Past SDWG Computing Projects

The Societal Dimensions Working Group (SDWG) has an open proposal process for computing projects that use the Community Earth System Model (CESM) and NCAR’s Yellowstone supercomputer to carry out work related to the working group. Below are the nine past projects for 2014-2016.

2014-2016 SDWG Computing Projects

THESIS development: High resolution regional climate and impact simulations for human and earth system model investigations

PI contact: Peter Lawrence
The Toolbox for Human-Earth System Integration and Scaling (THESIS) is an ongoing NSF-funded investigation (EaSM2) to create a framework that allows detailed assessment of the combined impacts of socio-economic development pathways and climate change. THESIS focuses on these impacts in the three key areas of cities, agriculture, and forests in regional case studies of the rapidly developing countries of China, India, and Brazil. To facilitate these investigations and to help develop the THESIS framework for wider community use, the project has been allocated SDWG computing hours to perform a small number of fully coupled simulations supplemented by high resolution land surface simulations of urban, agricultural and forest landscapes to evaluate climate change impacts in a historical baseline and Representative Concentration Pathway (RCP)4.5 transient climate. The framework developed will become available to the wider CESM community to facilitate regional investigations linking Integrated Assessment Models (IAMs) or impact models and CESM. 
 

Historical land use uncertainty: The effects of land use/cover conversion assumptions on the global carbon cycle and climate in historical CESM simulations

PI contact: Alan Di Vittorio
This computing project is evaluating developments to address a key land use/cover uncertainty encountered in the development of the integrated Earth System Model (iESM) 1.0 and relevant to CESM application for the Coupled Model Intercomparison Project Phase 6 (CMIP6) by answering the following questions:
  • How are land use/cover change emissions affected by preferentially clearing or retaining forest during agricultural land use conversion?
  • How does this impact terrestrial ecosystem carbon dynamics, atmospheric CO2 concentrations, and average global surface temperature by 2005?
  • What is the potential to improve the historical land use/cover distribution by calibrating land conversion assumptions to observed CO2 concentrations and fluxes
The iESM directly couples the Global Change Assessment Model (GCAM) with CESM and identifies developments needed to meet requirements of energy, land, and water resource studies. These simulations will exercise the code link between land use modeling and CESM land cover and provide outputs for evaluating the robustness of this link. 
 

Hydrologic impacts sensitivity and downscaling: Sensitivity of Hydrologic Impacts Assessment to Downscaling Methodology and Spatial Resolution

PI contact: Martyn Clark
As a part of an ongoing project supported by the U.S. Bureau of Reclamation and the U.S. Army Corps of Engineers, this computing project is evaluating impacts of modeling methodological choices on hydrologic sensitivity to climate change at continental scale to help inform understanding of appropriate hydrology research applications of downscaled climate projections data. In particular, the project will answer questions such as: Is the portrayal of hydrologic impacts under climate change dependent on the chosen downscaling methods and hydrologic models? The results will provide information that guides downscaling and hydrologic modeling for evaluating climate change impact on water planning assessments. 
 

Output processing tools for large daily output volumes for societal needs analysis

PI contact: Caspar Ammann
The Impacts, Adaptation, and Vulnerability (IAV) community has expressed a need for at least daily temporal resolution climate model results, since climate impacts occur primarily through weather and its cumulative evolution. Currently, CESM’s operational ability to deal with daily resolution of global climate data is limited, and new approaches and tools to facilitate the processing, analysis, and verification are necessary. This computing project is developing a post-processing suite for standardized analyses and diagnostics, efficient calculation of relevant indices, and data visualization. One emphasis is on efficient extraction of key “weather scenarios” required by model output users to test the resilience of management systems to perturbations. These capabilities will open the CESM output to the SDWG user community. 
 

