Concurrent calculation of radiative transfer in the atmospheric simulation in ECHAM-6.3.05p2.

Heidari, Mohammad Reza, Song, Zhaoyang, Degregori, Enrico, Behrens, Jörg and Bockelmann, Hendryk (2021) Concurrent calculation of radiative transfer in the atmospheric simulation in ECHAM-6.3.05p2. Open Access Geoscientific Model Development, 14 (12). pp. 7439-7457. DOI 10.5194/gmd-14-7439-2021.

[thumbnail of gmd-14-7439-2021.pdf]
Preview
Text
gmd-14-7439-2021.pdf - Published Version
Available under License Creative Commons: Attribution 4.0.

Download (14MB) | Preview
[thumbnail of gmd-14-7439-2021-supplement.pdf]
Preview
Text
gmd-14-7439-2021-supplement.pdf - Supplemental Material
Available under License Creative Commons: Attribution 4.0.

Download (10MB) | Preview

Supplementary data:

Abstract

The scalability of the atmospheric model ECHAM6 at low resolution, as used in palaeoclimate simulations, suffers from the limited number of grid points. As a consequence, the potential of current high-performance computing architectures cannot be used at full scale for such experiments, particularly within the available domain decomposition approach. Radiation calculations are a relatively expensive part of the atmospheric simulations, taking up to approximately 50 % or more of the total runtime. This current level of cost is achieved by calculating the radiative transfer only once in every 2 h of simulation. In response, we propose extending the available concurrency within the model further by running the radiation component in parallel with other atmospheric processes to improve scalability and performance. This paper introduces the concurrent radiation scheme in ECHAM6 and presents a thorough analysis of its impact on the performance of the model. It also evaluates the scientific results from such simulations. Our experiments show that ECHAM6 can achieve a speedup of over 1.9× using the concurrent radiation scheme. By performing a suite of stand-alone atmospheric experiments, we evaluate the influence of the concurrent radiation scheme on the scientific results. The simulated mean climate and internal climate variability by the concurrent radiation generally agree well with the classical radiation scheme, with minor improvements in the mean atmospheric circulation in the Southern Hemisphere and the atmospheric teleconnection to the Southern Annular Mode. This empirical study serves as a successful example that can stimulate research on other concurrent components in atmospheric modelling whenever scalability becomes challenging.

Document Type: Article
Refereed: Yes
Open Access Journal?: Yes
Publisher: Copernicus Publications (EGU)
Related URLs:
Projects: PalMod
Date Deposited: 09 Dec 2021 11:11
Last Modified: 07 Feb 2024 15:45
URI: https://oceanrep.geomar.de/id/eprint/54581

Actions (login required)

View Item View Item