Articles | Volume 40, issue 3
https://doi.org/10.5194/angeo-40-407-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/angeo-40-407-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Regular paper
| 
15 Jun 2022
Regular paper |
| 15 Jun 2022
| 15 Jun 2022
On the colour of noctilucent clouds
Anna Lange
CORRESPONDING AUTHOR
Institute of Physics, University of Greifswald, Felix-Hausdorff-Str. 6, 17487 Greifswald, Germany
Gerd Baumgarten
Leibniz-Institute of Atmospheric Physics at the University of Rostock, Schlossstraße 6, 18225 Kühlungsborn, Germany
Alexei Rozanov
Institute of Environmental Physics, University of Bremen, Otto-Hahn-Allee 1, 27359 Bremen, Germany
Christian von Savigny
Institute of Physics, University of Greifswald, Felix-Hausdorff-Str. 6, 17487 Greifswald, Germany
Related authors
Anna Lange, Ulrike Niemeier, Alexei Rozanov, and Christian von Savigny
EGUsphere, https://doi.org/10.5194/egusphere-2025-1005, https://doi.org/10.5194/egusphere-2025-1005, 2025
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Our paper investigates whether it is possible to observe injections of 1 and 2 Tg S/y (sulphur per year) into the stratosphere with the currently active satellite occultation instruments. The calculations show that, considering the natural variability and the assumptions made here, the stratospheric aerosols formed from emissions of 1 and 2 Tg S/y in the quasi steady-state phase can be detected, which is not the case in the first month of the two-year initial phase.
Christian von Savigny, Anna Lange, Christoph G. Hoffmann, and Alexei Rozanov
Atmos. Chem. Phys., 24, 2415–2422, https://doi.org/10.5194/acp-24-2415-2024, https://doi.org/10.5194/acp-24-2415-2024, 2024
Short summary
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It is well known that volcanic eruptions strongly affect the colours of the twilight sky. Typically, volcanic eruptions lead to enhanced reddish and violet twilight colours. In rare cases, however, volcanic eruptions can also lead to green sunsets. This study provides an explanation for the occurrence of these unusual green sunsets based on simulations with a radiative transfer model. Green volcanic sunsets require a sufficient stratospheric aerosol optical depth and specific aerosol sizes.
Anna Lange, Alexei Rozanov, and Christian von Savigny
Atmos. Chem. Phys., 23, 14829–14839, https://doi.org/10.5194/acp-23-14829-2023, https://doi.org/10.5194/acp-23-14829-2023, 2023
Short summary
Short summary
We were able to demonstrate quantitatively that the blue colour of the sky cannot be solely attributed to Rayleigh scattering. The influence of ozone on the blue colour of the sky is calculated for different viewing geometries, total ozone columns and an enhanced stratospheric aerosol scenario. Furthermore, the effects of polarisation, surface albedo and observer height are investigated.
Christian von Savigny, Anna Lange, Anne Hemkendreis, Christoph G. Hoffmann, and Alexei Rozanov
Clim. Past, 18, 2345–2356, https://doi.org/10.5194/cp-18-2345-2022, https://doi.org/10.5194/cp-18-2345-2022, 2022
Short summary
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This study investigates the possibility of inferring information on aerosol optical depth from photographs of historic paintings. The idea – which has been applied in previous studies – is very interesting because it would provide an archive of the atmospheric aerosol loading covering many centuries. We show that twilight colours depend not only on the aerosol optical thickness, but also on several other parameters, making a quantitative estimate of aerosol optical depth very difficult.
Nellie Wullenweber, Anna Lange, Alexei Rozanov, and Christian von Savigny
Clim. Past, 17, 969–983, https://doi.org/10.5194/cp-17-969-2021, https://doi.org/10.5194/cp-17-969-2021, 2021
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This study investigates the physical processes leading to the rare phenomenon of the sun appearing blue or green. The phenomenon is caused by anomalous scattering by, e.g., volcanic or forest fire aerosols. Unlike most other studies, our study includes a full treatment of the effect of Rayleigh scattering on the colour of the sun. We investigate different factors and revisit a historic example, i.e. the Canadian forest fires in 1950, that led to blue sun events in different European countries.
Mohamed Mossad, Irina Strelnikova, Robin Wing, Gerd Baumgarten, and Michael Gerding
EGUsphere, https://doi.org/10.5194/egusphere-2025-3267, https://doi.org/10.5194/egusphere-2025-3267, 2025
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
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We recorded atmospheric waves over seven years with a lidar in northern Norway, analysing temperature and wind from 35 to 60 km altitude. This yielded the first long-term picture of how wave energy varies with height and season at this location. Winter carried up to ten times more energy than summer, and the balance shifted with wavelength and frequency. Energy patterns often diverged from textbook slopes. These findings refine our view of the upper atmosphere at high latitudes.
Carlo Arosio, Viktoria Sofieva, Andrea Orfanoz-Cheuquelaf, Alexei Rozanov, Klaus-Peter Heue, Diego Loyola, Edward Malina, Ryan M. Stauffer, David Tarasick, Roeland Van Malderen, Jerry R. Ziemke, and Mark Weber
Atmos. Meas. Tech., 18, 3247–3265, https://doi.org/10.5194/amt-18-3247-2025, https://doi.org/10.5194/amt-18-3247-2025, 2025
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Tropospheric ozone affects air quality and climate, being a pollutant and a greenhouse gas. We analyze satellite data of tropospheric ozone columns obtained by combining two types of observations: one providing stratospheric and the other total ozone. We compare common climatological features and study the influence of the tropopause (troposphere to stratosphere boundary) on the results. We also examine trends over the last 20 years and compare satellite data with ozonesondes to identify drifts.
Clair Duchamp, Bernard Legras, Aurélien Podglajen, Pasquale Sellitto, Adam E. Bourassa, Alexei Rozanov, Ghassan Taha, and Daniel J. Zawada
EGUsphere, https://doi.org/10.5194/egusphere-2025-3355, https://doi.org/10.5194/egusphere-2025-3355, 2025
This preprint is open for discussion and under review for Atmospheric Measurement Techniques (AMT).
