LASSO Alpha 1 Release: Shallow Convection


Update April 30, 2018: The Alpha 1 release of the Large-Eddy Simulation (LES) ARM Symbiotic Simulation and Observation (LASSO) activity has been substantially superseded by adding new runs to the Alpha 2 release. For the most up-to-date data, please use Alpha 2.

The Alpha 1 release from LASSO is the first iteration of the data bundle concept combining large-eddy simulations with ARM observations to enhance the observations’ value for research purposes. The data bundles are available in the ARM Data Center.

This release contains 192 simulations from five shallow convection days during spring-summer 2015. These 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.

Note that the Alpha 1 data bundles have been largely superseded by capabilities developed for the Alpha 2 release. Because of this, the Bundle Browser no longer queries Alpha 1 simulations and instead returns results for Alpha 2. A subset of the Alpha 1 simulations have been re-run using the code from Alpha 2 to fix bugs and enable hosting of the 2015 case dates within the Bundle Browser.

To avoid possible issues with incorrect statistical output calculations with the Weather Research and Forecasting (WRF) model simulations and an error with an uninitialized variable in the System for Atmospheric Modeling (SAM) simulations from Alpha 1, users are encouraged to use the newer 2015 runs available via a supplement to Alpha 2.

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

Citing Alpha 1

Citing Alpha 1 includes the following combination of the LASSO overview journal article in the Bulletin of the American Meteorological Society and the Alpha 1 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 1 Release. U.S. Department of Energy. DOE/SC-ARM-TR-194,

To cite use of the Alpha 1 data set, use:

Atmospheric Radiation Measurement (ARM) user facility. July 2016. LASSO Alpha 1 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