File Descriptions

LASSO-CACTI consists of a suite of data organized around each simulation. This section describes how the available files are organized and the contents of the different file types. The method for downloading the files is explained in the Bundle Browser section of the documentation.

The categories of available files are model inputs, model restart data, raw model output, output subsets, and evaluation data. Each of these comprises an independent data set in ARM parlance, but collectively they are all part of LASSO-CACTI. Users can download whichever pieces of LASSO-CACTI they require without having to acquire the other file types.

File Naming Convention

Filenames for LASSO-CACTI model data follow a similar convention for both the raw model outputs and the subsets. This is like a typical ARM data file, but LASSO-CACTI requires additional characters to uniquely identify the files from each other. An exception to ARM’s filename standard has been granted for LASSO and we are amending ARM’s standard to include this approach for the model files.

The LASSO-CACTI filename convention is as follows, with the first line identifying the different pieces of information and the second line showing an example:


Table 19 describes the various pieces of the filename.

Table 19 Information Contained in LASSO-CACTI Filenames.




ARM site identifier, “cor” for CACTI


Instrument name, “lasso” for LASSO


File type, i.e., the file type abbreviations for the various LASSO-CACTI data types, e.g., wrfin, wrfrst, wrfout, and the subset categories, e.g., met, cld, and pbl


Case date, i.e., model start time


Ensemble member data source (ERA5, EDA, FNL, or GEFS)


Ensemble member number within EEEE (optional, not needed for deterministic inputs)


Domain number with leading “d” for parsing purposes


Configuration label to identify model settings and other variations between simulations, typical “base” for default configuration in LASSO-CACTI


ARM facility designation, always M1 for LASSO-CACTI


Data level, either m0 (raw model data) or m1 (post-processed model data) for LASSO


Time of data in the file


Filename extension, “nc” for netCDF files and “tar” for compilations of files held within a tar file

The example filename above is for the meteorological subset file with data interpolated to heights above sea level, with the case date of 29-Jan-2019 0 UTC, driven by the GEFS ensemble number 5, using the D4 WRF domain, the model configured in the “base” setup, and the data in the file for the time 29-Jan-2019 15:35:00 UTC.

The configuration label is the one portion of the filename that is somewhat vague. This is a catchall label to identify everything outside of the other information categories. For example, the default LASSO-CACTI model configuration uses the Thompson-Eidhammer microphysics. However, some simulations use the Morrison microphysics instead, and this information would be identified via the configuration label. The typical configuration is labeled as base and non-base configurations are generally labelled for what differs from the base configuration. A list of currently available configurations is shown in Table 14.

File Types