UP1.5 | Atmospheric measurements: Instruments, experiments, networks and long-term programs using in-situ and remote sensing techniques
Atmospheric measurements: Instruments, experiments, networks and long-term programs using in-situ and remote sensing techniques
Convener: Frank Beyrich | Co-conveners: Jens Bange, Domenico Cimini, Mariska Koning
Orals Wed3
| Wed, 10 Sep, 14:00–15:30 (CEST)
 
Room M1
Orals Wed4
| Wed, 10 Sep, 16:00–17:15 (CEST)
 
Room M1
Orals Thu1
| Thu, 11 Sep, 09:00–10:30 (CEST)
 
Room M1
Orals Thu2
| Thu, 11 Sep, 11:00–13:00 (CEST)
 
Room M1
Posters P-Thu
| Attendance Thu, 11 Sep, 16:00–17:15 (CEST) | Display Wed, 10 Sep, 08:00–Fri, 12 Sep, 13:00
 
Grand Hall, P80–84
Wed, 14:00
Wed, 16:00
Thu, 09:00
Thu, 11:00
Thu, 16:00
Measurements are essential to provide information on the actual state of the atmosphere for nowcasting purposes, for climate monitoring, for assimilation into numerical weather prediction (NWP) systems, as input to AI algorithms, and to improve our understanding of atmospheric processes and their role in the Earth system. In particular, there is a strong need for complex observations suitable to develop, improve and validate parameterizations used in NWP and climate models and to provide ground-truth against which to compare atmospheric parameters derived from satellite data. With a new generation of high-resolution forecast models (1-3 km) used for the prediction of high-impact weather, dense observational networks focusing on measurements in the lower few kilometers of the atmosphere are required.
This session is intended to give a forum to discuss recent developments and achievements in local to regional measurement concepts and technology. There will be a special emphasis on measurements which seek to improve our understanding of complex atmospheric processes – especially those characterizing interactions in the climate system – through obtaining comprehensive data sets. The focus is on measurements of atmospheric dynamics and thermodynamics, energy and water cycle components, and on the interaction of the atmosphere with the underlying surface.
The session will also include consideration of novel measurement approaches and networks under development for future operational use, e.g., within the frame of the Eumetnet observations program and various COST actions, and the performance of new measurement techniques. Manufacturers of hydro-meteorological instruments and system solutions are thus explicitly invited to present news on sensor development, sensor performance and system integration.
Techniques may cover in-situ and remote sensing measurements from various platforms. Special attention will be given to the creation of a new generation of reliable unmanned instrument networks across Europe that provide calibrated and controlled data on the boundary layer structure in near-real time. This also includes metrological aspects of sensor characterization. Contributions are also welcome that make use of advanced data sets for satellite data validation.
With reference to the special conference focus we specifically invite contributions making use of machine learning techniques for quality control or product generation of atmospheric measurement data.

Orals Wed3: Wed, 10 Sep, 14:00–15:30 | Room M1

Chairpersons: Mariska Koning, Jens Bange
Aerosols, trace gases and snow
14:00–14:30
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EMS2025-669
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solicited
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Onsite presentation
Griša Močnik and the b_abs

Measuring the aerosol absorption coefficient is central for the determination of the aerosol influence on the climate and for the determination of sources of carbonaceous aerosol, especially black carbon (BC). Different methods can be used to determine or measure the aerosol absorption coefficient. Filter absorption photometers (FPs) are most easy to deploy but feature artefacts and require sophisticated calibration with a reference method. Few direct methods for in-situ aerosol absorption measurement exist, with photothermal interferometry (PTI) showing several advantages. We present how the PTI can be traceably calibrated, used as a reference method in the laboratory and in the field. 

A photothermal interferometer measures the change of the refractive index caused by light absorption in (and the subsequent heating of) the sample – the change of phase in the interferometer is proportional to the aerosol absorption coefficient. The detection is linear and can be traced to first principles. Since the laser-sample interaction region is monitored continuously, the method does not suffer from artefacts. The interferometric measurement can be calibrated to first principles. 

In-situ absorption instruments use different calibration schemes. NO2 is used for calibration in the visible range and can be traceable to SI units. Particles, on the other hand, allow calibration without wavelength limitations. We compare different calibration schemes in light of their measurement uncertainty and ease of implementation. The experimental results and a comparison with the Mie model monodisperse nigrosin aerosols show that mass-based parameters are more suitable for the modelling rather than mobility-based ones. The resulting aerosol absorption coefficient uncertainty is smaller than 5%.

