Toward unification of the multiscale modeling of the atmosphere

By A. Arakawa, Joon-Hee Jung, Chien‐Ming Wu. 2011

201 citations recorded by the source corpus.

Abstract. As far as the representation of deep moist convection is concerned, only two kinds of model physics are used at present: highly parameterized as in the conventional general circulation models (GCMs) and explicitly simulated as in the cloud-resolving models (CRMs). Ideally, these two kinds of model physics should be unified so that a continuous transition of model physics from one kind to the other takes place as the resolution changes. With such unification, the GCM can converge to a global CRM (GCRM) as the grid size is refined. This paper suggests two possible routes to achieve the unification. ROUTE I continues to follow the parameterization approach, but uses a unified parameterization that is applicable to any horizontal resolutions between those typically used by GCMs and CRMs. It is shown that a key to construct such a unified parameterization is to eliminate the assumption of small fractional area covered by convective clouds, which is commonly used in the conventional cumulus parameterizations either explicitly or implicitly. A preliminary design of the unified parameterization is presented, which demonstrates that such an assumption can be eliminated through a relatively minor modification of the existing mass-flux based parameterizations. Partial evaluations of the unified parameterization are also presented. ROUTE II follows the "multi-scale modeling framework (MMF)" approach, which takes advantage of explicit representation of deep moist convection and associated cloud-scale processes by CRMs. The Quasi-3-D (Q3-D) MMF is an attempt to broaden the applicability of MMF without necessarily using a fully three-dimensional CRM. This is accomplished using a network of cloud-resolving grids with large gaps. An outline of the Q3-D algorithm and highlights of preliminary results are reviewed.

Subfields: Atmospheric Science, Global and Planetary Change

View Paper: https://www.semanticscholar.org/paper/51bd78951ea45463c12c2ff91ce5892f8749b2ca

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Atmospheric Science

1. H. Shin
2. Xiaohong Liu
3. Minghuai Wang
4. Andreas F. Prein
5. Y. Qian
6. Sally McFarlane
7. Chun Zhao
8. Seiji Kato

In Global and Planetary Change

1. Xiaohong Liu
2. H. Shin
3. Minghuai Wang
4. Andreas F. Prein
5. Y. Qian
6. Sally McFarlane
7. Chun Zhao
8. Seiji Kato

Citations in the corpus

• Representation of the Subgrid-Scale Turbulent Transport in Convective Boundary Layers at Gray-Zone Resolutions (2015, background): “…cloud-resolving scale because this grid mesh size is comparable to or smaller than the cloud diameter and cumulus parameterization schemes (CPSs) can be turned off ‘‘in the view of cloud microphysics’’ (i.e., the cloud fraction of a grid is either 0 or 1 at this resolution) (Arakawa et al. 2011).”
• A review on regional convection‐permitting climate modeling: Demonstrations, prospects, and challenges (2015, methodology): “The inherent assumptions made in convection parameterization schemes were assessed critically in previous studies [e.g., Molinari and Dudek, 1992; Romps, 2010; Jones and Randall, 2011; Arakawa et al., 2011].”
• Uncertainty quantification and parameter tuning in the CAM5 Zhang‐McFarlane convection scheme and impact of improved convection on the global circulation and climate (2013, methodology): “The dependence of CPS parameters on model grid size and climate regime is an important issue for weather and climate simulations [Arakawa et al., 2011].”
• Some issues in uncertainty quantification and parameter tuning: a case study of convective parameterization scheme in the WRF regional climate model (2011, background): “It is well known that the performance of CPS may vary with model resolution as current convective parameterizations generally exhibit scale dependence (Arakawa et al., 2011).”
• Online coupled regional meteorology chemistry models in Europe: current status and prospects (2013, background): “The use of parameterisations in convection-aware simulations (sometimes also called grey scales), when no clear-cut scale separation exists, has become a major area of research (Kuell et al., 2007; Gerard et al., 2009; Arakawa et al., 2011; Grell and Freitas, 2013).”
• Challenges and Prospects for Reducing Coupled Climate Model SST Biases in the Eastern Tropical Atlantic and Pacific Oceans: The U.S. CLIVAR Eastern Tropical Oceans Synthesis Working Group (2016, background): “Higher grid resolutions challenge a basic assumption of most convection schemes— namely, that the updraft fraction is small within a grid box, introducing new difficulties in parameterizing mesoscale organization (Arakawa 2004; Arakawa et al. 2011; Del Genio 2012).”