Sky Oaks Field Station
                 San Diego State University 


INSTRUMENTATION


Eddy Correlation Flux Measurement System provides in situ
half-hour averages of CO2, H2O and sensible heat and latent heat
fluxes using a three axis ATI sonic anemometer with a closed-path
CO2/H2O (LI-COR 6262) analyzer.  Additionally, meteorological
variables such as net radiation, photosynthetically active
radiation, ground heat flux, air temperature, relative humidity,
soil temperature and precipitation are measured as 30-min
averages.

DATA FORMAT 
Variable List (Symbols and Units)

The file is in Ascii comma delimited text format. Missing values are
represented by "-9999"

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Symbol     Description             Instrument                      Unit
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Rn         Net radiation           Q-7 (REBS)                      W m-2
LE         Latent Heat Flux        LI-6262 (LI-COR)                W m-2
H          Sensible Heat Flux      Sonic Anemometer (ATI Inc.)     W m-2
G_1        Soil Heat Flux          HFT-3 (REBS)                    W m-2 
G_2        Soil Heat Flux          HFT-3 (REBS)                    W m-2 
PAR        Photosynthetically      LI-190SB (LI-COR)               uE m-2 s-1 
           Active Radiation

Air T      Air Temperature         x HMP 35C (Vaisala)             degrees C 
Soil T_0   Soil temperature        Type-T Thermocouple             degrees C 
           at 0 cm

Soil T_5   Soil temperature        Type-T Thermocouple             degrees C 
           at -5 cm

Soil T_10  Soil temperature        Type-T Thermocouple             degrees C 
           at -10 cm

RH         Relative Humidity       HMP 35C (Vaisala)               % 
Rain       Precipitation           TE525 (Texas Electronics)       mm 
WD         Wind Direction          Sonic Anemometer (ATI Inc.)     degree 
WS         Wind Speed              Sonic Anemometer (ATI Inc.)     m s-1 
u*         Friction Velocity       Sonic Anemometer (ATI Inc.)     m s-1 
FCO2       CO2 Flux                LI-6262 (LI-COR)                mg m-2 s-1 
FH2O       H2O Flux                LI-6262 (LI-COR)                mg m-2 s-1 
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Keep us informed of how you are using our data.   Data processed in 1999 and 
2000 have to be regarded as preliminary, estimates can change considerably.