Laboratory and ambient campaigns have shown similar FP calibration parameter values for ambient aerosols and laboratory experiments. We have also determined the absorption enhancement by coating BC with non-absorbing secondary organic matter in laboratory and ambient campaigns in contrasted environments (Slovenia, France). Mass absorption cross-section increase due to coatings were determined using different mass metrics – elemental carbon or refractory black carbon.

We present measurements with calibrated FPs at the Virtual Alpine Observatory station Otlica, where we determined the BC emission rates, and airplane measurements, where the atmospheric heating rate was measured separately for BC and Saharan desert dust. 

This work was supported by EURAMET (22NRM02 stanBC), ARIS (P1-0385, I-0033, L2-4485) and ESA (4000131931/20/NL/FF/an).

How to cite: Močnik, G. and the b_abs: Direct measurements of aerosol absorption coefficient using photo-thermal interferometry – methodology, traceable calibration and laboratory and ambient measurements, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-669, https://doi.org/10.5194/ems2025-669, 2025.

14:30–14:45
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EMS2025-500
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Onsite presentation
David Tichopad and Kamil Láska

The aim of this study is to assess trends in the total ozone column (TOC) and the atmospheric factors influencing ozone variability at three Antarctic stations (Marambio, Troll and Concordia) in the period 2007–2023. For this purpose, ground-based TOC measurements were used supplemented by satellite observations from the Ozone Monitoring Instrument on board the NASA's Aura satellite. TOC trends were derived using a multiple linear regression model provided by the Long-term Ozone Trends and Uncertainties in the Stratosphere (LOTUS) project. The selected LOTUS model was able to explain 95–98 % of the TOC variability at all three stations. Several predictors were evaluated in the regression model, and it was found that the lower stratospheric temperature and the polar stratospheric cloud volume contribute most to the ozone variability at these stations. A statistically significant increasing trend was found at the Marambio station (3.33 DU/decade), while the statistically insignificant trends were detected at the other two stations. Using MERRA-2 reanalyses, the LOTUS model was applied to each grid point in the 40–90°S region, which effectively illustrates the spatial distribution of the impacts of individual predictors. It was found that warmer conditions in the Antarctic stratosphere in September 2019 caused TOC to be up to 100 DU higher than normal, especially over East Antarctica. The results contribute to a better understanding of regional TOC trends and the influence of atmospheric factors on TOC in the southern high latitudes, which is essential for assessing how the Antarctic ozone layer responds to changes in ozone-depleting substances under the Montreal Protocol regulations.

How to cite: Tichopad, D. and Láska, K.: Assessment of total ozone trends and their driving factors at three Antarctic stations in 2007–2023, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-500, https://doi.org/10.5194/ems2025-500, 2025.

Show EMS2025-500 recording (12min) recording
14:45–15:00
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EMS2025-522
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Onsite presentation
Andrea Balotti, Marco Iarlori, Raffaele Lidori, Saverio Di Fabio, Emanuele Avocone, and Vincenzo Rizi

Accurate characterization of aerosol optical and microphysical properties is crucial for understanding their role in atmospheric processes and climate. Remote sensing instruments, such as photometers and ceilometers, offer complementary information: photometers provide column-integrated aerosol observations, while ceilometers give vertically-resolved backscatter profiles. The synergy between these instruments can be enhanced through advanced inversion algorithms. In this study, we investigate the retrieval of aerosol properties using the Generalized Retrieval of Atmosphere and Surface Properties (GRASP) algorithm, as shown in Roman et al. (2018), focusing particularly on the integration of lunar photometer observations.

While solar photometry is well-established for daytime aerosol characterization, nighttime retrievals remain challenging due to the absence of sunlight. The last decade developments in lunar photometry (e.g. Barreto et al. 2016), allow for aerosol measurements using the moon as a light source. This opens new possibilities for continuous, 24-hour aerosol monitoring, especially when complemented with ceilometer measurements.

