A machine-learning-based cloud detection and thermodynamic-phase classification algorithm using passive spectral observations
Chenxi Wang, Steven Platnick, Kerry Meyer, Zhibo Zhang, and Yaping Zhou
Atmos. Meas. Tech., 13, 2257–2277, https://doi.org/10.5194/amt-13-2257-2020, 2020
A machine-learning (ML)-based approach that can be used for cloud mask and phase detection is developed. An all-day model that uses infrared (IR) observations and a daytime model that uses shortwave and IR observations from a passive instrument are trained separately for different surface types. The training datasets are selected by using reference pixel types from collocated space lidar. The ML approach is validated carefully and the overall performance is better than traditional methods.
Toward a variational assimilation of polarimetric radar observations in a convective-scale numerical weather prediction (NWP) model
Guillaume Thomas, Jean-François Mahfouf, and Thibaut Montmerle
Atmos. Meas. Tech., 13, 2279–2298, https://doi.org/10.5194/amt-13-2279-2020, 2020
This paper presents the potential of a polarimetric weather radar observation operator for hydrometeor content initialization. The non-linear operator allows to simulate ZHH, ZDR, KDP and ρHV, using the T-Matrix method, prognostic variables forecasted by the AROME-France NWP model and a one-moment microphysical scheme. After sensitivity studies, it has been found that ZHH and ZDR are good candidates for hydrometeor initialization and that KDP seems useful for rain content only.
Validation of the vertical profiles of HCl over the wide range of the stratosphere to the lower thermosphere measured by SMILES
Seidai Nara, Tomohiro O. Sato, Takayoshi Yamada, Tamaki Fujinawa, Kota Kuribayashi, Takeshi Manabe, Lucien Froidevaux, Nathaniel J. Livesey, Kaley A. Walker, Jian Xu, Franz Schreier, Yvan J. Orsolini, Varavut Limpasuvan, Nario Kuno, and Yasuko Kasai
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2020-105,2020
Preprint under review for AMT (discussion: open, 0 comments)
In the atmosphere, more than 80 % of chlorine compounds are anthropogenic. Hydrogen chloride (HCl), the main stratospheric chlorine reservoir, is useful to estimate the total budget of the atmospheric chlorine compounds. We for the first time report the HCl vertical distribution from the middle troposphere to the lower thermosphere using a high sensitive SMILES measurement; the data quality is quantified by comparisons with other measurements and via theoretical error analysis.
Validation of the vertical profiles of HCl over the wide range of the stratosphere to the lower thermosphere measured by SMILES
Seidai Nara, Tomohiro O. Sato, Takayoshi Yamada, Tamaki Fujinawa, Kota Kuribayashi, Takeshi Manabe, Lucien Froidevaux, Nathaniel J. Livesey, Kaley A. Walker, Jian Xu, Franz Schreier, Yvan J. Orsolini, Varavut Limpasuvan, Nario Kuno, and Yasuko Kasai
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-105,2020
Preprint under review for AMT (discussion: open, 0 comments)
In the atmosphere, more than 80 % of chlorine compounds are anthropogenic. Hydrogen chloride (HCl), the main stratospheric chlorine reservoir, is useful to estimate the total budget of the atmospheric chlorine compounds. We for the first time report the HCl vertical distribution from the middle troposphere to the lower thermosphere using a high sensitive SMILES measurement; the data quality is quantified by comparisons with other measurements and via theoretical error analysis.
Evaluation of single-footprint AIRS CH4 Profile Retrieval Uncertainties Using Aircraft Profile Measurements
Susan S. Kulawik, John R. Worden, Vivienne H. Payne, Dejian Fu, Steve C. Wofsy, Kathryn McKain, Colm Sweeney, Bruce C. Daube Jr., Alan Lipton, Igor Polonsky, Yuguang He, Karen E. Cady-Pereira, Edward J. Dlugokencky, Daniel J. Jacob, and Yi Yin
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-145,2020
Preprint under review for AMT (discussion: open, 0 comments)
This paper shows comparisons of a new methane product from the AIRS satellite to aircraft-based observations. We show that this AIRS methane product provides useful information to study seasonal and global methane trends of this important greenhouse gas.
