Articles | Volume 18, issue 2
https://doi.org/10.5194/amt-18-555-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/amt-18-555-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
31 Jan 2025
Research article |
| 31 Jan 2025
| 31 Jan 2025
Developments on a 22 GHz microwave radiometer and reprocessing of 13-year time series for water vapour studies
Institute of Applied Physics, University of Bern, Bern, Switzerland
Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
Eric Sauvageat
Institute of Applied Physics, University of Bern, Bern, Switzerland
Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
now at: Federal Office for Meteorology and Climatology MeteoSwiss, Payerne, Switzerland
Gunter Stober
Institute of Applied Physics, University of Bern, Bern, Switzerland
Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
Klemens Hocke
Institute of Applied Physics, University of Bern, Bern, Switzerland
Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
Axel Murk
Institute of Applied Physics, University of Bern, Bern, Switzerland
Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
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Gunter Stober, Alan Liu, Alexander Kozlovsky, Zishun Qiao, Witali Krochin, Guochun Shi, Johan Kero, Masaki Tsutsumi, Njål Gulbrandsen, Satonori Nozawa, Mark Lester, Kathrin Baumgarten, Evgenia Belova, and Nicholas Mitchell
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Pragya Vishwakarma, Julien Delanoë, Susana Jorquera, Pauline Martinet, Frederic Burnet, Alistair Bell, and Jean-Charles Dupont
Atmos. Meas. Tech., 16, 1211–1237, https://doi.org/10.5194/amt-16-1211-2023, https://doi.org/10.5194/amt-16-1211-2023, 2023
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Cloud observations are necessary to characterize the cloud properties at local and global scales. The observations must be translated to cloud geophysical parameters. This paper presents the estimation of liquid water content (LWC) using radar and microwave radiometer (MWR) measurements. Liquid water path from MWR scales LWC and retrieves the scaling factor (ln a). The retrievals are compared with in situ observations. A climatology of ln a is built to estimate LWC using only radar information.
Eric Sauvageat, Eliane Maillard Barras, Klemens Hocke, Alexander Haefele, and Axel Murk
Atmos. Meas. Tech., 15, 6395–6417, https://doi.org/10.5194/amt-15-6395-2022, https://doi.org/10.5194/amt-15-6395-2022, 2022
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Gunter Stober, Alan Liu, Alexander Kozlovsky, Zishun Qiao, Ales Kuchar, Christoph Jacobi, Chris Meek, Diego Janches, Guiping Liu, Masaki Tsutsumi, Njål Gulbrandsen, Satonori Nozawa, Mark Lester, Evgenia Belova, Johan Kero, and Nicholas Mitchell
Atmos. Meas. Tech., 15, 5769–5792, https://doi.org/10.5194/amt-15-5769-2022, https://doi.org/10.5194/amt-15-5769-2022, 2022
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Precise and accurate measurements of vertical winds at the mesosphere and lower thermosphere are rare. Although meteor radars have been used for decades to observe horizontal winds, their ability to derive reliable vertical wind measurements was always questioned. In this article, we provide mathematical concepts to retrieve mathematically and physically consistent solutions, which are compared to the state-of-the-art non-hydrostatic model UA-ICON.
Alistair Bell, Pauline Martinet, Olivier Caumont, Frédéric Burnet, Julien Delanoë, Susana Jorquera, Yann Seity, and Vinciane Unger
Atmos. Meas. Tech., 15, 5415–5438, https://doi.org/10.5194/amt-15-5415-2022, https://doi.org/10.5194/amt-15-5415-2022, 2022
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Cloud radars and microwave radiometers offer the potential to improve fog forecasts when assimilated into a high-resolution model. As this process can be complex, a retrieval of model variables is sometimes made as a first step. In this work, results from a 1D-Var algorithm for the retrieval of temperature, humidity and cloud liquid water content are presented. The algorithm is applied first to a synthetic dataset and then to a dataset of real measurements from a recent field campaign.
