To date, there are two releases of Large-Eddy Simulation (LES) ARM Symbiotic Simulation and Observation (LASSO) data bundles, produced during the LASSO pilot phase.

These releases are preliminary versions of the final product that will go into operation in 2017. The Alpha 1 and Alpha 2 bundles serve the purpose of demonstrating the overall LASSO concept to researchers, providing a means for facilitating community discussion and feedback, and making available initial sets of simulations and accompanying observations for research purposes.

Each release is a collection of data files, which entails a collection of what ARM calls “data bundles,” which consists of:

  • LES input and outputs
  • ARM observations co-registered on the model grid
  • Model diagnostics and skill scores
  • Data plots of various fields.

Simulations from the System for Atmospheric Modeling (SAM) and the Weather Research and Forecasting (WRF) model are available that have been driven using a range of forcings under consideration for use with LASSO. Many of the simulations are directly comparable, e.g., they use the same model configuration and only differ in the forcing or initial conditions used to drive the model.

Other simulations differ in aspects such as the particular choice of microphysics and grid configuration. The release also serves as an initial introduction to the skill scores being designed for model evaluation.

More complete details are available in the Alpha 2 release documentation.

LASSO Bundle Browser

The Bundle Browser interface has been designed to help users find simulations of relevance for their needs. The browser is a tool based on the Cassandra NoSQL database methodology that permits search by value queries of the skill scores and dynamically creates data plots or “quicklooks” of selected simulations for selected metrics.

As of Alpha 2, the Bundle Browser returns results for the 2016 shallow convection cases and is the easiest method for accessing the Alpha 2 data bundles. See the LASSO Alpha 2 Description for details on the browser.

Using LASSO Alpha Products

The simulations within this release represent the typical behavior expected from LES using best-practice configurations and are valid for use in various research applications. However, as made evident by the comparisons to observations, there is a range of model behavior, and Alpha 2 has corrected some deficiencies in Alpha 1 simulations.

We recommend users contact the LASSO team to ensure the details of the simulations are understood and that the simulations are used appropriately for a given application.

Looking for Feedback

An objective for the Alpha releases is to solicit feedback from the community. Efforts to improve the model configuration, forcings, and analysis tools are ongoing and will evolve based on user feedback and continued effort. We encourage users to explore the available simulations and tools and to share their experience and ideas for improvement with the LASSO team at Users may also contact William Gustafson, lead principal investigator or Andrew Vogelmann, co-principal investigator, directly.