Atmospheric Measurements Techniques Discussions

Syndicate content
Combined list of the recent articles of the journal Atmospheric Measurement Techniques and the recent discussion forum Atmospheric Measurement Techniques Discussions
Updated: 2 days 20 hours ago

Negligible influence of livestock contaminants and sampling system on ammonia measurements with cavity ring-down spectroscopy

Fri, 05/17/2019 - 16:13
Negligible influence of livestock contaminants and sampling system on ammonia measurements with cavity ring-down spectroscopy
Jesper Nørlem Kamp, Albarune Chowdhury, Anders Peter S. Adamsen, and Anders Feilberg
Atmos. Meas. Tech., 12, 2837-2850, https://doi.org/10.5194/amt-12-2837-2019, 2019
We tested the performance of a cavity ring-down spectroscopy (CRDS) instrument from Picarro for measuring ammonia. Interference tests with 10 volatile organic compounds (VOCs) were conducted to find potential interference of these VOCs. Calibrations show excellent linearity over a large dynamic range of NH3 concentrations. There is negligible interference from humidity and few of the tested VOCs. Overall, the CRDS system performs well with only negligible influence from other compounds.

Studying boundary layer methane isotopy and vertical mixing processes at a rewetted peatland site by unmanned aircraft system

Fri, 05/17/2019 - 16:13
Studying boundary layer methane isotopy and vertical mixing processes at a rewetted peatland site by unmanned aircraft system
Astrid Lampert, Falk Pätzold, Magnus O. Asmussen, Lennart Lobitz, Thomas Krüger, Thomas Rausch, Torsten Sachs, Christian Wille, and Ellen Damm
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2019-111,2019
Manuscript under review for AMT (discussion: open, 0 comments)
Methane has a high climate warming potential. Sources of methane can be distinguished by the isotopic composition. To investigate the origin of methane, an airborne sampling system has ben developed that can take air samples worldwide. The article shows the performance of the overall system from taking samples to laboratory analyses. As known methane source, a rewetted peatland site was studied, and surprising local inhomogeneities are investigated.

Combined use of volume radar observations and high-resolution numerical weather predictions to estimate precipitation at the ground: methodology and proof of concept

Fri, 05/17/2019 - 16:13
Combined use of volume radar observations and high-resolution numerical weather predictions to estimate precipitation at the ground: methodology and proof of concept
Tony Le Bastard, Olivier Caumont, Nicolas Gaussiat, and Fatima Karbou
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2019-166,2019
Manuscript under review for AMT (discussion: open, 0 comments)
The estimation of surface rainfall from radars becomes less effective at long ranges or in mountainous regions where the radar beam is far from the ground. The method proposed in this paper investigates how vertical profiles simulated from high-resolution model can be used to predict the evolution of the precipitation below the radar beam. Our results show that this novel method leads to better results than the current operational methods that either use climatological or idealised profiles.

SAETTA: high resolution 3D mapping of the total lightning activity in the Mediterranean basin over Corsica, with a focus on a MCS event

Fri, 05/17/2019 - 16:13
SAETTA: high resolution 3D mapping of the total lightning activity in the Mediterranean basin over Corsica, with a focus on a MCS event
Sylvain Coquillat, Eric Defer, Pierre de Guibert, Dominique Lambert, Jean-Pierre Pinty, Véronique Pont, Serge Prieur, Ronald J. Thomas, Paul R. Krehbiel, and William Rison
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2019-192,2019
Manuscript under review for AMT (discussion: open, 0 comments)
Characteristics of SAETTA lightning imager installed in Corsica are presented, with original observations of lightning activity at regional and lightning scales. SAETTA monitors thunderstorms in a maritime and mountainous region, complex for weather forecasting and sensitive to global warming. A 3-year lightning climatology highlights frequent activity over a specific region due to relief. Original high discharges in stratiform area of a thundercloud support a recent model of charging process.