Witali Krochin, Francisco Navas-Guzmán, David Kuhl, Axel Murk, and Gunter Stober
Atmos. Meas. Tech., 15, 2231–2249, https://doi.org/10.5194/amt-15-2231-2022, https://doi.org/10.5194/amt-15-2231-2022, 2022
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Ann. Geophys., 40, 179–190, https://doi.org/10.5194/angeo-40-179-2022, https://doi.org/10.5194/angeo-40-179-2022, 2022
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Christoph Jacobi, Friederike Lilienthal, Dmitry Korotyshkin, Evgeny Merzlyakov, and Gunter Stober
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We compare winds and tidal amplitudes in the upper mesosphere/lower thermosphere region for cases with disturbed and undisturbed geomagnetic conditions. The zonal winds in both the mesosphere and lower thermosphere tend to be weaker during disturbed conditions. The summer equatorward meridional wind jet is weaker for disturbed geomagnetic conditions. The effect of geomagnetic variability on tidal amplitudes, except for the semidiurnal tide, is relatively small.
Gian Lieberherr, Kevin Auderset, Bertrand Calpini, Bernard Clot, Benoît Crouzy, Martin Gysel-Beer, Thomas Konzelmann, José Manzano, Andrea Mihajlovic, Alireza Moallemi, David O'Connor, Branko Sikoparija, Eric Sauvageat, Fiona Tummon, and Konstantina Vasilatou
Atmos. Meas. Tech., 14, 7693–7706, https://doi.org/10.5194/amt-14-7693-2021, https://doi.org/10.5194/amt-14-7693-2021, 2021
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Gunter Stober, Alexander Kozlovsky, Alan Liu, Zishun Qiao, Masaki Tsutsumi, Chris Hall, Satonori Nozawa, Mark Lester, Evgenia Belova, Johan Kero, Patrick J. Espy, Robert E. Hibbins, and Nicholas Mitchell
Atmos. Meas. Tech., 14, 6509–6532, https://doi.org/10.5194/amt-14-6509-2021, https://doi.org/10.5194/amt-14-6509-2021, 2021
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Wind observations at the edge to space, 70–110 km altitude, are challenging. Meteor radars have become a widely used instrument to obtain mean wind profiles above an instrument for these heights. We describe an advanced mathematical concept and present a tomographic analysis using several meteor radars located in Finland, Sweden and Norway, as well as Chile, to derive the three-dimensional flow field. We show an example of a gravity wave decelerating the mean flow.
Gunter Stober, Ales Kuchar, Dimitry Pokhotelov, Huixin Liu, Han-Li Liu, Hauke Schmidt, Christoph Jacobi, Kathrin Baumgarten, Peter Brown, Diego Janches, Damian Murphy, Alexander Kozlovsky, Mark Lester, Evgenia Belova, Johan Kero, and Nicholas Mitchell
Atmos. Chem. Phys., 21, 13855–13902, https://doi.org/10.5194/acp-21-13855-2021, https://doi.org/10.5194/acp-21-13855-2021, 2021
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Little is known about the climate change of wind systems in the mesosphere and lower thermosphere at the edge of space at altitudes from 70–110 km. Meteor radars represent a well-accepted remote sensing technique to measure winds at these altitudes. Here we present a state-of-the-art climatological interhemispheric comparison using continuous and long-lasting observations from worldwide distributed meteor radars from the Arctic to the Antarctic and sophisticated general circulation models.
Alistair Bell, Pauline Martinet, Olivier Caumont, Benoît Vié, Julien Delanoë, Jean-Charles Dupont, and Mary Borderies
Atmos. Meas. Tech., 14, 4929–4946, https://doi.org/10.5194/amt-14-4929-2021, https://doi.org/10.5194/amt-14-4929-2021, 2021
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This paper presents work towards making retrievals on the liquid water content in fog and low clouds. Future retrievals will rely on a radar simulator and high-resolution forecast. In this work, real observations are used to assess the errors associated with the simulator and forecast. A selection method to reduce errors associated with the forecast is proposed. It is concluded that the distribution of errors matches the requirements for future retrievals.
Gunter Stober, Diego Janches, Vivien Matthias, Dave Fritts, John Marino, Tracy Moffat-Griffin, Kathrin Baumgarten, Wonseok Lee, Damian Murphy, Yong Ha Kim, Nicholas Mitchell, and Scott Palo
Ann. Geophys., 39, 1–29, https://doi.org/10.5194/angeo-39-1-2021, https://doi.org/10.5194/angeo-39-1-2021, 2021
Gunter Stober, Kathrin Baumgarten, John P. McCormack, Peter Brown, and Jerry Czarnecki
Atmos. Chem. Phys., 20, 11979–12010, https://doi.org/10.5194/acp-20-11979-2020, https://doi.org/10.5194/acp-20-11979-2020, 2020
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This paper presents a first cross-comparison of meteor ground-based observations and a meteorological analysis (NAVGEM-HA) to compare a seasonal climatology of winds and temperatures at the mesosphere/lower thermosphere. The validation is insofar unique as we not only compare the mean state but also provide a detailed comparison of the short time variability of atmospheric tidal waves. Our analysis questions previous results claiming the importance of lunar tides.
