Articles | Volume 14, issue 4
https://doi.org/10.5194/amt-14-2749-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Special issue:
https://doi.org/10.5194/amt-14-2749-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
08 Apr 2021
Research article |
| 08 Apr 2021
| 08 Apr 2021
Integrated water vapor and liquid water path retrieval using a single-channel radiometer
Anne-Claire Billault-Roux
Environmental Remote Sensing Laboratory, Swiss Federal Institute of Technology, Lausanne, Switzerland
Environmental Remote Sensing Laboratory, Swiss Federal Institute of Technology, Lausanne, Switzerland
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Alfonso Ferrone, Anne-Claire Billault-Roux, and Alexis Berne
Atmos. Meas. Tech., 15, 3569–3592, https://doi.org/10.5194/amt-15-3569-2022, https://doi.org/10.5194/amt-15-3569-2022, 2022
Short summary
Short summary
The Micro Rain Radar PRO (MRR-PRO) is a meteorological radar, with a relevant set of features for deployment in remote locations. We developed an algorithm, named ERUO, for the processing of its measurements of snowfall. The algorithm addresses typical issues of the raw spectral data, such as interference lines, but also improves the quality and sensitivity of the radar variables. ERUO has been evaluated over four different datasets collected in Antarctica and in the Swiss Jura.
Jeong-Su Ko, Kyo-Sun Sunny Lim, Kwonil Kim, Gyuwon Lee, Gregory Thompson, and Alexis Berne
Geosci. Model Dev., 15, 4529–4553, https://doi.org/10.5194/gmd-15-4529-2022, https://doi.org/10.5194/gmd-15-4529-2022, 2022
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This study evaluates the performance of the four microphysics parameterizations, the WDM6, WDM7, Thompson, and Morrison schemes, in simulating snowfall events during the ICE-POP 2018 field campaign. Eight snowfall events are selected and classified into three categories (cold-low, warm-low, and air–sea interaction cases). The evaluation focuses on the simulated hydrometeors, microphysics budgets, wind fields, and precipitation using the measurement data.
Paraskevi Georgakaki, Georgia Sotiropoulou, Étienne Vignon, Anne-Claire Billault-Roux, Alexis Berne, and Athanasios Nenes
Atmos. Chem. Phys., 22, 1965–1988, https://doi.org/10.5194/acp-22-1965-2022, https://doi.org/10.5194/acp-22-1965-2022, 2022
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Monika Feldmann, Urs Germann, Marco Gabella, and Alexis Berne
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Mesocyclones are the rotating updraught of supercell thunderstorms that present a particularly hazardous subset of thunderstorms. A first-time characterisation of the spatiotemporal occurrence of mesocyclones in the Alpine region is presented, using 5 years of Swiss operational radar data. We investigate parallels to hailstorms, particularly the influence of large-scale flow, daily cycles and terrain. Improving understanding of mesocyclones is valuable for risk assessment and warning purposes.
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
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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.
Marc Schwaerzel, Dominik Brunner, Fabian Jakub, Claudia Emde, Brigitte Buchmann, Alexis Berne, and Gerrit Kuhlmann
Atmos. Meas. Tech., 14, 6469–6482, https://doi.org/10.5194/amt-14-6469-2021, https://doi.org/10.5194/amt-14-6469-2021, 2021
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NO2 maps from airborne imaging remote sensing often appear much smoother than one would expect from high-resolution model simulations of NO2 over cities, despite the small ground-pixel size of the sensors. Our case study over Zurich, using the newly implemented building module of the MYSTIC radiative transfer solver, shows that the 3D effect can explain part of the smearing and that building shadows cause a noticeable underestimation and noise in the measured NO2 columns.
Anna Špačková, Vojtěch Bareš, Martin Fencl, Marc Schleiss, Joël Jaffrain, Alexis Berne, and Jörg Rieckermann
Earth Syst. Sci. Data, 13, 4219–4240, https://doi.org/10.5194/essd-13-4219-2021, https://doi.org/10.5194/essd-13-4219-2021, 2021
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An original dataset of microwave signal attenuation and rainfall variables was collected during 1-year-long field campaign. The monitored 38 GHz dual-polarized commercial microwave link with a short sampling resolution (4 s) was accompanied by five disdrometers and three rain gauges along its path. Antenna radomes were temporarily shielded for approximately half of the campaign period to investigate antenna wetting impacts.
