About the Earth Observing System

Our Interdisciplinary Science investigation addresses the primary biogeochemical cycles of planet Earth and considers, in particular, how they are being changed by humans. The efforts focus on the cycles of water, carbon, nitrogen, and selected trace gases. Process-based models are developed as modules, in concert with database management techniques which synthesize the in-situ and remote sensing data needed to characterize regional and global scales.

Models of the Earth's biogeochemical cycles are a central theme. They provide a rigorous means for developing quantitative projections of the interactions of atmospheric composition, climate, terrestrial and aquatic ecosystems, ocean circulation and sea level, and the effects of human activities. The family of models being developed in this investigation provide the predictive link between the physical and biological Earth system and the human dimensions of global change.

The long-term goal of our IDS research is to understand the primary biogeochemical cycles of the planet, the nature of the coupling between the Biogeochemical Subsystem and the Physical-Climate Subsystem, and the characteristics of the human forcing of the Biogeochemical Subsystem and hydrological cycle. Our strategy is to study how element cycles function in natural systems where perturbations in biogeochemical states are driven primarily by climate variability and in systems where disturbance gradients induced by human activity have modified significantly exchanges of water, carbon, nitrogen, or sulfur.

To execute this strategy, we have been developing regional and global, geographically-specific, mathematical models and databases. These describe ecosystem distribution and condition, the biological processes that determine the exchange of CO₂ and trace gases with the atmosphere, and the fluxes of carbon and nutrients to aquatic ecosystems. This suite of models rest within interactive information systems that integrate geographic information systems, remote sensing systems, database management systems, graphics packages, and model interface shells. In time a macro Information Management System will be developed to "wrap" the specific subsystem information management systems.

Five science Objectives form the basis for our IDS research.

• To describe the global pattern and distribution of terrestrial ecosystems and to describe the geographical and temporal forcing agents of anthropogenic disturbance, particularly deforestation.
• To describe globally for terrestrial ecosystems key biological processes such as net primary production, heterotrophic respiration, transpiration, nutrient uptake, carbon allocation, and leaching which bear upon global biogeochemical cycles.
• To determine the baseline and changing fluxes of water, carbon, nitrogen and phosphorus from terrestrial biomes to the world's oceans.
• To determine the spatial and temporal patterns of the fluxes in CO₂, CH₄, CO, N₂O, NH₃, reduced sulfur gases, and the nonmethane hydrocarbons between terrestrial biomes and the atmosphere, and between aquatic systems and the atmosphere.
• To develop the background trace gas release data associated directly with human industrial and urban activities.

Each Objective is pursued through the development of a set of specific regional-global databases and/or models. This Objective-focused approach is complemented by a set of "cross-cutting" projects which exercise and test various aspects of the models, often at finer scales, with the focus on timely scientific results.

The results of this investigation have supported and will continue to support the priority research needs of the Intergovernmental Panel on Climate Change (IPCC) and other regional and global integrated assessment activities concerning large-scale environmental change.