Articles | Volume 10, issue 9
https://doi.org/10.5194/amt-10-3453-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/amt-10-3453-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
21 Sep 2017
Research article |
| 21 Sep 2017
Smoothing data series by means of cubic splines: quality of approximation and introduction of a repeating spline approach
Deutsches Fernerkundungsdatenzentrum (DFD), Deutsches Zentrum für Luft- und Raumfahrt (DLR), 82234 Oberpfaffenhofen, Germany
Verena Wendt
Deutsches Fernerkundungsdatenzentrum (DFD), Deutsches Zentrum für Luft- und Raumfahrt (DLR), 82234 Oberpfaffenhofen, Germany
Umweltforschungsstation Schneefernerhaus, Zugspitze, Germany
Institut für industrielle Informationstechnik, Hochschule Ostwestfalen-Lippe, Ostwestfalen-Lippe, Germany
Ricarda Linz
Deutsches Fernerkundungsdatenzentrum (DFD), Deutsches Zentrum für Luft- und Raumfahrt (DLR), 82234 Oberpfaffenhofen, Germany
now at: Willis Re GmbH & Co KG, München, Germany
Michael Bittner
Deutsches Fernerkundungsdatenzentrum (DFD), Deutsches Zentrum für Luft- und Raumfahrt (DLR), 82234 Oberpfaffenhofen, Germany
Institut für Physik, Universität Augsburg, 86159 Augsburg, Germany
Related authors
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
Preprint under review for AMT
Short summary
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
Patrick Hannawald, Carsten Schmidt, René Sedlak, Sabine Wüst, and Michael Bittner
Atmos. Meas. Tech., 12, 457–469, https://doi.org/10.5194/amt-12-457-2019, https://doi.org/10.5194/amt-12-457-2019, 2019
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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.
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.
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
Preprint under review for AMT
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
Patrick Hannawald, Carsten Schmidt, René Sedlak, Sabine Wüst, and Michael Bittner
Atmos. Meas. Tech., 12, 457–469, https://doi.org/10.5194/amt-12-457-2019, https://doi.org/10.5194/amt-12-457-2019, 2019
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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.
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: In Situ Measurement | Topic: Data Processing and Information Retrieval
The role of time averaging of eddy covariance fluxes on water use efficiency dynamics of maize
Number- and size-controlled rainfall regimes in the Netherlands: physical reality or statistical mirage?
The Far-INfrarEd Spectrometer for Surface Emissivity (FINESSE) – Part 2: First measurements of the emissivity of water in the far-infrared
Bias Correction and Application of Labeled Smartphone Pressure Data for Evaluating the Best Track of Landfalling Tropical Cyclones
Hailstorm events in the Central Andes of Peru: insights from historical data and radar microphysics
Hybrid instrument network optimization for air quality monitoring
Double moment normalization of hail size number distributions over Switzerland
Objective identification of pressure wave events from networks of 1 Hz, high-precision sensors
Adjustment of 1 min rain gauge time series using co-located drop size distribution and wind speed measurements
Estimating turbulent energy flux vertical profiles from uncrewed aircraft system measurements: exemplary results for the MOSAiC campaign
Gap filling of turbulent heat fluxes over rice–wheat rotation croplands using the random forest model
Estimation of raindrop size distribution and rain rate with infrared surveillance camera in dark conditions
Estimates of the spatially complete, observational-data-driven planetary boundary layer height over the contiguous United States
Detection of turbulence occurrences from temperature, pressure, and position measurements under superpressure balloons
Inferring surface energy fluxes using drone data assimilation in large eddy simulations
Raindrop size distribution (DSD) during the passage of tropical cyclone Nivar: effect of measuring principle and wind on DSDs and retrieved rain integral and polarimetric parameters from impact and laser disdrometers
Automatic quality control of telemetric rain gauge data providing quantitative quality information (RainGaugeQC)
Testing the efficacy of atmospheric boundary layer height detection algorithms using uncrewed aircraft system data from MOSAiC
Considerations for improving data quality of thermo-hygrometer sensors on board unmanned aerial systems for planetary boundary layer research
Characteristics of the derived energy dissipation rate using the 1 Hz commercial aircraft quick access recorder (QAR) data
Low-level buoyancy as a tool to understand boundary layer transitions
Estimating vertical wind power density using tower observation and empirical models over varied desert steppe terrain in northern China
Air temperature equation derived from sonic temperature and water vapor mixing ratio for turbulent airflow sampled through closed-path eddy-covariance flux systems
Wind speed and direction estimation from wave spectra using deep learning
Options to correct local turbulent flux measurements for large-scale fluxes using an approach based on large-eddy simulation
Global ensemble of temperatures over 1850–2018: quantification of uncertainties in observations, coverage, and spatial modeling (GETQUOCS)
Reconstruction of the mass and geometry of snowfall particles from multi-angle snowflake camera (MASC) images
A new zenith hydrostatic delay model for real-time retrievals of GNSS-PWV
Sampling error in aircraft flux measurements based on a high-resolution large eddy simulation of the marine boundary layer
Separation of convective and stratiform precipitation using polarimetric radar data with a support vector machine method
An approach to minimize aircraft motion bias in multi-hole probe wind measurements made by small unmanned aerial systems
Interpolation uncertainty of atmospheric temperature profiles
Unsupervised classification of snowflake images using a generative adversarial network and K-medoids classification
