Title Modeling and Analysis of Global Biosphere-Atmosphere Interactions
 Collaborators Elena Shevliakova (Princeton), Michael Schlesinger (UIUC),
Andrew Friend (Institute of Terrestrial Ecology, Edinburgh Research Station), Hadi Dowlatabadi (CMU), Louis Pitelka (University of Maryland), Randal Koster (NASA Goddard Space Flight Center)
 Keywords climate change, land cover change, biosphere- atmosphere interactions
 Abstract Integration of key earth-system processes is a distant and defining goal for natural and social scientists. The inclusion of physical and chemical dimensions of the earth system has progressed farther than inclusion of many anthropogenic factors. Consideration of different atmospheric compositions has dominated much of the analyses to date. However, the land-atmosphere interface is shaped by land cover, and modulated by human land use.

The goal of the project is to explore the couplings between the different components of the Earth system in an interactive and internally consistent manner. Three models will be linked: (1) the UIUC 11-layer troposphere/lower-stratosphere general circulation/mixed-layer-ocean model (GCM), (2) the Mosaic land-surface model, and (3) the dynamic vegetation-growth model Hybrid. During the first phase of the project we reviewed relevant literature, identify a land surface and a vegetation models suitable for integration with the UIUC GCM, developed an integration framework, gathered data necessary for land surface parameterization (e.g. current global plant functional type distribution), and performed preliminary off-line testing of the Mosaic and Hybrid models.

Once an integrated biosphere-atmosphere/ocean model is constructed, we will explore the sensitivity of the climate system to dynamic changes in the vegetation structure and functioning. We also propose to explore two different mechanisms, which may lead to a redistribution of vegetation and alter its functioning. The first mechanism is the climate change caused by anthropogenic releases of CO2. The second mechanism is anthropogenic land-use change. An integrated assessment model (ICAM-3) will be used to generate land-use scenarios for different regions of the world. In conducting this research we will explore a number of issues related to the complexity and uncertainty of the models used and specification of their interactions.