Paraskevi Georgakaki, Aikaterini Bougiatioti, Jörg Wieder, Claudia Mignani, Fabiola Ramelli, Zamin A. Kanji, Jan Henneberger, Maxime Hervo, Alexis Berne, Ulrike Lohmann, and Athanasios Nenes
Atmos. Chem. Phys., 21, 10993–11012, https://doi.org/10.5194/acp-21-10993-2021, https://doi.org/10.5194/acp-21-10993-2021, 2021
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Aerosol and cloud observations coupled with a droplet activation parameterization was used to investigate the aerosol–cloud droplet link in alpine mixed-phase clouds. Predicted droplet number, Nd, agrees with observations and never exceeds a characteristic “limiting droplet number”, Ndlim, which depends solely on σw. Nd becomes velocity limited when it is within 50 % of Ndlim. Identifying when dynamical changes control Nd variability is central for understanding aerosol–cloud interactions.
Noémie Planat, Josué Gehring, Étienne Vignon, and Alexis Berne
Atmos. Meas. Tech., 14, 4543–4564, https://doi.org/10.5194/amt-14-4543-2021, https://doi.org/10.5194/amt-14-4543-2021, 2021
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We implement a new method to identify microphysical processes during cold precipitation events based on the sign of the vertical gradient of polarimetric radar variables. We analytically asses the meteorological conditions for this vertical analysis to hold, apply it on two study cases and successfully compare it with other methods informing about the microphysics. Finally, we are able to obtain the main vertical structure and characteristics of the different processes during these study cases.
Daniel Wolfensberger, Marco Gabella, Marco Boscacci, Urs Germann, and Alexis Berne
Atmos. Meas. Tech., 14, 3169–3193, https://doi.org/10.5194/amt-14-3169-2021, https://doi.org/10.5194/amt-14-3169-2021, 2021
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In this work, we present a novel quantitative precipitation estimation method for Switzerland that uses random forests, an ensemble-based machine learning technique. The estimator has been trained with a database of 4 years of ground and radar observations. The results of an in-depth evaluation indicate that, compared with the more classical method in use at MeteoSwiss, this novel estimator is able to reduce both the average error and bias of the predictions.
Josué Gehring, Alfonso Ferrone, Anne-Claire Billault-Roux, Nikola Besic, Kwang Deuk Ahn, GyuWon Lee, and Alexis Berne
Earth Syst. Sci. Data, 13, 417–433, https://doi.org/10.5194/essd-13-417-2021, https://doi.org/10.5194/essd-13-417-2021, 2021
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This article describes a dataset of precipitation and cloud measurements collected from November 2017 to March 2018 in Pyeongchang, South Korea. The dataset includes weather radar data and images of snowflakes. It allows for studying the snowfall intensity; wind conditions; and shape, size and fall speed of snowflakes. Classifications of the types of snowflakes show that aggregates of ice crystals were dominant. This dataset represents a unique opportunity to study snowfall in this region.
Georgia Sotiropoulou, Étienne Vignon, Gillian Young, Hugh Morrison, Sebastian J. O'Shea, Thomas Lachlan-Cope, Alexis Berne, and Athanasios Nenes
Atmos. Chem. Phys., 21, 755–771, https://doi.org/10.5194/acp-21-755-2021, https://doi.org/10.5194/acp-21-755-2021, 2021
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Summer clouds have a significant impact on the radiation budget of the Antarctic surface and thus on ice-shelf melting. However, these are poorly represented in climate models due to errors in their microphysical structure, including the number of ice crystals that they contain. We show that breakup from ice particle collisions can substantially magnify the ice crystal number concentration with significant implications for surface radiation. This process is currently missing in climate models.
