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Task ID:  6195  Temperature factor for Cotton assimilation goes negative    
 
Created by har297 on 2017-02-14 11:43 AM, 460 days ago
Project:  Module Code
Category:  Bug
Priority:  [no priority]
Assigned to:  [not assigned]  
Status:  Submitted
Apsim Version:7.8
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 comment 42513 posted by har297 on 2017-02-14 11:43 AM, 460 days ago 

In mvOZCOT.cs, public void ozcot_assimilation() the code to calculate a temperature scaling factor for assimilation goes negative at high and low average temperatures.

The relevant code is -

            //------------------------------------------------------------------------------
            //     effect of temperature on dry matter production
            //------------------------------------------------------------------------------

            tf = (tempav - t_base) / (t_opt - t_base);     // temperature scalar after
            tf = 2 * tf - Math.Pow(tf, 2);                 // angus & wilson 1976, constable 1981
            assimilate = assimilate * tf;                  // adjust assimilate for temp

t_base is 8 and t_opt is 25. TF goes negative below tempav=8 and above tempav=42.