In our work, we apply the GRASP algorithm to combined datasets consisting of daytime/nighttime photometer AOD and radiances, and ceilometer backscatter profiles, collected at ACTRIS L’Aquila station in Italy. GRASP is used for the retrievals, leveraging the synergy between photometric and lidar-like observations to constrain aerosol properties such as size distribution, refractive index, volume concentration and vertical profile.

We present case studies that demonstrate the added value of incorporating lunar photometer data, especially during nighttime long-range transport episodes. Preliminary results show that the inclusion of lunar observations significantly improves the temporal coverage and consistency of aerosol retrievals, allowing for better constraints on nighttime aerosol dynamics.

This study highlights the potential of integrating lunar photometry into routine aerosol monitoring networks, as recently done in the AERONET network, particularly when used in combination with ceilometers and advanced inversion tools like GRASP. The approach supports continuous observation capabilities, improving our ability to monitor aerosol variability and support atmospheric and climate research.

  • BARRETO, África, et al. The new sun-sky-lunar Cimel CE318-T multiband photometer–a comprehensive performance evaluation. Atmospheric Measurement Techniques, 2016, 9.2: 631-654.
  • ROMÁN, Roberto, et al. Retrieval of aerosol profiles combining sunphotometer and ceilometer measurements in GRASP code. Atmospheric Research, 2018, 204: 161-177.

How to cite: Balotti, A., Iarlori, M., Lidori, R., Di Fabio, S., Avocone, E., and Rizi, V.: Retrieval of Aerosol Properties from Combined Sun-Lunar Photometer and Ceilometer Observations Using the GRASP Algorithm at L’Aquila site (Italy), EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-522, https://doi.org/10.5194/ems2025-522, 2025.

Show EMS2025-522 recording (11min) recording
15:00–15:15
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EMS2025-585
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Onsite presentation
Filip Najman and Miloslav Staněk

Detection of non-meteorological targets, such as fires, clear-air turbulence, and biological targets (e.g., insects and birds), using solid-state weather radar is crucial across various industries. These include agriculture, the construction of wind farms in areas outside bird migration corridors, and air traffic control. Each of these fields requires reliable identification of such targets to support operations, mitigate risks, and ensure safety. We have conducted a comprehensive study and in-depth analysis of the unique signatures of these non-meteorological targets using our solid-state radars, which are capable of capturing detailed polarimetric information.

In our presentation, we will explore the typical characteristics of polarimetric variables and several derived products for clear-air conditions, birds, bats, and fire plumes as measured by solid-state weather radars. We will present not only typical values and their distribution in histograms, but also the spatial variability of these polarimetric variables for each non-meteorological target type. These variations in polarimetric properties provide insight into the structure and movement of different targets. Additionally, we will highlight the differences between the various categories, allowing for a clearer distinction in classification. Special attention will also be given to the change in the values of polarimetric variables in areas where water vapor condenses on particles from fire, which creates unique radar signatures.

Particular emphasis will also be placed on the scanning strategy we’ve adopted for clear-air detection, aimed at improving the identification of clear-air echoes and turbulence. The results presented have significant potential for further application, including the development of algorithms using traditional classification methods, such as K-Means or the Random Forest Algorithm, as well as new AI-based methods. These approaches are expected to enable more effective classification and detection of non-meteorological targets, advancing radar technology and its practical use across multiple domains.

 

How to cite: Najman, F. and Staněk, M.: Signatures of Smoke, Clear-Air, Birds, and Insects on Solid-State Radars , EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-585, https://doi.org/10.5194/ems2025-585, 2025.

Show EMS2025-585 recording (13min) recording
15:15–15:30
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EMS2025-53
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Onsite presentation
Ivan Bogoev