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We analyzed the stratospheric aerosol plume from the 2022 Hunga eruption using satellite lidar data. We implemented a method to retrieve some aerosol properties, as standard products failed in this case. We found very high optical depth values in the days following the eruption, which decreased rapidly but remained elevated for months. Our results are broadly validated, though some satellite products underestimate the values due, in part, to the unusual aerosol size distribution in the plume.
Jens Fiedler, Gerd Baumgarten, Michael Gerding, Torsten Köpnick, Reik Ostermann, and Bernd Kaifler
EGUsphere, https://doi.org/10.5194/egusphere-2025-1995, https://doi.org/10.5194/egusphere-2025-1995, 2025
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We developed a system for frequency control and monitoring of pulsed high-power lasers. It works in real-time, controls the laser cavity length, and performs a spectral analyzes of each individual laser pulse. The motivation for this work was to improve the retrieval of Doppler winds measured by lidar in the middle atmosphere by taking the frequency stability of the lidar transmitter into account.
Sandra Wallis, Matthew DeLand, and Christian von Savigny
Atmos. Chem. Phys., 25, 3635–3645, https://doi.org/10.5194/acp-25-3635-2025, https://doi.org/10.5194/acp-25-3635-2025, 2025
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The 2022 Hunga Tonga – Hunga Ha'apai eruption emitted about 150 Tg H2O that partly reached the upper polar Southern Hemisphere mesosphere in the beginning of 2024. Noctilucent clouds (NLCs) did not show a clear perturbation in their occurrence frequency, but the slight increase from mid-January to February could potentially have been caused by the additional H2O. It needed 2 years to reach the summer polar mesopause region, analogous to the 1883 Krakatoa eruption that is argued to have caused the first sightings of NLCs.
Felix Wrana, Terry Deshler, Christian Löns, Larry W. Thomason, and Christian von Savigny
Atmos. Chem. Phys., 25, 3717–3736, https://doi.org/10.5194/acp-25-3717-2025, https://doi.org/10.5194/acp-25-3717-2025, 2025
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There is a natural and globally occurring layer of small droplets (aerosols) at roughly 20 km altitude in the atmosphere. In this work, the size of these droplets is calculated from satellite measurements for the years 2002 to 2005, which is important for the aerosol cooling effect on Earth's climate. These years are interesting because there were no large volcanic eruptions that would change the background state of the aerosols. The results are compared to reliable balloon-borne measurements.
Anna Lange, Ulrike Niemeier, Alexei Rozanov, and Christian von Savigny
EGUsphere, https://doi.org/10.5194/egusphere-2025-1005, https://doi.org/10.5194/egusphere-2025-1005, 2025
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Our paper investigates whether it is possible to observe injections of 1 and 2 Tg S/y (sulphur per year) into the stratosphere with the currently active satellite occultation instruments. The calculations show that, considering the natural variability and the assumptions made here, the stratospheric aerosols formed from emissions of 1 and 2 Tg S/y in the quasi steady-state phase can be detected, which is not the case in the first month of the two-year initial phase.
Arno Keppens, Daan Hubert, José Granville, Oindrila Nath, Jean-Christopher Lambert, Catherine Wespes, Pierre-François Coheur, Cathy Clerbaux, Anne Boynard, Richard Siddans, Barry Latter, Brian Kerridge, Serena Di Pede, Pepijn Veefkind, Juan Cuesta, Gaelle Dufour, Klaus-Peter Heue, Melanie Coldewey-Egbers, Diego Loyola, Andrea Orfanoz-Cheuquelaf, Swathi Maratt Satheesan, Kai-Uwe Eichmann, Alexei Rozanov, Viktoria F. Sofieva, Jerald R. Ziemke, Antje Inness, Roeland Van Malderen, and Lars Hoffmann
EGUsphere, https://doi.org/10.5194/egusphere-2024-3746, https://doi.org/10.5194/egusphere-2024-3746, 2025
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The first Tropospheric Ozone Assessment Report (TOAR) encountered discrepancies between several satellite sensors’ estimates of the distribution and change of ozone in the free troposphere. Therefore, contributing to the second TOAR, we harmonise as much as possible the observational perspective of sixteen tropospheric ozone products from satellites. This only partially accounts for the observed discrepancies, with a reduction of 10–40 % of the inter-product dispersion upon harmonisation.
Natalie Kaifler, Bernd Kaifler, Markus Rapp, Guiping Liu, Diego Janches, Gerd Baumgarten, and Jose-Luis Hormaechea
Atmos. Chem. Phys., 24, 14029–14044, https://doi.org/10.5194/acp-24-14029-2024, https://doi.org/10.5194/acp-24-14029-2024, 2024
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Noctilucent clouds (NLCs) are silvery clouds that can be viewed during twilight and indicate atmospheric conditions like temperature and water vapor in the upper mesosphere. High-resolution measurements from a remote sensing laser instrument provide NLC height, brightness, and occurrence rate since 2017. Most observations occur in the morning hours, likely caused by strong tidal winds, and NLC ice particles are thus transported from elsewhere to the observing location in the Southern Hemisphere.
Alexei Rozanov, Christine Pohl, Carlo Arosio, Adam Bourassa, Klaus Bramstedt, Elizaveta Malinina, Landon Rieger, and John P. Burrows
Atmos. Meas. Tech., 17, 6677–6695, https://doi.org/10.5194/amt-17-6677-2024, https://doi.org/10.5194/amt-17-6677-2024, 2024
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We developed a new algorithm to retrieve vertical distributions of aerosol extinction coefficients in the stratosphere. The algorithm is applied to measurements of scattered solar light from the spaceborne OMPS-LP (Ozone Mapper and Profiler Suite Limb Profiler) instrument. The retrieval results are compared to data from other spaceborne instruments and used to investigate the evolution of the aerosol plume following the eruption of the Hunga Tonga–Hunga Ha'apai volcano in January 2022.
Jens Fiedler and Gerd Baumgarten
Atmos. Meas. Tech., 17, 5841–5859, https://doi.org/10.5194/amt-17-5841-2024, https://doi.org/10.5194/amt-17-5841-2024, 2024
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This article describes the current status of a lidar installed at ALOMAR in northern Norway. It has investigated the Arctic middle atmosphere on a climatological basis for 30 years. We discuss major upgrades of the system implemented during recent years, including methods for reliable remote operation of this complex lidar. We also show examples that illustrate the performance of the lidar during measurements at different altitude ranges and timescales.
