Articles | Volume 19, issue 15
https://doi.org/10.5194/amt-19-5091-2026
https://doi.org/10.5194/amt-19-5091-2026
Research article
 | 
07 Aug 2026
Research article |  | 07 Aug 2026

The “Golden Points” and nonequilibrium correction of high-accuracy frost point hygrometers

Yann Poltera, Beiping Luo, Frank G. Wienhold, and Thomas Peter

Related authors

Accurate and high-resolution measurements of UTLS water vapor by balloon-borne laser absorption spectroscopy
Simone Brunamonti, Yann Poltera, Gonzague Romanens, Alex Weitnauer, Philipp Scheidegger, Adrianos Filinis, Alistair Bell, Giovanni Martucci, Frank Gunther Wienhold, Thomas Peter, Peter Oelsner, Ruud Dirksen, Alexander Haefele, Lukas Emmenegger, Gunter Stober, and Béla Tuzson
EGUsphere, https://doi.org/10.5194/egusphere-2026-4762,https://doi.org/10.5194/egusphere-2026-4762, 2026
This preprint is open for discussion and under review for Atmospheric Measurement Techniques (AMT).
Short summary
Assessment of humidity ground checks for GRUAN-compliant automatic radiosonde operations
Gonzague Romanens, Giovanni Martucci, Marco Rosoldi, Yann Poltera, Cristina Cardós, Natalia Prats, Sunji Ambe, Gessica Cosimato, Antoine Farah, Christian Félix, Ilaria Gandolfi, Alexander Haefele, Miguel Hernández, Masami Iwabuchi, Patrick Jann, Jason Ming Chun Lam, Fabrizio Marra, José María Rodríguez, Yves-Alain Roulet, Yuta Tanaka, Ruud Dirksen, and Fabio Madonna
EGUsphere, https://doi.org/10.5194/egusphere-2026-3215,https://doi.org/10.5194/egusphere-2026-3215, 2026
This preprint is open for discussion and under review for Atmospheric Measurement Techniques (AMT).
Short summary

Cited articles

Antikainen, V. and Paukkunen, A.: Studies on improving humidity measurement in radiosondes, in: Proc. WMO Technical Conf. on Instruments and Methods of Observation (TECO-94), Geneva, Switzerland, 28 February–2 March 1994, WMO Instruments and Observing Methods Rep. 57, WMO/TD-No. 588, 137–141, https://library.wmo.int/idurl/4/41796 (last access: 17 April 2025), 1994. 
Asher, E., Todt, M., Rosenlof, K., Thornberry, T., Gao, R.-S., Taha, G., Walter, P., Alvarez, S., Flynn, J., Davis, S. M., Evan, S., Brioude, J., Metzger, J.-M., Hurst, D. F., Hall, E., and Xiong, K.: Unexpectedly rapid aerosol formation in the Hunga Tonga plume, P. Nat. Acad. Sci. USA, 120, 1–7, https://doi.org/10.1073/pnas.2219547120, 2023. 
Barrett, E. W. and Herndon, L. R.: An Improved Electronic Dew-Point Hygrometer, J. Meteorol., 8, 40–51, https://doi.org/10.1175/1520-0469(1951)008<0040:AIEDPH>2.0.CO;2, 1951. 
Bertaux, J.-L. and Delannoy, A.: Vertical distribution of H2O in the stratosphere as determined by UV fluorescence in-situ measurements, Geophys. Res. Lett., 5, 1017–1020, https://doi.org/10.1029/GL005i012p01017, 1978. 
Brabec, M., Wienhold, F. G., Luo, B. P., Vömel, H., Immler, F., Steiner, P., Hausammann, E., Weers, U., and Peter, T.: Particle backscatter and relative humidity measured across cirrus clouds and comparison with microphysical cirrus modelling, Atmos. Chem. Phys., 12, 9135–9148, https://doi.org/10.5194/acp-12-9135-2012, 2012. 
Download
Short summary
Chilled mirror hygrometers are the most accurate instruments for measuring water vapor in the upper troposphere and lower stratosphere. The “Golden Points” and nonequilibrium correction are a new post-processing technique for these instruments, which can correct frost point data using mirror reflectance information to achieve unprecedented accuracy of better than 4 % in the H2O mixing ratio, even under rapidly changing humidity conditions, from the ground to the middle stratosphere.
Share