An improved post-processing technique for automatic precipitation gauge time series
Retrieval of eddy dissipation rate from derived equivalent vertical gust included in Aircraft Meteorological Data Relay (AMDAR)
Atmospheric condition identification in multivariate data through a metric for total variation
Identifying persistent temperature inversion events in a subalpine basin using radon-222
Evaluation of wake influence on high-resolution balloon-sonde measurements
Improving the mean and uncertainty of ultraviolet multi-filter rotating shadowband radiometer in situ calibration factors: utilizing Gaussian process regression with a new method to estimate dynamic input uncertainty
Empirical high-resolution wind field and gust model in mountainous and hilly terrain based on the dense WegenerNet station networks
Performance of the FMI cosine error correction method for the Brewer spectral UV measurements
Computational efficiency for the surface renewal method
Raindrop fall velocities from an optical array probe and 2-D video disdrometer
Novel approaches to estimating the turbulent kinetic energy dissipation rate from low- and moderate-resolution velocity fluctuation time series
Data-driven clustering of rain events: microphysics information derived from macro-scale observations
Solid hydrometeor classification and riming degree estimation from pictures collected with a Multi-Angle Snowflake Camera
Dust opacities inside the dust devil column in the Taklimakan Desert
Comparison of GPS tropospheric delays derived from two consecutive EPN reprocessing campaigns from the point of view of climate monitoring
Ensemble mean density and its connection to other microphysical properties of falling snow as observed in Southern Finland
An automated nowcasting model of significant instability events in the flight terminal area of Rio de Janeiro, Brazil
Arun Rao Karimindla, Shweta Kumari, Saipriya S R, Syam Chintala, and BVN P. Kambhammettu
Atmos. Meas. Tech., 17, 5477–5490, https://doi.org/10.5194/amt-17-5477-2024, https://doi.org/10.5194/amt-17-5477-2024, 2024
Short summary
Short summary
This study investigates the role of the averaging period of eddy covariance fluxes on the energy balance ratio and further propagation into water use efficiency dynamics. Application was demonstrated on a maize field considering EC flux data. We found that the time averages of EC fluxes that yield the most effective EBR are at 45 and 60 min. The 30 min averaging period was insufficient to capture low-frequency fluxes. Time averaging of EC fluxes needs to be performed based on crop growth stage.
Marc Schleiss
Atmos. Meas. Tech., 17, 4789–4802, https://doi.org/10.5194/amt-17-4789-2024, https://doi.org/10.5194/amt-17-4789-2024, 2024
Short summary
Short summary
Research is conducted to identify special rainfall patterns in the Netherlands using multiple types of rainfall sensors. A total of eight potentially unique events are analyzed, considering both the number and size of raindrops. However, no clear evidence supporting the existence of a special rainfall regime could be found. The results highlight the challenges in experimentally confirming well-established theoretical ideas in the field of precipitation sciences.
Laura Warwick, Jonathan E. Murray, and Helen Brindley
Atmos. Meas. Tech., 17, 4777–4787, https://doi.org/10.5194/amt-17-4777-2024, https://doi.org/10.5194/amt-17-4777-2024, 2024
Short summary
Short summary
We describe a method for measuring the emissivity of natural surfaces using data from the new Far-INfrarEd Spectrometer for Surface Emissivity (FINESSE) instrument. We demonstrate our method by making measurements of the emissivity of water. We then compare our results to the emissivity predicted using a model and find good agreement. The observations from FINESSE are novel because they allow us to determine surface emissivity at longer wavelengths than have been routinely measured before.
Ge Qiao, Yuyao Cao, Qinghong Zhang, and Juanzhen Sun
EGUsphere, https://doi.org/10.5194/egusphere-2024-1505, https://doi.org/10.5194/egusphere-2024-1505, 2024
Short summary
Short summary
Smartphones equipped with multiple sensors have great potential to form high-resolution meteorological observation fields. In this study, we focused on smartphone pressure observation in tropical cyclone environment. We developed a machine learning-based quality control program that greatly reduced errors and found that smartphone data led to significant improvements in analysis fields. Some traditional best tracks were found to consistently underestimate the minimum sea level pressure.
Jairo M. Valdivia, José Luis Flores-Rojas, Josep J. Prado, David Guizado, Elver Villalobos-Puma, Stephany Callañaupa, and Yamina Silva-Vidal
Atmos. Meas. Tech., 17, 2295–2316, https://doi.org/10.5194/amt-17-2295-2024, https://doi.org/10.5194/amt-17-2295-2024, 2024
Short summary
Short summary
In this study, we explored hailstorms in the Central Andes of Peru. We used historical records and radar measurements to understand the frequency, timing, and characteristics of these hail events. Our research found a trend of decreasing hail frequency, probably due to anthropogenic climate change. Understanding these weather patterns is critical for local communities, as it can help improve weather forecasts and manage risks related to these potentially destructive events.
Nishant Ajnoti, Hemant Gehlot, and Sachchida Nand Tripathi
Atmos. Meas. Tech., 17, 1651–1664, https://doi.org/10.5194/amt-17-1651-2024, https://doi.org/10.5194/amt-17-1651-2024, 2024
Short summary
Short summary
This research focuses on the optimal placement of hybrid instruments (sensors and monitors) to maximize satisfaction function considering population, PM2.5 concentration, budget, and other factors. Two algorithms are developed in this study: a genetic algorithm and a greedy algorithm. We tested these algorithms on various regions. The insights of this work aid in quantitative placement of air quality monitoring instruments in large cities, moving away from ad hoc approaches.
