Register for Tutorial on ARM’s Large-Eddy Simulation Activity

Published: 26 April 2021

Learn how to use LASSO simulations of Southern Great Plains shallow convection and run new software with your models

Illustration of clouds over ARM’s Southern Great Plains atmospheric observatory
This illustration of clouds over ARM’s Southern Great Plains atmospheric observatory captures how the Large-Eddy Simulation (LES) ARM Symbiotic Simulation and Observation (LASSO) activity blends observations and LES modeling. The Bulletin of the American Meteorological Society (BAMS) chose this image for its June 2020 cover. Image is by Rose Perry, formerly at Pacific Northwest National Laboratory.

For those curious about the Large-Eddy Simulation (LES) ARM Symbiotic Simulation and Observation (LASSO) activity, the LASSO team will hold a virtual tutorial on Zoom from 2 to 4 p.m. Eastern time on Thursday, May 20.

During this two-hour tutorial, participants will learn more about the LASSO shallow convection scenario at the Atmospheric Radiation Measurement (ARM) user facility’s Southern Great Plains (SGP) atmospheric observatory. Participants will also learn how they may access the data for their research or classwork, and how they can use the LASSO evaluation software on their own model output.

Registration is now open for the tutorial.

The LASSO activity generated LES ensembles for five years’ worth of shallow convection cases (2015–2019) at the SGP. These simulations, combined with a suite of relevant observations, skill scores, and diagnostics, are packaged into “data bundles” that can be used for many purposes, such as providing data for cloud studies or for providing prepackaged data sets to simplify student interaction with atmospheric observations and model data.

The tutorial is for individuals wanting to use or better understand LASSO data, integrate LASSO into their coursework, or generate LASSO-like statistics and skill scores with their own model output.

What’s Covered?

LASSO team members will lead the tutorial, which will address beginning and advanced aspects of LASSO. Material will be divided into three parts:

Part 1 will focus on the LES methodology used in LASSO and how to obtain LASSO data. LASSO team members will walk through how the LASSO LES runs are configured, the LES ensembles generated for each case day, and what model output and post-processed data are available in the bundle files. Instructors will explain the Metadata Table, which contains the configurations used in the ensembles.

Part 2 will focus on the observation suite included in the LASSO bundles. LASSO team members will walk through the various instruments used and how the measurements are used within LASSO. Instructors will also describe the observational data sets developed for LASSO, such as the shallow convection cloud-base height and special processing of the Clouds Optically Gridded in Stereo (COGS) value-added product within the LASSO context. LASSO team members will explain the skill scores and diagnostics generated for LASSO. They will then walk through how to use the LASSO Bundle Browser to identify which LASSO bundles are of interest for the user, and how to download the selected bundles most easily.

Part 3 will focus on the LASSO workflow. LASSO team members will demonstrate how users can run the LASSO-Operations (LASSO-O) workflow software in a container, such as Docker, to produce LASSO skill scores and diagnostics for one’s own purposes. This new capability opens new possibilities for users. For example, it allows them to reproduce LASSO results but with their own modified statistical methods. Modelers could also produce the skill scores and diagnostics using one’s own model output instead of the LASSO LES data.

LASSO team members will also briefly describe the upcoming LASSO scenarios. Currently in development is a scenario focused on deep convection during the Cloud, Aerosol, and Complex Terrain Interactions (CACTI) field campaign in Argentina. Later this year, the LASSO team will begin development of a marine stratocumulus scenario largely based on the Aerosol and Cloud Experiments in the Eastern North Atlantic (ACE-ENA) campaign in the Azores.

Register now for the LASSO virtual tutorial.

Questions about the tutorial may be sent to

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ARM is a DOE Office of Science user facility operated by nine DOE national laboratories.