Intercomparison of model simulations of mixed-phase clouds observed during the ARM Mixed-Phase Arctic Cloud Experiment. II: Multi layered cloud

• Published in: Quarterly journal of the Royal Meteorological Society Vol. 135; no. 641 Pt.B
• Main Authors: Morrison, H., McCoy, Renata, Klein, Stephen A., Xie, Shaocheng, Luo, Yali, Avramov, Alexander, Chen, Mingxuan, Cole, Jason N., Falk, Michael, Foster, Mike, Del Genio, Anthony D., Harrington, Jerry Y., Hoose, Corinna, Khrairoutdinov, Marat, Larson, Vince, Liu, Xiaohong, McFarquhar, Greg, Poellot, M. R., Von Salzen, Knut, Shipway, Ben, Shupe, Matthew D., Sud, Yogesh C., Turner, David D., Veron, Dana, Walker, Gregory K., Wang, Zhien, Wolf, Audrey, Xu, Kuan-Man, Yang, Fanglin, Zhang, G.
• Format: Journal Article
• Language: English
• Published: United States 21.05.2009
• Subjects: BOUNDARY LAYERS; CLIMATE MODELS; CLOUDS; COMPARATIVE EVALUATIONS; Environmental Molecular Sciences Laboratory; ENVIRONMENTAL SCIENCES; ICE; PHASE STUDIES; SENSITIVITY; WATER VAPOR
• ISSN: 0035-9009; 1477-870X
• DOI: 10.1002/qj.415

Results are presented from an intercomparison of single-column and cloud resolving model simulations of a deep, multi-layered, mixed-phase cloud system observed during the ARM Mixed-Phase Arctic Cloud Experiment. This cloud system was associated with strong surface turbulent sensible and latent heat fluxes as cold air flowed over the open Arctic Ocean, combined with a low pressure system that supplied moisture at mid-level. The simulations, performed by 13 single-column and 4 cloud-resolving models, generally overestimate the liquid water path and strongly underestimate the ice water path, although there is a large spread among the models. This finding is in contrast with results for the single-layer, low-level mixed-phase stratocumulus case in Part I of this study, as well as previous studies of shallow mixed-phase Arctic clouds, that showed an underprediction of liquid water path. The overestimate of liquid water path and underestimate of ice water path occur primarily when deeper mixed-phase clouds extending into the mid-troposphere were observed. These results suggest important differences in the ability of models to simulate Arctic mixed-phase clouds that are deep and multi-layered versus shallow and single-layered. In general, the cloud-resolving models and models with a more sophisticated, two-moment treatment of the cloud microphysics produce a somewhat smaller liquid water path that is closer to observations. The cloud-resolving models also tend to produce a larger cloud fraction than the single column models. The liquid water path and especially the cloud fraction have a large impact on the cloud radiative forcing at the surface, which is dominated by the longwave flux for this case.