Cited articles
Bevis, M., Businger, S., Chiswell, S., Herring, T. A., Anthes, R. A., Rocken,
C., and Ware, R. H.: GPS Meteorology: Mapping Zenith Wet Delays onto
Precipitable Water, J. Appl. Meteorol. Clim., 33, 379–386, https://doi.org/10.1175/1520-0450(1994)033<0379:GMMZWD>2.0.CO;2, 1994. a
Cadeddu, M. P., Turner, D. D., and Liljegren, J. C.: A Neural Network for
Real-Time Retrievals of PWV and LWP From Arctic Millimeter-Wave Ground-Based
Observations, IEEE T. Geosci. Remote, 47, 1887–1900, https://doi.org/10.1109/TGRS.2009.2013205, 2009. a, b
Cadeddu, M. P., Liljegren, J. C., and Turner, D. D.: The Atmospheric radiation measurement (ARM) program network of microwave radiometers: instrumentation, data, and retrievals, Atmos. Meas. Tech., 6, 2359–2372, https://doi.org/10.5194/amt-6-2359-2013, 2013. a
Cadeddu, M. P., Marchand, R., Orlandi, E., Turner, D. D., and Mech,
M.: Microwave Passive Ground-Based Retrievals of Cloud and Rain Liquid Water
Path in Drizzling Clouds: Challenges and Possibilities, IEEE T. Geosci. Remote, 55, 6468–6481, https://doi.org/10.1109/TGRS.2017.2728699, 2017. a, b
Cadeddu, M. P., Ghate, V. P., and Mech, M.: Ground-based observations of cloud and drizzle liquid water path in stratocumulus clouds, Atmos. Meas. Tech., 13, 1485–1499, https://doi.org/10.5194/amt-13-1485-2020, 2020. a, b
Chollet, F.: Keras, available at: https://keras.io/ (last access: 10 February 2021), 2015. a
Chollet, F.: Deep Learning with Python, Manning, ISBN: 9781617294433, 2017. a
Ebell, K., Löhnert, U., Crewell, S., and Turner, D. D.: On characterizing
the error in a remotely sensed liquid water content
profile, Atmos. Res., 98, 57–68, https://doi.org/10.1016/j.atmosres.2010.06.002, 2010. a
Ebell, K., Löhnert, U., Päschke, E., Orlandi, E., Schween, J. H., and
Crewell, S.: A 1D variational retrieval of temperature, humidity, and liquid
cloud properties: Performance under idealized and real conditions, J. Geophys. Res.-Atmos., 122, 1746–1766, https://doi.org/10.1002/2016JD025945, 2017. a, b
Ellison, W. J.: Permittivity of Pure Water, at Standard Atmospheric Pressure,
over the Frequency Range 0–25 THz and the Temperature Range 0–100 ∘C, J. Phys. Chem. Ref. Data, 36, 1–18,
https://doi.org/10.1063/1.2360986, 2007. a
Gaussiat, N., Hogan, R. J., and Illingworth, A. J.: Accurate Liquid Water Path Retrieval from Low-Cost Microwave Radiometers Using Additional Information from a Lidar Ceilometer and Operational Forecast Models,
J. Atmos. Ocean. Tech., 24, 1562–1575, https://doi.org/10.1175/JTECH2053.1, 2007. a
Gehring, J., Ferrone, A., Billault-Roux, A.-C., Besic, N., Ahn, K. D., Lee, G., and Berne, A.: Radar and ground-level measurements of precipitation collected by the École Polytechnique Fédérale de Lausanne during the International Collaborative Experiments for PyeongChang 2018 Olympic and Paralympic winter games, Earth Syst. Sci. Data, 13, 417–433, https://doi.org/10.5194/essd-13-417-2021, 2021. a
Hartmann, D. L. and Short, D. A.: On the Use of Earth Radiation Budget
Statistics for Studies of Clouds and Climate, J. Atmos. Sci., 37, 1233–1250,
https://doi.org/10.1175/1520-0469(1980)037<1233:OTUOER>2.0.CO;2, 1980. a
Hartmann, D. L., Ockert-Bell, M. E., and Michelsen, M. L.: The Effect of Cloud Type on Earth's Energy Balance: Global Analysis, J. Climate, 5,
1281–1304, https://doi.org/10.1175/1520-0442(1992)005<1281:TEOCTO>2.0.CO;2, 1992. a
Karstens, U., Simmer, C., and Ruprecht, E.: Remote sensing of cloud liquid
water, Meteorol. Atmos. Phys., 54, 157–171, https://doi.org/10.1007/BF01030057, 1994. a, b
Kneifel, S., Löhnert, U., Battaglia, A., Crewell, S., and Siebler, D.: Snow scattering signals in ground-based passive microwave radiometer measurements, J. Geophys. Res.-Atmos., 115, D16214, https://doi.org/10.1029/2010JD013856, 2010. a, b
Lenaerts, J. T. M., Van Tricht, K., Lhermitte, S., and L'Ecuyer, T. S.: Polar