A convolutional neural network for classifying cloud particles recorded by imaging probes
Georgios Touloupas, Annika Lauber, Jan Henneberger, Alexander Beck, and Aurélien Lucchi
Atmos. Meas. Tech., 13, 2219–2239, https://doi.org/10.5194/amt-13-2219-2020, 2020
Images of cloud particles give important information for improving our understanding of microphysical cloud processes. For phase-resolved measurements, a large number of water droplets and ice crystals need to be classified by an automated approach. In this study, a convolutional neural network was designed, which exceeds the classification ability of traditional methods and therefore shortens the analysis procedure of cloud particle images.
Intercomparison study of atmospheric 222Rn and 222Rn progeny monitors
Claudia Grossi, Scott D. Chambers, Olivier Llido, Felix R. Vogel, Victor Kazan, Alessandro Capuana, Sylvester Werczynski, Roger Curcoll, Marc Delmotte, Arturo Vargas, Josep-Anton Morguí, Ingeborg Levin, and Michel Ramonet
Atmos. Meas. Tech., 13, 2241–2255, https://doi.org/10.5194/amt-13-2241-2020, 2020
The sustainable support of radon metrology at the environmental level offers new scientific possibilities for the quantification of greenhouse gas (GHG) emissions and the determination of their source terms as well as for the identification of radioactive sources for the assessment of radiation exposure. This study helps to harmonize the techniques commonly used for atmospheric radon and radon progeny activity concentration measurements.
Validation of XCO2 and XCH4 retrieved from a portable Fourier transform spectrometer with those from in-situ profiles from aircraft borne instruments
Hirofumi Ohyama, Isamu Morino, Voltaire A. Velazco, Theresa Klausner, Gerry Bagtasa, Matthäus Kiel, Matthias Frey, Akihiro Hori, Osamu Uchino, Tsuneo Matsunaga, Nicholas Deutscher, Joshua P. DiGangi, Yonghoon Choi, Glenn S. Diskin, Sally E. Pusede, Alina Fiehn, Anke Roiger, Michael Lichtenstern, Hans Schlager, Pao K. Wang, Charles C.-K. Cho, Maria Dolores Andrés-Hernández, and John P. Burrows
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2020-170,2020
Preprint under review for AMT (discussion: open, 0 comments)
Column-averaged dry-air mole fractions of CO2 and CH4 measured by a solar viewing portable Fourier transform spectrometer (EM27/SUN) were validated with in-situ profile data obtained during the transfer flights of two aircraft campaigns. Atmospheric dynamical properties based on ERA5 and WRF-Chem were used as criteria for selecting the best aircraft profiles for the validation. The resulting air mass independent correction factors for the EM27/SUN data were 0.9878 for CO2 and 0.9833 for CH4.
A convolutional neural network for classifying cloud particles recorded by imaging probes
Georgios Touloupas, Annika Lauber, Jan Henneberger, Alexander Beck, and Aurélien Lucchi
Atmos. Meas. Tech., 13, 2219–2239, https://doi.org/10.5194/amt-13-2219-2020, 2020
Images of cloud particles give important information for improving our understanding of microphysical cloud processes. For phase-resolved measurements, a large number of water droplets and ice crystals need to be classified by an automated approach. In this study, a convolutional neural network was designed, which exceeds the classification ability of traditional methods and therefore shortens the analysis procedure of cloud particle images.
Intercomparison study of atmospheric 222Rn and 222Rn progeny monitors
Claudia Grossi, Scott D. Chambers, Olivier Llido, Felix R. Vogel, Victor Kazan, Alessandro Capuana, Sylvester Werczynski, Roger Curcoll, Marc Delmotte, Arturo Vargas, Josep-Anton Morguí, Ingeborg Levin, and Michel Ramonet
Atmos. Meas. Tech., 13, 2241–2255, https://doi.org/10.5194/amt-13-2241-2020, 2020
The sustainable support of radon metrology at the environmental level offers new scientific possibilities for the quantification of greenhouse gas (GHG) emissions and the determination of their source terms as well as for the identification of radioactive sources for the assessment of radiation exposure. This study helps to harmonize the techniques commonly used for atmospheric radon and radon progeny activity concentration measurements.