Global greenhouse gas (GHG) emissions from natural and agricultural ecosystems are continuously increasing, but the accurate quantification of their sources and sinks to guide mitigation strategies still remain challenging. There is a need for measurement technologies capable of tracking and identification of GHG sources with high temporal and spatial resolution that will inform sustainable agricultural management practices. To this end, a prototype of a compact low-power mid-IR tunable diode laser spectrometer platform has been developed for high-precision fast-response trace gas measurements. The instrument leverages on a proven field rugged closed path design and on the advancements of stable low-noise interband cascade lasers. It incorporates a novel miniature single pass sample cell with and power efficient laser driving technique. The platform includes integrated pump and thermoelectric modules for automatic pressure, flow and temperature control enabling fully autonomous unattended operation in diverse environmental conditions. Under laboratory conditions the device achieves precision (Alan variance) of 1.5 ppb N2O and 7 ppb CH4 with 100 ms averaging.  A sub-ppb performance is possible at longer averaging times allowing for atmospheric methane and nitrous oxide concentration and flux monitoring. Field deployment in remote areas using solar energy is possible due to the low power consumption. Laboratory and field tests were performed to quantify the effects of pressure, temperature and humidity on the operation of the instrument. We describe the design rational of an inertial particle separator acting as a non-barrier filter to prevent contamination of the optics and the use of sulfonated tetrafluoroethylene ionomer intake tube acting as water vapor permeable membrane to dry the air sample and minimize the effects of humidity on the concentration measurements. The results of a field deployment over fertilized corn field will be presented.

How to cite: Bogoev, I.: A Compact Low-Power Direct Absorption Spectrometer for Trace Gas Measurements, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-53, https://doi.org/10.5194/ems2025-53, 2025.

Orals Wed4: Wed, 10 Sep, 16:00–17:15 | Room M1

Chairpersons: Jens Bange, Frank Beyrich
Monitoring and case studies
16:00–16:15
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EMS2025-63
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Onsite presentation
Alexander Haefele, Giovanni Martucci, Vasura Jayaweera, Bas Crezee, Daniel Leuenberger, Robert J. Sica, Renaud Matthey, and Marco Arpagaus

Raman lidars are widely used in research to measure the atmospheric profile of temperature and humidity. In operational meteorology, however, the technology is still emerging mostly because of its high costs, the high complexity and the difficulty of calibrating the measurements. The Raman Lidar for Meteorological Observations (RALMO) located at the Federal Office of Meteorology and Climatology MeteoSwiss in Payerne, Switzerland, measures humidity and temperature profiles continuously since 2008 demonstrating the technique’s potential for operational use. We have developed and implemented a calibration method based on the lidar’s solar background measurements allowing for daily calibrations  and independently from external references like radiosondes. We assessed the impact of RALMO observations in the MeteoSwiss operational, convective-scale ensemble data assimilation and forecasting system in two two-week summer and winter experiments revealing the potential to improve the analysis, especially in regions without other profile observations. We further compiled a climatology of tropospheric temperature, water vapor mixing ratio and relative humidity from the 15-year data set and will present first results of relative humidity trends in the troposphere above Payerne, Switzerland. 

How to cite: Haefele, A., Martucci, G., Jayaweera, V., Crezee, B., Leuenberger, D., Sica, R. J., Matthey, R., and Arpagaus, M.: 15 years of research and operations with a Raman lidar for meteorological and climatological applications, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-63, https://doi.org/10.5194/ems2025-63, 2025.

Show EMS2025-63 recording (13min) recording
16:15–16:30
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EMS2025-418
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Onsite presentation
Duc Nguyen, Philipp Gasch, and Annika Oertel

Forecasting high-impact convective events, which pose significant risks to people and property, remains a persistent challenge. This difficulty can partly be attributed to biases and errors in analysis data, which serve as initial conditions for numerical weather predictions (NWP), are often used to improve process understanding of such events from the model perspective. A systematic validation of the quality of analysis and forecast data, in particular in complex terrain, is often restricted by the limited availability of detailed observations.

Here we leverage observations from the ‘Swabian MOSES 2023’ field campaign, which took place in the Black Forest region, Southwestern Germany, during the summer 2023. Among others, the field campaign included an extended meso-scale network of 10 Doppler wind lidars, which are used to retrieve vertical profiles of the wind speed and direction.  These observations enable the characterization of the dynamic structure of the lower troposphere on the mesoscale in moderately complex terrain.

