ACCESS-ESM1-5",
+            frequency=["fx"],
+            variable_id=["volcello"],
+            experiment_id=["historical"],
+        ),
+        remove_ensembles=True,
+        time_span=None,
+    ),
     # PMP modes of variability data
     CMIP6Request(
         id="pmp-modes-of-variability",