Large aperture scintillometer intercomparison

Large Aperture Scintillometers (LAS) are powerful instruments to obtain spatially averaged measurements of the sensible heat flux over distances up to 5 km.

Four Kipp&Zonen LAS were intercompared over different transects in central New Mexico. The transects were slanted path over dry shrubland with distances between transmitter and receiver of one to three km. The averaging time was varied between 1 minute and 10 minutes. An eddy correlation station was operated for validation and to measure wind speed and temperature as input for the sensible heat flux derivation of the scintillometer.

The resulting sensible heat fluxes from the scintillometers typically agreed within 5% and were 10-20% larger than the EC measurements. The sensitivity of the LAS sensible heat flux to different parameters and practical setup issue will also be discussed.