Alfonso Ferrone, Jérôme Kopp, Martin Lainer, Marco Gabella, Urs Germann, and Alexis Berne
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2024-2, https://doi.org/10.5194/amt-2024-2, 2024
Revised manuscript accepted for AMT
Short summary
Short summary
Estimates of hail size have been collected by a network of hail sensors, installed in three regions of Switzerland, since September 2018. In this study, we use a technique called “double moment normalization” to model the distribution of diameter sizes. The parameters of the method have been defined over 70 % of the dataset, and testes over the remaining 30 %. An independent distribution of hail sizes, collected by a drone, has also been used to evaluate the method.
Luke R. Allen, Sandra E. Yuter, Matthew A. Miller, and Laura M. Tomkins
Atmos. Meas. Tech., 17, 113–134, https://doi.org/10.5194/amt-17-113-2024, https://doi.org/10.5194/amt-17-113-2024, 2024
Short summary
Short summary
We present a data set of high-precision surface air pressure observations and a method for detecting wave signals from the time series of pressure. A wavelet-based method is used to find wave signals at specific times and wave periods. From networks of pressure sensors spaced tens of kilometers apart, the wave phase speed and direction are estimated. Examples of wave events and their meteorological context are shown using radar data, weather balloon data, and other surface weather observations.
Arianna Cauteruccio, Mattia Stagnaro, Luca G. Lanza, and Pak-Wai Chan
Atmos. Meas. Tech., 16, 4155–4163, https://doi.org/10.5194/amt-16-4155-2023, https://doi.org/10.5194/amt-16-4155-2023, 2023
Short summary
Short summary
Adjustments for the wind-induced bias of traditional rainfall gauges are applied to data from the Hong Kong Observatory using numerical simulation results. An optical disdrometer allows us to infer the collection efficiency of the rainfall gauge. Due to the local climatology, adjustments are limited but result in a significant amount of available freshwater resources that would be missing from the calculated hydrological budget of the region should the adjustments be neglected.
Ulrike Egerer, John J. Cassano, Matthew D. Shupe, Gijs de Boer, Dale Lawrence, Abhiram Doddi, Holger Siebert, Gina Jozef, Radiance Calmer, Jonathan Hamilton, Christian Pilz, and Michael Lonardi
Atmos. Meas. Tech., 16, 2297–2317, https://doi.org/10.5194/amt-16-2297-2023, https://doi.org/10.5194/amt-16-2297-2023, 2023
Short summary
Short summary
This paper describes how measurements from a small uncrewed aircraft system can be used to estimate the vertical turbulent heat energy exchange between different layers in the atmosphere. This is particularly important for the atmosphere in the Arctic, as turbulent exchange in this region is often suppressed but is still important to understand how the atmosphere interacts with sea ice. We present three case studies from the MOSAiC field campaign in Arctic sea ice in 2020.
Jianbin Zhang, Zexia Duan, Shaohui Zhou, Yubin Li, and Zhiqiu Gao
Atmos. Meas. Tech., 16, 2197–2207, https://doi.org/10.5194/amt-16-2197-2023, https://doi.org/10.5194/amt-16-2197-2023, 2023
Short summary
Short summary
In this paper, we used a random forest model to fill the observation gaps of the fluxes measured during 2015–2019. We found that the net radiation was the most important input variable. And we justified the reliability of the model. Further, it was revealed that the model performed better after relative humidity was removed from the input. Lastly, we compared the results of the model with those of three other machine learning models, and we found that the model outperformed all of them.
Jinwook Lee, Jongyun Byun, Jongjin Baik, Changhyun Jun, and Hyeon-Joon Kim
Atmos. Meas. Tech., 16, 707–725, https://doi.org/10.5194/amt-16-707-2023, https://doi.org/10.5194/amt-16-707-2023, 2023
Short summary
Short summary
Our study addresses raindrop size distribution and rain rate by extracting rain streaks using a k-nearest-neighbor-based algorithm, estimating rainfall intensity using raindrop size distribution based on physical optics analysis, and verifying the estimated raindrop size distribution using a disdrometer. Experimentation demonstrated the possibility of estimating an image-based raindrop size distribution and rain rate obtained based on such low-cost equipment in dark conditions.
Zolal Ayazpour, Shiqi Tao, Dan Li, Amy Jo Scarino, Ralph E. Kuehn, and Kang Sun
Atmos. Meas. Tech., 16, 563–580, https://doi.org/10.5194/amt-16-563-2023, https://doi.org/10.5194/amt-16-563-2023, 2023
Short summary
Short summary
Accurate knowledge of the planetary boundary layer height (PBLH) is essential to study air pollution. However, PBLH observations are sparse in space and time, and PBLHs used in atmospheric models are often inaccurate. Using PBLH observations from the Aircraft Meteorological DAta Relay (AMDAR), we present a machine learning framework to produce a spatially complete PBLH product over the contiguous US that shows a better agreement with reference PBLH observations than commonly used PBLH products.
Richard Wilson, Clara Pitois, Aurélien Podglajen, Albert Hertzog, Milena Corcos, and Riwal Plougonven
Atmos. Meas. Tech., 16, 311–330, https://doi.org/10.5194/amt-16-311-2023, https://doi.org/10.5194/amt-16-311-2023, 2023
Short summary
Short summary
Strateole-2 is an French–US initiative designed to study atmospheric events in the tropical upper troposphere–lower stratosphere. In this work, data from several superpressure balloons, capable of staying aloft at an altitude of 18–20 km for over 3 months, were used. The present article describes methods to detect the occurrence of atmospheric turbulence – one efficient process impacting the properties of the atmosphere composition via stirring and mixing.
