Articles | Volume 12, issue 1
https://doi.org/10.5194/amt-12-457-2019
© Author(s) 2019. 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-12-457-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Seasonal and intra-diurnal variability of small-scale gravity waves in OH airglow at two Alpine stations
Patrick Hannawald
CORRESPONDING AUTHOR
University of Augsburg, Institute of Physics, Augsburg, Germany
Carsten Schmidt
German Aerospace Center, German Remote Sensing Data Center, Oberpfaffenhofen, Germany
René Sedlak
University of Augsburg, Institute of Physics, Augsburg, Germany
Sabine Wüst
German Aerospace Center, German Remote Sensing Data Center, Oberpfaffenhofen, Germany
Michael Bittner
University of Augsburg, Institute of Physics, Augsburg, Germany
German Aerospace Center, German Remote Sensing Data Center, Oberpfaffenhofen, Germany
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René Sedlak, Andreas Welscher, Patrick Hannawald, Sabine Wüst, Rainer Lienhart, and Michael Bittner
Atmos. Meas. Tech., 16, 3141–3153, https://doi.org/10.5194/amt-16-3141-2023, https://doi.org/10.5194/amt-16-3141-2023, 2023
Short summary
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We show that machine learning can help in classifying images of the OH* airglow, a thin layer in the middle atmosphere (ca. 86 km height) emitting infrared radiation, in an efficient way. By doing this,
dynamicepisodes of strong movement in the OH* airglow caused predominantly by waves can be extracted automatically from large data sets. Within these dynamic episodes, turbulent wave breaking can also be found. We use these observations of turbulence to derive the energy released by waves.
René Sedlak, Patrick Hannawald, Carsten Schmidt, Sabine Wüst, Michael Bittner, and Samo Stanič
Atmos. Meas. Tech., 14, 6821–6833, https://doi.org/10.5194/amt-14-6821-2021, https://doi.org/10.5194/amt-14-6821-2021, 2021
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High-resolution images of the OH* airglow layer (ca. 87 km height) acquired at Otlica Observatory, Slovenia, have been analysed. A statistical analysis of small-scale wave structures with horizontal wavelengths up to 4.5 km suggests strong presence of instability features in the upper mesosphere or lower thermosphere. The dissipated energy of breaking gravity waves is derived from observations of turbulent vortices. It is concluded that dynamical heating plays a vital role in the atmosphere.
Sabine Wüst, Carsten Schmidt, Patrick Hannawald, Michael Bittner, Martin G. Mlynczak, and James M. Russell III
Atmos. Chem. Phys., 19, 6401–6418, https://doi.org/10.5194/acp-19-6401-2019, https://doi.org/10.5194/acp-19-6401-2019, 2019
Short summary
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In winter 2016, the camera system FAIM derived information about the OH* airglow at ca. 86 km height during six flights on board the research aircraft FALCON in northern Scandinavia. Coincident ground- and satellite-based measurements (GRIPS and TIMED-SABER) complete the data set. The data are analysed with respect to the temporal and spatial evolution of small-scale atmospheric dynamics just before a minor stratospheric warming. Special emphasis is placed on possible instability features.
René Sedlak, Patrick Hannawald, Carsten Schmidt, Sabine Wüst, and Michael Bittner
Atmos. Meas. Tech., 9, 5955–5963, https://doi.org/10.5194/amt-9-5955-2016, https://doi.org/10.5194/amt-9-5955-2016, 2016
Short summary
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In this paper a SWIR airglow imager is presented. It is especially designed for the observation of small-scale gravity waves and turbulence features in the OH airglow layer with a high spatio-temporal resolution of up to 17 m (at mesopause heights) and 2.5 to 2.8 s. Two case studies show small-scale wave structures with horizontal wavelengths of approximately 550 m as well as vortex formation and decomposition of wave fronts, both indicating the onset of turbulence.
Patrick Hannawald, Carsten Schmidt, Sabine Wüst, and Michael Bittner
Atmos. Meas. Tech., 9, 1461–1472, https://doi.org/10.5194/amt-9-1461-2016, https://doi.org/10.5194/amt-9-1461-2016, 2016
Short summary
Short summary
This paper presents a ground-based, short-wave infrared camera system for measurements of the OH airglow originating in the middle atmosphere. The camera has a high temporal and spatial resolution of 0.5 s and 200 m (at 90 km height), which allows for detailed observations of atmospheric waves and other transient phenomena. Details regarding the instrument, calibration and preprocessing are discussed exemplarily for an event of two superposing gravity waves with associated instability structures.
Sabine Wüst, Lisa Küchelbacher, Franziska Trinkl, and Michael Bittner
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2024-18, https://doi.org/10.5194/amt-2024-18, 2024
Revised manuscript under review for AMT
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Information about the energy of gravity waves (GWs) is crucial for improving atmosphere models. Most space-based studies report on the potential energy. We use ADM-Aeolus wind data to derive a lower limit of the kinetic energy density. However, the data quality is a challenge for such analyses, as the accuracy of the data is in the range of typical GW amplitudes. We find a temporal coincidence between enhanced or breaking planetary waves and enhanced gravity wave kinetic energy density.
Stefan Noll, John M. C. Plane, Wuhu Feng, Konstantinos S. Kalogerakis, Wolfgang Kausch, Carsten Schmidt, Michael Bittner, and Stefan Kimeswenger
Atmos. Chem. Phys., 24, 1143–1176, https://doi.org/10.5194/acp-24-1143-2024, https://doi.org/10.5194/acp-24-1143-2024, 2024
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The Earth's nighttime radiation in the range from the near-UV to the near-IR mainly originates between 75 and 105 km and consists of lines of different species, which are important indicators of the chemistry and dynamics at these altitudes. Based on astronomical spectra, we have characterised the structure and variability of a pseudo-continuum of a high number of faint lines and discovered a new emission process in the near-IR. By means of simulations, we identified HO2 as the likely emitter.
Carsten Schmidt, Lisa Küchelbacher, Sabine Wüst, and Michael Bittner
Atmos. Meas. Tech., 16, 4331–4356, https://doi.org/10.5194/amt-16-4331-2023, https://doi.org/10.5194/amt-16-4331-2023, 2023
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Two identical instruments in a parallel setup were used to observe the mesospheric OH airglow for more than 10 years (2009–2020) at 47.42°N, 10.98°E. This allows unique analyses of data quality aspects and their impact on the obtained results. During solar cycle 24 the influence of the sun was strong (∼6 K per 100 sfu). A quasi-2-year oscillation (QBO) of ±1 K is observed mainly during the maximum of the solar cycle. Unlike the stratospheric QBO the variation has a period of or below 24 months.
René Sedlak, Andreas Welscher, Patrick Hannawald, Sabine Wüst, Rainer Lienhart, and Michael Bittner
Atmos. Meas. Tech., 16, 3141–3153, https://doi.org/10.5194/amt-16-3141-2023, https://doi.org/10.5194/amt-16-3141-2023, 2023
Short summary
Short summary
We show that machine learning can help in classifying images of the OH* airglow, a thin layer in the middle atmosphere (ca. 86 km height) emitting infrared radiation, in an efficient way. By doing this,
dynamicepisodes of strong movement in the OH* airglow caused predominantly by waves can be extracted automatically from large data sets. Within these dynamic episodes, turbulent wave breaking can also be found. We use these observations of turbulence to derive the energy released by waves.
