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

• Published in: Quarterly journal of the Royal Meteorological Society 2009-04, Vol.135 (641), p.1003-1019
• Main Authors: Morrison, Hugh, McCoy, Renata B., Klein, Stephen A., Xie, Shaocheng, Luo, Yali, Avramov, Alexander, Chen, Mingxuan, Cole, Jason N. S., Falk, Michael, Foster, Michael J., Del Genio, Anthony D., Harrington, Jerry Y., Hoose, Corinna, Khairoutdinov, Marat F., Larson, Vincent E., Liu, Xiaohong, McFarquhar, Greg M., Poellot, Michael R., von Salzen, Knut, Shipway, Ben J., Shupe, Matthew D., Sud, Yogesh C., Turner, David D., Veron, Dana E., Walker, Gregory K., Wang, Zhien, Wolf, Audrey B., Xu, Kuan‐Man, Yang, Fanglin, Zhang, Gong
• Format: Article
• Language: English
• Subjects: Arctic clouds; cloud‐resolving models; Earth, ocean, space; Exact sciences and technology; External geophysics; Marine; Meteorology; mixed‐phase cloud; Physics of the high neutral atmosphere; single‐column models
• 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, multilayered, mixed‐phase cloud system observed during the Atmospheric Radiation Measurement (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‐levels. The simulations, performed by 13 single‐column and 4 cloud‐resolving models, generally overestimate liquid water path and strongly underestimate ice water path, although there is a large spread among models. This finding is in contrast with results for the single‐layer, low‐level mixed‐phase stratocumulus case in Part I, as well as previous studies of shallow mixed‐phase Arctic clouds, that showed an underprediction of liquid water path. These results suggest important differences in the ability of models to simulate deeper Arctic mixed‐phase clouds versus the shallow, single‐layered mixed‐phase clouds in Part I. The observed liquid‐ice mass ratios were much smaller than in Part I, despite the similarity of cloud temperatures. Thus, models employing microphysics schemes with temperature‐based partitioning of cloud liquid and ice masses are not able to produce results consistent with observations for both cases. Models with more sophisticated, two‐moment treatment of cloud microphysics produce a somewhat smaller liquid water path closer to observations. Cloud‐resolving models tend to produce a larger cloud fraction than single‐column models. The liquid water path and cloud fraction have a large impact on the cloud radiative forcing at the surface, which is dominated by long‐wave flux. Copyright © 2009 Royal Meteorological Society