It is the spirit and purpose of the NDACC to foster the broadest possible collaboration among interested scientists via quick access to NDACC data. Data in the NDACC archive are provided by individual NDACC Instrument Principal Investigators (NDACC PIs) in cooperation with and under the guidelines and best practices of the Instrument Working Groups (IWGs). It is the NDACC PI’s responsibility to ensure data quality, and the data user’s responsibility to use the data correctly with appropriate attribution, as defined below.
NDACC data products are archived at the DHF and publicly available and free of charge at the latest one year after data acquisition. Most NDACC PIs also allow public release of their NDACC data as soon as they are posted to the DHF, which is often earlier than one year after observation.
Rapid Delivery
Some Instrument PIs provide public and free of charge preliminary data to the Rapid Delivery (RD) section of the DHF shortly after acquisition. These data have not yet been fully reviewed and certified to be of full NDACC quality, and are not considered part of the validated NDACC archive, but may be useful to the scientific community e.g. for quick satellite validation, or examination of timely events. All data policies and rules of use detailed herein for NDACC validated data apply.
Data Use Agreement
If an NDACC data file or its documentation files contain an explicit Data License and/or explicit DATA_RULES_OF_USE, then the indicated Rules of Use prevail over the following General Rules of Use. In the absence of a Data License or explicit DATA_RULES_OF_USE associated with the datafile, the following General Rules of Use apply:
General Rules of Use
In recognition that data providers need acknowledgement and co-authorship in order to continue their valuable measurements, we provide the following recommendations. All data users at a minimum should acknowledge the NDACC DHF and the PIs, if feasible, in any publication, as follows:
| Recommended acknowledgement: “The data used in this publication were obtained from “NDACC PI name” as part of the Network for the Detection of Atmospheric Composition Change (NDACC) and are available through the NDACC website www.ndacc.org.” |
When it is envisaged to use NDACC data in a publication or communication, the respective NDACC PI(s) or IWG co-chairs should be contacted early during the preparation of the publication or communication, to discuss possible collaboration and co-authorship or acknowledgement.
In all cases, NDACC data users are expected to consult the online documentation and reference articles to fully understand the scope and limitations of the NDACC datasets available at the NDACC DHF. They are strongly encouraged to contact the respective NDACC PI (listed in the data documentation on the web page) to receive any additional information regarding the data product that could be useful in their studies/applications and as such ensure the proper use of specific data sets. Users of RD data should consult the PIs using the information in the data file metadata for information about the datasets.
Data Aggregators or Institutional Data Users
It is paramount to the continuance of the network that all use of network data can be demonstrated to sponsors and shareholders.
In some cases, NDACC data are used in support of an operational system such as operational validation of satellite products or verification of assimilation models, and this usage typically does not result in a targeted scientific publication in the open literature, but rather in regular technical reports. An example of such use is the systematic use of NDACC data and/or RD data in the context of the European Copernicus space segment or services.
In such cases, the following protocol applies:
- NDACC and Instrument PIs must be informed about the use of data that are accessible from the NDACC DHF, either individually or through the respective IWG co-chairs. It is strongly recommended that the user has (a) contact point(s) in the relevant NDACC community(ies) in order to fully understand the scope and limitations of the NDACC and RD datasets that are used in the application.
- The NDACC DHF manager must be informed about systematic data downloads.
- Data downloads may be programmatically linked to the NDACC DHF but the data are not to be reposted at another website for public dissemination unless there is a written agreement with NDACC - see Appendix ‘Institutional Data Use Agreement”.
- Use of the data must comply with the specified dataset licenses.
- At the point of dissemination (e.g. website, presentations, and broadcasts) appropriate attribution of NDACC data must be made, commensurate with the Data Use Agreement above and including the NDACC logo.
Appendix – Institutional Data Use Agreement
An Institutional data user who has the intention to repost NDACC or RD data for public dissemination, must sign a MoU with NDACC, represented by its co-chairs and DHF manager.
The MoU shall include the following items:
- Institute & Individual Name
- Data Products Used with mechanism for modifications and additions:
- Instrument Working Group(s)
- Dataset type e.g. RD or NDACC Affiliated
- Species
- Sites if appropriate
- Version(s) of data used
- Modifications of / additions to downloaded data
- Explanation of Data use
- Downstream expected users and scope of downstream data. Be as specific as possible.
- Location of downstream data products if posted on Data archive or Web page.
- Date of the agreement, renewal/end date, mechanism for termination
Example of Institutional Data Use Agreement
- ECMWF / Copernicus Climate Change Service
- Start: DD/MM/YYYY, End: DD/MM/YYYY. This agreement can be terminated by either party with proper 6 month written notification
- Selected consolidated NDACC affiliated data
- IRWG, UVVIS WG, LIDAR WG, Microwave WG (and soon also Dobson/Brewer WG)
- GEOMS HDF files
- O3, NO2, HCHO, CH4, CO
- IRWG2020, Lidar: GLASS, or MONTHLY
- Provision of in-situ reference climate data records on the Copernicus Climate Data Store
- Climate research and services based on in-situ reference data
- Copernicus Climate Data Store
- Signatures & dates of signature by all Parties, duration of Agreement and termination clause (e.g., “This agreement can be terminated by either Party with proper 6 months written notification”).
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Current online version: September 15, 2025
Revision: September 15, 2025
Added clearer distinction between NDACC Affiliated data and Rapid Delivery data. Removed section on Proprietary data and Privileged data users. Clarified when an MOU is needed for Institutional Data users.
Revision: February 18, 2021
The statement of the Acknowledgement is changed from ‘must acknowledge’ to ‘should acknowledge’ to accommodate requirements of some journals.
Revision: August 31, 2020
The original Data Protocol is separated into 3 documents, one for Data Providers, and one for Data Users.; A Data Use Agreement section is added expanding the information about the expected acknowledgement in publications and conditions when co-authorship should be offered. A section on Data Aggregators or Institutional Data Users is added.
Revision: March 7, 2017
Statement of priorities (Goals/Objectives) removed.; Data is now designated as public at one year, instead of two. Adds explicit mention of documentation, and annual reporting. Adds guidance on reprocessing of data. Information for users of NDACC data is expanded giving guidance on gaining access to restricted data.
Revision: March 27, 2014
Adds suggestion to offer co-authorship on publications with substantial use of data.
Revision: February 17, 2009
Changes name of network to NDACC. Adds statement of expanded NDACC priorities (often called goals or objectives). Removes Primary/Complementary Station distinction. Adds explicit encouragement for early release of data to the public.
Revision: August 1, 2000
Adds a statement requesting citation in publications using NDSC data.
Original Version: September 26, 1996