All,

I don't think Jon is right on this.  I think that if you specify the FAO-56 ET option and only have SRAD, Tmin, Tmax, and rainfall, the model will still run FAO-56, but it does this with the assumption that Tdew is equal to Tmin, and with a default windspeed that is buried in the code somewhere.

Jon is right in saying that you should really only use Priestley-Taylor in this case.  But I think the model runs FAO-56 with the two assumptions that I indicated.

Happy computing,
Ken Boote

-----Original Message-----
From: DSSAT - Crop Models and Applications [mailto:[log in to unmask]] On Behalf Of Jon I. Lizaso
Sent: Thursday, April 28, 2011 11:40 AM
To: [log in to unmask]
Subject: Re: Evapotranspiration Model

Kelsey,
If only the minimum weather data set is available, then the model will use
the Priestley-Taylor method. To use Penman-Monteith-FAO56 method you will
need information on wind and dew-point temperature.
Best regards,
Jon

-----Mensaje original-----
De: DSSAT - Crop Models and Applications [mailto:[log in to unmask]] En
nombre de Brandt, Kelsey
Enviado el: Thursday, April 28, 2011 4:13 PM
Para: [log in to unmask]
Asunto: Evapotranspiration Model

Hi all,



If we only have a minimum data set (SRAD, Minimum Temperature, Maximum
Temperature and Precipitation), and select FAO56 as our evapotranspiration
model, what model is actually used?  Does DSSAT default to a certain model,
or will it calculate values so it can use the FAO56 model?



Thanks,

Kelsey



Kelsey Brandt
Semiarid Prairie Agricultural Research Centre | Centre de resecherches
agricoles de la region semi-aride
Agriculture and Agri-Food Canada | Agriculture et Agroalimentaire Canada
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