Falco Monsees, Alexei Rozanov, John P. Burrows, Mark Weber, Annette Rinke, Ralf Jaiser, and Peter von der Gathen
Atmos. Chem. Phys., 24, 9085–9099, https://doi.org/10.5194/acp-24-9085-2024, https://doi.org/10.5194/acp-24-9085-2024, 2024
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Cyclones strongly influence weather predictability but still cannot be fully characterised in the Arctic because of the sparse coverage of meteorological measurements. A potential approach to compensate for this is the use of satellite measurements of ozone, because cyclones impact the tropopause and therefore also ozone. In this study we used this connection to investigate the correlation between ozone and the tropopause in the Arctic and to identify cyclones with satellite ozone observations.
Christine Pohl, Felix Wrana, Alexei Rozanov, Terry Deshler, Elizaveta Malinina, Christian von Savigny, Landon A. Rieger, Adam E. Bourassa, and John P. Burrows
Atmos. Meas. Tech., 17, 4153–4181, https://doi.org/10.5194/amt-17-4153-2024, https://doi.org/10.5194/amt-17-4153-2024, 2024
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Knowledge of stratospheric aerosol characteristics is important for understanding chemical and climate aerosol feedbacks. Two particle size distribution parameters, the aerosol extinction coefficient and the effective radius, are obtained from SCIAMACHY limb observations. The aerosol characteristics show good agreement with independent data sets from balloon-borne and satellite observations. This data set expands the limited knowledge of stratospheric aerosol characteristics.
Michael Gerding, Robin Wing, Eframir Franco-Diaz, Gerd Baumgarten, Jens Fiedler, Torsten Köpnick, and Reik Ostermann
Atmos. Meas. Tech., 17, 2789–2809, https://doi.org/10.5194/amt-17-2789-2024, https://doi.org/10.5194/amt-17-2789-2024, 2024
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This paper describes a new lidar system developed in Germany intended to study wind and temperature at night in the middle atmosphere. The paper explains how we have set up the system to work automatically and gives technical details for anyone who wants to build a similar system. We present a case study showing temperatures and winds at different altitudes. In a future article, we will present how we process the data and deal with uncertainties.
Matthew S. Johnson, Alexei Rozanov, Mark Weber, Nora Mettig, John Sullivan, Michael J. Newchurch, Shi Kuang, Thierry Leblanc, Fernando Chouza, Timothy A. Berkoff, Guillaume Gronoff, Kevin B. Strawbridge, Raul J. Alvarez, Andrew O. Langford, Christoph J. Senff, Guillaume Kirgis, Brandi McCarty, and Larry Twigg
Atmos. Meas. Tech., 17, 2559–2582, https://doi.org/10.5194/amt-17-2559-2024, https://doi.org/10.5194/amt-17-2559-2024, 2024
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Monitoring tropospheric ozone (O3), a harmful pollutant negatively impacting human health, is primarily done using ground-based measurements and ozonesondes. However, these observation types lack the coverage to fully understand tropospheric O3. Satellites can retrieve tropospheric ozone with near-daily global coverage; however, they are known to have biases and errors. This study uses ground-based lidars to validate multiple satellites' ability to observe tropospheric O3.
Andrea Orfanoz-Cheuquelaf, Carlo Arosio, Alexei Rozanov, Mark Weber, Annette Ladstätter-Weißenmayer, John P. Burrows, Anne M. Thompson, Ryan M. Stauffer, and Debra E. Kollonige
Atmos. Meas. Tech., 17, 1791–1809, https://doi.org/10.5194/amt-17-1791-2024, https://doi.org/10.5194/amt-17-1791-2024, 2024
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Valuable information on the tropospheric ozone column (TrOC) can be obtained globally by combining space-borne limb and nadir measurements (limb–nadir matching, LNM). This study describes the retrieval of TrOC from the OMPS instrument (since 2012) using the LNM technique. The OMPS-LNM TrOC was compared with ozonesondes and other satellite measurements, showing a good agreement with a negative bias within 1 to 4 DU. This new dataset is suitable for pollution studies.
Thorben H. Mense, Josef Höffner, Gerd Baumgarten, Ronald Eixmann, Jan Froh, Alsu Mauer, Alexander Munk, Robin Wing, and Franz-Josef Lübken
Atmos. Meas. Tech., 17, 1665–1677, https://doi.org/10.5194/amt-17-1665-2024, https://doi.org/10.5194/amt-17-1665-2024, 2024
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A novel lidar system with five beams measured horizontal and vertical winds together, reaching altitudes up to 25 km. Developed in Germany, it revealed accurate horizontal wind data compared to forecasts, but vertical wind estimates differed. The lidar's capability to detect small-scale wind patterns was highlighted, advancing atmospheric research.
Christian von Savigny, Anna Lange, Christoph G. Hoffmann, and Alexei Rozanov
Atmos. Chem. Phys., 24, 2415–2422, https://doi.org/10.5194/acp-24-2415-2024, https://doi.org/10.5194/acp-24-2415-2024, 2024
Short summary
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It is well known that volcanic eruptions strongly affect the colours of the twilight sky. Typically, volcanic eruptions lead to enhanced reddish and violet twilight colours. In rare cases, however, volcanic eruptions can also lead to green sunsets. This study provides an explanation for the occurrence of these unusual green sunsets based on simulations with a radiative transfer model. Green volcanic sunsets require a sufficient stratospheric aerosol optical depth and specific aerosol sizes.
Eframir Franco-Diaz, Michael Gerding, Laura Holt, Irina Strelnikova, Robin Wing, Gerd Baumgarten, and Franz-Josef Lübken
Atmos. Chem. Phys., 24, 1543–1558, https://doi.org/10.5194/acp-24-1543-2024, https://doi.org/10.5194/acp-24-1543-2024, 2024
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We use satellite, lidar, and ECMWF data to study storm-related waves that propagate above Kühlungsborn, Germany, during summer. Although these events occur in roughly half of the years of the satellite data we analyzed, we focus our study on two case study years (2014 and 2015). These events could contribute significantly to middle atmospheric circulation and are not accounted for in weather and climate models.