Sabine Wüst, Michael Bittner, Patrick J. Espy, W. John R. French, and Frank J. Mulligan
Atmos. Chem. Phys., 23, 1599–1618, https://doi.org/10.5194/acp-23-1599-2023, https://doi.org/10.5194/acp-23-1599-2023, 2023
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Ground-based OH* airglow measurements have been carried out for almost 100 years. Advanced detector technology has greatly simplified the automatic operation of OH* airglow observing instruments and significantly improved the temporal and/or spatial resolution. Studies based on long-term measurements or including a network of instruments are reviewed, especially in the context of deriving gravity wave properties. Scientific and technical challenges for the next few years are described.
René Sedlak, Patrick Hannawald, Carsten Schmidt, Sabine Wüst, Michael Bittner, and Samo Stanič
Atmos. Meas. Tech., 14, 6821–6833, https://doi.org/10.5194/amt-14-6821-2021, https://doi.org/10.5194/amt-14-6821-2021, 2021
Short summary
Short summary
High-resolution images of the OH* airglow layer (ca. 87 km height) acquired at Otlica Observatory, Slovenia, have been analysed. A statistical analysis of small-scale wave structures with horizontal wavelengths up to 4.5 km suggests strong presence of instability features in the upper mesosphere or lower thermosphere. The dissipated energy of breaking gravity waves is derived from observations of turbulent vortices. It is concluded that dynamical heating plays a vital role in the atmosphere.
Sabine Wüst, Michael Bittner, Jeng-Hwa Yee, Martin G. Mlynczak, and James M. Russell III
Atmos. Meas. Tech., 13, 6067–6093, https://doi.org/10.5194/amt-13-6067-2020, https://doi.org/10.5194/amt-13-6067-2020, 2020
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With airglow spectrometers, the temperature in the upper mesosphere/lower thermosphere can be derived each night. The data allow to estimate the amount of energy which is transported by small-scale atmospheric waves, known as gravity waves. In order to do this, information about the Brunt–Väisälä frequency and its evolution during the year is necessary. This is provided here for low and midlatitudes based on 18 years of satellite data.
René Sedlak, Alexandra Zuhr, Carsten Schmidt, Sabine Wüst, Michael Bittner, Goderdzi G. Didebulidze, and Colin Price
Atmos. Meas. Tech., 13, 5117–5128, https://doi.org/10.5194/amt-13-5117-2020, https://doi.org/10.5194/amt-13-5117-2020, 2020
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Gravity wave (GW) activity in the UMLT in the period range 6-480 min is calculated by applying a wavelet analysis to nocturnal temperature time series derived from OH* airglow spectrometers. We analyse measurements from eight different locations at different latitudes.
GW activity shows strong period dependence. We find hardly any seasonal variability for periods below 60 min and a semi-annual cycle for periods longer than 60 min that evolves into an annual cycle around a period of 200 min.
Sabine Wüst, Carsten Schmidt, Patrick Hannawald, Michael Bittner, Martin G. Mlynczak, and James M. Russell III
Atmos. Chem. Phys., 19, 6401–6418, https://doi.org/10.5194/acp-19-6401-2019, https://doi.org/10.5194/acp-19-6401-2019, 2019
Short summary
Short summary
In winter 2016, the camera system FAIM derived information about the OH* airglow at ca. 86 km height during six flights on board the research aircraft FALCON in northern Scandinavia. Coincident ground- and satellite-based measurements (GRIPS and TIMED-SABER) complete the data set. The data are analysed with respect to the temporal and spatial evolution of small-scale atmospheric dynamics just before a minor stratospheric warming. Special emphasis is placed on possible instability features.
Sabine Wüst, Thomas Offenwanger, Carsten Schmidt, Michael Bittner, Christoph Jacobi, Gunter Stober, Jeng-Hwa Yee, Martin G. Mlynczak, and James M. Russell III
Atmos. Meas. Tech., 11, 2937–2947, https://doi.org/10.5194/amt-11-2937-2018, https://doi.org/10.5194/amt-11-2937-2018, 2018
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OH*-spectrometer measurements allow the analysis of gravity wave ground-based periods, but spatial information cannot necessarily be deduced. We combine the approach of Wachter at al. (2015) in order to derive horizontal wavelengths (but based on only one OH* spectrometer) with additional information about wind and temperature and compute vertical wavelengths. Knowledge of these parameters is a precondition for the calculation of further information such as the wave group velocity.
Sabine Wüst, Michael Bittner, Jeng-Hwa Yee, Martin G. Mlynczak, and James M. Russell III
Atmos. Meas. Tech., 10, 4895–4903, https://doi.org/10.5194/amt-10-4895-2017, https://doi.org/10.5194/amt-10-4895-2017, 2017
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In the Alpine region, the most dense subnetwork of identical NDMC (Network for the Detection of Mesospheric Change) instruments can be found. With these instruments the mesopause temperature is derived each night. The data can be used for the investigation of the amount of energy which is transported by small-scale atmospheric waves, known as gravity waves, provided that the so-called Brunt–Väisälä frequency is known. Information about the variability of this parameter is provided here.
Sabine Wüst, Verena Wendt, Ricarda Linz, and Michael Bittner
Atmos. Meas. Tech., 10, 3453–3462, https://doi.org/10.5194/amt-10-3453-2017, https://doi.org/10.5194/amt-10-3453-2017, 2017
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Cubic splines with equidistant spline sampling points are a common method in atmospheric science for the approximation of background conditions by means of filtering superimposed fluctuations from a data series. However, splines can generate considerable artificial oscillations in the background and the residuals. We introduce a repeating spline approach which is able to significantly reduce this phenomenon and to apply it to TIMED-SABER vertical temperature profiles from 2010 to 2014.
René Sedlak, Patrick Hannawald, Carsten Schmidt, Sabine Wüst, and Michael Bittner
Atmos. Meas. Tech., 9, 5955–5963, https://doi.org/10.5194/amt-9-5955-2016, https://doi.org/10.5194/amt-9-5955-2016, 2016
Short summary
Short summary
In this paper a SWIR airglow imager is presented. It is especially designed for the observation of small-scale gravity waves and turbulence features in the OH airglow layer with a high spatio-temporal resolution of up to 17 m (at mesopause heights) and 2.5 to 2.8 s. Two case studies show small-scale wave structures with horizontal wavelengths of approximately 550 m as well as vortex formation and decomposition of wave fronts, both indicating the onset of turbulence.
Patrick Hannawald, Carsten Schmidt, Sabine Wüst, and Michael Bittner
Atmos. Meas. Tech., 9, 1461–1472, https://doi.org/10.5194/amt-9-1461-2016, https://doi.org/10.5194/amt-9-1461-2016, 2016
Short summary
Short summary
This paper presents a ground-based, short-wave infrared camera system for measurements of the OH airglow originating in the middle atmosphere. The camera has a high temporal and spatial resolution of 0.5 s and 200 m (at 90 km height), which allows for detailed observations of atmospheric waves and other transient phenomena. Details regarding the instrument, calibration and preprocessing are discussed exemplarily for an event of two superposing gravity waves with associated instability structures.