Leonie Bernet, Elmar Brockmann, Thomas von Clarmann, Niklaus Kämpfer, Emmanuel Mahieu, Christian Mätzler, Gunter Stober, and Klemens Hocke
Atmos. Chem. Phys., 20, 11223–11244, https://doi.org/10.5194/acp-20-11223-2020, https://doi.org/10.5194/acp-20-11223-2020, 2020
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Franziska Schranz, Jonas Hagen, Gunter Stober, Klemens Hocke, Axel Murk, and Niklaus Kämpfer
Atmos. Chem. Phys., 20, 10791–10806, https://doi.org/10.5194/acp-20-10791-2020, https://doi.org/10.5194/acp-20-10791-2020, 2020
Short summary
Short summary
We measured middle-atmospheric ozone, water vapour and zonal and meridional wind with two ground-based microwave radiometers which are located at Ny-Alesund, Svalbard, in the Arctic. In this article we present measurements of the small-scale horizontal ozone gradients during winter 2018/2019. We found a distinct seasonal variation of the ozone gradients which is linked to the planetary wave activity. We further present the signatures of the SSW in the ozone, water vapour and wind measurements.
Cited articles
Bell, A.: Retrieved Water Vapour Profiles from MIAWARA at the Zimmerwald Observatory, Bern, Switzerland, NDACC/EVDC – ESA Atmospheric Validation Data Centre [data set], https://doi.org/10.60897/pdyc-8v84, 2023. a
Bell, A.: alistairbbell/devs_22ghz_radiometer: Article analysis, Zenodo [code], https://doi.org/10.5281/zenodo.14608688, 2025. a
Benz, A. O., Grigis, P. C., Hungerbühler, V., Meyer, H., Monstein, C., Stuber, B., and Zardet, D.: A broadband FFT spectrometer for radio and millimeter astronomy, Astron. Astrophys., 442, 767–773, 2005. a
Brasseur, G. P. and Solomon, S.: Aeronomy of the middle atmosphere: Chemistry and physics of the stratosphere and mesosphere, Vol. 32, Springer Science & Business Media, https://doi.org/10.1007/1-4020-3824-0, 2005. a
Brunamonti, S., Graf, M., Bühlmann, T., Pascale, C., Ilak, I., Emmenegger, L., and Tuzson, B.: SI-traceable validation of a laser spectrometer for balloon-borne measurements of water vapor in the upper atmosphere, Atmos. Meas. Tech., 16, 4391–4407, https://doi.org/10.5194/amt-16-4391-2023, 2023. a
Buehler, S. A., Mendrok, J., Eriksson, P., Perrin, A., Larsson, R., and Lemke, O.: ARTS, the Atmospheric Radiative Transfer Simulator – version 2.2, the planetary toolbox edition, Geosci. Model Dev., 11, 1537–1556, https://doi.org/10.5194/gmd-11-1537-2018, 2018. a, b
De Boor, C.: A practical guide to splines, Vol. 27, Springer-verlag New York, ISBN: 978-0-387-95366-3, 1978. a
Deuber, B. and Kämpfer, N.: Minimized standing waves in microwave radiometer balancing calibration, Radio Sci., 39, 1–8, 2004. a
Forkman, P., Eriksson, P., and Winnberg, A.: The 22 GHz radio-aeronomy receiver at onsala space observatory, J. Quant. Spectrosc. Ra., 77, 23–42, 2003. a
Gomez, R. M., Nedoluha, G. E., Neal, H. L., and McDermid, I. S.: The fourth-generation water vapor millimeter-wave spectrometer, Radio Sci., 47, 1–11, 2012. a
Graf, M., Scheidegger, P., Kupferschmid, A., Looser, H., Peter, T., Dirksen, R., Emmenegger, L., and Tuzson, B.: Compact and lightweight mid-infrared laser spectrometer for balloon-borne water vapor measurements in the UTLS, Atmos. Meas. Tech., 14, 1365–1378, https://doi.org/10.5194/amt-14-1365-2021, 2021. a
Gustincic, J.: A quasi-optical receiver design, in: 1977 IEEE MTT-S International Microwave Symposium Digest, San Diego, California, USA, IEEE, 99–102, 1977. a
