[RegCNET] Time step problem or something else ?

[Dilip Ganguly]

Dear all,

I am facing problem in running RegCM3. The program hangs and does not seem 
to work after a particular time and I am getting messages on the screen 
like the following.

 BATS variables written at   2004120121   180.000000000000
     at day =  396.8762, ktau =     210200 :  1st, 2nd time deriv of ps =  
0.10915E-02 0.49528E-05,  no. of points w/convection =   81
     at day =  396.8849, ktau =     210250 :  1st, 2nd time deriv of ps =  
0.97549E-03 0.41641E-05,  no. of points w/convection =   71
     at day =  396.8936, ktau =     210300 :  1st, 2nd time deriv of ps =  
NaN        NaN        ,  no. of points w/convection =    0

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It do not know if it is due to improper choice of time steps. I have 
restarted the program several times with lower and lower values of time 
step dt but every time the program hangs around a certain period of time 
and not able to cross this period. I have tried with numerous combinations 
of gradually decreasing time steps. Some are given below.

radfrq= 30	30	30	30	15	15	15
abemh = 18	18	18	18	9	9	9 
abatm = 300	120	90	45	30	9	3
dt    = 100	60	30	15	10	3	1

But none of them worked. Everytime it shows the same problem possibly due 
to convective instability as told by Jagadish. I am using a 90 km 
horizontal resolution in my simulation.

Can anyone suggest a way to solve this problem ?

Thanking you in advance.

Dilip. 
  
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        DILIP GANGULY                               
        Postdoctoral Fellow                     
        Space And Atmospheric Sciences Division      
        Physical Research Laboratory                
        Ahmedabad 380009
	Gujarat, India
        Phone: +91 79 26314558 (Laboratory)    
               +91 79 26300505 (Hostel)
	Fax:   +91 79 26314659
	Alternate Email: ganguly.dilip at gmail.com          
            Visit me at   http://www.prl.res.in/~dganguly
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