Related subject area
Subject: Others (Wind, Precipitation, Temperature, etc.) | Technique: Remote Sensing | Topic: Data Processing and Information Retrieval
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Atmos. Meas. Tech., 17, 6603–6624, https://doi.org/10.5194/amt-17-6603-2024, https://doi.org/10.5194/amt-17-6603-2024, 2024
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Atmos. Meas. Tech., 17, 6301–6314, https://doi.org/10.5194/amt-17-6301-2024, https://doi.org/10.5194/amt-17-6301-2024, 2024
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The paper presents a comprehensive approach to improve the geolocation accuracy of spaceborne radar and lidar systems, crucial for the successful interpretation of data from the upcoming EarthCARE mission. The paper details the technical background of the presented methods and various examples of geolocation analyses, including a short period of CloudSat observations when the star tracker was not operating properly and lifetime statistics from the CloudSat and CALIPSO missions.
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Atmos. Meas. Tech., 17, 6223–6245, https://doi.org/10.5194/amt-17-6223-2024, https://doi.org/10.5194/amt-17-6223-2024, 2024
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Atmos. Meas. Tech., 17, 6025–6046, https://doi.org/10.5194/amt-17-6025-2024, https://doi.org/10.5194/amt-17-6025-2024, 2024
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Atmos. Meas. Tech., 17, 5601–5618, https://doi.org/10.5194/amt-17-5601-2024, https://doi.org/10.5194/amt-17-5601-2024, 2024
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Daniel Durbin, Yadong Wang, and Pao-Liang Chang
Atmos. Meas. Tech., 17, 5397–5411, https://doi.org/10.5194/amt-17-5397-2024, https://doi.org/10.5194/amt-17-5397-2024, 2024
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Witali Krochin, Axel Murk, and Gunter Stober
Atmos. Meas. Tech., 17, 5015–5028, https://doi.org/10.5194/amt-17-5015-2024, https://doi.org/10.5194/amt-17-5015-2024, 2024
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Matteo Ottaviani, Gabriel Harris Myers, and Nan Chen
Atmos. Meas. Tech., 17, 4737–4756, https://doi.org/10.5194/amt-17-4737-2024, https://doi.org/10.5194/amt-17-4737-2024, 2024
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We analyze simulated polarization observations over snow to investigate the capabilities of remote sensing to determine surface and atmospheric properties in snow-covered regions. Polarization measurements are demonstrated to aid in the determination of snow grain shape, ice crystal roughness, and the vertical distribution of impurities in the snow–atmosphere system, data that are critical for estimating snow albedo for use in climate models.
Yudong Gao, Lidou Huyan, Zheng Wu, and Bojun Liu
Atmos. Meas. Tech., 17, 4675–4686, https://doi.org/10.5194/amt-17-4675-2024, https://doi.org/10.5194/amt-17-4675-2024, 2024
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A symmetric error model built by symmetric rain rates handles the non-Gaussian error structure of the reflectivity error. The accuracy and linearization of rain rates can further improve the Gaussianity.
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Atmos. Meas. Tech., 17, 4687–4694, https://doi.org/10.5194/amt-17-4687-2024, https://doi.org/10.5194/amt-17-4687-2024, 2024
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We study how the spectral characteristics of a solid-state laser in an atmospheric temperature profiling lidar using the Raman technique impact the temperature retrieval accuracy. We find that the spectral widening, with respect to a seeded laser, has virtually no impact, while crystal-rod temperature variations in the laser must be kept within a range of 1 K for the uncertainty in the atmospheric temperature below 1 K. The study is carried out through spectroscopy simulations.
Robert Reichert, Natalie Kaifler, and Bernd Kaifler
Atmos. Meas. Tech., 17, 4659–4673, https://doi.org/10.5194/amt-17-4659-2024, https://doi.org/10.5194/amt-17-4659-2024, 2024
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Imagine you want to determine how quickly the pitch of a passing ambulance’s siren changes. If the vehicle is traveling slowly, the pitch changes only slightly, but if it is traveling fast, the pitch also changes rapidly. In a similar way, the wind in the middle atmosphere modulates the wavelength of atmospheric gravity waves. We have investigated the question of how strong the maximum wind may be so that the change in wavelength can still be determined with the help of wavelet transformation.
Qiang Guo, Yuning Liu, Xin Wang, and Wen Hui
Atmos. Meas. Tech., 17, 4613–4627, https://doi.org/10.5194/amt-17-4613-2024, https://doi.org/10.5194/amt-17-4613-2024, 2024
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Non-linearity (NL) correction is a critical procedure to guarantee that the calibration accuracy of a spaceborne sensor approaches a reasonable level. Different from the classical method, a new NL correction method for a spaceborne Fourier transform spectrometer is proposed. To overcome the inaccurate linear coefficient from two-point calibration influencing NL correction, an iteration algorithm is established that is suitable for NL correction of both infrared and microwave sensors.
Yuanxin Pan, Grzegorz Kłopotek, Laura Crocetti, Rudi Weinacker, Tobias Sturn, Linda See, Galina Dick, Gregor Möller, Markus Rothacher, Ian McCallum, Vicente Navarro, and Benedikt Soja
Atmos. Meas. Tech., 17, 4303–4316, https://doi.org/10.5194/amt-17-4303-2024, https://doi.org/10.5194/amt-17-4303-2024, 2024
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Crowdsourced smartphone GNSS data were processed with a dedicated data processing pipeline and could produce millimeter-level accurate estimates of zenith total delay (ZTD) – a critical atmospheric variable. This breakthrough not only demonstrates the feasibility of using ubiquitous devices for high-precision atmospheric monitoring but also underscores the potential for a global, cost-effective tropospheric monitoring network.
Almudena Velázquez Blázquez, Edward Baudrez, Nicolas Clerbaux, and Carlos Domenech
Atmos. Meas. Tech., 17, 4245–4256, https://doi.org/10.5194/amt-17-4245-2024, https://doi.org/10.5194/amt-17-4245-2024, 2024
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The Broadband Radiometer measures shortwave and total-wave radiances filtered by the spectral response of the instrument. To obtain unfiltered solar and thermal radiances, the effect of the spectral response needs to be corrected for, done within the BM-RAD processor. Errors in the unfiltering are propagated into fluxes; thus, accurate unfiltering is required for their proper estimation (within BMA-FLX). Unfiltering errors are estimated to be <0.5 % for the shortwave and <0.1 % for the longwave.
Qihou Zhou, Yanlin Li, and Yun Gong
Atmos. Meas. Tech., 17, 4197–4209, https://doi.org/10.5194/amt-17-4197-2024, https://doi.org/10.5194/amt-17-4197-2024, 2024
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We discuss several robust estimators to compute the variance of a normally distributed random variable to deal with interference. Compared to rank-based estimators, the methods based on the geometric mean are more accurate and are computationally more efficient. We apply three robust estimators to incoherent scatter power and velocity processing, along with the traditional sample mean estimator. The best estimator is a hybrid estimator that combines the sample mean and a robust estimator.
