Welcome to CGD

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Summary

The goal of the Terrestrial Sciences Section (TSS) is to increase scientific understanding of land-atmosphere interactions, in particular surface forcing of climate, through model development, application, and observational analyses and to represent that understanding in climate models. Research in TSS spans a broad knowledge of the relationships among the biosphere, hydrosphere, cryosphere, and atmosphere. Scientists in TSS develop and use appropriate multi-scale models, remote sensing, advanced analytical techniques, and observations to study the role of the terrestrial biosphere in the climate system. Topics of study include the regulation of planetary energetics, planetary ecology, and planetary metabolism through exchanges of energy, momentum, and materials (e.g., water, carbon, mineral aerosols) with the atmosphere and ocean and the response of the climate system to changes in land cover and land use.

Scientists in TSS are involved in developing the land model used in the Community Atmosphere Model (CAM) and the Community Climate System Model (CCSM). This model, the Community Land Model (CLM), includes biogeophysics and hydrology, the traditional physical core components of land models, and is being further developed to include river routing, biogeochemistry (carbon, nitrogen, mineral aerosols, biogenic volatile organic compounds, water isotopes), and vegetation dynamics. Gordon Bonan co-chairs the CCSM Land Model Working Group, Natalie Mahowald co-chairs the CCSM Biogeochemistry Working Group, and other TSS scientists actively participate in both working groups, providing strong input to model development and implementing and testing model parameterizations. Model development is based on process studies of the relevant physical, chemical, and biological mechanisms and the numerical modeling techniques required to represent these mechanisms. TSS scientists compare model output with observed atmospheric, ecological, and hydrological data to validate and improve the model on a wide range of spatial and temporal scales. TSS provides a focal point for CGD and university ecological and hydrological research and serves as a resource to these communities in their use of CCSM.

CLM hydrology

Keith Oleson, David Lawrence, and Gordon Bonan led a project within the CCSM land model working group to improve the surface hydrology of CLM. [ more]

CLM/CCSM biogeochemistry

TSS scientists conducted several projects to implement biogeochemistry in CLM and CCSM. This research broadly addresses how biogeochemical coupling of carbon, nitrogen, and iron cycles affects climate, air quality, radiative forcing, and ecosystem function on regional to global scales. It involves two specific research agendas related to the terrestrial carbon cycle and mineral aerosols. [ more]

Land cover and land use change

A major research focus for TSS is natural and human-mediated changes in land cover and ecosystem functions and their effects on climate, water resources, and biogeochemistry. TSS scientists worked on several projects to implement land cover and land use change in CLM and to use climate models to study the impact of these processes on climate. [ more]

Carbon Data Assimilation

Through the activities of Dave Schimel, Steven Aulenbach, David Baker and collaborators, TSS holds a leadership position in the development of data assimilation techniques for biogeochemistry and carbon cycle studies. [ more]

High resolution surface weather interpolation and terrestrial biogeochemistry

Peter Thornton led a technology development project to produce a user interface to two widely used models: Daymet (for interpolation and extrapolation of surface weather observations to a high-resolution grid) and Biome-BGC (for terrestrial carbon, nitrogen, water, and energy cycle modeling). [ more]