Mohamed Mossad, Irina Strelnikova, Robin Wing, and Gerd Baumgarten
Atmos. Meas. Tech., 17, 783–799, https://doi.org/10.5194/amt-17-783-2024, https://doi.org/10.5194/amt-17-783-2024, 2024
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This numerical study addresses observational gaps' impact on atmospheric gravity wave spectra. Three methods, fast Fourier transform (FFT), generalized Lomb–Scargle periodogram (GLS), and Haar structure function (HSF), were tested on synthetic data. HSF is best for spectra with negative slopes. GLS excels for flat and positive slopes and identifying dominant frequencies. Accurately estimating these aspects is crucial for understanding gravity wave dynamics and energy transfer in the atmosphere.
Anna Lange, Alexei Rozanov, and Christian von Savigny
Atmos. Chem. Phys., 23, 14829–14839, https://doi.org/10.5194/acp-23-14829-2023, https://doi.org/10.5194/acp-23-14829-2023, 2023
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We were able to demonstrate quantitatively that the blue colour of the sky cannot be solely attributed to Rayleigh scattering. The influence of ozone on the blue colour of the sky is calculated for different viewing geometries, total ozone columns and an enhanced stratospheric aerosol scenario. Furthermore, the effects of polarisation, surface albedo and observer height are investigated.
John M. C. Plane, Jörg Gumbel, Konstantinos S. Kalogerakis, Daniel R. Marsh, and Christian von Savigny
Atmos. Chem. Phys., 23, 13255–13282, https://doi.org/10.5194/acp-23-13255-2023, https://doi.org/10.5194/acp-23-13255-2023, 2023
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The mesosphere or lower thermosphere region of the atmosphere borders the edge of space. It is subject to extreme ultraviolet photons and charged particles from the Sun and atmospheric gravity waves from below, which tend to break in this region. The pressure is very low, which facilitates chemistry involving species in excited states, and this is also the region where cosmic dust ablates and injects various metals. The result is a unique and exotic chemistry.
Christoph G. Hoffmann, Lena G. Buth, and Christian von Savigny
Atmos. Chem. Phys., 23, 12781–12799, https://doi.org/10.5194/acp-23-12781-2023, https://doi.org/10.5194/acp-23-12781-2023, 2023
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The Madden–Julian oscillation is an important feature of weather in the tropics. Although it is mainly active in the troposphere, we show that it systematically influences the air temperature in the layers above, up to about 100 km altitude and from pole to pole. We have linked this to another known far-reaching process, interhemispheric coupling. This is basic research on atmospheric couplings and variability but might also be of interest for intraseasonal weather forecasting models.
Michael Kiefer, Dale F. Hurst, Gabriele P. Stiller, Stefan Lossow, Holger Vömel, John Anderson, Faiza Azam, Jean-Loup Bertaux, Laurent Blanot, Klaus Bramstedt, John P. Burrows, Robert Damadeo, Bianca Maria Dinelli, Patrick Eriksson, Maya García-Comas, John C. Gille, Mark Hervig, Yasuko Kasai, Farahnaz Khosrawi, Donal Murtagh, Gerald E. Nedoluha, Stefan Noël, Piera Raspollini, William G. Read, Karen H. Rosenlof, Alexei Rozanov, Christopher E. Sioris, Takafumi Sugita, Thomas von Clarmann, Kaley A. Walker, and Katja Weigel
Atmos. Meas. Tech., 16, 4589–4642, https://doi.org/10.5194/amt-16-4589-2023, https://doi.org/10.5194/amt-16-4589-2023, 2023
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We quantify biases and drifts (and their uncertainties) between the stratospheric water vapor measurement records of 15 satellite-based instruments (SATs, with 31 different retrievals) and balloon-borne frost point hygrometers (FPs) launched at 27 globally distributed stations. These comparisons of measurements during the period 2000–2016 are made using robust, consistent statistical methods. With some exceptions, the biases and drifts determined for most SAT–FP pairs are < 10 % and < 1 % yr−1.
Felix Wrana, Ulrike Niemeier, Larry W. Thomason, Sandra Wallis, and Christian von Savigny
Atmos. Chem. Phys., 23, 9725–9743, https://doi.org/10.5194/acp-23-9725-2023, https://doi.org/10.5194/acp-23-9725-2023, 2023
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The stratospheric aerosol layer is a naturally occurring and permanent layer of aerosol, in this case very small droplets of mostly sulfuric acid and water, that has a cooling effect on our climate. To quantify this effect and for our general understanding of stratospheric microphysical processes, knowledge of the size of those aerosol particles is needed. Using satellite measurements and atmospheric models we show that some volcanic eruptions can lead to on average smaller aerosol sizes.
Ashique Vellalassery, Gerd Baumgarten, Mykhaylo Grygalashvyly, and Franz-Josef Lübken
Ann. Geophys., 41, 289–300, https://doi.org/10.5194/angeo-41-289-2023, https://doi.org/10.5194/angeo-41-289-2023, 2023
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The solar cycle affects the H2O concentration in the upper mesosphere mainly in two ways: directly through photolysis and, at the time and place of NLC formation, indirectly through temperature changes. The H2O–Lyman-α response is modified by NLC formation, resulting in a positive response at the ice formation region (due to the temperature change effect on the ice formation rate) and a negative response at the sublimation zone (due to the photolysis effect).
Sandra Wallis, Hauke Schmidt, and Christian von Savigny
Atmos. Chem. Phys., 23, 7001–7014, https://doi.org/10.5194/acp-23-7001-2023, https://doi.org/10.5194/acp-23-7001-2023, 2023
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Strong volcanic eruptions are able to alter the temperature and the circulation of the middle atmosphere. This study simulates the atmospheric response to an idealized strong tropical eruption and focuses on the impact on the mesosphere. The simulations show a warming of the polar summer mesopause in the first November after the eruption. Our study indicates that this is mainly due to dynamical coupling in the summer hemisphere with a potential contribution from interhemispheric coupling.