Evolution of DARDAR-CLOUD ice cloud retrievals: new parameters and impacts on the retrieved microphysical properties

Thu, 05/16/2019 - 16:13
Evolution of DARDAR-CLOUD ice cloud retrievals: new parameters and impacts on the retrieved microphysical properties
Quitterie Cazenave, Marie Ceccaldi, Julien Delanoë, Jacques Pelon, Silke Groß, and Andrew Heymsfield
Atmos. Meas. Tech., 12, 2819-2835, https://doi.org/10.5194/amt-12-2819-2019, 2019
The impact of ice clouds on the water cycle and radiative budget is still uncertain due to the complexity of cloud processes that makes it difficult to acquire adequate observations of ice cloud properties and parameterize them into climate and weather prediction models. In this paper we present the latest refinements brought to the DARDAR-CLOUD product, which contains ice cloud microphysical properties retrieved from the cloud radar and lidar measurements from the A-Train space mission.

Intercomparison of nitrous acid (HONO) measurement techniques in a megacity (Beijing)

Wed, 05/15/2019 - 16:13
Intercomparison of nitrous acid (HONO) measurement techniques in a megacity (Beijing)
Leigh R. Crilley, Louisa J. Kramer, Bin Ouyang, Jun Duan, Wenqian Zhang, Shengrui Tong, Maofa Ge, Ke Tang, Min Qin, Pinhua Xe, Marvin D. Shaw, Alastair C. Lewis, Archit Mehra, Thomas J. Bannan, Stephen D. Worrall, Michael Priestley, Asan Bacak, Hugh Coe, James Allan, Carl J. Percival, Olalekan A. M. Popoola, Roderic L. Jones, and William J. Bloss
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2019-139,2019
Manuscript under review for AMT (discussion: open, 0 comments)
Nitrous acid (HONO) is key species for understanding tropospheric chemistry, yet accurate and precise measurements are challenging. Here we report an inter-comparison exercise of a number of instruments that measured HONO in a highly polluted location (Beijing). All instruments agreed on the temporal trends, yet displayed divergence in absolute concentrations. The causes of this divergence was unclear, but may in part be due to spatial variability in instrument location.

Is a scaling factor required to obtain closure between measured and modelled atmospheric O4 absorptions? An assessment of uncertainties of measurements and radiative transfer simulations for 2 selected days during the MAD-CAT campaign

Tue, 05/14/2019 - 16:13
Is a scaling factor required to obtain closure between measured and modelled atmospheric O4 absorptions? An assessment of uncertainties of measurements and radiative transfer simulations for 2 selected days during the MAD-CAT campaign
Thomas Wagner, Steffen Beirle, Nuria Benavent, Tim Bösch, Ka Lok Chan, Sebastian Donner, Steffen Dörner, Caroline Fayt, Udo Frieß, David García-Nieto, Clio Gielen, David González-Bartolome, Laura Gomez, François Hendrick, Bas Henzing, Jun Li Jin, Johannes Lampel, Jianzhong Ma, Kornelia Mies, Mónica Navarro, Enno Peters, Gaia Pinardi, Olga Puentedura, Janis Puķīte, Julia Remmers, Andreas Richter, Alfonso Saiz-Lopez, Reza Shaiganfar, Holger Sihler, Michel Van Roozendael, Yang Wang, and Margarita Yela
Atmos. Meas. Tech., 12, 2745-2817, https://doi.org/10.5194/amt-12-2745-2019, 2019
In this study the consistency between MAX-DOAS measurements and radiative transfer simulations of the atmospheric O4 absorption is investigated. The study is based on measurements (2 selected days during the MADCAT campaign) as well as synthetic spectra. The uncertainties of all relevant aspects (spectral retrieval and radiative transfer simulations) are quantified. For one of the selected days, measurements and simulations do not agree within their uncertainties.