clouds and radiation in satellite observations, reanalyses, and climate
models, Geophys. Res. Lett., 44, 3355–3364,
https://doi.org/10.1002/2016GL072242, 2017. a
Liljegren, J. C., Clothiaux, E. E., Mace, G. G., Kato, S., and Dong, X.: A new retrieval for cloud liquid water path using a ground-based microwave
radiometer and measurements of cloud temperature, J. Geophys. Res.-Atmos., 106, 14485–14500, https://doi.org/10.1029/2000JD900817, 2001. a
Liljegren, J. C., Boukabara, S.-A., Cady-Pereira, K., and Clough, S. A.:
The effect of the half-width of the 22 GHz water vapor line on retrievals of
temperature and water vapor profiles with a 12-channel microwave radiometer,
IEEE T. Geosci. Remote, 43, 1102–1108,
https://doi.org/10.1109/TGRS.2004.839593, 2005. a
Löhnert, U. and Crewell, S.: Accuracy of cloud liquid water path from
ground-based microwave radiometry 1. Dependency on cloud model
statistics, Radio Sci., 38, 8041, https://doi.org/10.1029/2002RS002654, 2003. a, b
Löhnert, U. and Maier, O.: Operational profiling of temperature using ground-based microwave radiometry at Payerne: prospects and challenges, Atmos. Meas. Tech., 5, 1121–1134, https://doi.org/10.5194/amt-5-1121-2012, 2012. a
Löhnert, U., Crewell, S., and Simmer, C.: An Integrated Approach toward
Retrieving Physically Consistent Profiles of Temperature, Humidity, and Cloud
Liquid Water, J. Appl. Meteorol., 43, 1295–1307,
https://doi.org/10.1175/1520-0450(2004)043<1295:AIATRP>2.0.CO;2, 2004. a
Maahn, M.: Exploiting vertically pointing Doppler radar for advancing snow and ice cloud observations, PhD thesis, Universität zu Köln, Cologne, Germany, 2015. a
Mace, G. G., Benson, S., Sonntag, K. L., Kato, S., Min, Q., Minnis, P., Twohy, C. H., Poellot, M., Dong, X., Long, C., Zhang, Q., and Doelling, D. R.: Cloud radiative forcing at the Atmospheric Radiation Measurement Program Climate Research Facility: 1. Technique, validation, and comparison to satellite-derived diagnostic quantities, J. Geophys. Res.-Atmos., 111, D11S90, https://doi.org/10.1029/2005JD005921, 2006. a
Mallet, C., Moreau, E., Casagrande, L., and Klapisz, C.: Determination of
integrated cloud liquid water path and total precipitable water from SSM/I
data using a neural network algorithm,
Int. J. Remote Sens., 23, 661–674, https://doi.org/10.1080/01431160110045959, 2002. a
Massaro, G., Stiperski, I., Pospichal, B., and Rotach, M. W.: Accuracy of retrieving temperature and humidity profiles by ground-based microwave radiometry in truly complex terrain, Atmos. Meas. Tech., 8, 3355–3367, https://doi.org/10.5194/amt-8-3355-2015, 2015. a, b
Mattioli, V., Basili, P., Bonafoni, S., Ciotti, P., and Westwater, E. R.:
Analysis and improvements of cloud models for propagation studies, Radio Sci., 44, RS2005, https://doi.org/10.1029/2008RS003876, 2009. a, b
Mätzler, C. and Morland, J.: Refined Physical Retrieval of Integrated
Water Vapor and Cloud Liquid for Microwave Radiometer Data, IEEE T. Geosci. Remote, 47, 1585–1594, https://doi.org/10.1109/TGRS.2008.2006984, 2009. a
McFarlane, S. A., Mather, J. H., Ackerman, T. P., and Liu, Z.: Effect of clouds on the calculated vertical distribution of shortwave absorption in the
tropics, J. Geophys. Res., 113, D18203, https://doi.org/10.1029/2008JD009791, 2008. a
Mech, M., Maahn, M., Kneifel, S., Ori, D., Orlandi, E., Kollias, P., Schemann, V., and Crewell, S.: PAMTRA 1.0: the Passive and Active Microwave radiative TRAnsfer tool for simulating radiometer and radar measurements of the cloudy atmosphere, Geosci. Model Dev., 13, 4229–4251, https://doi.org/10.5194/gmd-13-4229-2020, 2020. a
Oolman, L.: Atmospheric Soundings, University of Wyoming, College of Engineering, Department of Atmospheric Science, Worldwide Radiosonde Soundings of the Atmosphere, data available at:
http://weather.uwyo.edu/upperair/sounding.html, last access: 28 November 2020. a
Pierdicca, N., Pulvirenti, L., and Marzano, F. S.: A model to predict cloud
