diff --git a/cime_config/namelist_definition_drv.xml b/cime_config/namelist_definition_drv.xml
index f6e1d4442..bfe991383 100644
--- a/cime_config/namelist_definition_drv.xml
+++ b/cime_config/namelist_definition_drv.xml
@@ -1235,7 +1235,7 @@
     </values>
   </entry>
 
-  <!-- MED histaux atm2med file1 -->
+  <!-- MED histaux atm2med file 1 -->
   <entry id="histaux_atm2med_file1_enabled">
     <type>logical</type>
     <category>aux_hist</category>
@@ -1267,7 +1267,7 @@
     <type>integer</type>
     <category>aux_hist</category>
     <group>MED_attributes</group>
-    <desc>history option type</desc>
+    <desc>history option span</desc>
     <values>
       <value>1</value>
     </values>
@@ -1300,7 +1300,7 @@
     </values>
   </entry>
 
-  <!-- MED histaux atm2med file2 -->
+  <!-- MED histaux atm2med file 2 -->
   <entry id="histaux_atm2med_file2_enabled">
     <type>logical</type>
     <category>aux_hist</category>
@@ -1332,7 +1332,7 @@
     <type>integer</type>
     <category>aux_hist</category>
     <group>MED_attributes</group>
-    <desc>history option type</desc>
+    <desc>history option span</desc>
     <values>
       <value>1</value>
     </values>
@@ -1365,7 +1365,7 @@
     </values>
   </entry>
 
-  <!-- MED histaux atm2med file3 -->
+  <!-- MED histaux atm2med file 3 -->
   <entry id="histaux_atm2med_file3_enabled">
     <type>logical</type>
     <category>aux_hist</category>
@@ -1381,7 +1381,7 @@
     <type>char</type>
     <category>aux_hist</category>
     <group>MED_attributes</group>
-    <desc>Auxiliary mediator atm2med precipitation history output every 3 hours</desc>
+    <desc>Auxiliary mediator atm2med precipitation fields history output every 3 hours</desc>
     <values>
       <value>Faxa_rainc:Faxa_rainl:Faxa_snowc:Faxa_snowl</value>
     </values>
@@ -1399,7 +1399,7 @@
     <type>integer</type>
     <category>aux_hist</category>
     <group>MED_attributes</group>
-    <desc>history option type</desc>
+    <desc>history option span</desc>
     <values>
       <value>3</value>
     </values>
@@ -1432,13 +1432,13 @@
     </values>
   </entry>
 
-  <!-- MED histaux atm2med file4 -->
+  <!-- MED histaux atm2med file 4 -->
   <entry id="histaux_atm2med_file4_enabled">
     <type>logical</type>
     <category>aux_hist</category>
     <group>MED_attributes</group>
     <desc>
-      Auxiliary mediator a2x precipitation history output every 3 hours
+      Auxiliary mediator a2x dynamic, radiation, and precipitation history output every 3 hours
     </desc>
     <values>
       <value>.false.</value>
@@ -1449,7 +1449,7 @@
     <category>aux_hist</category>
     <group>MED_attributes</group>
     <desc>
-      Auxiliary mediator a2x precipitation history output every 3 hours
+      Auxiliary mediator a2x dynamic, radiation, and precipitation fields history output every 3 hours
     </desc>
     <values>
       <value>Sa_z:Sa_topo:Sa_u:Sa_v:Sa_tbot:Sa_ptem:Sa_shum:Sa_dens:Sa_pbot:Sa_pslv:Faxa_lwdn:Faxa_rainc:Faxa_rainl:Faxa_snowc:Faxa_snowl:Faxa_swndr:Faxa_swvdr:Faxa_swndf:Faxa_swvdf:Sa_co2diag:Sa_co2prog</value>
@@ -1468,7 +1468,7 @@
     <type>integer</type>
     <category>aux_hist</category>
     <group>MED_attributes</group>
-    <desc>history option type</desc>
+    <desc>history option span</desc>
     <values>
       <value>3</value>
     </values>
@@ -1501,12 +1501,12 @@
     </values>
   </entry>
 
-  <!-- MED histaux atm2med file5 -->
+  <!-- MED histaux atm2med file 5 -->
   <entry id="histaux_atm2med_file5_enabled">
     <type>logical</type>
     <category>aux_hist</category>
     <group>MED_attributes</group>
-    <desc>Auxiliary mediator a2x precipitation history output every 3 hours</desc>
+    <desc>Auxiliary mediator a2x aerosol and ghg history output daily or endofrun</desc>
     <values>
       <value>.false.</value>
     </values>
@@ -1515,7 +1515,7 @@
     <type>char</type>
     <category>aux_hist</category>
     <group>MED_attributes</group>
-    <desc>Auxiliary mediator a2x precipitation history output every 3 hours</desc>
+    <desc>Auxiliary mediator a2x aerosol and ghg history output daily or endofrun</desc>
     <values>
       <value>Faxa_bcph:Faxa_ocph:Faxa_dstwet:Faxa_dstdry:Sa_co2prog:Sa_co2diag</value>
     </values>
@@ -1533,9 +1533,9 @@
     <type>integer</type>
     <category>aux_hist</category>
     <group>MED_attributes</group>
-    <desc>history option type</desc>
+    <desc>history option span</desc>
     <values>
-      <value>1</value>
+      <value>3</value>
     </values>
   </entry>
   <entry id="histaux_atm2med_file5_doavg">
@@ -1553,7 +1553,7 @@
     <group>MED_attributes</group>
     <desc>Number of time samples per file.</desc>
     <values>
-      <value>1</value>
+      <value>2</value>
     </values>
   </entry>
   <entry id="histaux_atm2med_file5_auxname">
@@ -1801,7 +1801,7 @@
   <!-- MED ocn history files -->
   <!-- ======================================= -->
 