Validation of XCO2 and XCH4 retrieved from a portable Fourier transform spectrometer with those from in-situ profiles from aircraft borne instruments
Hirofumi Ohyama, Isamu Morino, Voltaire A. Velazco, Theresa Klausner, Gerry Bagtasa, Matthäus Kiel, Matthias Frey, Akihiro Hori, Osamu Uchino, Tsuneo Matsunaga, Nicholas Deutscher, Joshua P. DiGangi, Yonghoon Choi, Glenn S. Diskin, Sally E. Pusede, Alina Fiehn, Anke Roiger, Michael Lichtenstern, Hans Schlager, Pao K. Wang, Charles C.-K. Cho, Maria Dolores Andrés-Hernández, and John P. Burrows
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-170,2020
Preprint under review for AMT (discussion: open, 0 comments)
Column-averaged dry-air mole fractions of CO2 and CH4 measured by a solar viewing portable Fourier transform spectrometer (EM27/SUN) were validated with in-situ profile data obtained during the transfer flights of two aircraft campaigns. Atmospheric dynamical properties based on ERA5 and WRF-Chem were used as criteria for selecting the best aircraft profiles for the validation. The resulting air mass independent correction factors for the EM27/SUN data were 0.9878 for CO2 and 0.9833 for CH4.
Evaluation of single-footprint AIRS CH4 Profile Retrieval Uncertainties Using Aircraft Profile Measurements
Susan S. Kulawik, John R. Worden, Vivienne H. Payne, Dejian Fu, Steve C. Wofsy, Kathryn McKain, Colm Sweeney, Bruce C. Daube Jr., Alan Lipton, Igor Polonsky, Yuguang He, Karen E. Cady-Pereira, Edward J. Dlugokencky, Daniel J. Jacob, and Yi Yin
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2020-145,2020
Preprint under review for AMT (discussion: open, 0 comments)
This paper shows comparisons of a new methane product from the AIRS satellite to aircraft-based observations. We show that this AIRS methane product provides useful information to study seasonal and global methane trends of this important greenhouse gas.
Mapping ice formation to mineral-surface topography using a micro mixing chamber with video and atomic-force microscopy
Raymond W. Friddle and Konrad Thürmer
Atmos. Meas. Tech., 13, 2209–2218, https://doi.org/10.5194/amt-13-2209-2020, 2020
An obstacle to predicting ice content in mixed-phase clouds is the inability to directly view atmospheric ice nucleation at the nanoscale, where this process occurs. Here we show how a cloud-like environment can be created in a small atomic-force microscopy (AFM) sample cell. By colocating video microscopy of ice formation with high-resolution AFM images, we quantitatively show how the surface topography, down to nanometer-length scales, can determine the preferential locations of ice formation.
Improved chloride quantification in quadrupole aerosol chemical speciation monitors (Q-ACSMs)
Anna K. Tobler, Alicja Skiba, Dongyu S. Wang, Philip Croteau, Katarzyna Styszko, Jarosław Nęcki, Urs Baltensperger, Jay G. Slowik, and André S. H. Prévôt
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-117,2020
Preprint under review for AMT (discussion: open, 0 comments)
Some quadrupole aerosol chemical speciation monitors (Q-ACSMs) have shown issues with the quantification of particulate chloride, resulting in apparent negative chloride concentrations. We can show that this is due to the different behavior of Cl+ and HCl+ and we present a correction for more accurate quantification of chloride. The correction can be applied for measurements in environments where the particulate chloride is dominated by NH4Cl.
TomoSim: a tomographic simulator for DOAS
Rui Valente de Almeida, Nuno Matela, and Pedro Vieira
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-26,2020
Preprint under review for AMT (discussion: open, 0 comments)
Air pollution is quite literally one of the most present concerns of modern day Western societies. It is widely recognized (namely by the European Union) that technology plays a very important role in the fighting of this problem. One of such technologies is the spectroscopic measurement of air pollutant concentration known as DOAS. In this paper, the technique is applied with an Unmanned Aerial Vehicle, using tomographic techniques to map pollutant concentration in two dimensions.
Mapping ice formation to mineral-surface topography using a micro mixing chamber with video and atomic-force microscopy
Raymond W. Friddle and Konrad Thürmer
Atmos. Meas. Tech., 13, 2209–2218, https://doi.org/10.5194/amt-13-2209-2020, 2020
An obstacle to predicting ice content in mixed-phase clouds is the inability to directly view atmospheric ice nucleation at the nanoscale, where this process occurs. Here we show how a cloud-like environment can be created in a small atomic-force microscopy (AFM) sample cell. By colocating video microscopy of ice formation with high-resolution AFM images, we quantitatively show how the surface topography, down to nanometer-length scales, can determine the preferential locations of ice formation.