Norbert Pirk, Kristoffer Aalstad, Sebastian Westermann, Astrid Vatne, Alouette van Hove, Lena Merete Tallaksen, Massimo Cassiani, and Gabriel Katul
Atmos. Meas. Tech., 15, 7293–7314, https://doi.org/10.5194/amt-15-7293-2022, https://doi.org/10.5194/amt-15-7293-2022, 2022
Short summary
Short summary
In this study, we show how sparse and noisy drone measurements can be combined with an ensemble of turbulence-resolving wind simulations to estimate uncertainty-aware surface energy exchange. We demonstrate the feasibility of this drone data assimilation framework in a series of synthetic and real-world experiments. This new framework can, in future, be applied to estimate energy and gas exchange in heterogeneous landscapes more representatively than conventional methods.
Basivi Radhakrishna
Atmos. Meas. Tech., 15, 6705–6722, https://doi.org/10.5194/amt-15-6705-2022, https://doi.org/10.5194/amt-15-6705-2022, 2022
Short summary
Short summary
Raindrop size distributions (DSDs) measured by various types of disdrometers are different in the same environmental conditions. The mass-weighted mean diameter (Dm) measured from JWD is larger, and ZDR is smaller than LPM and PARSIVEL due to the resonance effect at X-band frequency. The effect of wind on DSD measured by various disdrometers is not uniform in different regions of a tropical cyclone.
Katarzyna Ośródka, Irena Otop, and Jan Szturc
Atmos. Meas. Tech., 15, 5581–5597, https://doi.org/10.5194/amt-15-5581-2022, https://doi.org/10.5194/amt-15-5581-2022, 2022
Short summary
Short summary
The quality control of sub-hourly rain gauge data is a challenging task due to the high variability and low spatial consistency of the data. We developed an innovative approach to the quality control of telemetric rain gauge data focused on assessing the reliability of individual observations. Our scheme employs weather radar data to detect erroneous rain gauge measurements and to assess the data reliability. The scheme is used operationally by the Polish meteorological and hydrological service.
Gina Jozef, John Cassano, Sandro Dahlke, and Gijs de Boer
Atmos. Meas. Tech., 15, 4001–4022, https://doi.org/10.5194/amt-15-4001-2022, https://doi.org/10.5194/amt-15-4001-2022, 2022
Short summary
Short summary
During the MOSAiC expedition, meteorological conditions over the lowest 1 km of the atmosphere were sampled with the DataHawk2 uncrewed aircraft system. These data were used to identify the best method for atmospheric boundary layer height detection by comparing visually identified subjective boundary layer height to that identified by several objective automated detection methods. The results show a bulk Richardson number-based approach gives the best estimate of boundary layer height.
Antonio R. Segales, Phillip B. Chilson, and Jorge L. Salazar-Cerreño
Atmos. Meas. Tech., 15, 2607–2621, https://doi.org/10.5194/amt-15-2607-2022, https://doi.org/10.5194/amt-15-2607-2022, 2022
Short summary
Short summary
The mitigation of undesired contamination, sensor characterization, and signal conditioning and restoration is crucial to improve the reliability of the weather unmanned aerial system (UAS) deliverables. This study presents an overview of the general considerations and procedures to compensate for slow sensor response and other sources of error for temperature and humidity measurements collected using a UAS.
Soo-Hyun Kim, Jeonghoe Kim, Jung-Hoon Kim, and Hye-Yeong Chun
Atmos. Meas. Tech., 15, 2277–2298, https://doi.org/10.5194/amt-15-2277-2022, https://doi.org/10.5194/amt-15-2277-2022, 2022
Short summary
Short summary
The cube root of the energy dissipation rate (EDR), as a standard reporting metric of atmospheric turbulence, is estimated using 1 Hz commercial quick access recorder data from Korean-based national air carriers with two different types of aircraft. Various EDRs are estimated using zonal, meridional, and derived vertical wind components and the derived equivalent vertical gust. Characteristics of the observed EDR estimates using 1 Hz flight data are examined to observe strong turbulence cases.
Francesca M. Lappin, Tyler M. Bell, Elizabeth A. Pillar-Little, and Phillip B. Chilson
Atmos. Meas. Tech., 15, 1185–1200, https://doi.org/10.5194/amt-15-1185-2022, https://doi.org/10.5194/amt-15-1185-2022, 2022
Short summary
Short summary
This study evaluates how a classically defined variable, air parcel buoyancy, can be used to interpret transitions in the atmospheric boundary layer (ABL). To capture the high-resolution variations, remotely piloted aircraft systems are used to collect data in two field campaigns. This paper finds that buoyancy has distinct evolutions prior to low-level jet and convective initiation cases. Additionally, buoyancy mixes well to act as an ABL height indicator comparable to other methods.
Shaohui Zhou, Yuanjian Yang, Zhiqiu Gao, Xingya Xi, Zexia Duan, and Yubin Li
Atmos. Meas. Tech., 15, 757–773, https://doi.org/10.5194/amt-15-757-2022, https://doi.org/10.5194/amt-15-757-2022, 2022
Short summary
Short summary
Our research has determined the possible relationship between Weibull natural wind mesoscale parameter c and shape factor k with height under the conditions of a desert steppe terrain in northern China, which has great potential in wind power generation. We have gained an enhanced understanding of the seasonal changes in the surface roughness of the desert grassland and the changes in the incoming wind direction.
Xinhua Zhou, Tian Gao, Eugene S. Takle, Xiaojie Zhen, Andrew E. Suyker, Tala Awada, Jane Okalebo, and Jiaojun Zhu
Atmos. Meas. Tech., 15, 95–115, https://doi.org/10.5194/amt-15-95-2022, https://doi.org/10.5194/amt-15-95-2022, 2022
Short summary
Short summary
Air temperature from sonic temperature and air moisture has been used without an exact equation. We present an exact equation of such air temperature for closed-path eddy-covariance flux measurements. Air temperature from this equation is equivalent to sonic temperature in its accuracy and frequency response. It is a choice for advanced flux topics because, with it, thermodynamic variables in the flux measurements can be temporally synchronized and spatially matched at measurement scales.