The retrieved wind profile observations, which extend from the near-surface to approximately 4 km above ground, are compared to the regional convective-scale analysis dataset. For this purpose, the ICON-D2 analysis data from Deutscher Wetterdienst, available at 2.2 km horizontal resolution and produced using the Icosahedral Nonhydrostatic (ICON) model , are used. The three months of continuous observations provide a comprehensive independent data set for validating the representation of mesoscale wind characteristics in the analysis across the Black Forest region. Overall, the convective-scale analysis captures the vertical profiles of horizontal wind well, with wind speed bias remaining on average below 0.5 m s-1. Yet, we find differences between different measurement locations, depending to some extent on the local topography, with the largest differences in areas with more complex terrain. Moreover, the analysis tends to overestimate the zonal wind component at lower altitudes, while underestimating the meridional wind component at higher altitudes. Furthermore, the data show that the mean absolute error between the analysis and the observations is larger during rainy than during dry weather conditions, which highlights the added value of the observations, particularly during convective situations. Finally, we demonstrate the value of a high-resolution analysis dataset by comparing the observations against a range of analysis datasets, including ICON-D2, ICON-EU, and ICON-global, with spatial resolutions of 2.2 km, 6.5 km, and up to 13 km, respectively.  

How to cite: Nguyen, D., Gasch, P., and Oertel, A.: Representation of mesoscale flow characteristics in a convective-scale analysis dataset: validation using Doppler wind lidar measurements from the 'Swabian MOSES 2023' Campaign, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-418, https://doi.org/10.5194/ems2025-418, 2025.

Show EMS2025-418 recording (14min) recording
16:30–16:45
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EMS2025-331
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Onsite presentation
Moon-Soo Park, Kitae Baek, Seok-Cheol Kim, Minsoo Kang, and Sung-Joon Na

A building-block urban meteorological observation experiment – wind (BBMEX-Wind) campaign was carried out to observe vertical profile of 3-dimensional wind speed below and above the building canopy of a street canyon at Gangnam district in Seoul City, Korea for the period of 10 to 24 May 2023. A wind lidar was installed center of the street canyon with a width of 50 m and a height of 70 m, and observed 3-dimensial wind speed and signal-to-noise ratio at around 1 Hz at 25 heights between 40 m and 350 m. Among total 15 days, 7 days were fine (cloud cover < 3/10), while 3 days were cloudy (cloud cover > 7/10). There were 4 rainy days, but total precipitation was as low as 1.5 mm. Skimming flows were observed below the building canopy when lateral winds blow, and channel flows were observed when longitudinal winds blow. In spite of low-speed winds below the building canopy, strong winds above 20 m s−1 above the canopy were observed. Surface roughness length over the building block was calculated as values minimizing the sum of squared error assuming the log-wind profile in the surface layer. It was found that the surface roughness length was about 8 m during the daytime (09 to 16 LST) and about 6 m during the nighttime (22 to 04 LST). Mean values of turbulent kinetic energy (TKE) during the daytime were about 2 times larger than those during the nighttime, while median values of TKE during the daytime were 3 times larger than those during the nighttime. 

 

Key words: BBMEX-Wind, street canyon, surface roughness length, wind lidar

 

Acknowledgements: This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2021R1I1A2052562) and Korea Aerospace Research Institute (KARI).

How to cite: Park, M.-S., Baek, K., Kim, S.-C., Kang, M., and Na, S.-J.: Structure of Wind and Turbulence below and above a building canopy during the BBMEX–Wind Campaign period in Seoul, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-331, https://doi.org/10.5194/ems2025-331, 2025.

Show EMS2025-331 recording (14min) recording
16:45–17:00
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EMS2025-18
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Onsite presentation
Esther Luján Amoraga, Carlos Román-Cascón, Marina Bolado-Penagos, Pablo Ortiz-Corral, Juan Alberto Jimenez-Rincón, Alfredo Izquierdo, Juan Carbone-Diaz, and Carlos Yagüe

Sea breezes are mesoscale meteorological phenomena driven by the thermal contrast between land and sea, which significantly affect local atmospheric circulation. These phenomena play a crucial role in regulating extreme temperatures, transporting atmospheric pollutants, as well as for wind energy resources. This study focuses on the Gulf of Cádiz, located in the southwest of   the Iberian Peninsula.

The main objective of our research is to use observational data to characterise the sea breeze system in this region, with a special focus on how the turbulent variables (turbulent kinetic energy (TKE), friction velocity (u*)) and the surface turbulent fluxes vary throughout the diurnal cycle under sea breeze conditions. This is especially interesting in the area of study since it is characterized by a mesotidal regime with sea-level oscillations of up to 4 meters. In this sense, turbulence data were obtained using a sonic anemometer installed at 10 m above sea level (asl) just on the coastline, in front of a surface that periodically changes its characteristics due to the tides. Besides, an IRGASON system was installed nearby on the top of a lighthouse, at 68 m asl, to investigate the fluxes and turbulent parameters at higher levels. The horizontal characterisation of the breeze system was obtained from observations of a network of weather stations strategically distributed along the coast. In addition, vertical atmospheric profiles before and during sea breeze events were analysed using radiosonde data to better understand the associated vertical structure and atmospheric dynamics.