A portable dual-smog-chamber system for atmospheric aerosol field studies

Tue, 05/14/2019 - 16:13
A portable dual-smog-chamber system for atmospheric aerosol field studies
Christos Kaltsonoudis, Spiro D. Jorga, Evangelos Louvaris, Kalliopi Florou, and Spyros N. Pandis
Atmos. Meas. Tech., 12, 2733-2743, https://doi.org/10.5194/amt-12-2733-2019, 2019
A portable dual-smog-chamber system was developed using two identical pillow-shaped smog chambers surrounded by UV lamps. The system has been designed to use ambient air as the starting point of the experiments. It can be easily disassembled and transported, enabling the study of various atmospheric environments and it can be used with natural sunlight. The results of test experiments using ambient air are discussed as examples of applications of this system.

Quantifying organic matter and functional groups in particulate matter filter samples from the southeastern United States, part I: Methods

Tue, 05/14/2019 - 16:13
Quantifying organic matter and functional groups in particulate matter filter samples from the southeastern United States, part I: Methods
Alexandra J. Boris, Satoshi Takahama, Andrew T. Weakley, Bruno M. Debus, Carley D. Fredrickson, Martin Esparza-Sanchez, Charlotte Burki, Matteo Reggente, Stephanie L. Shaw, Eric S. Edgerton, and Ann M. Dillner
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2019-144,2019
Manuscript under review for AMT (discussion: open, 0 comments)
Organic species are abundant in atmospheric particle-phase (aerosol) pollution, and originate from a variety of biogenic and anthropogenic sources. Infrared spectrometry of filter-based atmospheric particle samples can afford a direct measurement of the particle organic matter concentration and a characterization of its composition. This work discusses recent method improvements and composition measured in samples from the Southeastern Aerosol Research and Characterization (SEARCH) network.

Underestimation of Column NO2 Amounts from the OMI Satellite Compared to Diurnally Varying Ground-Based Retrievals from Multiple Pandora Spectrometer Instruments

Tue, 05/14/2019 - 16:13
Underestimation of Column NO2 Amounts from the OMI Satellite Compared to Diurnally Varying Ground-Based Retrievals from Multiple Pandora Spectrometer Instruments
Jay Herman, Nader Abuhassan, Jhoon Kim, Jae Kim, Mavendra Dubey, Marcelo Raponi, and Maria Tzortziou
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2019-123,2019
Manuscript under review for AMT (discussion: open, 0 comments)
Total Column NO2 TCNO2 from the Ozone Measuring Instrument OMI are compared for 14 sites with ground-based PANDORA spectrometer instruments making direct-sun measurements. These sites have high TCNO2 and significant air quality problems that can affect human health. OMI almost always underestimates the amount TCNO2 by 50 to 100 %. OMI's large field of view FOV is the most likely factor when comparing OMI TCNO2 to retrievals with PANDORA. OMI misses higher afternoon values of TCNO2.

Recent advances in measurement techniques for atmospheric carbon monoxide and nitrous oxide observations

Tue, 05/14/2019 - 16:13
Recent advances in measurement techniques for atmospheric carbon monoxide and nitrous oxide observations
Christoph Zellweger, Rainer Steinbrecher, Olivier Laurent, Haeyoung Lee, Sumin Kim, Lukas Emmenegger, Martin Steinbacher, and Brigitte Buchmann
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2019-108,2019
Manuscript under review for AMT (discussion: open, 0 comments)
We analysed results obtained through CO and N2O performance audits conducted within the frame-work of the Global Atmosphere Watch (GAW) quality management system of the World Meteorology Organisation (WMO). The results reveal that current spectroscopic measurement techniques have clear advantages with respect to data quality objectives compared to more traditional methods. Further, they allow a smooth continuation of historic CO and N2O time series.

Temperature and water vapour measurements in the framework of NDACC

Tue, 05/14/2019 - 16:13
Temperature and water vapour measurements in the framework of NDACC
Benedetto De Rosa, Paolo Di Girolamo, and Donato Summa
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2019-140,2019
Manuscript under review for AMT (discussion: open, 0 comments)
Temperature and water vapour profiles measured by the lidar BASIL are compared with profiles from several sensors/models, namely radiosondings, the satellite sensors IASI and AIRS, and with model re-analyses data (ECMWF & ECMWF-ERA). The comparison effort allows assessing the performance of all considered sensors and models in terms of BIAS and RMS deviation. BASIL measurement quality is assess to be high enough for long-term monitoring of atmospheric composition and thermal structure changes.