Haoyu Jiang
Atmos. Meas. Tech., 15, 1–9, https://doi.org/10.5194/amt-15-1-2022, https://doi.org/10.5194/amt-15-1-2022, 2022
Short summary
Short summary
Sea surface wind and waves are important ocean parameters that can be continuously observed by meteorological buoys. Meteorological buoys are sparse in the ocean due to their high cost of deployment and maintenance. In contrast, low-cost compact wave buoys are suited for deployment in large numbers. Although wave buoys are not designed for wind measurement, we found that deep learning can estimate wind from wave measurements accurately, making wave buoys a good-quality data source for sea wind.
Matthias Mauder, Andreas Ibrom, Luise Wanner, Frederik De Roo, Peter Brugger, Ralf Kiese, and Kim Pilegaard
Atmos. Meas. Tech., 14, 7835–7850, https://doi.org/10.5194/amt-14-7835-2021, https://doi.org/10.5194/amt-14-7835-2021, 2021
Short summary
Short summary
Turbulent flux measurements suffer from a general systematic underestimation. One reason for this bias is non-local transport by large-scale circulations. A recently developed model for this additional transport of sensible and latent energy is evaluated for three different test sites. Different options on how to apply this correction are presented, and the results are evaluated against independent measurements.
Maryam Ilyas, Douglas Nychka, Chris Brierley, and Serge Guillas
Atmos. Meas. Tech., 14, 7103–7121, https://doi.org/10.5194/amt-14-7103-2021, https://doi.org/10.5194/amt-14-7103-2021, 2021
Short summary
Short summary
Instrumental temperature records are fundamental to climate science. There are spatial gaps in the distribution of these measurements across the globe. This lack of spatial coverage introduces coverage error. In this research, a methodology is developed and used to quantify the coverage errors. It results in a data product that, for the first time, provides a full description of both the spatial coverage uncertainties along with the uncertainties in the modeling of these spatial gaps.
Jussi Leinonen, Jacopo Grazioli, and Alexis Berne
Atmos. Meas. Tech., 14, 6851–6866, https://doi.org/10.5194/amt-14-6851-2021, https://doi.org/10.5194/amt-14-6851-2021, 2021
Short summary
Short summary
Measuring the shape, size and mass of a large number of snowflakes is a challenging task; it is hard to achieve in an automatic and instrumented manner. We present a method to retrieve these properties of individual snowflakes using as input a triplet of images/pictures automatically collected by a multi-angle snowflake camera (MASC) instrument. Our method, based on machine learning, is trained on artificially generated snowflakes and evaluated on 3D-printed snowflake replicas.
Longjiang Li, Suqin Wu, Kefei Zhang, Xiaoming Wang, Wang Li, Zhen Shen, Dantong Zhu, Qimin He, and Moufeng Wan
Atmos. Meas. Tech., 14, 6379–6394, https://doi.org/10.5194/amt-14-6379-2021, https://doi.org/10.5194/amt-14-6379-2021, 2021
Short summary
Short summary
The zenith hydrostatic delay (ZHD) derived from blind models are of low accuracy, especially in mid- and high-latitude regions. To address this issue, the ratio of the ZHD to zenith total delay (ZTD) is firstly investigated; then, based on the relationship between the ZHD and ZTD, a new ZHD model was developed using the back propagation artificial neural network (BP-ANN) method which took the ZTD as an input variable. The model outperforms blind models.
Grant W. Petty
Atmos. Meas. Tech., 14, 1959–1976, https://doi.org/10.5194/amt-14-1959-2021, https://doi.org/10.5194/amt-14-1959-2021, 2021
Short summary
Short summary
Aircraft measurements of turbulent fluxes of matter and energy are important in field investigations of the interaction of the Earth's surface and the atmosphere. Because these measurements are of randomly fluctuating quantities, averages must be taken over longer flight tracks to reduce uncertainty. This paper investigates the relationship between track length and measurement error using a computer model simulation of a marine environment and compares the results with published theory.
Yadong Wang, Lin Tang, Pao-Liang Chang, and Yu-Shuang Tang
Atmos. Meas. Tech., 14, 185–197, https://doi.org/10.5194/amt-14-185-2021, https://doi.org/10.5194/amt-14-185-2021, 2021
Short summary
Short summary
The motivation of this work is to develop a precipitation separation approach that can be implemented on those radars with fast scanning schemes. In these schemes, the higher tilt radar data are not available, which poses a challenge for the traditional approaches. This approach uses artificial intelligence, which integrates polarimetric radar variables. The quantitative precipitation estimation will benefit from the output of this algorithm.
Loiy Al-Ghussain and Sean C. C. Bailey
Atmos. Meas. Tech., 14, 173–184, https://doi.org/10.5194/amt-14-173-2021, https://doi.org/10.5194/amt-14-173-2021, 2021
Short summary
Short summary
Unmanned aerial vehicles equipped with multi-hole probes are an effective approach to measure the wind vector with high spatial and temporal resolution. However, the aircraft motion must be removed from the measured signal first, a process often introducing bias due to small errors in the relative orientation of coordinates. We present an approach that has successfully been applied in post-processing, which was found to minimize the influence of aircraft motion on wind measurements.
