|Kustas, William - Bill|
|HIPPS, L E|
Submitted to: Agricultural and Forest Meteorology Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 11/6/1998
Publication Date: N/A
Technical Abstract: Soil heat flux is an important component of the surface energy budget of most cultivated and natural surfaces. Under cultivated and relatively smooth flat surfaces and where a full canopy exists, soil heat flux values tend to be easier to estimate because of reduced spatial and temporal variability. However, for complex terrain with native vegetation estimating soil heat flux becomes much more complicated. This has important implications for estimating and evaluating surface energy budgets for large areal regions particularly when involving different scales of remote sensing platforms. A study was conducted in the Jornada Basin in south central New Mexico to evaluate the spatial distribution of soil heat of a single honey mesquite dune characteristic of the Northern Chihuahuan desert. The average height of the dune was approximately 2m with a large honey mesquite shrub on top of the dune. There are large expanses of these dunes throughout the southwest United States. Twenty soil heat flux plates were placed in a grid pattern over the dune. Thermocouples were located at two depths below the surface but above heat flux plates to estimate the storage component of the layer above the heat flux plates. Data were collected for over 60 days. Intitial results show that at any given time during the day a large range of soil heat flux values can be observed. Typical midday ranges were from 10-250 W m**-2 depending on time of day, position in the dune, microtopography and vegetative cover. The large range of values raises an important and difficult question as to which soil heat value should be used when evaluating surface energy budget for large expanses of complex surfaces.