NAMMA

Greg McFarquhar University of Illinois

M-PACE


Prof. McFarquhar and the rest of the M-PACE science team in front of the University of North Dakota Citation in Prudhoe Bay, Alaska.	No polar bears in range! Graduate student Gong Zhang prepares to a release a radiosonde at the site of operations in Oliktok Point, Alaska.	A photo taken by Greg McFarquhar from the University of North Dakota Citation over the ground-based remote sensing site at Oliktok Point, Alaska.

M-PACE: The Mixed-Phase Arctic Cloud Experiment (M-PACE) was based out of Prudhoe Bay and Oliktok Point, Alaska during September and October of 2004. The goal of the campaign was to collect a focused set of observations to advance the understanding of the dynamica and microphysical processes in mixed-phase clouds, including radiative transfer through clouds. In particular, M-PACE sought to answer the following 5 questions: 1) how are liquid and ice spatially and temporally partitioned, and how are ice crystals partitioned with size?; 2) what is the impact of this partitioning on radiative transfer and fall-out?; 3) how can in-situ observations be used to improve lidar/radar retrievals?; 4) why do mixed-phase clouds persist? and 5) how can we better represent mixed-phase clouds in model?

Uof Illinois Role and Interests:Professor Greg McFarquhar spent the entire time period of the project in Prudhoe Bay, Alaska, working on the Science Steering Committee. He played a major role in setting the flight tracks of the two aircraft involved in the project, the University of North Dakota Citation and the Scaled Composites Proteus. In addition, graduate student Gong Zhang spent the project in Oliktok Point, releasing radiosondes and working with the ground-based instrumentation. Since the end of the project, McFarquhar and Zhang have analyzed the data from the project and have developed an integrated cloud microphysical product that has been used in many model and remote sensing evaluation studies. They have also used this product to answer some fundamental questions about the nature of mixed-phase arctic clouds, as exemplified in the publications below.

Refereed Publications arising from M-PACE:

Fridlind, A.M., A.S. Ackerman, G.M. McFarquhar, G. Zhang, M.R. Poellot, P.J. DeMott, A.J. Prenni, and A.J. Heymsfield, 2007: Ice properties of single layer stratocumulus during the Mixed-Phase Arctic Cloud Experiment (MPACE). Part II: Model results. J. Geophys. Res., 112, D24202, doi:10.1029/2007JD008646.

McFarquhar, G.M., G. Zhang, M.R. Poellot, G.L. Kok, R. McCoy, T. Tooman, and A.J. Heymsfield, 2007: Ice properties of single layer stratocumulus during the Mixed-Phase Arctic Cloud Experiment (MPACE). Part I: Observations. J. Geophys. Res., 112, D24202, doi:10.1029/2007JD008646.

Verlinde, J., J.Y. Harrington, G.M. McFarquhar, V.T. Yannuzzi, A. Avramov, S. Greenberg, N. Johnson, M.R. Poellot, J.H. Mather, D.D. Turner, B.D. Zak, T.P. Tooman, A.J. Prenni, G.L. Kok, E.W. Eloranta, M.D. Ivey, C.P. Bahrmann, K. Sassen, P.J. DeMott and A.J. Heymsfield, 2007: The Mixed-Phase Arctic Cloud Experiment (M-PACE). Bull. Amer. Meteor. Soc., 88, 205-221.

Liou, K.N., Y. Gu, Q. Yue and G. McFarguhar, 2008: On the correlation between ice water content and ice crystal size and its application to radiative transfer and general circulation models. Geophys. Res. Lett., 35, L13805, doi:10.1029/2008GL033918.

Luo, Y., K.-M. Xu, H. Morrison and G. McFarquhar, 2008: Arctic mixed-phase clouds simulated by a cloud resolving model: Comparison with ARM observations and sensitivity to microphysics parameterizations. J. Atmos. Sci., 65, 1285-1303.

Luo, Y., H. Morrison, G.M. McFarquhar, Z. Wang and G. Zhang, 2008: Multi-layer Arctic mixed phase clouds simulated by a cloud resolving model: comparison with ARM observations and sensitivity experiments. J. Geophys. Res., 113, D12208, doi:10.1029/2007JD009563.

Morrison, H., J.O. Pinto, J.A. Curry and G.M. McFarquhar, 2008: Sensitivity of modeled arctic mixed-phase stratocumulus to cloud condensation and ice nuclei over regionally-varying surface conditions. J. Geophys. Res., 113, D05203, doi:10.1029/2007JD008729.

Sednev, I., S. Menon, and G. McFarquhar, 2008: Simulating mixed-phase Arctic stratus clouds: sensitivity to ice initiation mechanisms. Atmos. Chem. Phys., 8, 11755-11819.

Shupe, M.D., P. Kollias, O.G. Persson and G.M. McFarquhar, 2008: Vertical motions in Arctic mixed-phase stratus. J. Atmos. Sci., 65, 1304-1322.

Klein, S.A., R. McCoy, H. Morrison, A. Ackerman, A. Avramov, G. de Boer, M. Chen, J. Cole, A. D. DelGenio, M. Falk, M. Foster, A. Fridlind, J.-C. Golaz, T. Hashino, J. Harrington, C. Hoose, M. Khairoutdinov, V. Larson, X. Liu, Y. Luo, G. McFarquhar, S. Menon, R. Neggers, S. Park, K. von Salzen, J.M. Schmidt, I. Sednev, B. Shipway, M. Shupe, D. Spangenberg, Y. Sud, D. Turner, D. Veron, G. Walker, Z. Wang, A. Wolf, S. Xie, K.-M. Xu, G. Yang and G. Zhang, 2008: Intercomparison of model simulations of mixed-phase clouds observed during the ARM Mixed-Phase Arctic Cloud Experiment. Part I: Single layer cloud. Quart. J. Roy. Meteor. Soc., In press.

Morrison, H., R. McCoy, S. Klein, S. Xie, Y. Luo, A. Avramov, M. Chen, J. Cole, M. Falk, M. Foster, A. Del Genio, J. Harrington, C. Hoose, M. Khrairoutdinov, V. Larson, X. Liu, G. McFarquhar, B. Shipway, M. Shupe, Y. Sud, D. Turner, D. Veron, G. Walker, Z. Wang, A. Wolf, K.-M. Xu, F. Yang and G. Zhang, 2008: Intercomparison of model simulations of mixed-phase clouds observed during the ARM Mixed-Phase Arctic Cloud Experiment, Part II: Multi-layered cloud. Quart. J. Roy. Meteor. Soc., In press.

Prenni, A.J., P.J. DeMott, D.C. Rogers, S.M. Kreidenweis, G.M. McFarquhar, G. Zhang and M.R. Poellot, 2008: Ice nuclei characteristics from M-PACE and their relation to ice formation in clouds. Tellus B, In press.

Thesis arising from M-PACE:

Bae, Kenny, 2009: The properties of cirrus clouds in the arctic, M.S. thesis, In progress.

Zhang, Gong, 2010: The microphysical properties of arctic boundary layer clouds and their impacts on radiative transfer. Ph.D. thesis, In progress.