Linlu Mei, Vladimir Rozanov, Alexei Rozanov, and John P. Burrows
Geosci. Model Dev., 16, 1511–1536, https://doi.org/10.5194/gmd-16-1511-2023, https://doi.org/10.5194/gmd-16-1511-2023, 2023
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This paper summarizes recent developments of aerosol, cloud and surface reflectance databases and models in the framework of the software package SCIATRAN. These updates and developments extend the capabilities of the radiative transfer modeling, especially by accounting for different kinds of vertical inhomogeneties. Vertically inhomogeneous clouds and different aerosol types can be easily accounted for within SCIATRAN (V4.6). The widely used surface models and databases are now available.
Christian von Savigny, Anna Lange, Anne Hemkendreis, Christoph G. Hoffmann, and Alexei Rozanov
Clim. Past, 18, 2345–2356, https://doi.org/10.5194/cp-18-2345-2022, https://doi.org/10.5194/cp-18-2345-2022, 2022
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This study investigates the possibility of inferring information on aerosol optical depth from photographs of historic paintings. The idea – which has been applied in previous studies – is very interesting because it would provide an archive of the atmospheric aerosol loading covering many centuries. We show that twilight colours depend not only on the aerosol optical thickness, but also on several other parameters, making a quantitative estimate of aerosol optical depth very difficult.
Carlo Arosio, Alexei Rozanov, Victor Gorshelev, Alexandra Laeng, and John P. Burrows
Atmos. Meas. Tech., 15, 5949–5967, https://doi.org/10.5194/amt-15-5949-2022, https://doi.org/10.5194/amt-15-5949-2022, 2022
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This paper characterizes the uncertainties affecting the ozone profiles retrieved at the University of Bremen through OMPS limb satellite observations. An accurate knowledge of the uncertainties is relevant for the validation of the product and to correctly interpret the retrieval results. We investigate several sources of uncertainties, estimate a total random and systematic component, and verify the consistency of the combined OMPS-MLS total uncertainty.
John T. Sullivan, Arnoud Apituley, Nora Mettig, Karin Kreher, K. Emma Knowland, Marc Allaart, Ankie Piters, Michel Van Roozendael, Pepijn Veefkind, Jerry R. Ziemke, Natalya Kramarova, Mark Weber, Alexei Rozanov, Laurence Twigg, Grant Sumnicht, and Thomas J. McGee
Atmos. Chem. Phys., 22, 11137–11153, https://doi.org/10.5194/acp-22-11137-2022, https://doi.org/10.5194/acp-22-11137-2022, 2022
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A TROPOspheric Monitoring Instrument (TROPOMI) validation campaign (TROLIX-19) was held in the Netherlands in September 2019. The research presented here focuses on using ozone lidars from NASA’s Goddard Space Flight Center to better evaluate the characterization of ozone throughout TROLIX-19 as compared to balloon-borne, space-borne and ground-based passive measurements, as well as a global coupled chemistry meteorology model.
Sandra Wallis, Christoph Gregor Hoffmann, and Christian von Savigny
Ann. Geophys., 40, 421–431, https://doi.org/10.5194/angeo-40-421-2022, https://doi.org/10.5194/angeo-40-421-2022, 2022
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Although the 1991 eruption of Mt Pinatubo had a severe impact on Earth's climate, the effect of this event on the mesosphere is not well understood. We investigated satellite-borne temperature measurements from the HALOE instrument and found indications that a positive temperature anomaly is present in the tropical upper mesosphere at the beginning of the HALOE time series, which may be related to the eruption of Mt. Pinatubo.
William G. Read, Gabriele Stiller, Stefan Lossow, Michael Kiefer, Farahnaz Khosrawi, Dale Hurst, Holger Vömel, Karen Rosenlof, Bianca M. Dinelli, Piera Raspollini, Gerald E. Nedoluha, John C. Gille, Yasuko Kasai, Patrick Eriksson, Christopher E. Sioris, Kaley A. Walker, Katja Weigel, John P. Burrows, and Alexei Rozanov
Atmos. Meas. Tech., 15, 3377–3400, https://doi.org/10.5194/amt-15-3377-2022, https://doi.org/10.5194/amt-15-3377-2022, 2022
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This paper attempts to provide an assessment of the accuracy of 21 satellite-based instruments that remotely measure atmospheric humidity in the upper troposphere of the Earth's atmosphere. The instruments made their measurements from 1984 to the present time; however, most of these instruments began operations after 2000, and only a few are still operational. The objective of this study is to quantify the accuracy of each satellite humidity data set.
Nora Mettig, Mark Weber, Alexei Rozanov, John P. Burrows, Pepijn Veefkind, Anne M. Thompson, Ryan M. Stauffer, Thierry Leblanc, Gerard Ancellet, Michael J. Newchurch, Shi Kuang, Rigel Kivi, Matthew B. Tully, Roeland Van Malderen, Ankie Piters, Bogumil Kois, René Stübi, and Pavla Skrivankova
Atmos. Meas. Tech., 15, 2955–2978, https://doi.org/10.5194/amt-15-2955-2022, https://doi.org/10.5194/amt-15-2955-2022, 2022
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Vertical ozone profiles from combined spectral measurements in the UV and IR spectral ranges were retrieved by using data from TROPOMI/S5P and CrIS/Suomi-NPP. The vertical resolution and accuracy of the ozone profiles are improved by combining both wavelength ranges compared to retrievals limited to UV or IR spectral data only. The advancement of our TOPAS algorithm for combined measurements is required because in the UV-only retrieval the vertical resolution in the troposphere is very limited.
Mireia Papke Chica, Valerian Hahn, Tiziana Braeuer, Elena de la Torre Castro, Florian Ewald, Mathias Gergely, Simon Kirschler, Luca Bugliaro Goggia, Stefanie Knobloch, Martina Kraemer, Johannes Lucke, Johanna Mayer, Raphael Maerkl, Manuel Moser, Laura Tomsche, Tina Jurkat-Witschas, Martin Zoeger, Christian von Savigny, and Christiane Voigt
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2022-255, https://doi.org/10.5194/acp-2022-255, 2022
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The mixed-phase temperature regime in convective clouds challenges our understanding of microphysical and radiative cloud properties. We provide a rare and unique dataset of aircraft in situ measurements in a strong mid-latitude convective system. We find that mechanisms initiating ice nucleation and growth strongly depend on temperature, relative humidity, and vertical velocity and variate within the measured system, resulting in altitude dependent changes of the cloud liquid and ice fraction.