Carbon cycle disturbance and mitigation: Consequences to mitigation strategies and the energy market sector as a result of losing the global terrestrial carbon sink

PI contact: Jennifer Holm
The ability of forests to absorb CO2 has been estimated as equivalent to an economic subsidy worth hundreds of billions of dollars every year. As a result, any weakening or decreasing of the terrestrial carbon could have direct effects on land-atmosphere carbon cycle feedbacks and societal decision-making. Human influence on deforestation, degradation, and land-use change are all critical factors that can reduce the opportunity for terrestrial ecosystems to act as a carbon sink. This computing project is examining the removal of the current terrestrial carbon sink (1.2 Pg C yr-1) in the fully coupled iESM to answer the following questions:
  • What are the effects on climate mitigation strategies, and how would they be adapted to account for the loss of the terrestrial carbon sink, in order to reach proposed emission scenarios (i.e. RCP4.5)?
  • What are the effects of the loss of the terrestrial carbon sink on the energy system? What are the effects on climate-energy feedbacks (e.g. latent heat, sensible heat, temperature), and in turn how are terrestrial feedbacks affected (e.g. temperature and water stress on biomass, permafrost melt)? 
 

CESM Perturbed Physics Experiments to Improve Understanding of Predicted Change and Variability in Hydrological Cycle

PI contact: Chris Anderson
This computing experiment aims to better understand change of the hydrological cycle in the United States, with emphasis on extremes and regional expression. The simulations complement the existing CESM Large Ensemble by broadening uncertainty quantification to include uncertainties in modeling hydrologic processes. The project is engaging members of the civil engineering community who are seeking SDWG assistance in addressing impacts of climate change and future uncertainties on civil engineering design practices. 
 

Overshoot engineering: Impacts in an RCP4.5 scenario with mixed mitigation and geoengineering

PI contact: Simone Tilmes
This computing project is evaluating three inter-related questions of scientific and policy relevance regarding the effects on climate of scenarios that overshoot a given radiative forcing level before returning to it, as well as the consequences of geoengineering mitigation strategies designed to avoid overshoot. Geoengineering scenarios within an overshoot context are of particular interest because applying geoengineering to offset overshoot is a more plausible scenario than most geoengineering simulations to date, which test the effect of reducing climate change via geoengineering alone. In particular, the project is addressing the following questions:
  • What are the effects on climate of temporary exceedance of a future radiative forcing target before returning to that level (i.e., overshoot), in particular whether climate effects are symmetric as radiative forcing is increasing and then decreasing?
  • How large does overshoot need to be in order to produce a substantially different climate outcome at the local (grid cell) level?
  • If a forcing overshoot is offset by geoengineering (solar radiation management), is the resulting climate significantly different from the climate resulting from a scenario in which overshoot does not happen at all (and hence there is no geoengineering)? 
 

Investigating Land Cover Change in CESM 1.2/CLM4.5 to guide CMIP6

PI contact:Peter Lawrence

This computing project aims to improve understanding of the impacts of land use and land cover change in CESM and to use these results to inform the experimental design of the land use (LUMIP) and scenario (Scenario-MIP) model intercomparison projects. The project is investigating the impacts of land cover change on transient climate simulations with CESM 1.2 under historical and RCP climate forcing, and is investigating how the Community Land Model (CLM) 4.5 land surface impacts the climate and carbon responses, as well as the way the climate impacts from land cover change trajectory are impacted by the other forcings in the RCP trajectory. 

 

VHR reference data: New global 12km 20yr reference data-assimilation effort

PI contact: Caspar Ammann
To assess the quality of new high-resolution CESM simulations, a higher resolution "observational" reference is needed for preliminary assessments of model validity across the globe. The highest resolution operational reanalysis dataset, the North American Regional Reanalysis (NARR) dataset, is not global and is insufficient at 25 km and below, but CESM will likely run at 50km and possibly much higher resolution. This computing project is completing initial testing of an approach for a special 20-year data-assimilation run of CESM to generate a first generation, global, 3D product that contains many characteristics of observations.