They do! Well, at least some of them. There is for example a project called TAMDAR (Tropospheric Airborne Meteorological Data Reporting) that e.g. Icelandair is a part of. [There is a document published by the Icelandic Meteorological Office about it.][1]


  [1]: https://www.vedur.is/media/vedurstofan-utgafa-2017/VI_2017_002_rs.pdf