NDACC Data Protocol

The primary goal of the Network for the Detection of Atmospheric Composition Change (NDACC) is to obtain high quality measurements of a broad range of stratospheric chemical species and parameters. Through such dedicated measurements, the NDACC seeks to provide the basis for the earliest possible identification of long-term changes in the stratospheric ozone layer and to establish the cause(s) of such changes. The NDACC is an international activity, involving and requiring the participation of scientists around the world. It has been endorsed by the United Nations Environment Programme (UNEP) and the International Ozone Commission (IOC) of the International Association of Meteorology and Atmospheric Physics and by the World Meteorological Organization (WMO) as a major contributor of WMO's Global Ozone Observing System (GO3OS) within the framework of its Global Atmosphere Watch (GAW).

It is the spirit and purpose of the NDACC to foster the broadest possible collaboration among interested scientists as quickly as possible. However, with any good measurements, the investigators themselves bear the ultimate burden of responsibility for data quality. The NDACC Data Protocol recognizes that, in order to produce a verifiable data product, sufficient time is needed to collect, reduce, test, analyze, and intercompare the streams of preliminary analyses from each of the NDACC Primary Stations and numerous Complementary Sites. This protocol is structured to ensure excellent data quality while providing ready data access.

This data protocol has been established to guide and assist the activities of all NDACC investigators (Principal Investigators (PIs), co-investigators, Complementary Investigators (CIs), and Theory and Analysis Investigators (TIs)). It consists of the following principles:

1) The foremost tenet of the NDACC Data Protocol is that any NDACC experimental investigator may establish the scientific collaborations needed for the optimum testing and verification of his or her own measurements. Such collaborations are, in fact, strongly encouraged.

2) Intercomparison among NDACC instruments is a critical element of the analysis / verification process. To this end, all of the PIs and CIs shall place their preliminary analyses of measurements in the NDACC archive via the NDACC Data Host Facility (DHF) as rapidly as possible and no later than one year after being obtained. The DHFs will provide ready access of the data within the international NDACC science community.

3) Since the nature of small trends detection requires an extremely high level of measurement confidence, the Data Protocol recognizes that multiple seasonal analyses may be required for observations from both individual and multiple sites. It is expected that such a procedure shall yield the verifiable product referred to as "NDACC data" within a two-year period after acquisition. Co-authorship shall be offered on publications resulting from the verification procedure to those investigators participating in the process.

4) After the above verification, NDACC data will be available to anyone through centralized scientific data archiving and distribution facilities.

People who use NDACC data in a publication are requested to include the following acknowledgment: "The data used in this publication was obtained as part of the Network for the Detection of Atmospheric Composition Change (NDACC) and is publicly available (see http://www.ndacc.org)."

Special cases will, no doubt arise and will warrant discussion and resolution by the NDACC Steering Committee. For example, such exceptions might include (i) campaigns in the vicinity of an NDACC primary station for which earlier centralized access to the preliminary analyses described under item (2) would help to achieve the goals of the campaign, (ii) geophysical episodes for which such analyses might be useful in planning a research response, or (iii) satellite intercomparison and validation activities.