The analysis covers events recorded during the summers of recent years, using an objective algorithm based on previous studies (Borne et al., 1988; Arrillaga et al., 2018; Román-Cascón et al., 2019) to accurately identify breeze events.

Preliminary results show variations in turbulent characteristics throughout the tidal cycle, highlighting the complex interaction between turbulent dynamics and coastal conditions during sea breeze events. This research contributes to improving the understanding of the complex breeze system in the study area and provides valuable data to evaluate numerical models and improve atmospheric boundary layer parameterisations.

How to cite: Luján Amoraga, E., Román-Cascón, C., Bolado-Penagos, M., Ortiz-Corral, P., Jimenez-Rincón, J. A., Izquierdo, A., Carbone-Diaz, J., and Yagüe, C.: Analysis of sea breezes characteristics in south-west Spain using observational data, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-18, https://doi.org/10.5194/ems2025-18, 2025.

17:00–17:15
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EMS2025-598
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Onsite presentation
Michal Najman

Weather radar coverage remains sparse in many underdeveloped and remote parts of the world, where climate resilience, disaster preparedness, and early warning systems are most urgently needed. These areas are often the most vulnerable to extreme weather events, yet they frequently lack the infrastructure and resources necessary to support traditional radar systems. This presentation showcases our integrated approach to deploying advanced weather radar technology in some of the world’s most challenging environments, with a focus on a recent installation in the Kingdom of Tonga.

We detail the full deployment process—from the complex logistics of transporting a C-band radar system, prefabricated tower, and clean solar power infrastructure across the Pacific Ocean, to overcoming the technical, environmental, and cultural challenges faced during on-site installation. The Tonga project exemplifies how we design for resilience, ensuring that our systems can operate independently of fragile local utilities, with minimal environmental impact.

A key component of our strategy is sustainability. We invest in local training programs to empower communities with the knowledge and skills needed for basic maintenance and operation. This fosters a sense of ownership and long-term commitment. In parallel, our custom-built Remote Protection Box allows for continuous remote monitoring, diagnostics, and updates of all radar components—minimizing downtime and avoiding costly site visits in areas with limited technical support.

This work highlights not only the engineering innovations involved in remote radar deployment but also the human-centered and systemic strategies necessary to ensure that radar coverage is not only extended to underserved regions—but remains operational, effective, and trusted over time.

How to cite: Najman, M.: Sustainable Weather Radar Deployment in Underdeveloped Regions: A Case Study from the Pacific, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-598, https://doi.org/10.5194/ems2025-598, 2025.

Orals Thu1: Thu, 11 Sep, 09:00–10:30 | Room M1

Chairpersons: Mariska Koning, Frank Beyrich
New developments and opportunistic data
09:00–09:15
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EMS2025-131
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Onsite presentation
Anne-Claire Billault–Roux, Rolf Rüfenacht, Josef Höffner, Thorben Mense, Pablo Garfias, Frederik Ernst, Gerd Baumgarten, Martin Flügge, Alain Hauchecorne, Milena Martic, Alexander Munk, Laurynas Lukoševičius, Alexander Haefele, and Michael Strotkamp
As of today, there is a significant technological gap for continuous temperature and wind measurements at altitudes above 5 km, which is the maximum altitude reached by compact commercial lidar and radar wind profilers. Measuring higher up is not only crucial to better understand atmospheric dynamics and couplings and enhance climate models, but is also anticipated to bring substantial benefits for middle-range weather forecasting. The Horizon Europe project EULIAA aims to help close this gap with novel daylight-capable UV Doppler lidars with multiple fields of view to measure 3D-wind, temperature and aerosols from 5 to 50 km altitude at least. Within this range, the measurements shall have a high resolution and accuracy, compliant with WMO requirements. The instruments will be low-priced, highly autonomous (> 1 year without maintenance), compact (1m3), and with low power consumption, which opens up possibilities for deployment in remote and/or extreme environments. A high technological readiness level (TRL 6-8) is foreseen at the end of the project, which paves the way for operational deployments. The data processing is designed in a way which will eventually allow to use multiple lidar units with overlapping measurement regions as an array covering a large area.

