A Look at Amazon Basin Seasonal Dynamics with the Biophysical ...

Radiation Budget over the forest near Manaus, Amazonas – BrazilDallarosa¹, R.L.G.; Marques Filho¹, A. de O.; Araújo¹, A. C. de; Nobre¹, A. D.;Pacheco¹, V. B.; Oliveira¹, J. A. D. de¹Instituto Nacional de Pesquisas da AmazôniaCEP 69083-000, Manaus/AM–Brasil. Cx Postal 478, CPGC, e-mail: dalla@inpa.gov.brABSTRACTA study of the radiation budget over the forest of Reserva Biológica doCuieiras (ZF-2) was carried out, using data from the k34 micrometeorological tower.Further details of this site and the instrumentation used can be obtained in Araújo et al.(2002). The atmospheric cloudiness modulated the behavior of the shortwave and thelongwave fluxes near the surface. The longwave descending fluxes (Li) showed to besimilar during the day, in both seasons. However, during the night, they showed highervalues in the rainy season possibly due to the heating and reemission from the base ofthe clouds. The longwave ascending fluxes (Lo), showed to be similar in both seasonsduring the night, but showing higher values during the day, in response to a greaterheating of the surface. The seasonal budget showed higher values during the wet season,when a greater amount of cloudiness “trapped” the heat in the lower troposphere. Theincoming solar radiation (Si) and the reflected solar radiation (So) were also modulatedby the cloudiness, having shown higher values during the dry season. The mean albedowas around 0.13, in both seasons, agreeing with the results of the ABRACOS Project,having shown a greater daily variation in the early morning period.