HR: 13:55h
AN: B53B-02    [Abstracts]
TI: Coupling Between Cloud Base Height and Land Surface Processes in Lowland Amazonia
AU: * Pinto, E R
EM: erica.pinto@utoronto.ca
AF: Faculty of Forestry, University of Toronto, 33 Wilcocks Street, Toronto, ON M5S 3B3 Canada
AU: Shin, Y
EM: shiny@geog.utoronto.ca
AF: Department of Geography, University of Toronto, 100 St. George Street, Toronto, ON M5S 3G3 Canada
AU: Jones, C D
EM: chris.d.jones@metoffice.gov.uk
AF: Met Office, Hadley Centre for Climate Prediction and Research, Fitzroy Road, Exeter, Devon, EX1 3PB United Kingdom
AU: Cowling, S A
EM: cowling@geog.utoronto.ca
AF: Department of Geography, University of Toronto, 100 St. George Street, Toronto, ON M5S 3G3 Canada
AB: Investigating the coupling between vegetation and climate in lowland Amazonia is critical to understanding the importance of tropical forests to the region's hydrological cycle. Recent modelling studies illustrate the adverse consequences of land-use changes on cloud formation in tropical montane cloud forests, with deforestation resulting in an increasing cloud base height, or lifting condensation level (LCL). Similar circumstances may apply to lowland Amazonia; however, little research has been directed toward establishing the importance of feedback processes between LCL and vegetation in this region. By deriving the change in LCL under different climate scenarios, our aim is to quantify the relationship between LCL and vegetation cover in order to distinguish natural from anthropogenic components of land-atmosphere processes. Using the simulated surface temperature and specific humidity values generated by the Hadley Centre's coupled general circulation model HadCM3LC, we compute Amazonian LCL for five time periods: Last Glacial Maximum (LGM), Younger Dryas (YD), Pre-Industrial, Present Day and Future (IPCC IS92a scenario). Our results indicate that average LCL values for Present Day, Pre-Industrial and YD are similar, whereas LGM and Future values both exceed Present Day LCL. We analyze the relationship between LCL, evapotranspiration, precipitation and change in vegetation cover for each time period. The results of this analysis will be used to assess the impact of lowland deforestation on naturally-driven regional convective cloud formation. This project follows as part of an on-going research program aimed at exploring Amazonian forest-climate feedbacks over both short and long timescales.
DE: 0473 Paleoclimatology and paleoceanography (3344, 4900)
DE: 1622 Earth system modeling (1225)
DE: 1631 Land/atmosphere interactions (1218, 1843, 3322)
DE: 1800 HYDROLOGY
SC: Biogeosciences [B]
MN: Fall Meeting 2005