With this contribution, we will give an overview of the instruments and show the current status of the project after 2.5 years duration. We will outline the upcoming campaigns in various latitudes and environments, including polar and subtropical regions; during these deployments, existing infrastructure such as remote sensing instruments and radiosondes will be used for validation. First observations of a EULIAA lidar unit will be presented, which will emphasize their possible interest for different application areas in meteorology and climatology. Finally, we will present our data pipeline and the plan for the near real-time dissemination of the measurement data on different platforms.

How to cite: Billault–Roux, A.-C., Rüfenacht, R., Höffner, J., Mense, T., Garfias, P., Ernst, F., Baumgarten, G., Flügge, M., Hauchecorne, A., Martic, M., Munk, A., Lukoševičius, L., Haefele, A., and Strotkamp, M.: EULIAA : novel compact lidar systems for operational wind, temperature and aerosol measurements between 5 and 50 km altitude, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-131, https://doi.org/10.5194/ems2025-131, 2025.

Show EMS2025-131 recording (11min) recording
09:15–09:30
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EMS2025-401
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Onsite presentation
Phillip Chilson and Anders Petersson

The state-of-the-art of numerical weather prediction models continue to mature and contribute to better forecast skill at finer spatial and temporal resolutions. Our ability to generate atmospheric observations has not kept pace with these computational advancements, resulting in a “data gap”. There has been a push to develop and advance a broad spectrum of in-situ and remote-sensing atmospheric sampling technologies to address this need. This includes the need to advance and modernize conventional and mature instrumentation. In addition to providing trusted atmospheric measurements, data from these instruments can be used as a reference for newer, emerging technologies or signal-processing methods. Here we focus on recent developments in one such instrument, the rawinsonde (here simply referred to as radiosonde).,

In 2014, Sparv Embedded AB introduced a small, lightweight, and economical radiosonde called the Windsond S1 intended for use in the atmospheric boundary layer and lower free troposphere, typically below 8 km MSL. By focusing on the lower atmosphere, the S1 has been helping to fill one critical aspect of the data gap. As such, the S1 has been successfully used by numerous atmospheric researchers, within the international meteorological community, in fire-weather applications, for educational purposes, and more (e.g., Stouffer et al., 2024: J. Atmos. Oceanic Technol., 41, 1213–1228). Based on the popularity of the S1, Sparv has recently released a successor called the Windsond S2. Like its predecessor, the S2 is small, light-weight, and affordable; however, the new design offers many improvements over the S1. For example, the S2’s new battery and telemetry capabilities facilitate atmospheric soundings up to 10 km MSL. Moreover, the S2’s compact and robust design makes it better suited for launches in challenging environments. With a weight of only 9 g, the S2 requires less helium and smaller balloons than conventional radiosondes, which have typical weights of 60-80 g. As with the S1, the S2 still allows for simultaneous tracking of up to 126 radiosonde units. This feature can be used to map small spatial and temporal variations in atmospheric fields (e.g., Markowski et al., 2018: Bull. Amer. Meteorol. Soc., 99, 711-724). Such observations would also be valuable when validating improved high-resolution weather forecast models. In this presentation, we provide an overview of the Windsond S2, its technical specifications, and highlight several use case scenarios. Additionally we present and discuss S2 data collected under various meteorological conditions.

How to cite: Chilson, P. and Petersson, A.: Using small, light-weight radiosondes to enhance capacity for in-situ sampling of the lower atmosphere, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-401, https://doi.org/10.5194/ems2025-401, 2025.

Show EMS2025-401 recording (14min) recording
09:30–09:45
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EMS2025-85
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Onsite presentation
Lisa Graßmel, Josua Schindewolf, and Felix Pithan

The atmospheric temperature profile in Arctic winter plays a key role in the observed
Arctic amplification of global temperature changes. In the cold season, the Arctic atmo-
spheric temperature and moisture profiles are a product of advection and transformation
of air masses from lower latitudes [1, 2]. These poleward flowing air masses cool and dry
over several days, losing the majority of their initial heat and moisture content along
their trajectory. The occurrence of the resulting transition [3, 4] proves to be difficult to
understand using fixed-in-place (Eularian) observations [5, 6].