Alessandro Fassò, Michael Sommer, and Christoph von Rohden
Atmos. Meas. Tech., 13, 6445–6458, https://doi.org/10.5194/amt-13-6445-2020, https://doi.org/10.5194/amt-13-6445-2020, 2020
Short summary
Short summary
Modern radiosonde balloons fly from ground level up to the lower stratosphere and take temperature measurements. What is the uncertainty of interpolated values in the resulting atmospheric temperature profiles? To answer this question, we introduce a general statistical–mathematical model for the computation of interpolation uncertainty. Analysing more than 51 million measurements, we provide some understanding of the consequences of filling missing data with interpolated ones.
Jussi Leinonen and Alexis Berne
Atmos. Meas. Tech., 13, 2949–2964, https://doi.org/10.5194/amt-13-2949-2020, https://doi.org/10.5194/amt-13-2949-2020, 2020
Short summary
Short summary
The appearance of snowflakes provides a signature of the atmospheric processes that created them. To get this information from large numbers of snowflake images, automated analysis using computer image recognition is needed. In this work, we use a neural network that learns the structure of the snowflake images to divide a snowflake dataset into classes corresponding to different sizes and structures. Unlike with most comparable methods, only minimal input from a human expert is needed.
Amber Ross, Craig D. Smith, and Alan Barr
Atmos. Meas. Tech., 13, 2979–2994, https://doi.org/10.5194/amt-13-2979-2020, https://doi.org/10.5194/amt-13-2979-2020, 2020
Short summary
Short summary
The raw data derived from most automated accumulating precipitation gauges often suffer from non-precipitation-related fluctuations in the measurement of the gauge bucket weights from which the precipitation amount is determined. This noise can be caused by electrical interference, mechanical noise, and evaporation. This paper presents an automated filtering technique that builds on the principle of iteratively balancing noise to produce a clean precipitation time series.
Soo-Hyun Kim, Hye-Yeong Chun, Jung-Hoon Kim, Robert D. Sharman, and Matt Strahan
Atmos. Meas. Tech., 13, 1373–1385, https://doi.org/10.5194/amt-13-1373-2020, https://doi.org/10.5194/amt-13-1373-2020, 2020
Short summary
Short summary
We retrieve the eddy dissipation rate (EDR) from the derived equivalent vertical gust included in the Aircraft Meteorological Data Relay data for more reliable and consistent observations of aviation turbulence globally with the single preferred EDR metric. We convert the DEVG to the EDR using two methods (lognormal mapping scheme and best-fit curve between EDR and DEVG), and the DEVG-derived EDRs are evaluated against in situ EDR data reported by US-operated carriers.
Nicholas Hamilton
Atmos. Meas. Tech., 13, 1019–1032, https://doi.org/10.5194/amt-13-1019-2020, https://doi.org/10.5194/amt-13-1019-2020, 2020
Short summary
Short summary
The identification of atmospheric conditions within a multivariable atmospheric data set is an important step in validating emerging and existing models used to simulate wind plant flows and operational strategies. The total variation approach developed here offers a method founded in tested mathematical metrics and can be used to identify and characterize periods corresponding to quiescent conditions or specific events of interest for study or wind energy development.
Dafina Kikaj, Janja Vaupotič, and Scott D. Chambers
Atmos. Meas. Tech., 12, 4455–4477, https://doi.org/10.5194/amt-12-4455-2019, https://doi.org/10.5194/amt-12-4455-2019, 2019
Short summary
Short summary
A new method was developed to identify persistent temperature inversion events in a subalpine basin using a radon-based method (RBM). By comparing with an existing pseudo-vertical temperature gradient method, the RBM was shown to be more reliable and seasonally independent. The RBM has the potential to increase the understanding of meteorological controls on air pollution episodes in complex terrain beyond the capability of contemporary atmospheric stability classification tools.
Jens Faber, Michael Gerding, Andreas Schneider, Andreas Dörnbrack, Henrike Wilms, Johannes Wagner, and Franz-Josef Lübken
Atmos. Meas. Tech., 12, 4191–4210, https://doi.org/10.5194/amt-12-4191-2019, https://doi.org/10.5194/amt-12-4191-2019, 2019
Short summary
Short summary
Atmospheric measurements on rising balloons can be compromised by the balloon's wake. The aim of this study is to provide a tool for assessing the likelihood of encountering the balloon's wake at the position of the gondola. This includes an uncertainty analysis of the calculation and a retrieval of vertical winds. We find an average wake encounter probability of 28 % for a standard radiosonde. Additionally, we evaluate the influence of wake from smaller objects on turbulence measurements.
Maosi Chen, Zhibin Sun, John M. Davis, Yan-An Liu, Chelsea A. Corr, and Wei Gao
Atmos. Meas. Tech., 12, 935–953, https://doi.org/10.5194/amt-12-935-2019, https://doi.org/10.5194/amt-12-935-2019, 2019
Short summary
Short summary
Combining a new dynamic uncertainty estimation method with Gaussian process regression (GP), we provide a generic and robust solution to estimate the underlying mean and uncertainty functions of time series with variable mean, noise, sampling density, and length of gaps. The GP solution was applied and validated on three UV-MFRSR Vo time series at three ground sites with improved accuracy of the smoothed time series in terms of aerosol optical depth compared with two other smoothing methods.
Christoph Schlager, Gottfried Kirchengast, and Juergen Fuchsberger
Atmos. Meas. Tech., 11, 5607–5627, https://doi.org/10.5194/amt-11-5607-2018, https://doi.org/10.5194/amt-11-5607-2018, 2018
Short summary
Short summary
In this work we further developed and evaluated an operational weather diagnostic application, the WegenerNet Wind Product Generator (WPG), and applied it to the WegenerNet Johnsbachtal (JBT), a dense meteorological station network located in a mountainous Alpine region. The WPG automatically generates gridded high-resolution wind fields in near-real time with a temporal resolution of 30 min and a spatial resolution of 100 m x 100 m.
