aim_surfForc_NppCycle = 12
tNcyc = aim_surfForc_NppCycle
nm1 = 1 + MOD(nm0,aim_surfForc_NppCycle)
nm2 = nm0 + aim_surfForc_NppCycle
nm3 = nm1 + aim_surfForc_NppCycle
INTEGER aim_surfForc_NppCycle, nm0, nm1, nm2, nm3