Julia Koch, Adam Bourassa, Nick Lloyd, Chris Roth, and Christian von Savigny
Atmos. Chem. Phys., 22, 3191–3202, https://doi.org/10.5194/acp-22-3191-2022, https://doi.org/10.5194/acp-22-3191-2022, 2022
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The mesopause, the region of the earth's atmosphere between 85 and 100 km, is hard to access by direct measurements. Therefore we look for parameters that can be measured using satellite or ground-based measurements. In this study we researched sodium airglow, a phenomenon that occurs when sodium atoms are excited by chemical reactions. We compared satellite measurements of the airglow and resulting sodium concentration profiles to gain a better understanding of the sodium in that region.
Sandip S. Dhomse, Carlo Arosio, Wuhu Feng, Alexei Rozanov, Mark Weber, and Martyn P. Chipperfield
Earth Syst. Sci. Data, 13, 5711–5729, https://doi.org/10.5194/essd-13-5711-2021, https://doi.org/10.5194/essd-13-5711-2021, 2021
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High-quality long-term ozone profile data sets are key to estimating short- and long-term ozone variability. Almost all the satellite (and chemical model) data sets show some kind of bias with respect to each other. This is because of differences in measurement methodologies as well as simplified processes in the models. We use satellite data sets and chemical model output to generate 42 years of ozone profile data sets using a random-forest machine-learning algorithm that is named ML-TOMCAT.
Elizaveta Malinina, Alexei Rozanov, Ulrike Niemeier, Sandra Wallis, Carlo Arosio, Felix Wrana, Claudia Timmreck, Christian von Savigny, and John P. Burrows
Atmos. Chem. Phys., 21, 14871–14891, https://doi.org/10.5194/acp-21-14871-2021, https://doi.org/10.5194/acp-21-14871-2021, 2021
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In the paper, changes in the stratospheric aerosol loading after the 2018 Ambae eruption were analyzed using OMPS-LP observations. The eruption was also simulated with the MAECHAM5-HAM global climate model. Generally, the model and observations agree very well. We attribute the good consistency of the results to a precisely determined altitude and mass of the volcanic injection, as well as nudging of the meteorological data. The radiative forcing from the eruption was estimated to be −0.13 W m−2.
Nora Mettig, Mark Weber, Alexei Rozanov, Carlo Arosio, John P. Burrows, Pepijn Veefkind, Anne M. Thompson, Richard Querel, Thierry Leblanc, Sophie Godin-Beekmann, Rigel Kivi, and Matthew B. Tully
Atmos. Meas. Tech., 14, 6057–6082, https://doi.org/10.5194/amt-14-6057-2021, https://doi.org/10.5194/amt-14-6057-2021, 2021
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TROPOMI is a nadir-viewing satellite that has observed global atmospheric trace gases at unprecedented spatial resolution since 2017. The retrieval of ozone profiles with high accuracy has been demonstrated using the TOPAS (Tikhonov regularised Ozone Profile retrievAl with SCIATRAN) algorithm and applying appropriate spectral corrections to TROPOMI UV data. Ozone profiles from TROPOMI were compared to ozonesonde and lidar profiles, showing an agreement to within 5 % in the stratosphere.
Andrea Orfanoz-Cheuquelaf, Alexei Rozanov, Mark Weber, Carlo Arosio, Annette Ladstätter-Weißenmayer, and John P. Burrows
Atmos. Meas. Tech., 14, 5771–5789, https://doi.org/10.5194/amt-14-5771-2021, https://doi.org/10.5194/amt-14-5771-2021, 2021
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OMPS/NPP (2012–present) allows obtaining the tropospheric ozone column by combining ozone data from limb and nadir observations from the same instrument platform. In a first step, the retrieval of the total ozone column from the OMPS Nadir Mapper using the weighting function fitting approach (WFFA) is described here. The OMPS total ozone was compared with ground-based and other satellite measurements, showing agreement within 2.5 %.
Daniel Zawada, Ghislain Franssens, Robert Loughman, Antti Mikkonen, Alexei Rozanov, Claudia Emde, Adam Bourassa, Seth Dueck, Hannakaisa Lindqvist, Didier Ramon, Vladimir Rozanov, Emmanuel Dekemper, Erkki Kyrölä, John P. Burrows, Didier Fussen, and Doug Degenstein
Atmos. Meas. Tech., 14, 3953–3972, https://doi.org/10.5194/amt-14-3953-2021, https://doi.org/10.5194/amt-14-3953-2021, 2021
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Satellite measurements of atmospheric composition often rely on computer tools known as radiative transfer models to model the propagation of sunlight within the atmosphere. Here we have performed a detailed inter-comparison of seven different radiative transfer models in a variety of conditions. We have found that the models agree remarkably well, at a level better than previously reported. This result provides confidence in our understanding of atmospheric radiative transfer.
Michaela I. Hegglin, Susann Tegtmeier, John Anderson, Adam E. Bourassa, Samuel Brohede, Doug Degenstein, Lucien Froidevaux, Bernd Funke, John Gille, Yasuko Kasai, Erkki T. Kyrölä, Jerry Lumpe, Donal Murtagh, Jessica L. Neu, Kristell Pérot, Ellis E. Remsberg, Alexei Rozanov, Matthew Toohey, Joachim Urban, Thomas von Clarmann, Kaley A. Walker, Hsiang-Jui Wang, Carlo Arosio, Robert Damadeo, Ryan A. Fuller, Gretchen Lingenfelser, Christopher McLinden, Diane Pendlebury, Chris Roth, Niall J. Ryan, Christopher Sioris, Lesley Smith, and Katja Weigel
Earth Syst. Sci. Data, 13, 1855–1903, https://doi.org/10.5194/essd-13-1855-2021, https://doi.org/10.5194/essd-13-1855-2021, 2021
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An overview of the SPARC Data Initiative is presented, to date the most comprehensive assessment of stratospheric composition measurements spanning 1979–2018. Measurements of 26 chemical constituents obtained from an international suite of space-based limb sounders were compiled into vertically resolved, zonal monthly mean time series. The quality and consistency of these gridded datasets are then evaluated using a climatological validation approach and a range of diagnostics.
