Extended Abstract (308K)P2.7
The surface energy balance over a desert, and the relevance of soil heat flux measurements
Bert G. Heusinkveld, Meteorology and Air Quality Group, Wageningen Univ., Wageningen, Netherlands; and A. F. G. Jacobs, A. A. M. Holtslag, and S. M. Berkowicz
Very large soil heat fluxes can be observed in a desert. From observations in a desert, of the separate components of the surface energy balance, it is shown how important a correct soil heat flux measurement is. The soil heat flux can be as high as the sensible heat flux. Soil heat flux measurements are complex. It is a challenge to measure this correctly. This resulted in a new method to measure the soil heat flux. It comprises a standard soil heat flux sensor, but its placement is new. The sensor is buried at the surface and covered with less than 0.001m of sand. This new method is compared with traditional soil heat flux measurements.
Traditional techniques usually incorporate a soil heat flux sensor buried at a certain depth (example: 0.046m) together with a soil temperature sensor profile. These measurements reveal that the traditional soil heat flux measurement techniques with all its corrections, have their limitations with respect to accuracy and the ability to capture the very dynamic nature of the soil surface heat flux. With the growing interest in short term exchange processes near the surface, it becomes increasingly important to be able to capture these dynamics correctly.
Observations in a desert, with the new soil heat flux measurements and measurements of the other components of the surface energy balance, are validated using the so called surface energy balance closure test. This shows that these measurements together with the sensible and latent heat flux measurements, work fine.
Poster Session 2, Observational Methods
Monday, 15 July 2002, 2:00 PM-2:00 PM
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