Zhao Shi, Yuxiang Wen, and Jianxin He
Atmos. Meas. Tech., 17, 4121–4135, https://doi.org/10.5194/amt-17-4121-2024, https://doi.org/10.5194/amt-17-4121-2024, 2024
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The squall line is a type of convective system. Squall lines are often associated with damaging weather, so identifying and tracking squall lines plays an important role in early meteorological disaster warnings. A clustering-based method is proposed in this article. It can identify the squall lines within the radar scanning range with an accuracy rate of 95.93 %. It can also provide the three-dimensional structure and movement tracking results for each squall line.
Elizabeth N. Smith and Jacob T. Carlin
Atmos. Meas. Tech., 17, 4087–4107, https://doi.org/10.5194/amt-17-4087-2024, https://doi.org/10.5194/amt-17-4087-2024, 2024
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Boundary-layer height observations remain sparse in time and space. In this study we create a new fuzzy logic method for synergistically combining boundary-layer height estimates from a suite of instruments. These estimates generally compare well to those from radiosondes; plus, the approach offers near-continuous estimates through the entire diurnal cycle. Suspected reasons for discrepancies are discussed. The code for the newly presented fuzzy logic method is provided for the community to use.
Lev D. Labzovskii, Gerd-Jan van Zadelhoff, David P. Donovan, Jos de Kloe, L. Gijsbert Tilstra, Ad Stoffelen, Damien Josset, and Piet Stammes
EGUsphere, https://doi.org/10.5194/egusphere-2024-1926, https://doi.org/10.5194/egusphere-2024-1926, 2024
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The Atmospheric Laser Doppler Instrument (ALADIN) on the Aeolus satellite was the first of its kind to measure high-resolution vertical profiles of aerosols and cloud properties from space. We present an algorithm, producing Aeolus lidar surface returns (LSR) containing useful information for measuring UV reflectivity. Aeolus LSR matched well with existing UV reflectivity data from other satellites like GOME-2 and TROPOMI and demonstrated excellent sensitivity to modelled snow cover.
Laura Bianco, Bianca Adler, Ludovic Bariteau, Irina V. Djalalova, Timothy Myers, Sergio Pezoa, David D. Turner, and James M. Wilczak
Atmos. Meas. Tech., 17, 3933–3948, https://doi.org/10.5194/amt-17-3933-2024, https://doi.org/10.5194/amt-17-3933-2024, 2024
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The Tropospheric Remotely Observed Profiling via Optimal Estimation physical retrieval is used to retrieve temperature and humidity profiles from various combinations of passive and active remote sensing instruments, surface platforms, and numerical weather prediction models. The retrieved profiles are assessed against collocated radiosonde in non-cloudy conditions to assess the sensitivity of the retrievals to different input combinations. Case studies with cloudy conditions are also inspected.
Björn Linder, Peter Preusse, Qiuyu Chen, Ole Martin Christensen, Lukas Krasauskas, Linda Megner, Manfred Ern, and Jörg Gumbel
Atmos. Meas. Tech., 17, 3829–3841, https://doi.org/10.5194/amt-17-3829-2024, https://doi.org/10.5194/amt-17-3829-2024, 2024
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The Swedish research satellite MATS (Mesospheric Airglow/Aerosol Tomography and Spectroscopy) is designed to study atmospheric waves in the mesosphere and lower thermosphere. These waves perturb the temperature field, and thus, by observing three-dimensional temperature fluctuations, their properties can be quantified. This pre-study uses synthetic MATS data generated from a general circulation model to investigate how well wave properties can be retrieved.
Gia Huan Pham, Shu-Chih Yang, Chih-Chien Chang, Shu-Ya Chen, and Cheng Yung Huang
Atmos. Meas. Tech., 17, 3605–3623, https://doi.org/10.5194/amt-17-3605-2024, https://doi.org/10.5194/amt-17-3605-2024, 2024
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This research examines the characteristics of low-level GNSS radio occultation (RO) refractivity bias over ocean and land and its dependency on the RO retrieval uncertainty, atmospheric temperature, and moisture. We propose methods for estimating the region-dependent refractivity bias. Our methods can be applied to calibrate the refractivity bias under different atmospheric conditions and thus improve the applications of the GNSS RO data in the deep troposphere.
Sanja Dmitrovic, Johnathan W. Hair, Brian L. Collister, Ewan Crosbie, Marta A. Fenn, Richard A. Ferrare, David B. Harper, Chris A. Hostetler, Yongxiang Hu, John A. Reagan, Claire E. Robinson, Shane T. Seaman, Taylor J. Shingler, Kenneth L. Thornhill, Holger Vömel, Xubin Zeng, and Armin Sorooshian
Atmos. Meas. Tech., 17, 3515–3532, https://doi.org/10.5194/amt-17-3515-2024, https://doi.org/10.5194/amt-17-3515-2024, 2024
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This study introduces and evaluates a new ocean surface wind speed product from the NASA Langley Research Center (LARC) airborne High-Spectral-Resolution Lidar – Generation 2 (HSRL-2) during the NASA ACTIVATE mission. We show that HSRL-2 surface wind speed data are accurate when compared to ground-truth dropsonde measurements. Therefore, the HSRL-2 instrument is able obtain accurate, high-resolution surface wind speed data in airborne field campaigns.
Almudena Velázquez Blázquez, Carlos Domenech, Edward Baudrez, Nicolas Clerbaux, Carla Salas Molar, and Nils Madenach
EGUsphere, https://doi.org/10.5194/egusphere-2024-1539, https://doi.org/10.5194/egusphere-2024-1539, 2024
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This paper focuses on the BMA-FLX processor, in which thermal and solar top-of-atmosphere radiative fluxes are obtained from longwave and shortwave radiances measured along-track by the EarthCARE Broadband Radiometer (BBR). The BBR measurements, at three fixed viewing angles (fore, nadir, aft) are co-registered either at the surface or at a reference level. A combined flux from the three BRR views is obtained. The algorithm has been successfully validated against test scenes.
Laura M. Tomkins, Sandra E. Yuter, and Matthew A. Miller
Atmos. Meas. Tech., 17, 3377–3399, https://doi.org/10.5194/amt-17-3377-2024, https://doi.org/10.5194/amt-17-3377-2024, 2024
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We have created a new method to better identify enhanced features in radar data from winter storms. Unlike the clear-cut features seen in warm-season storms, features in winter storms are often fuzzier with softer edges. Our technique is unique because it uses two adaptive thresholds that change based on the background radar values. It can identify both strong and subtle features in the radar data and takes into account uncertainties in the detection process.
Eileen Päschke and Carola Detring
Atmos. Meas. Tech., 17, 3187–3217, https://doi.org/10.5194/amt-17-3187-2024, https://doi.org/10.5194/amt-17-3187-2024, 2024
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Little noise in radial velocity Doppler lidar measurements can contribute to large errors in retrieved turbulence variables. In order to distinguish between plausible and erroneous measurements we developed new filter techniques that work independently of the choice of a specific threshold for the signal-to-noise ratio. The performance of these techniques is discussed both by means of assessing the filter results and by comparing retrieved turbulence variables versus independent measurements.