Nellie Wullenweber, Anna Lange, Alexei Rozanov, and Christian von Savigny
Clim. Past, 17, 969–983, https://doi.org/10.5194/cp-17-969-2021, https://doi.org/10.5194/cp-17-969-2021, 2021
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This study investigates the physical processes leading to the rare phenomenon of the sun appearing blue or green. The phenomenon is caused by anomalous scattering by, e.g., volcanic or forest fire aerosols. Unlike most other studies, our study includes a full treatment of the effect of Rayleigh scattering on the colour of the sun. We investigate different factors and revisit a historic example, i.e. the Canadian forest fires in 1950, that led to blue sun events in different European countries.
Felix Wrana, Christian von Savigny, Jacob Zalach, and Larry W. Thomason
Atmos. Meas. Tech., 14, 2345–2357, https://doi.org/10.5194/amt-14-2345-2021, https://doi.org/10.5194/amt-14-2345-2021, 2021
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In this paper, we describe a new method for calculating the size of naturally occurring droplets (aerosols) made mostly of sulfuric acid and water that can be found roughly at 20 km altitude in the atmosphere. We use data from the instrument SAGE III/ISS that is mounted on the International Space Station. We show that our method works well, and that the size parameters we calculate are reasonable and can be a valuable addition for a better understanding of aerosols and their effect on climate.
Larry W. Thomason, Mahesh Kovilakam, Anja Schmidt, Christian von Savigny, Travis Knepp, and Landon Rieger
Atmos. Chem. Phys., 21, 1143–1158, https://doi.org/10.5194/acp-21-1143-2021, https://doi.org/10.5194/acp-21-1143-2021, 2021
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Measurements of the impact of volcanic eruptions on stratospheric aerosol loading by space-based instruments show show a fairly well-behaved relationship between the magnitude and the apparent changes to aerosol size over several orders of magnitude. This directly measured relationship provides a unique opportunity to verify the performance of interactive aerosol models used in climate models.
Lukas O. Muser, Gholam Ali Hoshyaripour, Julia Bruckert, Ákos Horváth, Elizaveta Malinina, Sandra Wallis, Fred J. Prata, Alexei Rozanov, Christian von Savigny, Heike Vogel, and Bernhard Vogel
Atmos. Chem. Phys., 20, 15015–15036, https://doi.org/10.5194/acp-20-15015-2020, https://doi.org/10.5194/acp-20-15015-2020, 2020
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Volcanic aerosols endanger aircraft and thus disrupt air travel globally. For aviation safety, it is vital to know the location and lifetime of such aerosols in the atmosphere. Here we show that the interaction of volcanic particles with each other eventually reduces their atmospheric lifetime. Moreover, we demonstrate that sunlight heats these particles, which lifts them several kilometers in the atmosphere. These findings support a more reliable forecast of volcanic aerosol dispersion.
Stefan Noël, Klaus Bramstedt, Alexei Rozanov, Elizaveta Malinina, Heinrich Bovensmann, and John P. Burrows
Atmos. Meas. Tech., 13, 5643–5666, https://doi.org/10.5194/amt-13-5643-2020, https://doi.org/10.5194/amt-13-5643-2020, 2020
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A new approach to derive stratospheric aerosol extinction profiles from SCIAMACHY solar occultation measurements based on an onion-peeling method is presented. The resulting extinctions at 452, 525 and 750 nm compare well with other limb and occultation data from, e.g. SAGE and SCIAMACHY, but show small oscillating features which vanish in monthly anomalies. Major volcanic eruptions, polar stratospheric clouds and influences of the quasi-biennial oscillation can be identified in the time series.
Cited articles
Avaste, O. A., Fedynsky, A. V., Grechko, G. M., Sevastyanov, V. I., and Willmann, Ch. I.: Advances in Noctilucent cloud research in the space era, Pure Appl. Geophys., 118, 528–580, 1980. a
Backhouse, T. W.: The luminous cirrus cloud of June and July,
Meteorol. Mag., 20, 133 pp., 1885. a
Baumgarten, G. and Fiedler, J.: Vertical structure of particle properties and water content in noctilucent clouds, Geophys. Res. Lett., 35, L10811, https://doi.org/10.1029/2007GL033084, 2008. a, b, c
Baumgarten, G., Fricke, K. H., and von Cossart, G.: Investigation of the shape of noctilucent cloud particles by polarization lidar technique, Geophys. Res. Lett., 29, 8-1–8-4, https://doi.org/10.1029/2001GL013877, 2002. a
Baumgarten, G., Gerding, M., Kaifler, B., and Müller, N.: A trans-European network of cameras for observation of noctilucent clouds from 37∘ N to 69∘ N, in: Proceedings 19th ESA Symposium on European Rocket and Ballon Programmes and Related Research, Bad Reichenhall, Germany, 7–11 June 2009 (ESA SP-671, September 2009), 2009. a
Baumgarten, G., Fiedler, J., and Rapp, M.: On microphysical processes of noctilucent clouds (NLC): observations and modeling of mean and width of the particle size-distribution, Atmos. Chem. Phys., 10, 6661–6668, https://doi.org/10.5194/acp-10-6661-2010, 2010. a
Billmeyer Jr., F. W. and Fairman, H. S.: CIE Method For Calculating Tristimulus Values, Color Res. Appl., 12, 27–36, https://doi.org/10.1002/col.5080120106, 1987. a
