diff --git a/da/carbondioxide/obspack_geocarbon.py b/da/carbondioxide/obspack_geocarbon.py
index ae4fcf6d424dbf9b42047f5516e555a1cf252e93..6bf6fad7d5ff37e78c44a3b15fbfa074b3791b50 100755
--- a/da/carbondioxide/obspack_geocarbon.py
+++ b/da/carbondioxide/obspack_geocarbon.py
@@ -242,6 +242,27 @@ class ObsPackObservations(Observations):
             savedict['missing_value'] = '!'
             f.add_data(savedict)
 
+	    data = self.getvalues('obs')
+
+	    savedict = io.std_savedict.copy()
+	    savedict['name'] = "observed"
+	    savedict['long_name'] = "observedvalues"
+	    savedict['units'] = "mol mol-1"
+	    savedict['dims'] = dimid
+	    savedict['values'] = data.tolist()
+	    savedict['comment'] = 'Observations used in optimization'
+	    f.add_data(savedict)
+    
+	    data = self.getvalues('mdm')
+    
+	    savedict = io.std_savedict.copy()
+	    savedict['name'] = "modeldatamismatch"
+	    savedict['long_name'] = "modeldatamismatch"
+	    savedict['units'] = "[mol mol-1]"
+	    savedict['dims'] = dimid
+	    savedict['values'] = data.tolist()
+	    savedict['comment'] = 'Standard deviation of mole fractions resulting from model-data mismatch'
+	    f.add_data(savedict)
             f.close()
 
             logging.debug("Successfully wrote data to obs file")