diff --git a/modules/util/acspo_validate.py b/modules/util/acspo_validate.py
index e61cb5c66c0fcca01b2b5e3534153aaee0957aa7..cef0ac0c804a763a27871e9731a2780ced2a88ae 100644
--- a/modules/util/acspo_validate.py
+++ b/modules/util/acspo_validate.py
@@ -5,7 +5,7 @@ import xarray as xr
 from util.util import get_grid_values_all
 
 
-def acspo_validate(oper_file, cspp_file, rel_tol=0.005, deg_tol=0.0002, outfile_nc=None):
+def acspo_validate(oper_file, cspp_file, rel_tol=0.0, abs_tol=0.01, deg_tol=0.0002, outfile_nc=None):
 
     h5f_oper = h5py.File(oper_file, 'r')
     h5f_cspp = h5py.File(cspp_file, 'r')
@@ -123,7 +123,7 @@ def acspo_validate(oper_file, cspp_file, rel_tol=0.005, deg_tol=0.0002, outfile_
     valid_lat_oper = lat_oper[both_clear]
 
     print('fraction SSTs approx equal: ',
-          np.sum(np.isclose(valid_sst_cspp, valid_sst_oper, rtol=rel_tol))/np.sum(both_clear))
+          np.sum(np.isclose(valid_sst_cspp, valid_sst_oper, rtol=rel_tol, atol=abs_tol))/np.sum(both_clear))
 
     xarray_data = xr.Dataset({
         'sst_cspp': xr.DataArray(valid_sst_cspp, coords=None, dims=None, name='sst_cspp'),