diff --git a/src/MNH/ch_aer_mod_init.f90 b/src/MNH/ch_aer_mod_init.f90
index b5a2409aae881e642fc93e797a0c011284024e94..6c22e54432cd4063b7c3facf2a3dc74ede01c378 100644
--- a/src/MNH/ch_aer_mod_init.f90
+++ b/src/MNH/ch_aer_mod_init.f90
@@ -1,4 +1,4 @@
-!ORILAM_LIC Copyright 1994-2019 CNRS, Meteo-France and Universite Paul Sabatier
+!ORILAM_LIC Copyright 2006-2019 CNRS, Meteo-France and Universite Paul Sabatier
 !ORILAM_LIC This is part of the ORILAM software governed by the CeCILL-C licence
 !ORILAM_LIC version 1. See LICENSE, CeCILL-C_V1-en.txt and CeCILL-C_V1-fr.txt
 !ORILAM_LIC for details.
@@ -41,6 +41,7 @@ END MODULE MODI_CH_AER_MOD_INIT
 !!    -------------
 !!    20/03/03   P . Tulet (CNRM/GMEI)   add  initialization tabulation
 !!  Philippe Wautelet: 05/2016-04/2018: new data structures and calls for I/O
+!  P. Wautelet: 07/06/2019: allocate weights only when needed
 !!
 !!    EXTERNAL
 !!    --------
@@ -83,6 +84,12 @@ TZFILE => NULL()
 !
 ! Initialize the mineral tabulation 
 IF (CMINERAL == 'NARES') THEN
+        ALLOCATE( W1IJA(100,100), W1JKA(100,100), W2IJA(100,100), W2JKA(100,100) )
+        ALLOCATE( W1IJB(100,100), W1JKB(100,100), W2IJB(100,100), W2JKB(100,100) )
+        ALLOCATE( W1IJC(100,100), W1JKC(100,100), W2IJC(100,100), W2JKC(100,100) )
+        ALLOCATE( X1MINA(2,100), X1MAXA(2,100), X1MODA(2,100), X2MINA(2,100), X2MAXA(2,100), X2MODA(2,100) )
+        ALLOCATE( X1MINB(2,100), X1MAXB(2,100), X1MODB(2,100), X2MINB(2,100), X2MAXB(2,100), X2MODB(2,100) )
+        ALLOCATE( X1MINC(2,100), X1MAXC(2,100), X1MODC(2,100), X2MINC(2,100), X2MAXC(2,100), X2MODC(2,100) )
 !       .. the file ares.w contains the weights of the model
         CALL IO_File_add2list(TZFILE,'ares1A.w','CHEMTAB','READ')
         CALL IO_File_open(TZFILE)
diff --git a/src/MNH/modd_ch_aerosol.f90 b/src/MNH/modd_ch_aerosol.f90
index e0019a581fbb165a4ee631c4bca6c7918c18cd96..4eb7fed5cc8a2c7f1fbe9a6820d1206842dfa513 100644
--- a/src/MNH/modd_ch_aerosol.f90
+++ b/src/MNH/modd_ch_aerosol.f90
@@ -1,13 +1,8 @@
-!ORILAM_LIC Copyright 1994-2014 CNRS, Meteo-France and Universite Paul Sabatier
+!ORILAM_LIC Copyright 2006-2019 CNRS, Meteo-France and Universite Paul Sabatier
 !ORILAM_LIC This is part of the ORILAM software governed by the CeCILL-C licence
 !ORILAM_LIC version 1. See LICENSE, CeCILL-C_V1-en.txt and CeCILL-C_V1-fr.txt
 !ORILAM_LIC for details.
 !-----------------------------------------------------------------
-!--------------- special set of characters for RCS information
-!-----------------------------------------------------------------
-! $Source: /home/cvsroot/MNH-VX-Y-Z/src/MNH/modd_ch_aerosol.f90,v $ $Revision: 1.1.2.2.2.1.2.1.2.1.2.2 $
-! MASDEV4_7 modd 2007/03/02 13:59:38
-!-----------------------------------------------------------------
 !!     ######################
        MODULE MODD_CH_AEROSOL
 !!     ######################
@@ -35,7 +30,8 @@
 !!     -------------
 !!     (30-01-01) P.Tulet (LA) * modifications for secondary biogenics aerosols
 !!     (25-08-16) M.Leriche (LA) * NM6_AER is now in SAVE and assign in ini_nsv
-!!
+!  P. Wautelet: 07/06/2019: allocate weights only when needed!!
+!
 !!--------------------------------------------------------------------
 !!     DECLARATIONS
 !!     ------------
@@ -231,12 +227,12 @@ REAL, SAVE, DIMENSION(:,:,:,:,:,:), ALLOCATABLE :: zf
 ! Declaration of  the neuronal coefficients
 
 !     .. weights 
-REAL, SAVE, DIMENSION(100,100) :: W1IJA,W1JKA,W2IJA,W2JKA
-REAL, SAVE, DIMENSION(100,100) :: W1IJB,W1JKB,W2IJB,W2JKB
-REAL, SAVE, DIMENSION(100,100) :: W1IJC,W1JKC,W2IJC,W2JKC
-REAL, SAVE, DIMENSION(2,100) :: X1MINA,X1MAXA,X1MODA,X2MINA,X2MAXA,X2MODA
-REAL, SAVE, DIMENSION(2,100) :: X1MINB,X1MAXB,X1MODB,X2MINB,X2MAXB,X2MODB
-REAL, SAVE, DIMENSION(2,100) :: X1MINC,X1MAXC,X1MODC,X2MINC,X2MAXC,X2MODC
+REAL, SAVE, DIMENSION(:,:), ALLOCATABLE :: W1IJA,W1JKA,W2IJA,W2JKA
+REAL, SAVE, DIMENSION(:,:), ALLOCATABLE :: W1IJB,W1JKB,W2IJB,W2JKB
+REAL, SAVE, DIMENSION(:,:), ALLOCATABLE :: W1IJC,W1JKC,W2IJC,W2JKC
+REAL, SAVE, DIMENSION(:,:), ALLOCATABLE :: X1MINA,X1MAXA,X1MODA,X2MINA,X2MAXA,X2MODA
+REAL, SAVE, DIMENSION(:,:), ALLOCATABLE :: X1MINB,X1MAXB,X1MODB,X2MINB,X2MAXB,X2MODB
+REAL, SAVE, DIMENSION(:,:), ALLOCATABLE :: X1MINC,X1MAXC,X1MODC,X2MINC,X2MAXC,X2MODC
 
 !     .. counters and indices
 INTEGER, SAVE :: I1IA,J1JA,K1KA,I2IA,J2JA,K2KA