A new discrete wavelength BUV algorithm for consistent volcanic SO2 retrievals from multiple satellite missions

Tue, 05/14/2019 - 16:13
A new discrete wavelength BUV algorithm for consistent volcanic SO2 retrievals from multiple satellite missions
Bradford L. Fisher, Nickolay A. Krotkov, Pawan K. Bhartia, Can Li, Simon Carn, Eric Hughes, and Peter J. T. Leonard
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2019-150,2019
Manuscript under review for AMT (discussion: open, 0 comments)
This paper describes a new discrete wavelength algorithm developed for retrieving volcanic sulfur dioxide (SO2) vertical column density (VCD) from UV observing satellites. The Multi-Satellite SO2 algorithm (MS_SO2) simultaneously retrieves column densities of sulfur dioxide, ozone, Lambertian Effective Reflectivity (LER) and its spectral dependence. It is used operationally to process measurements from the heritage Total Ozone Mapping Spectrometer (TOMS) on board NASA's Nimbus-7 satellite (N7/TOMS: 1978–1993) and from the current Earth Polychromatic Imaging Camera (EPIC) on board Deep Space Climate Observatory (DSCOVR: 2015–) from the Earth-Sun Lagrange (L1) orbit. Results from MS_SO2 algorithm for several volcanic cases were validated using the more sensitive principal component analysis (PCA) algorithm. The PCA is an operational algorithm used by NASA to retrieve SO2 from hyperspectral UV spectrometers, such as Ozone Monitoring Instrument (OMI) on board NASA’s Earth Observing System Aura satellite and Ozone Mapping and Profiling Suite (OMPS) on board NASA-NOAA Suomi National Polar Partnership (S-NPP) satellite. For this comparative study, the PCA algorithm was modified to use the discrete wavelengths of the Nimbus7/TOMS instrument, described in S1 of the paper supplement. Our results demonstrate good agreement between the two retrievals for the largest volcanic eruptions of the satellite era, such as 1991 Pinatubo eruption. To estimate SO2 retrieval uncertainties we use radiative transfer simulations explicitly accounting for volcanic sulfate and ash aerosols. Our results suggest that the discrete-wavelength MS_SO2 algorithm, although less sensitive than hyperspectral PCA algorithm, can be adapted to retrieve volcanic SO2 VCDs from contemporary hyperspectral UV instruments, such as OMI and OMPS, to create consistent, multi-satellite, long-term volcanic SO2 climate data records.

Field comparison of dry deposition samplers for collection of atmospheric mineral dust: results from single-particle characterization

Tue, 05/14/2019 - 16:13
Field comparison of dry deposition samplers for collection of atmospheric mineral dust: results from single-particle characterization
Andebo Waza, Kilian Schneiders, Jan May, Sergio Rodríguez, Bernd Epple, and Konrad Kandler
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2019-187,2019
Manuscript under review for AMT (discussion: open, 0 comments)
Deposition or other passive measurement techniques are used to sample mineral dust from the atmosphere. However, there exists a multitude of different collection instruments with different, usually not well-characterized sampling efficiencies, so the resulting data might be considerably biased with respect to their size representatively. In the paper, we report on collection properties of different deposition and other passive samplers based on single particle measurements.

A Gaussian Mixture Method for Specific Differential Phase Retrieval at X-band Frequency

Mon, 05/13/2019 - 16:13
A Gaussian Mixture Method for Specific Differential Phase Retrieval at X-band Frequency
Guang Wen, Neil I. Fox, and Patrick S. Market
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2019-189,2019
Manuscript under review for AMT (discussion: open, 0 comments)
In this study, we propose a probabilistic method based on Gaussian mixture model to estimate the slope of a data profile. The Gaussian mixture method (GMM) not only obtains the expected value of the slope by differentiating the conditional expectation of the data, but also yields the variance of the slope regarding the errors in the calculation of the first derivative.

