LASSO

LASSO enhances ARM observations by using large-eddy simulation (LES) modeling to provide context and a self-consistent representation of the atmosphere surrounding the observed location. The LASSO project connects processes and facilitates improved understanding. The initial implementation targeted shallow clouds at ARM’s Southern Great Plains (SGP) atmospheric observatory followed by deep convection observed during ARM’s Cloud, Aerosol, and Complex Terrain Interactions (CACTI) field campaign in Argentina. Current LASSO expansion efforts are focused on simulating marine clouds at the Eastern North Atlantic (ENA) atmospheric observatory.

LASSO consists of an ever-growing library of simulations that can be used to test the accuracy of climate model parameterizations and to serve as a proxy for the atmosphere to develop remote retrievals, as well as many other applications. LASSO has developed “data bundles” that combine ARM observations and high-resolution model output to provide a highly detailed description of the atmosphere in the vicinity of ARM sites.

To access the data bundles, LASSO developed web interfaces called “bundle browsers,” which allow researchers to search for data bundles using a variety of parameters. Fully published simulations and their accompanying diagnostics are available via the bundle browsers for SGP shallow convection and CACTI deep convection.

LASSO data are useful to a range of atmospheric researchers, including:

• observationalists, who could test retrieval algorithms and measurement strategies;
• theoreticians, who could examine the assumptions used in model parameterizations; and
• modelers, who could use the vetted simulations as a starting point for their own simulations tailored to their specific needs.

By enhancing metadata search capabilities, presenting a full set of parameters on a common grid, and including metrics and diagnostics to evaluate each case, these data bundles simplify data discovery, access, and analysis for climate researchers and modelers.

Each LASSO “scenario” is somewhat unique in terms of how it approaches a particular meteorological regime. This entails focused modeling around a particular suite of ARM measurements in conjunction with an overall scientific theme. Because of this, the data formats and bundle browser interfaces differ by scenario.

Presently, releases for the SGP shallow convection and CACTI deep convection scenarios are available. Simulations and associated analyses/diagnostics for the ENA marine cloud scenario are being produced, and they will be released in stages throughout 2025.

To ensure this DOE project meets researcher and modeler needs, community input is invaluable. In addition to regular email communications and updates at conferences and meetings, you can get more information from LASSO Principal Investigator William Gustafson. A community discussion forum is also available.

LASSO has evolved from an early pilot phase to the multiple scenarios available today: