#A15 Improving Radiative Transfer Efficiency and Coupling in ACME

Abstract

Compared to previous generations of Earth System Models, ACME has increased complexity, a greater degree of coupling among parameterizations, and higher spatial resolution, each of which leads to substantial increases in the computational demands. Realizing improved accuracy and efficiency in ACME, as well at its component parameterizations, is essential. While radiative transfer is fundamental to climate and weather prediction, the computational cost of this component remains a significant fraction of the total cost of model integration. Optimizing the efficiency and coupling of radiative transfer in ACME is the objective of this project. Although widely used for its accuracy, the RRTMG radiation code, which was developed at AER and is currently in ACME, is insufficient to meet the demands of modern parallel computing techniques. Under separate funding, the PIs of this project are developing a high-performance broadband radiation code for modern computer architectures called RRTMGP, which combines the strengths of RRTMG (high accuracy and the k-distribution treatment of gas absorption) with completely redesigned code to enable highly parallel processing across a range of platforms. This project supports the integration of RRTMGP into ACME through our collaboration with the ACME team.