Radiation Balance Data Example

The following data were collected at the University of Nebraska-Lincoln, East Campus research fields on July 15, 1992 over a soybean canopy. The yellow bands in the following graphs represent photographs were taken of sky conditions and a downward looking (nadir) view of the canopy at various locations. Canopy and sky pictures where not taken at the same time but within a short period of each other.

Time (CDT)
Canopy Picture
Sky Picture
9:48 am Canopy @ 55 SZA Not Available
10:20 am Canopy @ 45 SZA Sky @ 45 SZA
11:26 am Canopy @ 35 SZA Sky @ 35 SZA
12:38 pm Canopy @ 25 SZA Sky @ 25 SZA
1:37 pm Not Available Sky @ Solar Noon
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Longwave Radiation Graph

PIR - Epply Pyrgeometer
 IRT - Everest Infrared Transducer


SHort Wave GraphPyranometer - LI-COR (LI-200SA) Pyranometer
 PSP- Epply Precision Spectral Pyranometer
 Quantum - LI-COR (LI-190SA) Quantum sensor

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Net Radiation Graph

Longwave Incoming = Incoming Longwave Radiation{Eppley Pyrgeometer}
Longwave Outgoing = Outgoing Longwave Radiation {Epply Pyrgeometer}
Shortwave Incoming = Incoming Shortwave Radiation {Epply Precision Spectral Pyranometer}
Shortwave Outgoing = Outgoing Shortwave Radiation {Epply Precision Spectral Pyranometer}
 Rn = Net Radiation {REBS Model Q*6 net radiation sensor}


PAR Graph

All measurements except "TPAR Average: Measured" where made with LI-190SA Quantum Sensor (hemispherical point source).  The "TPAR Average: Measured" values were measured with a LI-191SA Line Quantum Sensor.

Soybeans with PAR sensors Up view of Canopy

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Mounting Information

Soybean Raditation Instruments
  • Everest IRT Transducer at nadir & 45o.  The  45o IRT is pointed toward the north to minimize it's view of shadows
  • Outgoing Epply PSP and PIR centered on support structure to reduce view of structure 
  • REB net radiometer pointed toward south to reduce views of shadows from support structure
Soybean Radiation Instruments
  • Incoming Epply PSP and PIR
Soybean radiation Instruments
  • Canopy growth as of July 15, 1992
  • Instrument approximately 1.5 meters above the soil surface. 
  • Transmitted PAR quantum sensors in row structure in foreground of the picture.

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