Revolutionizing Climate Modeling with Project Athena: A Multi-Institutional, International Collaboration

Abstract

The importance of using dedicated high-end computing resources to enable high spatial resolution in global climate models and advance knowledge of the climate system has been evaluated in an international collaboration called Project Athena. Inspired by the World Modeling Summit of 2008 and made possible by the availability of dedicated high-end computing resources provided by the National Science Foundation from October 2009 through March 2010, Project Athena demonstrated the sensitivity of climate simulations to spatial resolution and to the representation of subgrid-scale processes with horizontal resolutions up to 10 times higher than contemporary climate models. While many aspects of the mean climate were found to be reassuringly similar, beyond a suggested minimum resolution, the magnitudes and structure of regional effects can differ substantially. Project Athena served as a pilot project to demonstrate that an effective international collaboration can be formed to efficiently exploit dedicated supercomputing resources. The outcomes to date suggest that, in addition to substantial and dedicated computing resources, future climate modeling and prediction require a substantial research effort to efficiently explore the fidelity of climate models when explicitly resolving important atmospheric and oceanic processes.

Evaluating the utility of dynamical downscaling in agricultural impacts projections

“…Studies have suggested that dynamical downscaling of bias-corrected (as opposed to raw) GCM output does offer improvements in fidelity when reproducing historical climate (43,44). Some authors have also suggested that using high-resolution GCMs could reduce some of the large-scale biases seen in coarser model output (45). To date, no studies have evaluated the consequences in an impacts model.…”

High-resolution global climate modelling: the UPSCALE project, a large-simulation campaign

“…For example, due to the local Rossby radius of deformation a 1/3 • resolution ocean model cannot resolve the most important processes, eddies, while at 60 km the atmosphere can Shaffrey et al, 2009;Demory et al, 2014). Coarse-resolution simulations can produce representative data for global mean properties, but their limitations for studying regional effects and temporal variability are becoming more obvious Shaffrey et al, 2009;Scaife et al, 2011;Delworth et al, 2012;Kinter et al, 2013). Recent work by Demory et al (2014) demonstrates that the energy budgets in an ensemble of different resolution versions of the HadGEM3 (Hadley Centre Global Environment Model 3) and HadGEM1 are very consistent, but moisture transport and the balance of evaporation and precipitation over land, critically important for climate impacts, only converges at resolutions finer than 60 km (N216 and above).…”

Climate SPHINX: evaluating the impact of resolution and stochastic physics parameterisations in the EC-Earth global climate model

“…the European Union's Horizon 2020 PRIMAVERA project, https://www.primavera-h2020.eu/). In particular this study complements groundbreaking past initiatives in pioneering the use of HPC (high-performance Computing) for climate simulations such as the UPSCALE and the ATHENA (Kinter III et al, 2013) projects.…”

“…Each deterministic experiment included in Climate SPHINX has a counterpart where the sub-grid unresolved scales have been parameterised with two different stochastic physics schemes (namely the SPPT and SKEB schemes). This makes Climate SPHINX the first climate dataset that includes a large number of ensemble members with a stochastic parameterisation at different horizontal resolution; along with other high-resolution simulation campaigns such as UP-SCALE or ATHENA (Kinter III et al, 2013), this demonstrates the ability of the climate community to exploit the more recent HPC machines.…”

“…In fact it has been shown (e.g. van Oldenborgh et al, 2012) that at standard (low) climate resolution, forecast systems have pervasive systematic errors, which impact on quasi-persistent weather regimes (Dawson et al, 2012) and, more generally, on temporal variability and regional patterns of the leading modes of variability (Delworth et al, 2012;Kinter III et al, 2013). On the other hand, recent experiments have shown that high-resolution climate models are significantly better at simulating important physical processes, such as the global water cycle , as well as relevant features of the large-scale atmospheric circulation such as the jet stream (Lu et al, 2015), the Euro-Atlantic blocking and the Madden-Julian Oscillation (MJO; Peatman et al, 2015).…”