The EBAS atmospheric database, originally designed for the European Monitoring and Evaluation Programme (EMEP), archives today data on atmospheric composition from ground stations around the globe as well as aircraft platforms. Co-operating frameworks and projects include:
Data providers benefit from improved data dissemination through EBAS with an increased number of collaborations. Data submitted to EBAS are protected by a fair-use data policy while some projects/programmes requests a more restrictive data policy. The association of data to projects thus defines the associated data policy.
Data submitted to EBAS need to be formatted in the EBAS NASA-Ames format by the data provider. The EBAS NASA-Ames format is based on the ASCII text NASA-Ames 1001 format, but contains additional metadata specifications ensuring proper documentation, and is designed to be easily understandable (see reasoning behind this setup). This page provides links to data reporting templates for reporting data to EBAS.
The normal mode of submitting data to EBAS is the regular, annual data submission (see left margin, top). The deadline for a submission depends on the framework or project the dataset is associated with. EBAS also offers advanced data reporting that establishes complete traceability of the measurement and data analysis process. Participation in the advanced data reporting scheme is voluntary unless required by the associated project or framework. The usual steps for submitting data for the first time include:
- Initial contact with EBAS: Please establish the initial contact with EBAS by writing an e-mail to email@example.com. In your mail, please indicate the station you are intending to report data for. If your station is part of the Global Atmoshere Watch programme, please also provide us the GAWSIS station ID (if you wish to register a new GAW site. please follow the instructions available at https://gawsis.meteoswiss.ch). See also the GAW Implementation Plan for further details: http://www.wmo.int/pages/prog/arep/gaw/documents/IPFinalDraftMay11.pdf
- IDs: We will provide three further IDs: 1) the EBAS station code; 2) the EBAS platform code; 3) a code for your lab analysing the data, which you will need for the metadata in your submission. The three letter GAW IDs and the IDs used in the CLRTAP EMEP database EBAS were introduced independently and are maintained for consistency.
- Selection of time series to report: For sites that have been in operation back in time, we encourage that the full historic time series is submitted to the database (multi-year submission is easy to accommodate, but timeseries needs to be split according to any significant changes with regards to instrumentation etc).
- Quality assure your data: This step will probably take longest of all steps in this data submission guideline, and is prerequisite for any further use of the data. Please make sure that you followed the respective standard operating procedure (SOP) valid for your instrument, both during data collection and data processing and evaluation. There will likely be periods for which the data is invalid due to calibrations or malfunctions, and there may be additional conditions (activity around the station, etc.) you will want to convey to the data user. EBAS uses a system of flags for this purpose. Each flag is assigned a three digit integer number. A list of these flags can be found at http://www.nilu.no/projects/ccc/flags/flags.html. The list of flags is comprehensive, but may still not be complete. If there is a condition you think is not covered, please send an e-mail to firstname.lastname@example.org for guidance or an extension of the list of flags.
- Assemble / Update Metadata Header:
- First-time submitters: In assembling the header with metadata for a first-time data submission, it is probably easiest just to copy the respective template valid for the parameter to be reported (see menu on the left), and adapt it to the station and protocols used for data collection and processing. Each line in the online template is a link pointing to an explanation of the content. The explanation always begins with a specification of the syntax used. Items enclosed in “<>” mark a place holder to be replaced with content or key words as described. Please follow the syntax exactly since many lines contain a keyword identifying the content, and these keywords are recognised by string comparison.
- Experienced submitters: If you have submitted data for a given parameter to EBAS before, you can copy the header from the previous year to start with, and update at least the fields containing a date or time. However, please make sure to check through the metadata items and update them in case any changes occured in your setup. Especially for later trend analysis, it is rather important that any changes that may have caused a rupture in the dataset are documented in the metadata.
- Format data, join header and data sections: The data section of an EBAS NASA-Ames file consists of a fixed width, fixed number format ASCII table, with the number formats specified in the file header. Please refer to the parameter specific pages for examples (menu on left). Once the data section is constructed, please join header and data section into one file, and name the file using the file name stated in the header.
- Format checker: Please use our web based tool to check if your files are correctly formatted, and check also time seires for potential outliers or other indications of dubious data: EBAS Data Submission Tool. Please see this presentation for an introductory guide on the EBAS data format.
- Submit Data: The files containing the data submissions are also uploaded through the EBAS Data Submission Tool. Please note, that after submitting, the file will go through a manual QA and data curation workflow at NILU. Therefore it will take time before the actual data is available in EBAS.
To prevent abuse of this server, it is configured in "blind-drop" mode. It accepts uploads only and ignores directory requests, i.e. you won't be able to see the files you just uploaded, and you won't be able to delete them once they are uploaded. If you uploaded a file in error, please send an e-mail to email@example.com and specify the details. Currently, you won’t receive an automated acknowledgement of receipt, but this service is due to be added.
Further Background Information
- Why do we ask the data providers to format their data in a specific format?
- Adequate documentation of observations and associated meta-data compliant with the database infrastructure. Data are stored in a relational database, and proper ingestion of the data depend on a specific format
- Avoiding of errors: It has turned out that reformatting the data for the provider increases the number of errors in the data. The reformatting process involves often lengthy correspondence between data provider and centre on how to interpret the data, and is prone to misunderstanding and information loss. A clearly defined format as interface between data provider and centre avoids this information loss.
- Work load at data centre: EBAS collects over 6000 datasets per year. Most of the data submissions also include an iteration process with data originators, and re-submissions are frequent, With reformatting this amount of data, the number of other services EBAS could offer was rather limited. Together with data providers and users, it was decided to free these resources in favour of data interpretation and dissemination.