diff --git a/modules/aeolus/datasource.py b/modules/aeolus/datasource.py
index 6d396b8976fe4c90893b4c41ee51b50362d07b22..94c5eb61372c69581d6e56c0cb87ebdcb3dbfb48 100644
--- a/modules/aeolus/datasource.py
+++ b/modules/aeolus/datasource.py
@@ -33,7 +33,13 @@ def get_parameters_clavrx(filename=ancillary_path+'clavrx_parameters.pkl'):
     return var_names_2d
 
 
+caliop_clavrx_params = None
+
+
 def get_parameters_caliop_clavrx(filename='/data/Personal/rink/clavrx_calipso/g16_s20201050200_06kmCLay.matchup.calipso.h5'):
+    global caliop_clavrx_params
+    if caliop_clavrx_params is not None:
+        return caliop_clavrx_params
     rg = Dataset(filename, 'r')
     var_s = rg.variables
     var_names = list(var_s.keys())
@@ -48,6 +54,7 @@ def get_parameters_caliop_clavrx(filename='/data/Personal/rink/clavrx_calipso/g1
 
     rg.close()
 
+    caliop_clavrx_params = var_names_keep
     return var_names_keep