What’s new in the Community Earth System Model at NCAR

An overview of the various capabilities in CESM2, highlighting what is new in the model and how those changes have affected such things as its climate sensitivity.

Speakers: Dan Marsh and Bette Otto-Bliesner

Abstract

In the summer of 2018, the U.S. National Center for Atmospheric Research (NCAR) released version 2 of its flagship climate model, the Community Earth System Model (CESM2). This update is the most significant change in the model since CESM was first made available in 2010, with the addition of several new model components and all of the existing components being radically revised. CESM2 can be configured in a variety of ways, making it suitable for applications ranging from paleoclimate simulations and climate prediction to air quality and space weather forecasts.  CESM2 will be used extensively in model intercomparison projects as part of the next Intergovernmental Panel on Climate Change assessment activity (i.e., the Coupled Model Intercomparison Project Phase 6 or CMIP6). In the two years following CESM2’s release, NCAR alone will dedicate around 460 million CPU core hours to conducting CMIP6 simulations; the equivalent of 26,000 CPUs operating 24/7 for that entire period.

In this climate exchange, we will provide an overview of the various capabilities in CESM2, highlighting what is new in the model and how those changes have affected such things as its climate sensitivity. We will also discuss how staff at the University of Leeds can utilize CESM2 in their research, whether it is accessing model output to running the model on the University of Leeds’ HPC systems. Finally, we will briefly present our thoughts on future directions in climate model development and what new science problems can be tackled as a result.

Biographies

Professor Dan Marsh joined the Priestley International Centre for Climate as the Chair in Comparative Planetary Atmospheres in January 2018.  He holds the position jointly in the School of Physics and Astronomy and the School of Chemistry at the University of Leeds.
Dan divides his time between Leeds and the National Center for Atmospheric Research in Boulder, Colorado, where he is a senior scientist and heads the Multi-scale Chemistry Modeling Group. Dan’s research interests are in planetary atmospheres, whole atmosphere modeling, climate change, upper atmosphere composition and space weather.

Dr. Bette L. Otto-Bliesner is a Senior Scientist in the Climate and Global Dynamics Laboratory at the National Center for Atmospheric Research in Boulder, Colorado and Leverhulme Trust Visiting Professor at the University of Leeds. Her research focuses on using computer-based models of Earth’s climate system to investigate past climate change and climate variability across a wide range of time scales. She is co-chair of the CESM Paleoclimate Working Group.

This event will be followed by light refreshments in the SEE Foyer