30 New Case Dates Released for LASSO

Published: 21 January 2019
LASSO skill score comparison
This skill score comparison shows cloud fraction results from the large-eddy simulation compared with total sky imager (TSI) observations. Each number represents a different ensemble member from the July 21, 2017, case.

The Large-Eddy Simulation (LES) ARM Symbiotic Simulation and Observation (LASSO) team has processed and released 30 new case dates for the 2017 spring-summer period. Each date has an ensemble of eight simulations for a total of 240 new simulations made available.

The LASSO data product consists of data bundles combining LES input and output, relevant observations, skill scores, and diagnostics. The data bundles focus on shallow convection at the Atmospheric Radiation Measurement (ARM) user facility’s Southern Great Plains atmospheric observatory in Oklahoma.

The 2017 cases are the first operationally produced set of LASSO data bundles. The LES domain configuration within the data bundles has been standardized based on pilot phase testing. Each case date has an ensemble of simulations based on eight large-scale forcing conditions:

  • one for the ARM Variational Analysis datastream
  • three spatial scales from forcing based on the European Centre for Medium-Range Weather Forecasts Integrated Forecasting System (ECMWF IFS) model
  • three spatial scales using the Multiscale Data Assimilation 3DVar data assimilation system that incorporates ARM observations
  • one ensemble member that uses just initial conditions with no large-scale forcing tendencies.

As with earlier LASSO releases, the data bundles can be examined and downloaded via the LASSO Bundle Browser. A new addition is the LASSO Metadata Table, which is a tool designed to quickly examine metadata associated with each data bundle. The Metadata Table replaces the spreadsheet provided with earlier releases. Users desiring to do more complex queries of the metadata can download the data via a button on the web page.

The LASSO technical document has been updated to reflect the new release. Questions about LASSO and the associated datastream can be sent to lasso@arm.gov.

Researchers interested in receiving LASSO updates and other related information can join the LASSO email list.

# # #

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