Abstract
Two field studies with six large aperture scintillometers (LASs) were performed using horizontal and slant paths. The accuracy of this novel and increasingly popular technique for measuring sensible heat fluxes was quantified by comparing measurements from different instruments over nearly identical transects. Random errors in LAS measurements were small, since correlation coefficients between adjacent measurements were greater than 0.995. However, for an ideal set-up differences in linear regression slopes of up to 21% were observed with typical inter-instrument differences of 6%. Differences of 10% are typical in more realistic measurement scenarios over homogeneous natural vegetation and different transect heights and locations. Inaccuracies in the optics, which affect the effective aperture diameter, are the most likely explanation for the observed differences.
| Original language | English |
|---|---|
| Pages (from-to) | 133-150 |
| Number of pages | 18 |
| Journal | Boundary-Layer Meteorology |
| Volume | 128 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jul 2008 |
| Externally published | Yes |
Funding
Acknowledgements The following sponsors have contributed to this study: NSF EPSCoR grant EPS-0447691; U.S. Department of Agriculture, CSREES grant No.: 2003-35102-13654; and the NSF Science and Technology Center program Sustainability of Semi-Arid Hydrology and Riparian Areas (SAHRA; EAR-4619876800), USGS award 06HQGR0187, and NMSU-WRRI contract Q01112. We are indebted to the Sevilleta National Wildlife Refuge staff and affiliated scientists, in particular Renee Robichaud, Don Natvig, Renee Brown, and Mike Friggens for assistance with preparation and execution of the experiment. Without Bob Parmenter, Johnny, Albert, and Juglio of the Valles Caldera National Preserve our experiment would not have been possible. Assistance in the field by Kathy Fleming, Kimberly Bandy, and Jack Cheney is acknowledged.
Keywords
- Instrument intercomparison
- Large aperture scintillometer
- Sensible heat flux