Bringing the ARM constrained variational analysis to 3D

 

Authors

Minghua Zhang — Institute of Atmospheric Physics Chinese Academy of Sciences
Shuaiqi Tang — Pacific Northwest National Laboratory
Shaocheng Xie — Lawrence Livermore National Laboratory

Category

Dynamics/Vertical Motion

Description

The current ARM constrained variational analysis value-added product (VAP) was designed to derive atmospheric advective tendencies and vertical velocity for a single column of the atmosphere from field campaign measurements. The derived data have been used as specified dynamics to force physical parameterizations, single-column models (SCMs), cloud-resolving models (CRMs), and large-eddy simulations (LES) so that their simulations of clouds can be evaluated against observation. To take advantage of new measurements from ARM scanning cloud radars to evaluate and test these models, we extended the current constrained variational algorithm for a single column to gridded three-dimensional fields. The derived fields satisfy the internal consistency of column-integrated conservations of mass, water vapor, and energy at each spatial location. The magnitude and spatial feature of the variational adjustments to the first-guess state variables are assessed. Preliminary results are shown for the analysis of the Tropical Warm Pool-International Cloud Experiment (TWP-ICE) field campaign data. Remaining issues are discussed. The analyzed three-dimensional advective forcing and vertical velocity along with other dynamical and thermodynamical fields can be potentially used in SCM/CRM/LES to simulate three-dimensional fields of clouds, thereby significantly increasing the sampling number of observational data to evaluate and test these models.