P2.11
Soil heat flux and temperature profiles under Amazonian rain forest during the wet season of 1999
Ralf Gielow, Instituto Nacional de Pesquisas Espaciais, Sao Jose dos Campos, SP, Brazil; and R. C. S. Alvala, H. R. da Rocha, H. C. Freitas, and O. M. R. Cabral
Soil temperature influences most of the processes of the soil-plant continuum, and the soil heat flux is a minor, but not negligible component of the surface energy balance under the forest canopy. Thus, soil heat flux profiles were measured at the Rebio-Jaru Amazon Rain Forest site (10°04' S; 61°56' W) during the wet season campaign of 1999 (January-March), as part of the LBA-Large Scale Biosphere -Atmosphere Experiment in Amazonia. In no rain days the temperature shows a regular daily cycle, with an amplitude of about 2°C at the depth of 2cm, while it becomes practically constant at the depth of 40cm; on the other hand, the occurrence of rain causes an immediate change in the soil temperature, "flattening" it. The heat flux also shows a daily cycle, with maxima of the order of 40 Wm-2 in no rain days, and there is a strong change after the onset of rain. Finally, apparent soil thermal diffusivities are also computed and correlated with soil moisture data measured at the site.
Poster Session 2, TRMM Hydrology Poster
Thursday, 13 January 2000, 5:15 PM-7:00 PM
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