Dear Members,

During simulation of DSSAT3.5 I am using option of "FAO-Penman " under "Simulation control: Methods, Evaporation"  instead of Ritchie modified Priestly Taylor. I think my weather file should have input values for TDEW, PAR in addition to SRAD, TMAX, TMIN, RAIN and  WINDSP.

In the absence of measured data for Dew Point Temperature(including dry bulb and wet bulb temp), is it possible to calculate Dew Point Temperature(TDEW) from the measured values RH(Min & Max), Temp(Min & Max) and psycrometry. 

What is PAR (Photosynthetic active radiation) and how should I get these values? 

I will appreciate if someone suggests.

Thanks,

Uday Khodke
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Department of Agricultural & Food Engineering,
Indian Institute of Technology, 
Kharagpur - 721 302 (WB), India
Tel: +91-3222-83138
Fax: +91-3222-82244
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