diff --git a/doc/namelists/namtrc_dcy b/doc/namelists/namtrc_dcy
new file mode 100644
index 0000000000000000000000000000000000000000..0b369b09d0388e9a749e9043a1b5d951b0cc0972
--- /dev/null
+++ b/doc/namelists/namtrc_dcy
@@ -0,0 +1,5 @@
+!-----------------------------------------------------------------------
+&namtrc_dcy      !  Diurnal cycle
+!-----------------------------------------------------------------------
+   ln_trcdc2dm   =  .false.   !  Diurnal cycle for TOP
+/