All:

Watt is a unit of power
Joule is a unit of energy

Power = rate of energy (i.e., Energy/Time)

Apparently 1Watt = 1Joule/sec

1x10^6 Joule is 1 MegaJoule (MJ)

So converting W/m2 to MJ/m2-day is very straight forward... because 1W/m2=1J/s-m2 

Hope this one is correct now....

-----
Dr. Amor VM Ines
Dept. of Biological and Agricultural Engineering
Texas A&M University
2117 TAMU 301B Scoates Hall
College Station, TX 77843
Tel: 979-458-4651
Fax: 979-862-3442
Email: [log in to unmask]



-----Original Message-----
From: DSSAT - Crop Models and Applications on behalf of Gerrit Hoogenboom
Sent: Wed 5/23/2007 9:23 PM
To: [log in to unmask]
Subject:      Re: I NEED HELP CONVERT DATA CLIMATIC
 
Camerino Rojas Montes,

1 Ws/2 = 1 J/m2

Watts is normally expressed as W/s, which is the 
equivalent of radiation intensity. You, 
therefore, need to integrate the intensity over 
the day in order to calculate total energy  = MJ/m2/day.

Regards,

Gerrit



At 09:31 PM 05/23/2007, you wrote:

>I UNDERSTAND WHICH DSSAT OPERATE WITH CLIMATIC 
>DATA OF SOLAR RADIATION IN Megajoules/m2 BUT MY 
>WEATHER STATION TO CAST OUT DATA SOLAR RADIATION 
>IN Watss/m2.<?xml:namespace prefix = o ns = 
>"urn:schemas-microsoft-com:office:office" />
>
>
>
>I NEED HELP FOR CONVERT Watss/m2 TO Joules/m2.
>
>
>
>THANKS.
>
>
>
>CAMERINO ROJAS MONTES.
>
>UNIVERSIDAD AUTONOMA AGRARIA ANTONIO NARRO.
>
>SALTILLO, COAHUILA, MEXICO.
>
>
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