Haefele, A., Hocke, K., Kämpfer, N., Keckhut, P., Marchand, M., Bekki, S., Morel, B., Egorova, T., and Rozanov, E.: Diurnal changes in middle atmospheric H2O and O3: Observations in the Alpine region and climate models, J. Geophys. Res.-Atmos., 113, D17303, https://doi.org/10.1029/2008JD009892, 2008. a
Hagen, J., Luder, A., Murk, A., and Kämpfer, N.: Frequency-Agile FFT Spectrometer for Microwave Remote Sensing Applications, Atmosphere, 11, 490, https://doi.org/10.3390/atmos11050490, 2020. a, b
Han, Y. and Westwater, E. R.: Analysis and improvement of tipping calibration for ground-based microwave radiometers, IEEE T. Geosci. Remote, 38, 1260–1276, 2000. a
Hartogh, P.: High-resolution chirp transform spectrometer for middle atmospheric microwave sounding, in: Satellite Remote Sensing of Clouds and the Atmosphere II, SPIE, 3220, 115–124, 1997. a
Hocke, K., Lainer, M., Bernet, L., and Kämpfer, N.: Mesospheric inversion layers at mid-latitudes and coincident changes of ozone, water vapour and horizontal wind in the Middle Atmosphere, Atmosphere, 9, 171, https://doi.org/10.3390/atmos9050171, 2018. a
Hurst, D. F., Oltmans, S. J., Vömel, H., Rosenlof, K. H., Davis, S. M., Ray, E. A., Hall, E. G., and Jordan, A. F.: Stratospheric water vapor trends over Boulder, Colorado: Analysis of the 30 year Boulder record, J. Geophys. Res.-Atmos., 116, D02306, https://doi.org/10.1029/2010JD015065, 2011. a
Ingold, T., Peter, R., and Kämpfer, N.: Weighted mean tropospheric temperature and transmittance determination at millimeter-wave frequencies for ground-based applications, Radio Sci., 33, 905–918, 1998. a
Jost, H., Kampfer, N., Lecacheux, A., and Rosolen, C.: Broadband acoustooptic spectrometer used as backend for remote sensing of trace gases in the atmosphere, IEEE T. Geosci. Remote, 34, 927–935, 1996. a
Lambert, A., Read, W., and Livesey, N.: MLS/Aura Level 2 Water Vapor (H2O) Mixing Ratio V005, Goddard Earth Sciences Data and Information Services Center (GES DISC) [data set], Greenbelt, MD, USA, https://doi.org/10.5067/Aura/MLS/DATA2508, 2020. a
Lainer, M., Hocke, K., and Kämpfer, N.: Long-term observation of midlatitude quasi 2-day waves by a water vapor radiometer, Atmos. Chem. Phys., 18, 12061–12074, https://doi.org/10.5194/acp-18-12061-2018, 2018. a
Liebe, H. J.: An updated model for millimeter wave propagation in moist air, Radio Sci., 20, 1069–1089, https://doi.org/10.1029/RS020i005p01069, 1985. a
Livesey, N. J., Read, W. G., Froidevaux, L., Lambert, A., Santee, M. L., Schwartz, M. J., Millán, L. F., Jarnot, R. F., Wagner, P. A., Hurst, D. F., Walker, K. A., Sheese, P. E., and Nedoluha, G. E.: Investigation and amelioration of long-term instrumental drifts in water vapor and nitrous oxide measurements from the Aura Microwave Limb Sounder (MLS) and their implications for studies of variability and trends, Atmos. Chem. Phys., 21, 15409–15430, https://doi.org/10.5194/acp-21-15409-2021, 2021. a, b
Livesey, N. J., Read, W. G., Wagner, P. A., Froidevaux, L., Santee, M. L., Schwartz, M. J., Lambert, A., Valle, L. F. M., Pumphrey, H. C., Manney, G. L., Fuller, R. A., Jarnot, R. F., Knosp, B. W., and Lay, R. R.: Earth Observing System (EOS) Aura Microwave Limb Sounder (MLS) Version 5.0x Level 2 and 3 Data Quality and Description Document, Tech. rep., Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, 68–82, 2022. a
Maycock, A. C., Shine, K. P., and Joshi, M. M.: The temperature response to stratospheric water vapour changes, Q. J. Roy. Meteorol. Soc., 137, 1070–1082, 2011. a
