diff --git a/src/gen_modules_clock.F90 b/src/gen_modules_clock.F90
index 40f9abc31..cf4173f2b 100755
--- a/src/gen_modules_clock.F90
+++ b/src/gen_modules_clock.F90
@@ -12,6 +12,7 @@ module g_clock
   integer                  :: ndpyr                !number of days in yearnew 
   integer                  :: num_day_in_month(0:1,12)
   character(4)             :: cyearold, cyearnew   !year as character string      
+  character(2)             :: cmonth               !month as character string      
   data num_day_in_month(0,:) /31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31/
   data num_day_in_month(1,:) /31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31/
 
@@ -55,6 +56,7 @@ subroutine clock
        aux2=aux1+num_day_in_month(fleapyear,i)
        if(daynew>aux1 .and. daynew<=aux2) then
           month=i
+          write(cmonth, '(I2.2)') month
           day_in_month=daynew-aux1
           exit
        end if
diff --git a/src/io_meandata.F90 b/src/io_meandata.F90
index d3cab9aa3..57fcda543 100644
--- a/src/io_meandata.F90
+++ b/src/io_meandata.F90
@@ -68,6 +68,7 @@ module io_MEANDATA
   logical, save                  :: vec_autorotate=.FALSE.
   logical, save                  :: lnextGEMS=.FALSE.
   integer, save                  :: nlev_upper=1
+  character(len=1), save         :: filesplit_freq='y'
   type io_entry
         CHARACTER(len=15)        :: id        ='unknown   '
         INTEGER                  :: freq      =0
@@ -141,7 +142,7 @@ subroutine ini_mean_io(ice, dynamics, tracers, partit, mesh)
     type(t_tracer), intent(in)   , target :: tracers
     type(t_dyn)   , intent(in)   , target :: dynamics
     type(t_ice)   , intent(in)   , target :: ice
-    namelist /nml_general / io_listsize, vec_autorotate, lnextGEMS, nlev_upper
+    namelist /nml_general / io_listsize, vec_autorotate, lnextGEMS, nlev_upper, filesplit_freq
     namelist /nml_list    / io_list
 
 #include "associate_part_def.h"
@@ -1287,8 +1288,12 @@ subroutine output(istep, ice, dynamics, tracers, partit, mesh)
             entry%thread_running = .false.
             
             ! define filepath
-            filepath = trim(ResultPath)//trim(entry%name)//'.'//trim(runid)//'.'//cyearnew//'.nc'
-            
+            if (filesplit_freq=='m') then
+                filepath = trim(ResultPath)//trim(entry%name)//'.'//trim(runid)//'.'//cyearnew//'_'//cmonth//'.nc'
+            else
+                filepath = trim(ResultPath)//trim(entry%name)//'.'//trim(runid)//'.'//cyearnew//'.nc'
+            endif
+
             !___________________________________________________________________
             ! only root rank task does output
             if(partit%mype == entry%root_rank) then