Impact of deforestation in the Amazon basin on cloud climatology

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 106; no. 10; pp. 3670 - 3674
• Main Authors: Wang, Jingfeng, Chagnon, Frédéric J.F, Williams, Earle R, Betts, Alan K, Renno, Nilton O, Machado, Luiz A.T, Bisht, Gautam, Knox, Ryan, Bras, Rafael L
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 10-03-2009; National Acad Sciences
• Subjects: Algorithms; Atmospheric chemistry; Atmospheric circulation; Atmospherics; Basins; Boundary layers; Climate; Clouds; Conservation of Natural Resources; Convection; Convection clouds; convective available potential energy; deep clouds; Deforestation; energy transfer; Environmental impact; humidity; Land cover; meteorology and climatology; Pastures; Physical Sciences; relative humidity; Rivers; Satellite Communications; shallow clouds; Sounding; South America; tropical forests; tropical rain forests; Brazil; South America; Amazon Basin; South America, Amazon R
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.0810156106

Shallow clouds are prone to appear over deforested surfaces whereas deep clouds, much less frequent than shallow clouds, favor forested surfaces. Simultaneous atmospheric soundings at forest and pasture sites during the Rondonian Boundary Layer Experiment (RBLE-3) elucidate the physical mechanisms responsible for the observed correlation between clouds and land cover. We demonstrate that the atmospheric boundary layer over the forested areas is more unstable and characterized by larger values of the convective available potential energy (CAPE) due to greater humidity than that which is found over the deforested area. The shallow convection over the deforested areas is relatively more active than the deep convection over the forested areas. This greater activity results from a stronger lifting mechanism caused by mesoscale circulations driven by deforestation-induced heterogeneities in land cover.