Lei Liu, Natalia Bliankinshtein, Yi Huang, John R. Gyakum, Philip M. Gabriel, Shiqi Xu, and Mengistu Wolde
EGUsphere, https://doi.org/10.5194/egusphere-2024-1045, https://doi.org/10.5194/egusphere-2024-1045, 2024
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This study evaluates and compares a new microwave hyperspectrometer with an infrared hyperspectrometer for clear-sky temperature and water vapor retrievals. The analysis reveals that the information content of the infrared hyperspectrometer exceeds that of the microwave hyperspectrometer and provides higher vertical resolution in ground-based zenith measurements. Leveraging the ground-airborne synergy between the two instruments yielded optimal-sounding results.
Luuk D. van der Valk, Miriam Coenders-Gerrits, Rolf W. Hut, Aart Overeem, Bas Walraven, and Remko Uijlenhoet
Atmos. Meas. Tech., 17, 2811–2832, https://doi.org/10.5194/amt-17-2811-2024, https://doi.org/10.5194/amt-17-2811-2024, 2024
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Microwave links, often part of mobile phone networks, can be used to measure rainfall along the link path by determining the signal loss caused by rainfall. We use high-frequency data of multiple microwave links to recreate commonly used sampling strategies. For time intervals up to 1 min, the influence of sampling strategies on estimated rainfall intensities is relatively little, while for intervals longer than 5–15 min, the sampling strategy can have significant influences on the estimates.
Martin Lainer, Killian P. Brennan, Alessandro Hering, Jérôme Kopp, Samuel Monhart, Daniel Wolfensberger, and Urs Germann
Atmos. Meas. Tech., 17, 2539–2557, https://doi.org/10.5194/amt-17-2539-2024, https://doi.org/10.5194/amt-17-2539-2024, 2024
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This study uses deep learning (the Mask R-CNN model) on drone-based photogrammetric data of hail on the ground to estimate hail size distributions (HSDs). Traditional hail sensors' limited areas complicate the full HSD retrieval. The HSD of a supercell event on 20 June 2021 is retrieved and contains > 18 000 hailstones. The HSD is compared to automatic hail sensor measurements and those of weather-radar-based MESHS. Investigations into ground hail melting are performed by five drone flights.
Andreas Foth, Moritz Lochmann, Pablo Saavedra Garfias, and Heike Kalesse-Los
EGUsphere, https://doi.org/10.5194/egusphere-2024-919, https://doi.org/10.5194/egusphere-2024-919, 2024
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Microwave radiometers are usually not able to provide atmospheric quantities such as temperature profiles during rain. Here, we present a method based on a selection of specific frequencies and elevation angles from the microwave radiometer observation. A comparison with a numerical weather prediction model shows that the presented method allows to resolve temperature profiles during rain with rain rates up to 2 mm h−1 which was not possible before with state-of-the-art retrievals.
Andrea Camplani, Daniele Casella, Paolo Sanò, and Giulia Panegrossi
Atmos. Meas. Tech., 17, 2195–2217, https://doi.org/10.5194/amt-17-2195-2024, https://doi.org/10.5194/amt-17-2195-2024, 2024
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The paper describes a new machine-learning-based snowfall retrieval algorithm for Advanced Technology Microwave Sounder observations developed to retrieve high-latitude snowfall events. The main novelty of the approach is the radiometric characterization of the background surface at the time of the overpass, which is ancillary to the retrieval process. The algorithm shows a unique capability to retrieve snowfall in the environmental conditions typical of high latitudes.
Lusheng Liang, Wenying Su, Sergio Sejas, Zachary Eitzen, and Norman G. Loeb
Atmos. Meas. Tech., 17, 2147–2163, https://doi.org/10.5194/amt-17-2147-2024, https://doi.org/10.5194/amt-17-2147-2024, 2024
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This paper describes an updated process to obtain unfiltered radiation from CERES satellite instruments by incorporating the most recent developments in radiative transfer modeling and ancillary input datasets (e.g., realistic representation of land surface radiation and climatology of surface temperatures and aerosols) during the past 20 years. The resulting global mean of instantaneous SW and LW fluxes is changed by less than 0.5 W m−2 with regional differences as large as 2.0 W m−2.
Maximilian Graf, Andreas Wagner, Julius Polz, Llorenç Lliso, José Alberto Lahuerta, Harald Kunstmann, and Christian Chwala
Atmos. Meas. Tech., 17, 2165–2182, https://doi.org/10.5194/amt-17-2165-2024, https://doi.org/10.5194/amt-17-2165-2024, 2024
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Commercial microwave links (CMLs) can be used for rainfall retrieval. The detection of rainy periods in their attenuation time series is a crucial processing step. We investigate the usage of rainfall data from MSG SEVIRI for this task, compare this approach with existing methods, and introduce a novel combined approach. The results show certain advantages for SEVIRI-based methods, particularly for CMLs where existing methods perform poorly. Our novel combination yields the best performance.
Lieuwe G. Tilstra, Martin de Graaf, Victor J. H. Trees, Pavel Litvinov, Oleg Dubovik, and Piet Stammes
Atmos. Meas. Tech., 17, 2235–2256, https://doi.org/10.5194/amt-17-2235-2024, https://doi.org/10.5194/amt-17-2235-2024, 2024
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This paper introduces a new surface albedo climatology of directionally dependent Lambertian-equivalent reflectivity (DLER) observed by TROPOMI on the Sentinel-5 Precursor satellite. The database contains monthly fields of DLER for 21 wavelength bands at a relatively high spatial resolution of 0.125 by 0.125 degrees. The anisotropy of the surface reflection is handled by parameterisation of the viewing angle dependence.
Bing Cao and Alan Z. Liu
Atmos. Meas. Tech., 17, 2123–2146, https://doi.org/10.5194/amt-17-2123-2024, https://doi.org/10.5194/amt-17-2123-2024, 2024
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A narrow-band sodium lidar measures atmospheric waves but is limited to vertical variations. We propose to utilize phase shifts among observations from different laser beams to derive horizontal wave information. Two gravity wave packets were identified by this method. Both waves were found to interact with thin evanescent layers, partially reflected, but transmitted energy to higher altitudes. The method can detect more medium-frequency gravity waves for similar lidar systems worldwide.
Thomas Hocking, Thorsten Mauritsen, and Linda Megner
EGUsphere, https://doi.org/10.5194/egusphere-2024-356, https://doi.org/10.5194/egusphere-2024-356, 2024
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The imbalance between the energy the Earth absorbs from the Sun and the energy the Earth emits back to space gives rise to climate change, but measuring the small imbalance is challenging. We simulate satellites in various orbits to investigate how well they sample the imbalance, and find that the best option is to combine at least two satellites that see complementary parts of the Earth and cover the daily and annual cycles. This information is useful when planning future satellite missions.