Millan, L., Santee, M. L., Lambert, A., Livesey, N. J., Werner, F., Schwartz, M. J., Pumphrey, H. C., Manney, G. L., Wang, Y., Su, H., Wu, L., Read, W. G., and Froidevaux, L.: The Hunga Tonga-Hunga Ha'apai hydration of the stratosphere, Geophys. Res. Lett., 49, e2022GL099381, https://doi.org/10.1029/2022GL099381, 2022. a
Muller, S. C., Murk, A., Monstein, C., and Kampfer, N.: Intercomparison of digital fast Fourier transform and acoustooptical spectrometers for microwave radiometry of the atmosphere, IEEE T. Geosci. Remote, 47, 2233–2239, 2009. a
NASA Jet Propulsion Laboratory: Microwave Limb Sounder, https://mls.jpl.nasa.gov/ (last access: 2 May 2024), 2024. a
Nedoluha, G. E., Michael Gomez, R., Allen, D. R., Lambert, A., Boone, C., and Stiller, G.: Variations in middle atmospheric water vapor from 2004 to 2013, J. Geophys. Res.-Atmos., 118, 11285–11293, 2013. a
Nedoluha, G. E., Gomez, R. M., Boyd, I., Neal, H., Allen, D. R., Siskind, D. E., Lambert, A., and Livesey, N. J.: Measurements of mesospheric water vapor from 1992 to 2021 at three stations from the Network for the Detection of Atmospheric Composition Change, J. Geophys. Res.-Atmos., 127, e2022JD037227, https://doi.org/10.1029/2022JD037227, 2022. a
Nedoluha, G. E., Gomez, R. M., Boyd, I., Neal, H., Allen, D. R., Lambert, A., and Livesey, N. J.: Measurements of stratospheric water vapor at Mauna Loa and the effect of the Hunga Tonga eruption, J. Geophys. Res.-Atmos., 128, e2022JD038100, https://doi.org/10.1029/2022JD038100, 2023. a
Nedoluha, G. E., Gomez, R. M., Boyd, I., Neal, H., Allen, D. R., and Lambert, A.: The spread of the Hunga Tonga H2O plume in the middle atmosphere over the first two years since eruption, J. Geophys. Res.-Atmos., 129, e2024JD040907, https://doi.org/10.1029/2024JD040907, 2024. a
Oyj, V.: RS41-SG and RS41-SGP User Guide, Vaisala Oyj, Vanha Nurmijärventie 21, FI-01670 Vantaa, Finland, version M211667EN-H, https://www.vaisala.com (last access: 1 December 2022), 2022. a
Rodgers, C. D.: Inverse methods for atmospheric sounding: theory and practice, Vol. 2, World Scientific, https://doi.org/10.1142/3171, 2000. a
Sauvageat, E.: Calibration routine for ground-based passive microwave radiometer: a user guide, Tech. rep., University of Bern, Institute of Applied Physics, 2021-01-MW, 39 pp., https://doi.org/10.48350/164418, 2021. a
Sauvageat, E., Maillard Barras, E., Hocke, K., Haefele, A., and Murk, A.: Harmonized retrieval of middle atmospheric ozone from two microwave radiometers in Switzerland, Atmos. Meas. Tech., 15, 6395–6417, https://doi.org/10.5194/amt-15-6395-2022, 2022. a, b
Schranz, F., Tschanz, B., Rüfenacht, R., Hocke, K., Palm, M., and Kämpfer, N.: Investigation of Arctic middle-atmospheric dynamics using 3 years of H2O and O3 measurements from microwave radiometers at Ny-Ålesund, Atmos. Chem. Phys., 19, 9927–9947, https://doi.org/10.5194/acp-19-9927-2019, 2019. a
Virtanen, P., Gommers, R., Oliphant, T. E., Haberland, M., Reddy, T., Cournapeau, D., Burovski, E., Peterson, P., Weckesser, W., Bright, J., van der Walt, S. J., Brett, M., Wilson, J., Millman, K. J., Mayorov, N., Nelson, A. R. J., Jones, E., Kern, R., Larson, E., Carey, C J., Polat, İ., Feng, Y., Moore, E. W., VanderPlas, J., Laxalde, D., Perktold, J., Cimrman, R., Henriksen, I., Quintero, E. A., Harris, Charles R., Archibald, A. M., Ribeiro, A. H., Pedregosa, F., van Mulbregt, P., and SciPy 1.0 Contributors: SciPy 1.0: Fundamental Algorithms for Scientific Computing in Python, Nat. Methods, 17, 261–272, https://doi.org/10.1038/s41592-019-0686-2, 2020. a