density from midlatitude atmospheric soundings for microwave radiative
transfer applications, Radio Sci., 41, RS6005, https://doi.org/10.1029/2006RS003463,
2006. a
Poulida, O., Schwikowski, M., Baltensperger, U., Staehelin, J., and Gaeggeler, H.: Scavenging of atmospheric constituents in mixed phase clouds at the high-alpine site jungfraujoch – part II: Influence of riming on the
scavenging of particulate and gaseous chemical species, Atmos. Environ., 32, 3985–4000, https://doi.org/10.1016/S1352-2310(98)00131-9, 1998. a
Rose, T., Crewell, S., Löhnert, U., and Simmer, C.: A network suitable
microwave radiometer for operational monitoring of the cloudy atmosphere, Atmos. Res., 75, 183–200, https://doi.org/10.1016/j.atmosres.2004.12.005, 2005. a
Rosenkranz, P. W.: Water vapor microwave continuum absorption: A comparison of measurements and models, Radio Sci., 33, 919–928, https://doi.org/10.1029/98RS01182, 1998. a
RPG Radiometer Physics GmbH: Humidity And Temperature PROfilers, available at:
https://www.radiometer-physics.de/products/microwave-remote-sensing-instruments/radiometers/humidity-and-temperature-profilers/#tabs-container-0 (last access: 28 November 2020), 2014. a
Saleeby, S. M., Cotton, W. R., and Fuller, J. D.: The Cumulative Impact of
Cloud Droplet Nucleating Aerosols on Orographic Snowfall in Colorado,
J. Appl. Meteorol. Clim., 50, 604–625, https://doi.org/10.1175/2010JAMC2594.1, 2011. a
Salonen, E. and Uppala, S.: New prediction method of cloud
attenuation, Electron. Lett., 27, 1106–1108, https://doi.org/10.1049/el:19910687, 1991. a
Slingo, A.: Sensitivity of the Earth's radiation budget to changes in low
clouds, Nature, 343, 49–51, https://doi.org/10.1038/343049a0, 1990. a
Stephens, G. L.: Cloud Feedbacks in the Climate System: A Critical Review,
J. Climate, 18, 237–273, https://doi.org/10.1175/JCLI-3243.1, 2005. a
Turner, D. D., Clough, S. A., Liljegren, J. C., Clothiaux, E. E.,
Cady-Pereira, K. E., and Gaustad, K. L.: Retrieving Liquid Wat0er Path
and Precipitable Water Vapor From the Atmospheric Radiation Measurement (ARM)
Microwave Radiometers, IEEE T. Geosci. Remote, 45, 3680–3690, https://doi.org/10.1109/TGRS.2007.903703, 2007. a, b
Turner, D. D., Cadeddu, M. P., Lohnert, U., Crewell, S., and
Vogelmann, A. M.: Modifications to the Water Vapor Continuum in the
Microwave Suggested by Ground-Based 150 GHz Observations, IEEE T. Geosci. Remote, 47, 3326–3337, https://doi.org/10.1109/TGRS.2009.2022262, 2009.
a
Wang, J. and Rossow, W. B.: Effects of Cloud Vertical Structure on Atmospheric
Circulation in the GISS GCM, J. Climate, 11, 3010–3029,
https://doi.org/10.1175/1520-0442(1998)011<3010:EOCVSO>2.0.CO;2, 1998. a
Westwater, E. R., Han, Y., Shupe, M. D., and Matrosov, S. Y.: Analysis of
integrated cloud liquid and precipitable water vapor retrievals from
microwave radiometers during the Surface Heat Budget of the Arctic Ocean
project, J. Geophys. Res.-Atmos., 106, 32019–32030,
https://doi.org/10.1029/2000JD000055, 2001. a
Zhang, G., Vivekanandan, J., and Politovich, M.: Scattering Effects On
Microwave Passive Remote Sensing of Cloud Parameters, in: The 8th Conference
on Aviation, Range, and Aerospace Meteorology, Dallas, Texas, American Meteorological Society, 497–501, 10–15 January 1999. a
Short summary
In the context of climate studies, understanding the role of clouds on a global and local scale is of paramount importance. One aspect is the quantification of cloud liquid water, which impacts the Earth’s radiative balance. This is routinely achieved with radiometers operating at different frequencies. In this study, we propose an approach that uses a single-frequency radiometer and that can be applied at any location to retrieve vertically integrated quantities of liquid water and water vapor.
In the context of climate studies, understanding the role of clouds on a global and local scale...
