FastFind »   Lastname: doi:10.1029/ Year: Advanced Search  

Geophysical Monograph Series

 

Keywords

  • Rain forest ecology—Amazon River Region
  • Biosphere—Research—Amazon River Region
  • Climatic changes—Amazon River Region
  • Amazon River Region—Climate

Index Terms

  • 1637 Global Change: Regional climate change
  • 1694 Global Change: Instruments and techniques
  • 9360 Geographic Location: South America

Article

GEOPHYSICAL MONOGRAPH SERIES, VOL. 186, PP. 145-147, 2009

Understanding the climate of Amazonia: Progress from LBA

C. A. Nobre, J. A. Marengo, and P. Artaxo

The Amazon plays an important role in the functioning of the Earth's climate. It acts as one of the critical heat sources for the global atmosphere via evaporation of water vapor at the surface and release of heat in the middle and upper troposphere by latent heat of condensation in tropical convective clouds. Forest evaporation year-round is about 3 to 3.5 mm d−1. In contrast, for savanna regions bordering the Amazon forest, evaporation is reduced during the dry season because of the limitation of soil moisture. Deforestation causes a large reduction in dry season evaporation. The cloudiness-rainfall regime of the undisturbed forest is similar to that of a tropical ocean, which led us to call the Amazon Basin a “green ocean.” Biogenic volatile organic compounds are released by the forest into the atmosphere, where some play an important role in providing aerosols and cloud condensation nuclei. On the other hand, aerosols emitted by biomass burning may cause reduction of rainfall. Together the chapters in this section reveal a complex mix of interacting processes that acting in concert control the movement and composition of the atmosphere above Amazonia. Each separate study reveals some new insight into one facet, but together they reveal an integrated system in which change in one component will produce impacts in another. The most important message is that deforestation is not just a change in land use, but it impacts the functioning of the Amazonian ecosystem itself. Changes in the evaporation and the chemical composition of the atmosphere produce changes in the cloud physics and in the dynamics and thermodynamics of the atmospheric circulation. These, in turn, impact the rainfall and the hydrological cycle.

Citation: Nobre, C. A., J. A. Marengo, and P. Artaxo (2009), Understanding the climate of Amazonia: Progress from LBA, in Amazonia and Global Change, Geophys. Monogr. Ser., vol. 186, edited by M. Keller et al., pp. 145–147, AGU, Washington, D. C., doi:10.1029/2009GM000903.

Cited By

Please wait one moment ...