Performance of the Goddard multiscale modeling framework with Goddard ice microphysical schemes. (28th January 2016)

• Record Type: Journal Article
• Authors: Chern, Jiun‐Dar; Tao, Wei‐Kuo; Lang, Stephen E.; Matsui, Toshihisa; Li, J.‐L. F.; Mohr, Karen I.; Skofronick‐Jackson, Gail M.; Peters‐Lidard, Christa D.
• Is Part Of: Journal of advances in modeling earth systems. Volume 8:Number 1(2016)
• Page Start: 66
• Page End: 95
• Publication Date: 2016-01-28
• Subjects: superparameterization -- MMF -- microphysics -- CloudSat; Geological modeling -- Periodicals; Climatology -- Periodicals; Geochemical modeling -- Periodicals; 551.5011
• DOI: 10.1002/2015MS000469
• Languages: English
• ISSNs: 1942-2466

Abstract

Abstract: The multiscale modeling framework (MMF), which replaces traditional cloud parameterizations with cloud‐resolving models (CRMs) within a host atmospheric general circulation model (GCM), has become a new approach for climate modeling. The embedded CRMs make it possible to apply CRM‐based cloud microphysics directly within a GCM. However, most such schemes have never been tested in a global environment for long‐term climate simulation. The benefits of using an MMF to evaluate rigorously and improve microphysics schemes are here demonstrated. Four one‐moment microphysical schemes are implemented into the Goddard MMF and their results validated against three CloudSat/CALIPSO cloud ice products and other satellite data. The new four‐class (cloud ice, snow, graupel, and frozen drops/hail) ice scheme produces a better overall spatial distribution of cloud ice amount, total cloud fractions, net radiation, and total cloud radiative forcing than earlier three‐class ice schemes, with biases within the observational uncertainties. Sensitivity experiments are conducted to examine the impact of recently upgraded microphysical processes on global hydrometeor distributions. Five processes dominate the global distributions of cloud ice and snow amount in long‐term simulations: (1) allowing for ice supersaturation in the saturation adjustment, (2) three additional correction terms in the depositional growth of cloud ice to snow, (3) accounting for cloud ice fall speeds, (4) limiting cloud ice particle size, and (5) new size‐mapping schemes for snow and graupel. Despite the cloud microphysics improvements, systematic errors associated with subgrid processes, cyclic lateral boundaries in the embedded CRMs, and momentum transport remain and will require future improvement. Key Points: MMF is a valuable test bed for evaluating microphysical schemes globally A 4ICE scheme agrees better with CloudSat/CALIPSO products than earlier 3ICE schemes Cloud ice and snow highly depend on microphysics yet must balance with radiation globally