Improved chloride quantification in quadrupole aerosol chemical speciation monitors (Q-ACSMs)
Anna K. Tobler, Alicja Skiba, Dongyu S. Wang, Philip Croteau, Katarzyna Styszko, Jarosław Nęcki, Urs Baltensperger, Jay G. Slowik, and André S. H. Prévôt
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2020-117,2020
Preprint under review for AMT (discussion: open, 0 comments)
Some quadrupole aerosol chemical speciation monitors (Q-ACSMs) have shown issues with the quantification of particulate chloride, resulting in apparent negative chloride concentrations. We can show that this is due to the different behavior of Cl+ and HCl+ and we present a correction for more accurate quantification of chloride. The correction can be applied for measurements in environments where the particulate chloride is dominated by NH4Cl.
TomoSim: a tomographic simulator for DOAS
Rui Valente de Almeida, Nuno Matela, and Pedro Vieira
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2020-26,2020
Preprint under review for AMT (discussion: open, 0 comments)
Air pollution is quite literally one of the most present concerns of modern day Western societies. It is widely recognized (namely by the European Union) that technology plays a very important role in the fighting of this problem. One of such technologies is the spectroscopic measurement of air pollutant concentration known as DOAS. In this paper, the technique is applied with an Unmanned Aerial Vehicle, using tomographic techniques to map pollutant concentration in two dimensions.
Intercomparison of NO2, O4, O3 and HCHO slant column measurements by MAX-DOAS and zenith-sky UV–visible spectrometers during CINDI-2
Karin Kreher, Michel Van Roozendael, Francois Hendrick, Arnoud Apituley, Ermioni Dimitropoulou, Udo Frieß, Andreas Richter, Thomas Wagner, Johannes Lampel, Nader Abuhassan, Li Ang, Monica Anguas, Alkis Bais, Nuria Benavent, Tim Bösch, Kristof Bognar, Alexander Borovski, Ilya Bruchkouski, Alexander Cede, Ka Lok Chan, Sebastian Donner, Theano Drosoglou, Caroline Fayt, Henning Finkenzeller, David Garcia-Nieto, Clio Gielen, Laura Gómez-Martín, Nan Hao, Bas Henzing, Jay R. Herman, Christian Hermans, Syedul Hoque, Hitoshi Irie, Junli Jin, Paul Johnston, Junaid Khayyam Butt, Fahim Khokhar, Theodore K. Koenig, Jonas Kuhn, Vinod Kumar, Cheng Liu, Jianzhong Ma, Alexis Merlaud, Abhishek K. Mishra, Moritz Müller, Monica Navarro-Comas, Mareike Ostendorf, Andrea Pazmino, Enno Peters, Gaia Pinardi, Manuel Pinharanda, Ankie Piters, Ulrich Platt, Oleg Postylyakov, Cristina Prados-Roman, Olga Puentedura, Richard Querel, Alfonso Saiz-Lopez, Anja Schönhardt, Stefan F. Schreier, André Seyler, Vinayak Sinha, Elena Spinei, Kimberly Strong, Frederik Tack, Xin Tian, Martin Tiefengraber, Jan-Lukas Tirpitz, Jeroen van Gent, Rainer Volkamer, Mihalis Vrekoussis, Shanshan Wang, Zhuoru Wang, Mark Wenig, Folkard Wittrock, Pinhua H. Xie, Jin Xu, Margarita Yela, Chengxin Zhang, and Xiaoyi Zhao
Atmos. Meas. Tech., 13, 2169–2208, https://doi.org/10.5194/amt-13-2169-2020, 2020
In September 2016, 36 spectrometers from 24 institutes measured a number of key atmospheric pollutants during an instrument intercomparison campaign (CINDI-2) at Cabauw, the Netherlands. Here we report on the outcome of this intercomparison exercise. The three major goals were to characterise the differences between the participating instruments, to define a robust methodology for performance assessment, and to contribute to the harmonisation of the measurement settings and retrieval methods.
Variability of the Brunt-Väisälä frequency at the OH-airglow layer
height at low and mid latitudes
Sabine Wüst, Michael Bittner, Jeng-Hwa Yee, Martin G. Mlynczak, and James M. Russell III
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2020-73,2020
Preprint under review for AMT (discussion: open, 0 comments)
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 mid latitudes based on 18 years of satellite data.
