Atmospheric Humidity

Depending on altitude and spatial resolution requirements, atmospheric humidity can be derived using a multitude of approaches. Coarse vertical profiles covering the troposphere to lower stratosphere have been produced using microwave humidity sounders, with horizontal footprints of order 10–20 km and vertical resolution of a few kilometres. Tropospheric humidity profiles have been derived using GNSS (GPS) radio occultation, which tracks signals from a constellation of navigation satellites as they set or rise behind the Earth’s atmosphere (read more on this technology here). This now provides a multi‑decadal record of atmospheric refractivity from which temperature and humidity can be inferred. This approach enables vertical resolutions on the order of 150–200 m in the lower atmosphere, with typical values closer to 0.5–1.5 km.

Kilometre‑scale vertical resolution water vapour profiles over similar altitude ranges can also be produced using infrared interferometry by analysing thermal infrared spectra, typically with horizontal footprints of around 10 km.

If geostationary multi‑ or hyperspectral imagers are used, total column water vapour can be measured at sub‑hourly intervals (typically 5–15 minutes), but with only limited vertical discrimination rather than full profiling.

Indicative Cost Range Details

As use cases involving climate and weather data often require frequently updated or even ‘real-time’ observations rather than a once-off mapping exercise, pricing tends to follow a subscription model. License fees then often differentiate between various user groups. An example would be the European Centre for Medium-Range Weather Forecasts’ data pricing models.