Brainard, D. H. and Stockman, A.: Colorimetry, in: OSA Handbook of Optics, 3rd edn., edited by: Bass, M., McGraw-Hill, New York, 10.1–10.56, ISBN 13 9780071498913, 2010. a
Currie, B. W.: The need for Canadian observations of noctilucent clouds, J. Roy. Astron. Soc. Can., 56, 141–147, 1962. a
Debrestian, D. J., Lumpe, J. D., Shettle, E. P., Bevilacqua, R. M., Olivero, J. J., Hornstein, J. S., Glaccum, W., Rusch, D. W., Randall, C. E., and Fromm, M. D.: An analysis of POAM II solar occultation observations of polar mesospheric clouds in the southern hemisphere, J. Geophys. Res., 102, 1971–1981, 1997. a
Fogle, B.: Recent advances in research on noctilucent clouds, B. Am. Meteorol. Soc., 41, 781–787, 1966. a
Gadsden, M.: The colour of noctilucent clouds, Weather, 30, 190–197, https://doi.org/10.1002/j.1477-8696.1975.tb05292.x, 1975b. a, b, c, d
Grainger, R. G.: Some Useful Formulae for Aerosol Size Distributions and Optical Properties, Earth Observation Data Group, University of Oxford, available at: http://eodg.atm.ox.ac.uk/user/grainger/research/aerosols.pdf (last access: 29 April 2022), 2017. a
Gumbel, J. and Witt, G.: In situ measurements of the vertical structure of a noctilucent cloud, Geophys. Res. Lett., 25, 493–496, https://doi.org/10.1029/98GL00056, 1998. a
Hervig, M. E., Gordley, L. L., Stevens, M. H., Russell, J, M., Bailey, S. M., and Baumgarten, G.: Interpretation of SOFIE PMC measurements: Cloud identification and derivation of mass density, particle shape, and particle size, J. Atmos. Sol.-Terr. Phy., 71, 316–330, 2009. a
Hulburt, E. O.: Explanation of the Brightness and Color of the Sky, Particularly the Twilight Sky, J. Opt. Soc. Am., 43, 113–118, 1953. a
Judd, D. B.: Report of U. S. Secretariat Committee on Colorimetry and Artificial Daylight, in: Proceedings of the Twelfth Session of the CIE, Stockholm, Bureau Central de la CIE, Paris, 1, 11 pp., Paris, Bureau Central de la CIE, 1951. a
Kiliani, J., Baumgarten, G., Lübken, F.-J., and Berger, U.: Impact of particle shape on the morphology of noctilucent clouds, Atmos. Chem. Phys., 15, 12897–12907, https://doi.org/10.5194/acp-15-12897-2015, 2015. a
Leslie, R. C.: Sky glows, Nature, 32, 245 pp., 1885. a
Paton, J.: Noctilucent clouds, Meteorol. Mag., 93, 161–179, 1964. a
Rapp, M. and Thomas, G. E., Modeling the microphysics of mesospheric ice particles: Assessment of current capabilities and basic sensitivities, J. Atmos. Sol.-Terr. Phy., 68, 715–744, https://doi.org/10.1016/j.jastp.2005.10.015, 2006. a
Robert, C. E., von Savigny, C., Burrows, J. P., and Baumgarten, G.: Climatology of noctilucent cloud radii and occurrence frequency using SCIAMACHY, J. Atmos. Sol.-Terr. Phy., 71, 408–423, 2009. a
Sinnhuber, B. M., Weber, M., Amankwah, A., and Burrows, J. P.: Total ozone during the unusual Antarctic winter of 2002, Geophys. Res. Lett., 30, 1580, https://doi.org/10.1029/2002GL016798, 2003.
a
Thomas, G. E.: Mesospheric clouds and the physics of the mesopause region, Rev. Geophys., 29, 553–575, 1991. a
Thomas, G. E.: Climatology of Polar Mesospheric Clouds: Interannual Variability and Implications for Long-Term Trends, in: The Upper Mesosphere and Lower Thermosphere: A Review of Experiment and Theory, edited by: Johnson, R. M. and Killeen, T. L., Geophys. Monogr. Ser., 87, 185–200, https://doi.org/10.1029/GM087p0185, 1995. a
Ugolnikov, O. S., Maslov, I. A., Kozelov, B. V., and Dlugach, J. M.: Noctilucent cloud polarimetry: Twilight measurements in a wide range of scattering angles, Planet. Space Sci., 125, 105–113, 2016. a
von Savigny, C., Petelina, S. V., Karlsson, B., Llewellyn, E. J., Degenstein, D. A., Lloyd, N. D., and Burrows, J. P.: Vertical variation of NLC particle sizes retrieved from Odin/OSIRIS limb scattering observations, Geophys. Res. Lett., 32, L07806, https://doi.org/10.1029/2004GL021982, 2005. a
von Savigny, C., Baumgarten, G., and Lübken, F.-J.: Noctilucent Clouds: General Properties and Remote Sensing, in: Physics and Chemistry of the Arctic Atmosphere, edited by: Kokhanovsky, A. and Tomasi, C., Springer Polar Sciences, Springer, Cham, 469–504, https://doi.org/10.1007/978-3-030-33566-3_8, 2020. a
Vos, J. J.: Colorimetric and photometric properties of a 2-deg fundamental observer, Color Res. Appl., 3, 125–128, 1978. a
Woods, T., Harder, J., and Snow, M.: SORCE Combined XPS, SOLSTICE, and SIM Solar Spectral Irradiance 24-Hour Means V001, Greenbelt, MD, USA, Goddard Earth Sciences Data and Information Services Center (GES DISC) [data set], https://doi.org/10.5067/9PRENS3AL461, 2021 (data available at: http://lasp.colorado.edu/lisird/data/sorce_ssi_l3/, last access: 29 April 2022). a
Wullenweber, N., Lange, A., Rozanov, A., and von Savigny, C.: On the phenomenon of the blue sun, Clim. Past, 17, 969–983, https://doi.org/10.5194/cp-17-969-2021, 2021. a
Short summary
We investigate the influence of different parameters on the colour of noctilucent clouds (highest clouds in the atmosphere), using radiative transfer calculations. We determined the effect of the particle size, optical depth, single scattering/multiple scattering and ozone. For sufficiently large optical depth and for specific viewing geometries, ozone plays only a minor role in the blueish colour of noctilucent clouds (new result).
We investigate the influence of different parameters on the colour of noctilucent clouds...
