Increasing the speed, scalability, and resolution of global climate models is a key step toward improving the ability to simulate regional details of climate change and improving our assessments of the impacts of climate change on extreme events. The

Community Earth System Model (CESM) is a community, global climate model that provides computer simulations of the Earth’s past, present, and future climate states. This comprehensive model, developed in collaboration with National Science Foundation and Department of Energy (DOE) laboratories, couples state-of-the-art atmosphere, ocean, land, and ice model components. It is one of the primary tools used in DOE climate change assessments and in U.S. contributions to the United Nations Intergovernmental Panel on Climate Change assessment reports. Through the support of DOE Basic Energy

Research, Sandia has been developing a spectral element dynamical core for the atmosphere component model in CESM. Sandia’s work removed the largest parallel scalability bottleneck in the CESM, allowing for faster simulation at higher resolutions. The improved model has the ability to capture hurricanes and other types of extreme weather not shown in lower-resolution simulations. The highest resolution CESM simulations, using Sandia’s configuration of the atmosphere model

running at 13 kilometer (km) resolution, also operates on DOE Leadership Computing Facilities at Oak Ridge and Argonne National Laboratories and scales out to 130,000 cores. The development work making these types of simulations possible was carried out primarily on Sandia’s Red Sky. This includes extensive low and moderate resolution simulations used for development, validation, and verification. Sandia also made use of the spectral elements unstructured grid support to perform global moderate resolutions simulations, which contain small continental-size regions of 13 km resolution, resulting in an efficient approach that enables scientists to use Red Sky to calibrate the global high-resolution model.

Contact: Mark Taylor |



The snapshot above illustrates precipitable water simulated by the CESM running at 13 km resolution using the spectral element atmosphere dynamical core. The image shows a Category 5 hurricane in the Gulf of Mexico, with another tropical cyclone forming in the mid-Atlantic. At these resolutions, the model has the ability to capture hurricanes not present in lower resolution simulations providing critical information for climate change assessments.