Index: trunk/LMDZ.COMMON/libf/evolution/atmosphere.F90
===================================================================
--- trunk/LMDZ.COMMON/libf/evolution/atmosphere.F90	(revision 4138)
+++ trunk/LMDZ.COMMON/libf/evolution/atmosphere.F90	(revision 4145)
@@ -470,14 +470,14 @@
     do i = 1,nlayer
         call compute_hybrid_sig(sig(i),pa,preff,newsig)
-        bp(i) = exp(1._dp - 1._dp/(newsig**2))
-        ap_l(i) = pa*(newsig - bp(i))
+        bp_l(i) = exp(1._dp - 1._dp/(newsig**2))
+        ap_l(i) = pa*(newsig - bp_l(i))
     end do
     ap_l(nlayer + 1) = 0._dp
-    bp(nlayer + 1) = 0._dp
+    bp_l(nlayer + 1) = 0._dp
 else
     call print_msg('> Defining sigma altitude coordinates',LVL_NFO)
     ap_l(:) = 0._dp
-    bp(1:nlayer) = sig(1:nlayer)
-    bp(nlayer + 1) = 0._dp
+    bp_l(1:nlayer) = sig(1:nlayer)
+    bp_l(nlayer + 1) = 0._dp
 end if