Kaisa Lakkala, Antti Arola, Julian Gröbner, Sergio Fabian León-Luis, Alberto Redondas, Stelios Kazadzis, Tomi Karppinen, Juha Matti Karhu, Luca Egli, Anu Heikkilä, Tapani Koskela, Antonio Serrano, and José Manuel Vilaplana
Atmos. Meas. Tech., 11, 5167–5180, https://doi.org/10.5194/amt-11-5167-2018, https://doi.org/10.5194/amt-11-5167-2018, 2018
Short summary
Short summary
The performance of the cosine error correction method for correcting spectral UV measurements of the Brewer spectroradiometer was studied. The correction depends on the sky radiation distribution, which can change during one spectral scan. The results showed that the correction varied between 4 and 14 %, and that the relative differences between the reference and the Brewer diminished by 10 %. The method is applicable to other instruments as long as the required input parameters are available.
Jason Kelley and Chad Higgins
Atmos. Meas. Tech., 11, 2151–2158, https://doi.org/10.5194/amt-11-2151-2018, https://doi.org/10.5194/amt-11-2151-2018, 2018
Short summary
Short summary
Measuring fluxes of energy and trace gases using the surface renewal (SR) method can be economical and robust, but it requires computationally intensive calculations. Several new algorithms were written to perform the required calculations more efficiently and rapidly, and were tested with field data and computationally rigorous SR methods. These efficient algorithms facilitate expanded use of SR in atmospheric experiments, for applied monitoring, and in novel field implementations.
Viswanathan Bringi, Merhala Thurai, and Darrel Baumgardner
Atmos. Meas. Tech., 11, 1377–1384, https://doi.org/10.5194/amt-11-1377-2018, https://doi.org/10.5194/amt-11-1377-2018, 2018
Short summary
Short summary
Raindrop fall velocities are important for rain rate estimation, soil erosion studies and in numerical modelling of rain formation in clouds. The assumption that the fall velocity is uniquely related to drop size is made inherently based on laboratory measurements under still air conditions from nearly 68 years ago. There have been very few measurements of drop fall speeds in natural rain under both still and turbulent wind conditions. We report on fall speed measurements in natural rain shafts.
Marta Wacławczyk, Yong-Feng Ma, Jacek M. Kopeć, and Szymon P. Malinowski
Atmos. Meas. Tech., 10, 4573–4585, https://doi.org/10.5194/amt-10-4573-2017, https://doi.org/10.5194/amt-10-4573-2017, 2017
Short summary
Short summary
We propose two novel methods to estimate turbulent kinetic energy dissipation rate applicable to airborne measurements. In this way we increase robustness of the dissipation rate retrieval and extend its applicability to a wider range of data sets. The new approaches relate the predicted form of the dissipation spectrum to the mean of zero crossings of the measured velocity fluctuations. The methods are easy to implement numerically, and estimates remain unaffected by certain measurement errors.
Mohamed Djallel Dilmi, Cécile Mallet, Laurent Barthes, and Aymeric Chazottes
Atmos. Meas. Tech., 10, 1557–1574, https://doi.org/10.5194/amt-10-1557-2017, https://doi.org/10.5194/amt-10-1557-2017, 2017
Short summary
Short summary
The concept of a rain event is used to obtain a parsimonious characterisation of rain events using a minimal subset of variables at macrophysical scale. A classification in five classes is obtained in a unsupervised way from this subset. Relationships between these classes of microphysical parameters of precipitation are highlighted. There are several implications especially for remote sensing in the context of weather radar applications and quantitative precipitation estimation.
Christophe Praz, Yves-Alain Roulet, and Alexis Berne
Atmos. Meas. Tech., 10, 1335–1357, https://doi.org/10.5194/amt-10-1335-2017, https://doi.org/10.5194/amt-10-1335-2017, 2017
Short summary
Short summary
The Multi-Angle Snowflake Camera (MASC) provides high-resolution pictures of individual falling snowflakes and ice crystals. A method is proposed to automatically classify these pictures into six classes of snowflakes as well to estimate the degree of riming and to detect whether or not the particles are melting. Multinomial logistic regression is used with a manually classified
reference set. The evaluation demonstrates the good and reliable performance of the proposed technique.
Zhaopeng Luan, Yongxiang Han, Tianliang Zhao, Feng Liu, Chong Liu, Mark J. Rood, Xinghua Yang, Qing He, and Huichao Lu
Atmos. Meas. Tech., 10, 273–279, https://doi.org/10.5194/amt-10-273-2017, https://doi.org/10.5194/amt-10-273-2017, 2017
Zofia Baldysz, Grzegorz Nykiel, Andrzej Araszkiewicz, Mariusz Figurski, and Karolina Szafranek
Atmos. Meas. Tech., 9, 4861–4877, https://doi.org/10.5194/amt-9-4861-2016, https://doi.org/10.5194/amt-9-4861-2016, 2016
Short summary
Short summary
In this paper two official processing strategies of GPS observations were analysed. The main purpose was to assess differences in long-term (linear trends) and short-term (oscillations) changes between these two sets of data. Investigation was based on 18-year and 16-year time series and showed that, despite the general consistency, for selected stations a change of processing strategy may have caused significant differences (compared to the uncertainties) in estimated linear trend values.
