LASSO High-Frequency Observations

In 2020, the Large-Eddy Simulation (LES) ARM Symbiotic Simulation and Observation (LASSO) team added a new data set to the Southern Great Plains (SGP) shallow convection scenario that consists of high-frequency observations provided at near-native sampling frequencies. This set is referred to as the LASSO High-Frequency Observations (LASSOHIGHFREQOBS) value-added product (VAP). These are the same observations used when calculating the LASSO skill scores and quicklook plots, but from earlier in the LASSO workflow, before being averaged to hourly intervals. These observations are being made available to users who require the more frequent sampling.

The individual VAPs that make up LASSOHIGHFREQOBS include:

• Cloud Fraction (CLDFRAC): cloud cover from the Ka-Band ARM Zenith Radar Active Remote Sensing of CLouds (KAZRARSCL) VAP and total sky imager at 1-minute resolution
• LASSO Boundary-Layer Thermodynamics (LASSOBLTHERMO): temperature and moisture measurements in the middle of the boundary layer retrieved from the atmospheric emitted radiance interferometer (AERI) and Raman lidar at 10-minute resolution
• LASSO Doppler Lidar Cloud-Base Height for Shallow Cumulus (LASSODLCBHSHCU): cloud-base heights from the SGP Doppler lidars at 10-minute resolution
• LASSO Liquid Water Path (LASSOLWP): liquid water path from the Atmospheric Emitted Radiance Interferometer Optimal Estimation (AERIOE) VAP at 10-second resolution
• Radar Wind Profiler Wind Consensus (RWPWINDCON): horizontal-wind estimates from the SGP radar wind profilers at 10-minute resolution.

Additional information about the LASSOHIGHFREQOBS VAP is included in the LASSO technical document.

The LASSOHIGHFREQOBS VAP can be downloaded from the LASSO Bundle Browser. Initially, the VAP has been prepared for the 2019 LASSO data bundles. Data for earlier years are being made available as they are processed. If the VAP is available for a given data bundle, an additional check box for downloading the data will be visible in the table at the bottom of the Bundle Browser.

To cite the LASSOHIGHFREQOBS VAP, please use https://doi.org/10.5439/1342961, which is the LASSO shallow convection data set.

In addition to the bundled observations in LASSOHIGHFREQOBS that are produced for each LASSO case day, users also might be interested in the related Lifting Condensation Level Height (LCLHEIGHT) VAP, which is produced for every day of the year. This VAP has 1-minute resolution and contains data for multiple sites around the SGP. The LCLHEIGHT VAP is available separately from the LASSO data bundles because it is available for all days of the year.

Also, a slightly different version of LCLHEIGHT data is included within the 2017 and 2018 shallow convection data bundles that use meteorological automatic weather station (MAWS) data at the SGP Central Facility when making the relevant lifting condensation level calculation; this is done to avoid instrument biases that existed in the surface meteorological instrumentation (MET) data during that period.