For NaN error, it is suggested to reduce the time step . As our Domain is of 25km resolution we used "dt = 60" & "abatm = 120" at first and after NaN the time step was reduced to "dt=30" & "abatm=90" but still the same error persists.

the regcm.in file used for our run is.......

&restartparam

ifrest = .false.,

idate0 = 2076090100,

idate1 = 2076090100,

idate2 = 2077010100,

nslice = 120,

&timeparam

radfrq = 30.,

abemh = 18.,

abatm = 90.,

dt = 30.,

ibdyfrq = 6,

&outparam

ifsave = .true. ,

savfrq = 24.,

iftape = .true. ,

tapfrq = 24.,

ifrad = .true. ,

radisp = 24.,

ifbat = .true. ,

ifsub = .true. ,

batfrq = 24.,

ifprt = .false.,

prtfrq = 12.,

kxout = 6,

jxsex = 40,

iotyp = 1,

ibintyp = 1,

ifchem = .false. ,

chemfrq = 6.,

&physicsparam

iboudy = 5,

ibltyp = 1,

icup = 2,

igcc = 2,

ipptls = 1,

iocnflx = 2,

ipgf = 0,

iemiss = 0,

lakemod = 0,

ichem = 0,

&subexparam

&grellparam

&emanparam

&chemparam

idirect = 2,

chtrname = 'SO2',

chtrsol = 0.20,

chtrdpv = 0.00300,0.00800,

dustbsiz = 0.01, 1.00,

System Details:

Mac OS X 10.5.8

Quad core intel processor

4GB RAM

Darwin jags-mac-pro.local 9.8.0 Darwin Kernel Version 9.8.0: Wed Jul 15 16:55:01 PDT 2009; root:xnu-1228.15.4~1/RELEASE_I386 i386

Regards

Rajalakshmi .D

M.Sc (Ag.Met)

Junior Research Fellow,

ACRC, TNAU,

Cbe - 3