Retrieval of Temperature From a Multiple Channel Pure Rotational Raman-Scatter Lidar Using an Optimal Estimation Method

Mon, 05/13/2019 - 16:13
Retrieval of Temperature From a Multiple Channel Pure Rotational Raman-Scatter Lidar Using an Optimal Estimation Method
Shayamila Mahagammulla Gamage, Robert J. Sica, Giovanni Martucci, and Alexander Haefele
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2019-107,2019
Manuscript under review for AMT (discussion: open, 0 comments)
We present a new method for retrieving temperature from Pure Rotational Raman lidar measurements using an optimal estimation method. We show that the error due to calibration can be reduced significantly using our method. The new method is tested on PRR temperature measurements from the MeteoSwiss Raman Lidar for Meteorological Observations system in different sky conditions. The next step in this research is to assimilate the temperature profiles into models to help improve weather forecasts.

The SPARC water vapour assessment II: profile-to-profile comparisons of stratospheric and lower mesospheric water vapour data sets obtained from satellites

Fri, 05/10/2019 - 16:13
The SPARC water vapour assessment II: profile-to-profile comparisons of stratospheric and lower mesospheric water vapour data sets obtained from satellites
Stefan Lossow, Farahnaz Khosrawi, Michael Kiefer, Kaley A. Walker, Jean-Loup Bertaux, Laurent Blanot, James M. Russell, Ellis E. Remsberg, John C. Gille, Takafumi Sugita, Christopher E. Sioris, Bianca M. Dinelli, Enzo Papandrea, Piera Raspollini, Maya García-Comas, Gabriele P. Stiller, Thomas von Clarmann, Anu Dudhia, William G. Read, Gerald E. Nedoluha, Robert P. Damadeo, Joseph M. Zawodny, Katja Weigel, Alexei Rozanov, Faiza Azam, Klaus Bramstedt, Stefan Noël, John P. Burrows, Hideo Sagawa, Yasuko Kasai, Joachim Urban, Patrick Eriksson, Donal P. Murtagh, Mark E. Hervig, Charlotta Högberg, Dale F. Hurst, and Karen H. Rosenlof
Atmos. Meas. Tech., 12, 2693-2732, https://doi.org/10.5194/amt-12-2693-2019, 2019

Within the framework of the second SPARC (Stratosphere-troposphere Processes And their Role in Climate) water vapour assessment (WAVAS-II), profile-to-profile comparisons of stratospheric and lower mesospheric water vapour were performed by considering 33 data sets derived from satellite observations of 15 different instruments. These comparisons aimed to provide a picture of the typical biases and drifts in the observational database and to identify data-set-specific problems. The observational database typically exhibits the largest biases below 70 hPa, both in absolute and relative terms. The smallest biases are often found between 50 and 5 hPa. Typically, they range from 0.25 to 0.5 ppmv (5 % to 10 %) in this altitude region, based on the 50 % percentile over the different comparison results. Higher up, the biases increase with altitude overall but this general behaviour is accompanied by considerable variations. Characteristic values vary between 0.3 and 1 ppmv (4 % to 20 %). Obvious data-set-specific bias issues are found for a number of data sets. In our work we performed a drift analysis for data sets overlapping for a period of at least 36 months. This assessment shows a wide range of drifts among the different data sets that are statistically significant at the 2σ uncertainty level. In general, the smallest drifts are found in the altitude range between about 30 and 10 hPa. Histograms considering results from all altitudes indicate the largest occurrence for drifts between 0.05 and 0.3 ppmv decade−1. Comparisons of our drift estimates to those derived from comparisons of zonal mean time series only exhibit statistically significant differences in slightly more than 3 % of the comparisons. Hence, drift estimates from profile-to-profile and zonal mean time series comparisons are largely interchangeable. As for the biases, a number of data sets exhibit prominent drift issues. In our analyses we found that the large number of MIPAS data sets included in the assessment affects our general results as well as the bias summaries we provide for the individual data sets. This is because these data sets exhibit a relative similarity with respect to the remaining data sets, despite the fact that they are based on different measurement modes and different processors implementing different retrieval choices. Because of that, we have by default considered an aggregation of the comparison results obtained from MIPAS data sets. Results without this aggregation are provided on multiple occasions to characterise the effects due to the numerous MIPAS data sets. Among other effects, they cause a reduction of the typical biases in the observational database.