Xiaozhen Xiong, Xu Liu, Robert Spurr, Ming Zhao, Qiguang Yang, Wan Wu, and Liqiao Lei
Atmos. Meas. Tech., 17, 1965–1978, https://doi.org/10.5194/amt-17-1965-2024, https://doi.org/10.5194/amt-17-1965-2024, 2024
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The term “hotspot” refers to the sharp increase in reflectance occurring when incident (solar) and reflected (viewing) directions coincide in the backscatter direction. The accurate simulation of hotspot directional signatures is important for many remote sensing applications, but current models typically require large values of computations to represent the hotspot accurately. This paper provides a numerically improved hotspot BRDF model that converges much faster and is used in VLIDORT.
Daniel Zawada, Kimberlee Dubé, Taran Warnock, Adam Bourassa, Susann Tegtmeier, and Douglas Degenstein
Atmos. Meas. Tech., 17, 1995–2010, https://doi.org/10.5194/amt-17-1995-2024, https://doi.org/10.5194/amt-17-1995-2024, 2024
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There remain large uncertainties in long-term changes of stratospheric–atmospheric temperatures. We have produced a time series of more than 20 years of satellite-based temperature measurements from the OSIRIS instrument in the upper–middle stratosphere. The dataset is publicly available and intended to be used for a better understanding of changes in stratospheric temperatures.
Natalie E. Theeuwes, Janet F. Barlow, Antti Mannisenaho, Denise Hertwig, Ewan O'Connor, and Alan Robins
EGUsphere, https://doi.org/10.5194/egusphere-2024-937, https://doi.org/10.5194/egusphere-2024-937, 2024
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A doppler lidar was placed in highly built-up area in London to measure wakes from tall buildings during a period of one year. We were able to detect wakes and assess their dependence on wind speed, wind direction, and atmospheric stability.
Alban Philibert, Marie Lothon, Julien Amestoy, Pierre-Yves Meslin, Solène Derrien, Yannick Bezombes, Bernard Campistron, Fabienne Lohou, Antoine Vial, Guylaine Canut-Rocafort, Joachim Reuder, and Jennifer K. Brooke
Atmos. Meas. Tech., 17, 1679–1701, https://doi.org/10.5194/amt-17-1679-2024, https://doi.org/10.5194/amt-17-1679-2024, 2024
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We present a new algorithm, CALOTRITON, for the retrieval of the convective boundary layer depth with ultra-high-frequency radar measurements. CALOTRITON is partly based on the principle that the top of the convective boundary layer is associated with an inversion and a decrease in turbulence. It is evaluated using ceilometer and radiosonde data. It is able to qualify the complexity of the vertical structure of the low troposphere and detect internal or residual layers.
Kamil Mroz, Alessandro Battaglia, and Ann M. Fridlind
Atmos. Meas. Tech., 17, 1577–1597, https://doi.org/10.5194/amt-17-1577-2024, https://doi.org/10.5194/amt-17-1577-2024, 2024
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In this study, we examine the extent to which radar measurements from space can inform us about the properties of clouds and precipitation. Surprisingly, our analysis showed that the amount of ice turning into rain was lower than expected in the current product. To improve on this, we came up with a new way to extract information about the size and concentration of particles from radar data. As long as we use this method in the right conditions, we can even estimate how dense the ice is.
Wolf Knöller, Gholamhossein Bagheri, Philipp von Olshausen, and Michael Wilczek
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2023-184, https://doi.org/10.5194/amt-2023-184, 2024
Revised manuscript accepted for AMT
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Three-dimensional (3D) wind velocity measurements are of major importance for the characterization of atmospheric turbulence. This paper presents a detailed study of the measurement uncertainty of a three-beam wind-LiDAR designed for mounting on airborne platforms. Considering the geometrical constraints, the analysis provides quantitative estimates for the measurement uncertainty of all components of the 3D wind vector. As a result, we propose an optimized post-processing for error reduction.
Volker Wulfmeyer, Christoph Senff, Florian Späth, Andreas Behrendt, Diego Lange, Robert M. Banta, W. Alan Brewer, Andreas Wieser, and David D. Turner
Atmos. Meas. Tech., 17, 1175–1196, https://doi.org/10.5194/amt-17-1175-2024, https://doi.org/10.5194/amt-17-1175-2024, 2024
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A simultaneous deployment of Doppler, temperature, and water-vapor lidar systems is used to provide profiles of molecular destruction rates and turbulent kinetic energy (TKE) dissipation in the convective boundary layer (CBL). The results can be used for the parameterization of turbulent variables, TKE budget analyses, and the verification of weather forecast and climate models.
Daisuke Hotta, Katrin Lonitz, and Sean Healy
Atmos. Meas. Tech., 17, 1075–1089, https://doi.org/10.5194/amt-17-1075-2024, https://doi.org/10.5194/amt-17-1075-2024, 2024
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Global Navigation Satellite System (GNSS) polarimetric radio occultation (PRO) is a new type of GNSS observations that can detect heavy precipitation along the ray path between the emitter and receiver satellites. As a first step towards using these observations in numerical weather prediction (NWP), we developed a computer code that simulates GNSS-PRO observations from forecast fields produced by an NWP model. The quality of the developed simulator is evaluated with a number of case studies.
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.
Kuo-Nung Wang, Chi O. Ao, Mary G. Morris, George A. Hajj, Marcin J. Kurowski, Francis J. Turk, and Angelyn W. Moore
Atmos. Meas. Tech., 17, 583–599, https://doi.org/10.5194/amt-17-583-2024, https://doi.org/10.5194/amt-17-583-2024, 2024
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In this article, we described a joint retrieval approach combining two techniques, RO and MWR, to obtain high vertical resolution and solve for temperature and moisture independently. The results show that the complicated structure in the lower troposphere can be better resolved with much smaller biases, and the RO+MWR combination is the most stable scenario in our sensitivity analysis. This approach is also applied to real data (COSMIC-2/Suomi-NPP) to show the promise of joint RO+MWR retrieval.
Filippo Emilio Scarsi, Alessandro Battaglia, Frederic Tridon, Paolo Martire, Ranvir Dhillon, and Anthony Illingworth
Atmos. Meas. Tech., 17, 499–514, https://doi.org/10.5194/amt-17-499-2024, https://doi.org/10.5194/amt-17-499-2024, 2024
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The WIVERN mission, one of the two candidates to be the ESA's Earth Explorer 11 mission, aims at providing measurements of horizontal winds in cloud and precipitation systems through a conically scanning W-band Doppler radar. This work discusses four methods that can be used to characterize and correct the Doppler velocity error induced by the antenna mispointing. The proposed methodologies can be extended to other Doppler concepts featuring conically scanning or slant viewing Doppler systems.
Luis Ackermann, Joshua Soderholm, Alain Protat, Rhys Whitley, Lisa Ye, and Nina Ridder
Atmos. Meas. Tech., 17, 407–422, https://doi.org/10.5194/amt-17-407-2024, https://doi.org/10.5194/amt-17-407-2024, 2024
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The paper addresses the crucial topic of hail damage quantification using radar observations. We propose a new radar-derived hail product that utilizes a large dataset of insurance hail damage claims and radar observations. A deep neural network was employed, trained with local meteorological variables and the radar observations, to better quantify hail damage. Key meteorological variables were identified to have the most predictive capability in this regard.
