Development of multi-scale large-scale forcing data sets for MC3E cloud modeling studies

 
Poster PDF

Authors

Shaocheng Xie — Lawrence Livermore National Laboratory
Yunyan Zhang — Lawrence Livermore National Laboratory
Renata B. McCoy — Lawrence Livermore National Laboratory
Minghua Zhang — Stony Brook University

Category

Dynamics/Vertical Motion

Description

The large-scale forcing fields (e.g., vertical velocity and horizontal advective tendencies) are required to run single-column and cloud-resolving models (SCMs/CRMs), which are the two key modeling frameworks widely used to link field data to climate model developments. In this study, we use an advanced objective analysis approach to derive the required forcing data from the soundings collected by the Midlatitude Continental Convective Cloud Experiment (MC3E) in support of its cloud modeling studies. MC3E was a major field campaign conducted during the period 22 April 2011 to 06 June 2011 in south-central Oklahoma through a joint effort between the DOE ARM Climate Research Facility and the NASA Global Precipitation Measurement Program. One of its primary goals is to provide a comprehensive data set that can be used to describe the large-scale environment of convective cloud systems and evaluate model cumulus parameterizations.

The objective analysis used in this study is the constrained variational analysis method. A unique feature of this approach is the use of domain-averaged surface and top-of-the atmosphere (TOA) observations (e.g., precipitation and radiative and turbulent fluxes) as constraints to adjust atmospheric state variables from soundings by the smallest possible amount to conserve column-integrated mass, moisture, and static energy so that the final analysis data is dynamically and thermodynamically consistent. To support modeling studies on various scale convective systems, the large-scale forcing data were created over three domains with the size of 300 km x 300 km, 150 km x 150 km, and 75 km x 75 km, respectively. This poster provides more details about the forcing development and shows preliminary analysis results on the characteristics of the large-scale forcing structures for several selected convective systems observed during MC3E.