LASSO Alpha 2 Release: Shallow Convection


Update April 30, 2018: The Alpha 2 release of the Large-Eddy Simulation (LES) ARM Symbiotic Simulation and Observation (LASSO) activity has been updated to include runs released originally in the Alpha 1 release.

The Alpha 2 release is the second and final prototype data release for the LASSO pilot phase. Alpha 2 builds upon Alpha 1 through improved LES models, increased use of observations for evaluating the model, and testing of incorporation of ARM wind profiles in the data assimilation process.

Simulations are carried out for both classical shallow convection days as well as borderline shallow convection days to better understand the overall LES model and forcing capabilities for the Southern Great Plains region. Complete details regarding differences between Alpha 1 and Alpha 2 can be found in Appendix B of the Alpha 2 technical document. A spreadsheet containing the complete list of simulations included in the Alpha 2 release is also available.

This release contains 544 simulations from 13 shallow convection days during spring–summer 2016. Simulations are packaged alongside corresponding model-observation comparisons for different LES models, large-scale forcings, model configurations, and preliminary observational products that the LASSO team is using to assess workflow options for use in operations.

Alpha 2 data bundles can be accessed via both ARM Data Discovery and the LASSO Bundle Browser. The latter is designed specifically for LASSO and is more efficient for most researchers seeking LASSO data. The browser includes the ability to query for specific simulations and provides links to data plots for each simulation and links to request delivery of the data bundles.

We recommend users contact the LASSO team for the details of the simulations and guidance for specific application.

Citing Alpha 2

Citing Alpha 2 includes the following combination of the LASSO overview journal article in the Bulletin of the American Meteorological Society and the Alpha 2 technical document:

Gustafson, WI, AM Vogelmann, Z Li, X Cheng, KK Dumas, S Endo, KL Johnson, B Krishna, T Fairless, and H Xiao. 2020. “The Large Eddy Simulation (LES) Atmospheric Radiation Measurement (ARM) Symbiotic Simulation and Observation (LASSO) Activity for Continental Shallow Convection.” Bulletin of the American Meteorological Society 101(4): E462–E479,

Gustafson, WI, AM Vogelmann, X Cheng, S Endo, B Krishna, Z Li, T Toto, and H Xiao. 2017. Description of the LASSO Alpha 2 Release. U.S. Department of Energy. DOE/SC-ARM-TR-199,

To cite use of the Alpha 2 data set, use:

Atmospheric Radiation Measurement (ARM) user facility. September 2017. LASSO Alpha 2 Data Bundles. <insert date range used of the data>, 36° 36′ 18.0″ N, 97° 29′ 6.0″ W: Southern Great Plains Central Facility (C1). Compiled by WI Gustafson, AM Vogelmann, X Cheng, S Endo, B Krishna, Z Li, T Toto, and H Xiao. ARM Data Center: Oak Ridge, Tennessee, USA. Data set accessed <insert date downloaded from the web> at