The Impacts of Tropical Deforestation on Regional and Global Hydroclimate

Duke University, Durham NC

Investigators

Abstract

This project follows a preliminary general circulation modeling (GCM) study conducted by the PI who found that deforestation of tropical regions, through teleconnections involving the activation of Rossby waves similar to those produced during El Nino events, has a significant impact on the rainfall of other regions. In particular, they found that the US Midwest is the continental region the most severely affected by the deforestation of Amazonia and Central Africa during spring and summer, when rainfall is crucial for agriculture in that region. Two ideas for a more robust experiment arose from that study and are the basis of the research: * The simulations performed in the preliminary study could be considerably improved by representing more realistic forcing conditions such as observed sea-surface temperatures (SSTs) and observed deforestation patterns during the past few decades; * Furthermore, reproducing these simulations with different climate models would contribute to improving confidence in the pattern and strength of such teleconnections. This research is aimed at studying these ideas using three major GCMs: the NCAR Community Climate System Model, the NASA Goddard Space Flight Center GCM and the PI's Ocean-Land-Atmosphere Model (OLAM). The ultimate goal of the study is to quantify the change of precipitation in all continental regions due to past, and present deforestation of tropical regions. Broader Impact: In the process of performing this research, an intercomparison of climate models and an evaluation of their capability of simulating global precipitation will be conducted. This project will also help introduce a new generation of earth system model (namely, the Ocean-Land-Atmosphere Model -- OLAM), which will help advance future climate research. Thus, the project has potential to improve scientists' ability to project global environmental change due to land cover/land use change and is relevant to issues of societal importance.