There are three types of Level 2 data products:
TROPESS-MUSES Level 2 data are in netcdf format and contain retrieved trace gas species (or temperature) profiles at the observation targets. Level 2 data are generated using legacy TES data processing algorithms and L1B inputs from either a single instrument (e.g. AIRS, CrIS, or TROPOMI) or combinations of multiple instruments (e.g. AIRS-OMI). Data products also include geolocation information, estimated errors, quality flags and other information needed for science and applications end uses.
Processing Streams: Forward Stream (FS), Reanalysis Stream (RS), and Special Collections (SC).
|FS||Forward Stream||Products are generated from the MUSES-SDPS forward processing streams.|
|RS||Reanalysis Stream||Products are generated from the MUSES-SDPS reanalysis processing streams.|
|SC||Special Collections||Special Collections including data products produced for measurement campaigns|
Level 2 Product Types and File Size Estimates
|Product Level||Product Name||Granularity||Description||Compressed File Size Estimate (per file, per species, per day)||Uncompressed File Size Estimate (per file, per species, per day)|
|L2 = Level 2||Full archival||Daily||Full, archival version of the L2 product, with daily granularity. Contains all variables required for science analysis|| |
|Standard||Daily||Standard data product, with daily granularity. “Lite” product that contains a limited set of variables needed for science analysis.||N/A - these files will be uncompressed netcdf|
|Summary||Daily||Summary data product, with daily granularity. Contains a limited set of variables needed for science analysis.||N/A - these files will be uncompressed netcdf||All species: ~70 MB|
Summary of species included for each data stream in the TROPESS “Regular Collections” for Archive and Distribution by GES DISC
|Data stream||Processing Strategy||Sub-streams||Day/Night Coverage||O3||CO||TATM||HDO_H2O**||CH4||NH3||PAN||O3 IRKs||Methanol||ISOP|
|AIRS+OMI||FS, RS||AIRS+OMI||Daytime only|
|AIRS||Daytime + Nighttime|
|CrIS+TROPOMI||FS, RS||CrIS+TROPOMI||Daytime only|
*Note: Surface Temperature (T_SURF) is included in the species product files, not as a separate file so it is not included in this table.
**H2O (water vapor) product was to be contained within the HDO product.
Below is an example of the file naming convention used to identify each granule:
- [ProjectID]: corresponds to the project identifier for the collection (i.e, TROPESS).
- [Instrument-Platform]: corresponds to the instrument/sensor and corresponding platform used as L1B input dataset(s) used in the generation of the L2 data products. For Collections where more than one [INSTRUMENT-PLATFORM] combination is used as throughout the record, the original heritage of the L1B input datasets will be traceable in the filename. For
sensor-platform sets we use a `-` (dash) for the platform specification. For multi-sensor and platform combinations, we use an `_` (underscore) to delineate the different instruments.
- Single sensor: [INSTRUMENT-PLATFORM]
- Multi-sensor: [INSTRUMENT-PLATFORM_INSTRUMENT-PLATFORM]
- [ProductLevel]: The data processing level of the file. All TROPESS collections are Level 2 (L2) products, following the NASA Data Processing Levels.
- [ProductName]: Short name to describe the data product name. Allowable values: Full, Standard and Summary. Standard products contain a subset of the parameters in the Full archival product.
- [ProductType]: A short name to describe the primary atmospheric species or parameter included in the data file. Gas phase species names follow the chemical compound name and contain the symbols of the atoms of the elements present in the compound, as well as how many there are for each element in the form of subscripts. Acceptable values are:
- O3 = Ozone
- CO = Carbon monoxide
- NH3 = Ammonia
- PAN = Peroxyacetyl nitrate
- [DateStamp]: Date stamp is the observation period of the data contained in the product. Products are aggregated daily and will use the [DateStamp] notation YYYYMMDD, where:
- YYYY: is the full calendar year.
- MM: is the 2-digit month of the year. Single-digit months employ a leading zero.
- DD: is the 2-digit day of the month. Single-digit days employ a leading zero.
- [AlgorithmName]: The algorithm used to produce the data products (MUSES). Information indicating where the data were processed is covered in the global attributes.
- [AlgorithmVersion]: 2-digit (zero-padded) version number following capital “R”. The initial version will be R0.0, with the first release being R1.0. This will reset only with Major version updates. Example: “Rxx”
- [ProcessingStrategy]: a two-letter code for the processing strategy used in generating the L2 science data products. Allowable values are:
- FS: Forward Steam. Low-latency data products generated from the MUSES-SDPS forward processing streams.
- RS: Reanalysis Stream. Products are generated from the MUSES-SDPS reanalysis processing streams.
- SC: Special Collections. Provided on an as-needed and as-available basis to support NASA field missions and individual-investigator requests over specific regions.
- FormatVersion: 2-digit number, prefixed by a capital F. A change in the format version signals a change in the netcdf file layout, which would likely require a change in the users’ data readers. Example: “Fxx”.
- Filename example: TROPESS_CrIS-SNPP_L2_Standard_CO_20200901_MUSES_R1p9_FS_F01.nc
File Format and Structure
The files in these collections are in NetCDF-4 format. NetCDF is a set of software libraries and self-describing, machine-independent data formats that support the creation, access, and sharing of array-oriented scientific data that was developed by UCAR/Unidata (http://doi.org/10.5065/D6H70CW6) https://www.unidata.ucar.edu/software/netcdf/.
Products that are typically made available through the DAAC include:
- West Coast Fires 2020
- CrIS CO dataset (Buchholz et al., 2020)
- Australian Fires 2019-2020