[Grad-postdoc-assn] Seminar this Wed: Mitch Moncrieff

[Yumin Moon]

The lunch after today's seminar will be in FL2-1002.

On Mon, 03 Mar 2014 10:05:12 -0700
  "Yumin Moon" <ymoon at ucar.edu> wrote:
> 
> Hello all,
> 
> The next ASP seminar by Mitch Moncrieff (NCAR/CGD) is 11 am this 
> Wednesday (March 5th) at FL2 Large Auditorium.
> 
> You are all more than welcomed to have a lunch with the speaker 
> afterward.
> 
> Organized Convection in Global Context
> 
> Satellite observations show that precipitating convective cloud 
> systems in Earth's atmosphere tend to organize into spatially 
>coherent 
> structures embedded in fields of cumulus notably, but not only, in 
>the 
> Tropics.  At a fundamental level this property is analogous to 
> coherent structures in turbulent fluids. Although organization can 
> occur in traditional climate models with 100s-km computational 
>meshes, 
> its morphology is usually not realistic. The reason for this 
> misbehavior is two-pronged. Firstly, convective parameterizations 
>were 
> designed with turbulent mixing by transient cumulus in mind, and 
> regardless of coherent convective systems. Secondly, the model 
> resolution is too coarse to permit explicit systems. Organization 
> involves interaction between diabatic heating, momentum transport, 
> vertical shear and wave dynamics across a range of scales.  We have 
> excellent knowledge of the O(1km - 1000km) meso-synoptic range from 
> field campaigns, cloud-system resolving models and dynamical 
>analogs. 
> Now that operational global weather models and experimental climate 
> models both have O(10km) mesoscale-permitting meshes, we need to 
> seriously consider the representation of organized convection in 
>these 
> models. Computational and theoretical insights are in place, and 
> high-resolution global weather analyses in the form of a 'virtual 
> global field campaign' provide useful information. The categories of 
> organization featured in this talk are propagating convective 
>systems 
> over the continental United States and multiscale convective systems 
> associated with the Madden-Julian oscillation, the leading mode of 
> intraseasonal tropical variability.
> 
> Sincerely,
> The ASP seminar committee
>Fang Fang, Rajesh Kumar, Yumin Moon, Jorge Salazar, and Hyeyum Shin
> 
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