Climate modeling at NCAR

In this presentation we review regional and global climate modeling at NCAR. For global climate modeling we will review the Community Earth System Model (CESM), a community model with NSF NCAR playing a leading role in its development. We will consider the history of CESM, its current status and future plans. In its history we will reflect on the early versions of the NCAR General Circulation Model (NCAR GCM), a freely available global atmosphere model created in the late 1970s. That atmospheric model was incorporated into the first global coupled climate model at NCAR in 1980 developed by a group led by Warren Washington that included Jerry Meehl and Bert Semtner. The Community Climate Model (CCM), an updated version of the NCAR GCM, was created in 1983, and that atmospheric model, along with components of ocean, land and sea ice, was used in the first global coupled climate model to not use flux correction run at NCAR in 1989 in a joint NCAR/DOE effort for climate change experiments with increasing CO2. A global coupled climate model developed as a facility to serve the NCAR community, the Community Climate System Model (CCSM), was released in the mid 90s with improved components of land surface, ocean, and sea ice. With the inclusion of biogeochemistry along with upgraded versions of atmosphere, ocean, land and sea ice, the CCSM evolved into the Community Earth System Model (CESM) with the first release of CESM1 in 2010, followed by the CESM2 in 2018. We will review the current state of CESM including the plans for CESM3 - a new release of CESM due in the next year, whose release will be timed to support contributions to CMIP. We will also consider our longer term plans for CESM and how these fit with national and international priorities in climate modeling.
In terms of regional climate modeling we will look at how the WRF model was developed to support regional climate modeling needs and look over some of the key contributions to climate science that have been made with this system.