Shi, G., Krochin, W., Sauvageat, E., and Stober, G.: Ozone and water vapor variability in the polar middle atmosphere observed with ground-based microwave radiometers, Atmos. Chem. Phys., 23, 9137–9159, https://doi.org/10.5194/acp-23-9137-2023, 2023. a
Sica, R. J. and Haefele, A.: Retrieval of water vapor mixing ratio from a multiple channel Raman-scatter lidar using an optimal estimation method, Appl. Optics, 55, 763–777, https://doi.org/10.1364/AO.55.000763, 2016. a
Solomon, S., Rosenlof, K. H., Portmann, R. W., Daniel, J. S., Davis, S. M., Sanford, T. J., and Plattner, G.-K.: Contributions of stratospheric water vapor to decadal changes in the rate of global warming, Science, 327, 1219–1223, 2010. a
Straub, C., Tschanz, B., Hocke, K., Kämpfer, N., and Smith, A. K.: Transport of mesospheric H2O during and after the stratospheric sudden warming of January 2010: observation and simulation, Atmos. Chem. Phys., 12, 5413–5427, https://doi.org/10.5194/acp-12-5413-2012, 2012. a, b
Thölix, L., Karpechko, A., Backman, L., and Kivi, R.: Linking uncertainty in simulated Arctic ozone loss to uncertainties in modelled tropical stratospheric water vapour, Atmos. Chem. Phys., 18, 15047–15067, https://doi.org/10.5194/acp-18-15047-2018, 2018. a
Verdes, C., Bühler, S., von Engeln, A., Kuhn, T., Künzi, K., Eriksson, P., and Sinnhuber, B.-M.: Pointing and temperature retrieval from millimeter-submillimeter limb soundings, J. Geophys. Res.-Atmos., 107, ACH 10-1–ACH 10-24, 2002. a
Waters, J. W., Froidevaux, L., Harwood, R. S., Jarnot, R. F., Pickett, H. M., Read, W. G., Siegel, P. H., Cofield, R. E., Filipiak, M. J., Flower, D. A., Holden, J. R., Lau, G. K., Livesey, N. J., Manney, G. L., Pumphrey, H. C., Santee, M. L., Wu, D. L., Cuddy, D. T., Lay, R. R., Loo, M. S., Perun, V. S., Schwartz, M. J., Stek, P. C., Thurstans, R. P., Boyles, M. A., Chandra, K. M., Chavez, M. C., Gun-Shing Chen and Chudasama, B. V., Dodge, R., Fuller, R. A., Girard, M. A., Jiang, J. H., Jiang, Y., Knosp, B. W., LaBelle, R. C., Lam, J. C., Lee, K. A., Miller, D., Oswald, J. E., Patel, N. C., Pukala, D. M., Quintero, O., Scaff, D. M., Van Snyder, W., Tope, M. C., Wagner, P. A., and Walch, M. J.: The earth observing system microwave limb sounder (EOS MLS) on the Aura satellite, IEEE T. Geosci. Remote, 44, 1075–1092, https://doi.org/10.1109/TGRS.2006.873771, 2006. a, b
Zhou, X., Dhomse, S. S., Feng, W., Mann, G., Heddell, S., Pumphrey, H., Kerridge, B. J., Latter, B., Siddans, R., Ventress, L., Querel, R., Smale, P., Asher, E., Hall, E. G., Bekki, S., and Chipperfield, M. P.: Antarctic vortex dehydration in 2023 as a substantial removal pathway for Hunga Tonga-Hunga Ha'apai water vapor, Geophys. Res. Lett., 51, e2023GL107630, https://doi.org/10.1029/2023GL107630, 2024. a
Short summary
Hardware and software developments have been made on a 22 GHz microwave radiometer for the measurement of middle-atmospheric water vapour near Bern, Switzerland. Previous measurements dating back to 2010 have been re-calibrated and an improved optimal estimation retrieval performed on these measurements, giving a 13-year dataset. Measurements made with new and improved instrumental hardware are used to correct previous measurements, which show better agreement than the non-corrected dataset.
Hardware and software developments have been made on a 22 GHz microwave radiometer for the...
