Earth System Modeling Project

PARTNERS: National Science Foundation; North Carolina State University; Argonne National Laboratory

SUMMARY: Eastern Threat Center scientists are contributing to a four-year National Science Foundation-funded project focused on decadal and regional climate prediction using earth system models. The project's specific goals are to improve upon and extend current modeling capabilities to offer new assessment tools for climate change research and management agencies. The research team asks the following questions:

• How will technology and policy choices under a variety of socioeconomic futures affect anthropogenic emissions that in turn affect future climate, air quality, and ecosystems?
• What are the interactions among decadal climate, air quality, and ecosystems at global, regional, and urban scales? How can their interplay affect future emission forecasts that are important in mitigation decisions?
• What are the choices for co-benefits of climate mitigation and air quality/ecosystem management at all scales?

Various products from this collaborative project will provide much needed information for land managers and decision makers to design mitigation and adaptation strategies for climate change and air pollution.

EFETAC's ROLE: Eastern Threat Center scientists are contributing collaborative research.

STATUS: Ongoing

PROGRESS: Eastern Threat Center scientists will couple the water-centric ecosystem model WaSSI-CB and other tools with new climate change predictions under multiple greenhouse gas emission scenarios. They will evaluate how future climate change and air pollution affect water resources (water quantity and quality) and forest carbon sequestration potential. The research team will employ super computers to generate climatic data with rather high spatial and temporal details and examine climate change impacts at multiple levels (city, state, and continental United States). The scientists have developed a high resolution national plant nitrogen availability map by integrating soil Total Kjeldahl Nitrogen, land cover type, topography, atmospheric deposing, and climate databases.

Pictured: Potential impacts of climate change on soil erosion during 1970-2090 as influenced by climate (R) (9 climatic change scenarios), soil (K), topography (Slope), and land cover conditions. Vulnerability increased from areas in dark blue to dark red. Click to enlarge.

Climate change affects both water quantity and water quality. Water temperature is a critical variable in aquatic ecosystems because it controls metabolic rates and distribution of aquatic organisms. Researchers developed an empirical model to investigate the effects of climate change on stream water temperature and applied the model across the conterminous United States. The model linearly describes site relationships between monthly-mean air temperature and stream water temperature as a function of climatic, hydrologic, and land cover characteristics.

Pictured: Spatial distribution of parameters of the linear model describing monthly air temperature and stream water temperature at 158 reference sites (from Segura et al., 2014 Hydrological Processes). Click to enlarge.

The WaSSI model was successfully linked to the Weather Research and Forecasting Model's (WRF) dynamically downscaled climate data for projecting water yield and ecosystem productivity across the United States.

Pictured: WaSSI modeled climate change impacts on annual water yield. The triangles represent mean water yield for each of 18 Water Resource Regions. Click to enlarge.

Pictured: Projected changes (%) in total Gross Ecosystem Productivity (GEP), Runoff (R), and the divergence of the two variables (DI) over National Forest areas from the baseline (1970-1999) to future periods (2020-2049 and 2070-2099) under RCP4.5 and RCP8.5 climate change scenarios. Click to enlarge.

Duan, K., Sun, G., Zhang, Y. et al. Impact of air pollution induced climate change on water availability and ecosystem productivity in the conterminous United States. Climatic Change (2017). doi:10.1007/s10584-016-1850-7. (PDF)

Duan, K., G. Sun, S. L. Sun, P. V. Caldwell, E. C. Cohen, S. G. McNulty, H. D. Aldridge, and Y. Zhang. 2016. Divergence of ecosystem services in US National Forests and Grasslands under a changing climate. Scientific Reports 6. (PDF)

Sun, S., Sun, G., Cohen, E., McNulty, S. G., Caldwell, P., Duan, K., & Zhang, Y. 2015. Predicting future US water yield and ecosystem productivity by linking an ecohydrological model to WRF dynamically downscaled climate projections. Hydrology and Earth System Sciences Discussion 12:12703-12746. (PDF)

Sun, S.-L., G. Sun, P. Caldwell, S. McNulty, E. Cohen, J.-F. Xiao, and Y. Zhang, 2015, Drought Impacts on Ecosystem Functions of the U.S. National Forests and Grasslands: Part I. Evaluation of a Water and Carbon Balance Model, Forest Ecology and Management, 353 (2015) 260–268. (PDF)

Sun, S.-L., G. Sun, P. Caldwell, S. McNulty, E. Cohen, J.-F. Xiao, and Y. Zhang, 2015, Drought Impacts on Ecosystem Functions of the U.S. National Forests and Grasslands: Part II Assessment Results and Management Implications, Forest Ecology and Management, 353 (2015) 269–279. http://dx.doi.org/10.1016/j.foreco.2015.04.002. (PDF)

Caldwell, P.V., C. Segura, S.G. Laird, G. Sun, S.G. McNulty, M. Sandercock, J. Boggs, J.M. Vose. 2014. Short-term stream water temperature observations permit rapid assessment of potential climate change impact. Hydrological Processes 29:2196-2211. (PDF)

Chapman, L.Y.,  S. McNulty, G. Sun and Y. Zhang. 2013. Net nitrogen mineralization in natural ecosystems across the conterminous US. International Journal of Geosciences 4(9):1300-1312. (PDF)

Segura, C., P. Caldwell, G. Sun, S.G. McNulty, and Y. Zhang. 2015. A model to predict stream water temperature across the conterminous USA. Hydrological Processes 29:2178-2195. (PDF)

Segura, C., G. Sun, S. McNulty, and Y. Zhang. 2014. Potential impacts of climate change on soil erosion vulnerability across the conterminous United States. Journal of Soil and Water Conservation 69(2):171-181. (PDF)

LINKS:

CONTACT: Ge Sun, Eastern Threat Center Research Hydrologist, ge.sun@usda.gov or 919-549-4070

Updated June 2017