A New Instrument for Time Resolved Measurement of HO2 Radicals

Fri, 05/10/2019 - 16:13
A New Instrument for Time Resolved Measurement of HO2 Radicals
Thomas H. Speak, Mark A. Blitz, Daniel Stone, and Paul W. Seakins
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2019-164,2019
Manuscript under review for AMT (discussion: open, 1 comment)
OH and HO2 radicals are important trace constituents of the atmosphere that are closely coupled via several types of reaction. This paper describes a new laboratory method to simultaneously determine OH kinetics and HO2 yields from chemical processes. The instrument also provides some time resolution on HO2 detection allowing one to separate HO2 produced from the target reaction from HO2 arising from secondary chemistry. Examples of applications are presented.

Estimation of turbulence parameters from scanning lidars and in-situ instrumentation in the Perdigão 2017 campaign

Fri, 05/10/2019 - 16:13
Estimation of turbulence parameters from scanning lidars and in-situ instrumentation in the Perdigão 2017 campaign
Norman Wildmann, Nicola Bodini, Julie K. Lundquist, Ludovic Bariteau, and Johannes Wagner
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2019-171,2019
Manuscript under review for AMT (discussion: open, 0 comments)
The understanding of the sources, spatial distribution and temporal variability of turbulence in the atmospheric boundary layer (ABL) and improved simulation of its forcing processes require observations in a broad range of terrain types and atmospheric conditions. In this study, we estimate turbulence kinetic energy (TKE) dissipation rate using multiple techniques, including traditional in-situ measurements of sonic anemometers on meteorological towers, a hot-wire anemometer on a tethered lifting system (TLS), as well as remote-sensing retrievals from a vertically staring lidar and two lidars performing range-height indicator (RHI) scans. For the retrieval of ε from the lidar RHI scans, we introduce a modification of the Doppler Spectral Width (DSW) method. This method uses spatio-temporal averages of the variance of the line-of-sight (LOS) velocity and the turbulent broadening of the Doppler backscatter spectrum. We validate this method against the observations from the other instruments, also including uncertainty estimations for each method. The synthesis of the results from all instruments enables a detailed analysis of the spatial and temporal variability of ε across a valley between two parallel ridges at the Perdigão 2017 campaign. We find that the shear zones above and below nighttime low-level jets (LLJ) experience turbulence enhancements, as does the wake of a wind turbine (WT). We analyze in detail how ε varies in the early morning of 14 June 2017, when the turbulence in the valley, approximately eleven rotor diameters downstream of the WT, is still significantly enhanced by the WT wake.

Application of Parametric Speakers to Radio Acoustic Sounding System

Fri, 05/10/2019 - 16:13
Application of Parametric Speakers to Radio Acoustic Sounding System
Ahoro Adachi and Hiroyuki Hashiguchi
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2019-92,2019
Manuscript under review for AMT (discussion: open, 1 comment)
The radio acoustic sounding system is a remote sensing technique that provides vertical profiles of temperature in the air. Since RASS is accompanied with loud noise around the site, acoustic sources having low sidelobe levels has been desired. Thus, the application of parametric acoustic array as a high directivity acoustic source was exploited in this study. The results show that the PAA-RASS has accuracy and precision comparable with conventional RASS despite its high directivity of sound.

Theme by Danetsoft and Danang Probo Sayekti inspired by Maksimer