Dear Jochen Hack,

The CHE site has a rich collection of links that could be useful for my search.

Thank you very much.

Dear Thanos Stasinopoulos,

yes, there are a number of groups worldwide who do either continuous CO2 measurements or regular fask sampling. The two largest ones are maintained by NOAA (USA) (https://gml.noaa.gov/ccgg/trends/gl_data.html) and from Scripps Institution of Oceanography (https://scrippsco2.ucsd.edu/). A good tarting point to find a list of CO2 measurements used to be the website of the Carbon Dioxide Information and Analysis Center (CDIAC), but that was closed during the Trump presidency in the USA. But the content of the webpage at the time of the closure was archived, and here you find a link to the main observational databases:

https://cdiac.ess-dive.lbl.gov/trends/co2/

Probably there are now a few more stations that are not on that list. But for the Scripps and NOAA networks, the links provided here still work, and point you to the newest data.

Another useful link is the global carbon project's webpage, where every year a complete carbon dioxide (and methane) budget is published for the preceding year:

https://www.globalcarbonproject.org/index.htm

I hope this helps.

Best regards, Christoph Völker

Dear Thanos Stasinopoulos,

You can check the link https://tccondata.org/ for

Total Carbon Column Observing Network (TCCON) . Which is for precise column-averaged abundances of CO2 and other GHGS.

Also check this link https://www.co2.earth/daily-co2

Thank you

Thank you Christoph Voelker and Mahalakshmi Dv for your valuable response to my question.

Dear Thanos N. Stasinopoulos

The World Data Centre for Greenhouse Gases (WDCGG.) collects and disseminates the atmospheric CO2 data. There are a lot of observing stations and you can find the list here; https://gaw.kishou.go.jp/documents/db_list/organization