Procedure: Station Inclusion in GAW Programme


Please carefully study the essential requirements for a GAW station to make sure that your station qualifies for one of the types.  You can suggest the type of the station in your application but final decision will be made based on the basic requirements met by the station (see part REQUIREMENTS).


Fill in the application letter and send it by email and by ordinary post (a signed paper version) to : ; (CC) and (CC).


To update the status of the registered stations similar letter is required.

Your application will be considered by respective expert group and confirmation will be sent to you. Please kindly specify your contact details in the application.

Together with a submission of the application please register your station in the GAW Station Information System (GAWSIS).


As soon as you get a confirmation of acceptance the status of the station in GAWSIS will be updated and the station becomes visible to the public.


If you have started your measurement earlier than a year ago, please submit the data to the respective World Data Center. If you have just started your measurement programme kindly submit the data and metadata in due time.


Annually (or more often if needed) check/update the information in GAWSIS on the data submission and station status (e.g. extension of the measurement programme). If this is not done, the station is moved to the non-active category.



The designation of observation sites as global, regional, local or mobile stations provides some indication about the station location while at the same time expressing a certain comprehensiveness of the measurement programme conducted at these sites (from the GAW Implementation Plan 2016-2023).

Requirements for Global Stations

These stations primarily observe GAW variables under background conditions, i.e. without permanent significant influence from local pollution sources. In addition to fulfilling the requirement of GAW Regional stations, Global stations must fulfil the following:

1) Measure at least two variables in at least three of the six GAW focal areas with the full implementation of GAW’s Quality Assurance system (Box 7.1 (A)).

2) Have a strong scientific supporting programme with appropriate data analysis and interpretation within the country and, if possible, the support of more than one agency.

    • The stations should have a confirmed track record of research campaigns and/or scientific products (within last 3 years) as a Regional station.
    • The measurements at the station have been audited or the quality of the measurements has been documented through other means of verification.
    • The data from at least two variables in at least three focal areas have been submitted to the respective World Data Centre(s) during at least three years within the data submission period of 1 year after measurement.

3) Provide a facility at which intensive campaign research can augment the long-term routine GAW observations and where testing and development of new GAW methods can be undertaken.

4) In case the measurements of some GAW variables are occasionally influenced by local pollution, the station shall subject the data to appropriate filter methods to extract the background concentrations and submit both a filtered and an unfiltered time series to the WDC. Also the station metadata on GAWSIS should describe the conditions under which pollution influences may be found and describe the applied filter methods.


Requirements for GAW Regional stations in particular include:

1.       The station location is chosen such that, for the variables measured, it is regionally representative and is normally free of the influence of significant local pollution sources or at least frequently experiences advection of pollution-free air from specific wind directions.

2.       There is a commitment by the responsible agency to long-term observations of at least two variables in at least one GAW focal areas (ozone, aerosols, greenhouse gases, reactive gases, UV radiation, precipitation chemistry/total deposition). To address measurements for multiple applications in more than one focal area are recommended.

3.       Adequate power, air conditioning, communication and building facilities are provided to sustain long-term observations with greater than 90% data capture (i.e. <10% missing data).

4.       Standard meteorological in situ observations (at least temperature, humidity, air pressure, and wind speed and direction), necessary for the accurate determination and interpretation of the GAW variables, are made of known quality.

5.       Technical staff are trained to operate station equipment.

6.       GAW observations are of known quality, follow GAW Quality Assurance principles and procedures, linked to the GAW Primary Standard where applicable and use the measurement methods recommended by GAW.

7.       A station logbook (i.e. record of observations made and activities that may affect observations) is maintained and is used in the data validation process.

8.       The data and associated metadata must be submitted to one of the GAW World Data Centres at least on a yearly basis documenting Year N no later than end of Year N+1. Changes of metadata including instrumentation, traceability, observation procedures, must be reported to the responsible WDC and GAWSIS in a timely manner following the WIGOS metadata standards.

9.       If feasible, data are submitted to a designated data distribution system in near-real-time.


Requirements for Mobile stations

 Mobile station is the station that uses moving platforms to perform atmospheric composition observations (aircraft, ship, train etc). In general the sitting requirements do not apply to this category of observations. The measurement techniques could be modified from the recommendation in GAW to ensure instruments accommodation at the platform. The Quality Assurance practices recommended for other categories of GAW stations should be followed. The goal is to achieve the observations which are compatible with the stationary platform to ensure the use of mobile stations data in global analysis and assessments.


Requirements for Local stations

Local stations reflect the growing interest in conducting research and supporting services related to urban environments, and in other locations impacted by nearby emissions (e.g. from biomass burning). GAW local stations are to satisfy the same requirements as for regional stations except for the sitting requirement.