Christos Gatidis, Marc Schleiss, and Christine Unal
Atmos. Meas. Tech., 17, 235–245, https://doi.org/10.5194/amt-17-235-2024, https://doi.org/10.5194/amt-17-235-2024, 2024
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A common method to retrieve important information about the microphysical structure of rain (DSD retrievals) requires a constrained relationship between the drop size distribution parameters. The most widely accepted empirical relationship is between μ and Λ. The relationship shows variability across the different types of rainfall (convective or stratiform). The new proposed power-law model to represent the μ–Λ relation provides a better physical interpretation of the relationship coefficients.
Liqin Jin, Jakob Mann, Nikolas Angelou, and Mikael Sjöholm
Atmos. Meas. Tech., 16, 6007–6023, https://doi.org/10.5194/amt-16-6007-2023, https://doi.org/10.5194/amt-16-6007-2023, 2023
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By sampling the spectra from continuous-wave Doppler lidars very fast, the rain-induced Doppler signal can be suppressed and the bias in the wind velocity estimation can be reduced. The method normalizes 3 kHz spectra by their peak values before averaging them down to 50 Hz. Over 3 h, we observe a significant reduction in the bias of the lidar data relative to the reference sonic data when the largest lidar focus distance is used. The more it rains, the more the bias is reduced.
Cited articles
Baker, D. J. and Romick, G. J.: The rayleigh: interpretation of the unit in
terms of column emission rate or apparent radiance expressed in SI units,
Appl. Optics, 15, 1966–1968, 1976.
Baker, D. J. and Stair Jr., A. T.: Rocket Measurements of the Altitude
Distributions of the Hydroxyl Airglow, Phys. Scripta, 37, 611–622, 1988. a
Becker, E.: Sensitivity of the Upper Mesosphere to the Lorenz Energy Cycle of
the Troposphere, J. Atmos. Sci., 66, 647–666, https://doi.org/10.1175/2008JAS2735.1,
2009. a
Bradski, G.: The OpenCV Library, Dr. Dobb's Journal of Software Tools, 2000. a
Coble, M. R., Papen, G. C., and Gardner, C. S.: Computing Two-Dimensional
Unambiguous Horizontal Wavenumber Spectra from OH Airglow Images, IEEE
T. Geosci. Remote, 36, 368–382, 1998. a
Conte, J. F., Chau, J. L., Laskar, F. I., Stober, G., Schmidt, H., and Brown,
P.: Semidiurnal solar tide differences between fall and spring transition
times in the Northern Hemisphere, Ann. Geophys., 36, 999–1008,
https://doi.org/10.5194/angeo-36-999-2018, 2018. a
Dowle, M. and Srinivasan, A.: data.table: Extension of “data.frame”,
r package version 1.11.8, available at:
https://CRAN.R-project.org/package=data.table (last access:
10 January 2019), 2018. a
Fleming, E. L., Chandra, S., Barnett, J., and Corney, M.: Zonal mean
temperature, pressure, zonal wind and geopotential height as functions of
latitude, Adv. Space Res., 10, 11–59, https://doi.org/10.1016/0273-1177(90)90386-e,
1990. a
Fritts, D. C. and Alexander, M. J.: Gravity wave dynamics and effects in the
middle atmosphere, Rev. Geophys., 41, 1003, https://doi.org/10.1029/2001RG000106, 2003. a, b
Garcia, F. J., Taylor, M. J., and Kelley, M. C.: Two-dimensional spectral
analysis of mesospheric airglow image data, Appl. Optics, 36, 7374–7385,
1997. a
Garcia, R. R. and Solomon, S.: The effect of breaking gravity waves on the
dynamics and chemical composition of the mesosphere and lower thermosphere,
J. Geophys. Res., 90, 3850, https://doi.org/10.1029/JD090iD02p03850, 1985. a
Gardner, C. S., Coble, M., Papen, G. C., and Swenson, G. R.: Observations of
the unambiguous 2-dimensional horizontal wave number spectrum of OH intensity
perturbations, Geophys. Res. Lett., 23, 3739–3742, https://doi.org/10.1029/96gl03158,
1996. a
Hecht, J. H., Fricke-Begemann, C., Walterscheid, R. L., and Höffner, J.:
Observations of the breakdown of an atmoshpreic gravity wave near the cold
summer mesopause at 54N, Geophys. Res. Lett., 6, 879–882, 2000. a
Holton, J. and Alexander, M.: The role of waves in the transport circulation
of the middle atmosphere, in: Atmospheric Science Across the Stratopause,
Geophysical Monograph, American Geophysical Union, https://doi.org/10.1029/GM123p0021, 2000. a
Holton, J. R.: The Influence of Gravity Wave Breaking on the General
Circulation of the Middle Atmosphere, J. Atmos. Sci., 40, 2497–2507,
https://doi.org/10.1175/1520-0469(1983)040<2497:TIOGWB>2.0.CO;2, 1983. a
Kaehler, A. and Bradski, G.: Learning OpenCV3 – Computer Vision in C
with the OpenCV Library, O'Reilly Media, Sebastopol, USA, 2017. a
Kaiser, J. and Schafer, R.: On the Use of the I0-Sinh Window for Spectrum
Analysis, IEEE T. Acoust. Speech, 28, 105–107,
https://doi.org/10.1109/TASSP.1980.1163349, 1980. a
Matsuda, T. S., Nakamura, T., Ejiri, M. K., Tsutsumi, M., and Shiokawa, K.:
New statistical analysis of the horizontal phase velocity distribution of
gravity waves observed by airglow imaging, J. Geophys. Res.-Atmos., 119,
9707–9718, https://doi.org/10.1002/2014jd021543, 2014. a
McLandress, C.: On the importance of gravity waves in the middle atmosphere
and their parameterization in general circulation models, J. Atmos.
Sol.-Terr. Phy., 60, 1357–1383, https://doi.org/10.1016/S1364-6826(98)00061-3, 1998. a
Meinel, A. B.: OH Emission band in the spectrum of the night sky I, American
Astronomical Society, 111, p. 555, https://doi.org/10.1086/145296, 1950. a
Mukherjee, G. K., R, P. S., Parihar, N., Ghodpage, R., and Patil, P. T.:
Studies of the wind filtering effect of gravity waves observed at Allahabad
(25.45∘ N, 81.85∘ E) in India, Earth Planets Space, 62,
309–318, https://doi.org/10.5047/eps.2009.11.008, 2010. a
Nakamura, T., Higashikawa, A., Tsuda, T., and Matsushita, Y.: Seasonal
variations of gravity wave structures in OH airglow with a CCD imager at
Shigaraki, Earth Planets Space, 51, 897–906, https://doi.org/10.1186/BF03353248, 1999. a
Oberheide, J., Hagan, M. E., and Roble, R. G.: Tidal signatures and aliasing
in temperature data from slowly precessing satellites, J. Geophys. Res., 108,
1055, https://doi.org/10.1029/2002JA009585, 2003. a
Pautet, D. and Moreels, G.: Ground-based satellite-type images of the
upper-atmosphere emissive layer, Appl. Optics, 41, 823–831, 2002.
