diff --git a/modules/aeolus/aeolus_amv.py b/modules/aeolus/aeolus_amv.py
index 3dd8986e99df209f2ad9c7ee59376ff779e96780..3c02246c650ffa9218e43293e4a8415765a61d86 100644
--- a/modules/aeolus/aeolus_amv.py
+++ b/modules/aeolus/aeolus_amv.py
@@ -441,6 +441,7 @@ def create_amv_to_aeolus_match_file(aeolus_files_dir, amv_files_dir, outfile=Non
 # match_file: pathname for the product file
 # dt_str_0: start time (YYYY-MM-DD_HH:MM)
 # dt_str_1: end time (YYYY-MM-DD_HH:MM)
+# returns: amvs[ntimes, max_num_amvs_per_prof, num_of_params], profs[ntimes, max_num_levs_per_prof, num_of_params], times[ntimes]
 def subset_by_time(match_file, dt_str_0, dt_str_1):
     rootgrp = Dataset(match_file, 'r', format='NETCDF4')
     all_dims = rootgrp.dimensions