Frequently asked questions about the TOAR Data Portal

The TOAR Data Portal is accessible at It is the home of tropospheric ozone data.

What functions does the TOAR Data Portal offer? provides the links to several sources of satellite, surface, aircraft, and ozone sonde & LiDAR data. In addition, it gives information on how to contribute data to the TOAR data base and on how to contribute to TOAR science.

Which data sources are linked from the TOAR Data Portal?

Currently the following sources are linked (click on the links below to see its contents):

How come my data are not listed in the TOAR data portal?

The TOAR data portal is maintained as a voluntary effort on a best effort basis. We rely on information from the scientific community to identify and describe the tropospheric ozone datasets which you can see at If you spot a dataset which is not listed there, please drop us that information via, and we will see if we can add it to the portal. Please note that we can only link to datasets if it is clear that the repository, which is linked, has the necessary permissions to provide the data.

How can ship-based measurements be contributed to TOAR?

Unfortunately, the database model of the TOAR database only allows for stationary observations. Our suggestion for ship-based data (generally: moving platform data) is to establish a collection of files in a homogenous format and publish those on the TOAR data publication server. Please fill out the form We will then work on this and will generate a doi for citations. A pointer to this collection can then be added to the TOAR data portal.

Concerning aircraft field campaigns: will there be one entry in the data portal for each field campaign? They reside on separate web pages.

The TOAR data portal allows for different levels of granularity and in the future we plan to make this granularity visible. It is up to the providers to define how they want data listed, be it as a collection or as separate entries.

I have datasets which include several species. Do I have to reformat those so that they can be included in the TOAR data portal?

No. As long as the dataset contains (also) ozone data, it is eligible to be included in the portal.

Do you have a preferred format and metadata profile for data that is listed in the data portal?

No. As we don‘t process your data, any format is accepted. It would be great if the TOAR-II working groups can contribute to the harmonisation of data formats and metadata, but this is out of scope for our data gathering efforts.

How do we inform you about an update to an existing entry in the TOAR data portal?

You can either write an email to or fill in the registration form again and make a comment that this is a revision and not a new entry.

Are you actively monitoring all the pointers in the TOAR data portal in case there are changes on the web pages or services hosting the original datasets?

No, this would be too much work for us. We will occasionally check the links, but we have to rely on you, the community, to provide us with updates or point us to broken links or other errors if you discover them.