Pautet, P.-D., Taylor, M. J., W. R. Pendleton, J., Zhao, Y., Yuan, T.,
Esplin, R., and McLain, D.: Advanced mesospheric temperature mapper for
high-latitude airglow studies, Appl. Optics, 53, 5934–5943,
https://doi.org/10.1364/AO.53.005934, 2014. a
Peterson, A. W.: Airglow events visible to the naked eye, Appl. Optics, 18,
3390–3393, https://doi.org/10.1364/ao.18.003390, 1979. a, b
Press, W. H., Teukolsky, S. A., Vetterling, W. T., and Flannery, B. P.:
Numerical Recipes, 3rd edn.: The Art of Scientific Computing, Cambridge
University Press, New York, NY, USA,
2007. a
R Core Team: R: A Language and Environment for Statistical Computing, R
Foundation for Statistical Computing, Vienna, Austria, available at:
https://www.r-project.org/ (last access:
10 January 2019), 2017. a
Sandford, D. J., Muller, H. G., and Mitchell, N. J.: Observations of lunar
tides in the mesosphere and lower thermosphere at Arctic and middle
latitudes, Atmos. Chem. Phys., 6, 4117–4127, https://doi.org/10.5194/acp-6-4117-2006,
2006. a
Sedlak, R., Hannawald, P., Schmidt, C., Wüst, S., and Bittner, M.:
High-resolution observations of small-scale gravity waves and turbulence
features in the OH airglow layer, Atmos. Meas. Tech., 9, 5955–5963,
https://doi.org/10.5194/amt-9-5955-2016, 2016. a
Silber, I., Price, C., Schmidt, C., Wüst, S., Bittner, M., and Pecora,
E.: First ground-based observations of mesopause temperatures above the
Eastern-Mediterranean Part I: Multi-day oscillations and tides, J. Atmos.
Sol.-Terr. Phy., 155, 95–103, https://doi.org/10.1016/j.jastp.2016.08.014, 2017. a
Tang, Y., Dou, X., Li, T., Nakamura, T., Xue, X., Huang, C., Manson, A.,
Meek, C., Thorsen, D., and Avery, S.: Gravity wave characteristics in the
mesopause region revealed from OH airglow imager observations over Northern
Colorado, J. Geophys. Res.-Space, 119, 630–645, https://doi.org/10.1002/2013JA018955,
2014. a, b, c, d, e
Taylor, M. J., Ryan, E. H., Tuan, T. F., and Edwards, R.: Evidence of
preferential directions for gravity wave propagation due to wind filtering in
the middle atmosphere, J. Geophys. Res., 98, 6047–6057,
https://doi.org/10.1029/92JA02604, 1993. a, b
Taylor, M. J., Bishop, M. B., and Taylor, V.: All-sky measurements of short
period waves image in the OI(557.7 nm), Na(589.2 nm) and near infrared OH
and O2(0,1) nightglow eemission during the ALOHA-93 campaign, Geophys.
Res. Lett., 22, 2833–2836, https://doi.org/10.1029/95GL02946, 1995. a
Vargas, F., Swenson, G., and Liu, A.: Evidence of high frequency gravity wave
forcing on the meridional residual circulation at the mesopause region, Adv.
Space Res., 56, 1844–1853, https://doi.org/10.1016/j.asr.2015.07.040, 2015. a
von Savigny, C.: Variability of OH(3-1) emission altitude from 2003 to 2011:
Long-term stability and universality of the emission rate-altitude
relationship, J. Atmos. Sol.-Terr. Phy., 127, 120–128,
https://doi.org/10.1016/j.jastp.2015.02.001, 2015. a
Wachter, P., Schmidt, C., Wüst, S., and Bittner, M.: Spatial gravity wave
characteristics obtained from multiple OH(3-1) airglow temperature time
series, J. Atmos. Sol.-Terr. Phy., 135, 192–201,
https://doi.org/10.1016/j.jastp.2015.11.008, 2015. a
Walterscheid, R., Hecht, J., Vincent, R., Reid, I., Woithe, J., and Hickey,
M.: Analysis and interpretation of airglow and radar observations of
quasi-monochromatic gravity waves in the upper mesosphere and lower
thermosphere over Adelaide, Australia (35∘ S, 138∘ E),
J. Atmos. Sol.-Terr. Phy., 61, 461–478, https://doi.org/10.1016/s1364-6826(99)00002-4,
1999. a
Wickham, H.: ggplot2: Elegant Graphics for Data Analysis, Springer-Verlag New
York, available at: https://ggplot2.tidyverse.org/ (last access:
10 January 2019), 2016. a
Wüst, S., Wendt, V., Schmidt, C., Lichtenstern, S., Bittner, M., Yee,
J.-H., Mlynczak, M. G., and Russell III, J. M.: Derivation of gravity wave
potential energy density from NDMC measurements, J. Atmos. Sol.-Terr. Phy.,
138–139, 32–46, https://doi.org/10.1016/j.jastp.2015.12.003, 2016. a
Wüst, S., Bittner, M., Yee, J.-H., Mlynczak, M. G., and Russell III, J.
M.: Variability of the Brunt-Väisälä frequency at the OH*
layer height, Atmos. Meas. Tech., 10, 4895–4903,
https://doi.org/10.5194/amt-10-4895-2017, 2017. a
Wüst, S., Offenwanger, T., Schmidt, C., Bittner, M., Jacobi, C., Stober,
G., Yee, J.-H., Mlynczak, M. G., and Russell III, J. M.: Derivation of
gravity wave intrinsic parameters and vertical wavelength using a single
scanning OH(3-1) airglow spectrometer, Atmos. Meas. Tech., 11, 2937–2947,
https://doi.org/10.5194/amt-11-2937-2018, 2018. a
Yuan, T., She, C.-Y., Krueger, D. A., Sassi, F., Garcia, R., Roble, R. G.,
Liu, H.-L., and Schmidt, H.: Climatology of mesopause region temperature,
zonal wind, and meridional wind over Fort Collins, Colorado (41∘ N,
105∘ W), and comparison with model simulations, J. Geophys. Res.,
113, D03105, https://doi.org/10.1029/2007JD008697, 2008. a
Zhang, S. D., Huang, C. M., Huang, K. M., Yi, F., Zhang, Y. H., Gong, Y., and
Gan, Q.: Spatial and seasonal variability of medium- and high-frequency
gravity waves in the lower atmosphere revealed by US radiosonde data, Ann.
Geophys., 32, 1129–1143, https://doi.org/10.5194/angeo-32-1129-2014, 2014. a
Short summary
We use a near-infrared camera for the investigation of gravity waves. The camera observes the airglow layer, which is modulated by the gravity waves. The image processing, including the removal of the stars is explained. We describe the analysis with a 2D fast Fourier transform and automatic derivation of the wave parameters. The results show a clear seasonal and intra-diurnal variability, which is characterised in order to improve our understanding of gravity waves in the middle atmosphere.
We use a near-infrared camera for the investigation of gravity waves. The camera observes the...