-  <!-- MED histaux ocn2med file1 -->
+  <!-- MED histaux ocn2med file 1 -->
   <entry id="histaux_ocn2med_file1_enabled">
     <type>logical</type>
     <category>aux_hist</category>
@@ -1978,7 +1978,7 @@
     <type>char</type>
     <category>aux_hist</category>
     <group>MED_attributes</group>
-    <desc>Auxiliary mediator rof2med precipitation history output.</desc>
+    <desc>Auxiliary mediator rof2med precipitation fields history output.</desc>
     <values>
       <value>all</value>
     </values>
@@ -1996,9 +1996,9 @@
     <type>integer</type>
     <category>aux_hist</category>
     <group>MED_attributes</group>
-    <desc>history option type</desc>
+    <desc>history option span</desc>
     <values>
-      <value>6</value>
+      <value>3</value>
     </values>
   </entry>
   <entry id="histaux_rof2med_file1_doavg">
@@ -2016,7 +2016,7 @@
     <group>MED_attributes</group>
     <desc>Number of time samples per file.</desc>
     <values>
-      <value>1</value>
+      <value>2</value>
     </values>
   </entry>
   <entry id="histaux_rof2med_file1_auxname">
diff --git a/mediator/med_io_mod.F90 b/mediator/med_io_mod.F90
index 3a8fb2d6f..d55ebc724 100644
--- a/mediator/med_io_mod.F90
+++ b/mediator/med_io_mod.F90
@@ -75,10 +75,6 @@ module med_io_mod
   character(*),parameter         :: prefix    = "med_io_"
   character(*),parameter         :: modName   = "(med_io_mod) "
   character(*),parameter         :: version   = "cmeps0"
-  integer    , parameter         :: number_strlen = 8
-  integer    , parameter         :: file_desc_t_cnt = 20 ! Note - this is hard-wired for now
-
-!  character(CL)                  :: wfilename(0:file_desc_t_cnt) = ''
   
   integer                        :: pio_iotype
   integer                        :: pio_ioformat
@@ -546,9 +542,6 @@ subroutine med_io_wopen(filename, io_file, vm, rc, clobber, file_ind, model_doi_
 
     if (.not. pio_file_is_open(io_file)) then
 
-       ! filename not open
-!       wfilename(lfile_ind) = trim(filename)
-
        if (med_io_file_exists(vm, filename)) then
           if (lclobber) then
              nmode = pio_clobber
@@ -585,16 +578,6 @@ subroutine med_io_wopen(filename, io_file, vm, rc, clobber, file_ind, model_doi_
           rcode = pio_put_att(io_file,pio_global,"model_doi_url",lmodel_doi_url)
        endif
 
-!    elseif (trim(wfilename(lfile_ind)) /= trim(filename)) then
-       ! filename is open, better match open filename
-!       if (iam==0) then
-!          write(logunit,'(a)') trim(subname)//' different  filename currently open '//trim(filename)
-!          write(logunit,'(a)') trim(subname)//' different wfilename currently open '//trim(wfilename(lfile_ind))
-!       end if
-!       call ESMF_LogWrite(trim(subname)//'different file currently open '//trim(filename), ESMF_LOGMSG_ERROR)
-!       rc = ESMF_FAILURE
-!       return
-
     else
        ! filename is already open, just return
     endif
diff --git a/mediator/med_phases_history_mod.F90 b/mediator/med_phases_history_mod.F90
index e647dc647..5f150a4b7 100644
--- a/mediator/med_phases_history_mod.F90
+++ b/mediator/med_phases_history_mod.F90
@@ -60,7 +60,7 @@ module med_phases_history_mod
   ! Instantaneous history files datatypes/variables per component
   ! ----------------------------
   type, public :: instfile_type
-     type(file_desc_t) :: io_file
+     type(file_desc_t):: io_file
      logical          :: write_inst
      character(CS)    :: hist_option
      integer          :: hist_n
@@ -76,7 +76,7 @@ module med_phases_history_mod
   ! Time averaging history files
   ! ----------------------------
   type, public :: avgfile_type
-     type(file_desc_t) :: io_file
+     type(file_desc_t)      :: io_file
      logical                :: write_avg
      type(ESMF_FieldBundle) :: FBaccum_import    ! field bundle for time averaging
      integer                :: accumcnt_import   ! field bundle accumulation counter
@@ -96,7 +96,7 @@ module med_phases_history_mod
   ! Auxiliary history files
   ! ----------------------------
   type, public :: auxfile_type
-     type(file_desc_t) :: io_file
+     type(file_desc_t)          :: io_file
      character(CS), allocatable :: flds(:)       ! array of aux field names
      character(CS)              :: auxname       ! name for history file creation
      character(CL)              :: histfile = '' ! current history file name