Technical note: Water vapour climatologies in the extra-tropical upper troposphere and lower stratosphere derived from a synthesis of passenger and research aircraft measurements
<p>This study presents a new methodology to derive adjusted water vapour (<span class="inline-formula">H<sub>2</sub>O</span>) climatologies for the extra-tropical upper troposphere and lowermost stratosphere (UT/LMS) from regular measurements on board passeng...
Saved in:
| Main Authors: | , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2025-04-01
|
| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/25/4269/2025/acp-25-4269-2025.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | <p>This study presents a new methodology to derive adjusted water vapour (<span class="inline-formula">H<sub>2</sub>O</span>) climatologies for the extra-tropical upper troposphere and lowermost stratosphere (UT/LMS) from regular measurements on board passenger aircraft between 1994 and 2022 within the IAGOS (In-service Aircraft for a Global Observing System) research infrastructure. A synthesis of mean <span class="inline-formula">H<sub>2</sub>O</span> is performed by sampling air mass bins of similar origin and thermodynamic conditions relative to the tropopause between a dataset from 60 000 flights employing the IAGOS-MOZAIC (Measurement of Ozone by AIRBUS In-Service Aircraft) and IAGOS-CORE capacitive hygrometer (ICH) and a dataset of 500 flights using the more sophisticated IAGOS-CARIBIC (Civil Aircraft for the Regular Investigation of the Atmosphere Based on an Instrument Container) hygrometer. The analysis is, in combination with ECMWF ERA5 meteorological data, accomplished for the extra-tropical Northern Hemisphere, where the datasets have the largest common coverage. We find very good agreement in the UT but a systematic positive humidity bias in the ICH measurements for the LMS. To account for this bias, mean <span class="inline-formula">H<sub>2</sub>O</span> of the ICH is adjusted to the IAGOS-CARIBIC measurements based on a new mapping and adjustment approach. After applying this new method, the LMS <span class="inline-formula">H<sub>2</sub>O</span> measurements are in good agreement between all investigated platforms. The extensive <span class="inline-formula">H<sub>2</sub>O</span> dataset from the compact IAGOS sensor can now be used to produce highly resolved <span class="inline-formula">H<sub>2</sub>O</span> climatologies for the climatically sensitive LMS region.</p> |
|---|---|
| ISSN: | 1680-7316 1680-7324 |