Jussi Tiira, Dmitri N. Moisseev, Annakaisa von Lerber, Davide Ori, Ali Tokay, Larry F. Bliven, and Walter Petersen
Atmos. Meas. Tech., 9, 4825–4841, https://doi.org/10.5194/amt-9-4825-2016, https://doi.org/10.5194/amt-9-4825-2016, 2016
Short summary
Short summary
In this study winter measurements collected in Southern Finland are used to document microphysical properties of falling snow. It is shown that a new video imager can be used for such studies. Snow properties do vary between winters.
Gutemberg Borges França, Manoel Valdonel de Almeida, and Alessana C. Rosette
Atmos. Meas. Tech., 9, 2335–2344, https://doi.org/10.5194/amt-9-2335-2016, https://doi.org/10.5194/amt-9-2335-2016, 2016
Short summary
Short summary
This paper presents a novel model, based on neural network techniques, to produce short-term and locally specific forecasts of significant instability for flights in the terminal area of Rio de Janeiro's airport, Brazil. Twelve years of data were used for neural network training/validation and test. The test showed that the proposed model can grab the physical content inside the data set, and its performance is encouraging for the first and second hours to nowcast significant instability events.
Cited articles
Baumgarten, G., Fiedler, J., Hildebrand, J., and Lübken, F.-J.: Inertia gravity wave in the stratosphere and mesosphere observed by Doppler wind and temperature lidar, Geophys. Res. Lett., 42, 10929–10936, https://doi.org/10.1002/2015GL066991, 2015.
Committee on Space Research: NASA National Space Science Data Center: COSPAR International Reference Atmosphere (CIRA-86): Global Climatology of Atmospheric Parameters, NCAS British Atmospheric Data Centre, available at: http://catalogue.ceda.ac.uk/uuid/4996e5b2f53ce0b1f2072adadaeda262 (last access: 16 February 2016), 2006.
Eckermann, S. D., Hirota, I., and Hocking, W. K.: Gravity wave and equatorial wave morphology of the stratosphere derived from long-term rocket soundings, Q. J. Roy. Meteor. Soc., 121, 149–186, https://doi.org/10.1002/qj.49712152108, 1995.
Ern, M., Preusse, P., Gille, J. C., Hepplewhite, C. L., Mlynczak, M. G., Russell III, J. M., and Riese, M.: Implications for atmospheric dynamics derived from global observations of gravity wave momentum flux in stratosphere and mesosphere. J. Geophys. Res., 116, D19107, https://doi.org/10.1029/2011JD015821, 2011.
Kramer, R., Wüst, S., and Bittner, M.: Climatology of convectively generated gravity waves at Prague based on operational radiosonde data from 13 years (1997–2009), J. Atmos. Sol.-Terr. Phy., 140, 23–33, https://doi.org/10.1016/j.jastp.2016.01.014, 2016.
Krebsbach, M. and Preusse, P.: Spectral analysis of gravity wave activity in SABER temperature data, Geophys. Res. Lett., 34, L03814, https://doi.org/10.1029/2006GL028040, 2007.
Lawson, C. L. and Hanson, R. J.: Solving least squares problems, Prentice-Hall, Inc., Englewood Cliffs, New Jersey, USA, 1974.
Mzé, N., Hauchecorne, A., Keckhut, P., and Thétis, M.: Vertical distribution of gravity wave potential energy from long-term Rayleigh lidar data at a northern middle-latitude site, J. Geophys. Res.-Atmos., 119, 12069–12083, https://doi.org/10.1002/2014JD022035, 2014.
Offermann, D., Gusev, O., Donner, M., Forbes, J. M., Hagan, M., Mlynczak, M. G., Oberheide, J., Preusse, P., Schmidt, H., and Russell III, J. M.: Relative intensities of middle atmosphere waves, J. Geophys. Res., 114, D06110, https://doi.org/10.1029/2008JD010662, 2009.
Shuai, J., Zhang, S., Huang, C., YI, F., Huang, K., Gan, Q., and Gong, Y.: Climatology of global gravity wave activity and dissipation revealed by SABER/TIMED temperature observations, Science China Technological Sciences, 57, 998–1009, https://doi.org/10.1007/s11431-014-5527-z, 2014.
Wright, C. J., Rivas, M. B., and Gille, J. C.: Intercomparisons of HIRDLS, COSMIC and SABER for the detection of stratospheric gravity waves, Atmos. Meas. Tech., 4, 1581–1591, https://doi.org/10.5194/amt-4-1581-2011, 2011.
Wüst, S. and Bittner, M.: Gravity wave reflection: case study based on rocket data, J. Atmos. Sol.-Terr. Phy., 70, 742–755, https://doi.org/10.1016/j.jastp.2007.10.010, 2008.
Wüst, S. and Bittner, M.: Resonant interaction between two planetary waves with zonal wave number two? J. Atmos. Sol.-Terr. Phy., 73, 771–778, https://doi.org/10.1016/j.jastp.2011.01.004, 2011.
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.
Young, L. A., Yelle, R. V., Young, R., Seiff, A., and Kirk, D. B.: Gravity Waves in Jupiter's Thermosphere, Science, 276, 108–111, https://doi.org/10.1126/science.276.5309.108, 1997.
Zhang, Y., Xiong, J., Liu, L., and Wan, W.: A global morphology of gravity wave activity in the stratosphere revealed by the 8-year SABER/TIMED data, J. Geophys. Res., 117, D21101, https://doi.org/10.1029/2012JD017676, 2012.
Short summary
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.
Cubic splines with equidistant spline sampling points are a common method in atmospheric science...