Altitude controlled drifting (CMET) balloons provide vertical profiles of the lower bound-
ary layer in an air-mass following (Lagrangian) perspective [7], deemed necessary for the
understanding of arctic air mass transformations [4].

While these balloons measure the same properties as commercial grade radiosondes,
their sensors have been found to be prone to radiative bias, lag and hysteresis effects dur-
ing previous deployments [8]. Accurate measurements within the arctic boundary layer
therefore require to distinguish between the sensor related errors, small-scale atmospheric
variability between adjacent ascending/descending legs and the observed processes.

Within this study, we followed established procedures used for calibrating and processing
radiosondes observations using a ground based standard humidity chamber, temperature
measurement and sensor manufacturer information.

We developed a pre-flight calibration routine combined with a processing tool for the
balloons’ raw data, correcting for the individual sensor characteristics, the balloons flight
dynamics and environmental factors. An evaluation of the radiative bias on temperature
measurements in a ground test chamber is planned later this year.

In summary, this will provide a comprehensive understanding of the total measurement
uncertainties of each sensor validated against a common reference standard for flight data
processing. Furthermore, our work aims at serving as a best-practice guideline for all
present and future users deploying the CMET system.

 

 

1. Wexler. Cooling in the lower atmosphere and the structure of polar continental
air. (1936)

2. Curry. On the Formation of Continental Polar Air. (1983)

3. Stramler et al. Synoptically Driven Arctic Winter
States. (2011)

4. Pithan et al. Role of air-mass transformations in exchange between the Arctic
and mid-latitudes. (2018)

5. Lonardi et al. Tethered balloon-borne observations of thermal-infrared irradiance
and cooling rate profiles in the Arctic atmospheric boundary layer. (2024)

6. Becker et al. In situ sounding of radiative flux profiles through the Arctic lower
troposphere. (2020)

7. Voss et al. Continuous In-Situ Soundings in the Arctic Boundary Layer: A
New Atmospheric Measurement Technique Using Controlled Meteorological Bal-
loons. (2012)

8. Roberts et al. Controlled meteorological (CMET) free balloon profiling of the
Arctic atmospheric boundary layer around Spitsbergen compared to ERA-Interim
and Arctic System Reanalyses. (2016)

How to cite: Graßmel, L., Schindewolf, J., and Pithan, F.: Calibrating the meteorological sensors of an air-mass following drifting balloon, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-85, https://doi.org/10.5194/ems2025-85, 2025.

09:45–10:00
|
EMS2025-661
|
Onsite presentation
Qinghong Zhang

Smartphones are now commonly used, with ownership ranging from 30 to 70 percent of the population in numerous countries. With GPS and pressure sensor installed, smartphones can measure ambient air pressure, and have the potential to be used as meteorological observations. Our recent studies have shown that the pressure of smartphones can be used to describe the strength and location of large-scale vortex, as well as mesoscale surface high and low during thunderstorm events. Nevertheless,  addressing the quality issues of smartphone barometric data owing to human activity and other factors remains a great challenge. Our study indicated that a machine-learning technique could significantly improve the usability of the smartphone data. Since smartphone users are mostly concentrated in urban areas, significantly higher-density pressure coverage is achieved than the conventional surface networks in large cities. However, can these high-density data improve the forecasting ability of weather-related disasters? This presentation will introduce the barometric pressure data observed by smartphones collected from Moji weather app, the bias correction process, and its applications in analysis and forecasting via case studies.

We used tropical cyclones (TCs) Lekima in 2019, Hagupit in 2020 and In-fa in 2021 as examples to conduct bias correction on labeled smartphone pressure data from the Moji Weather app. A quality control procedure was proposed utilizing random forest machine learning models. By applying this quality control approach to the selected TCs, we discovered that the performance of the method for labeled data significantly surpassed that for unlabeled data developed in a previous study, reducing the mean absolute error from 3.105 to 0.904 hPa.

The smartphone (SPO) and traditional weather stations (TWS) pressure data during a hailstorm that occurred on 30 June 2021 in Beijing, are assimilated into a one-hour frequent 3DVAR system based on WRF model, respectively. The results demonstrate that the spatial density of SPO data is tens of times larger than that of TWS. Compared with the control experiment and assimilation experiment which only use the TWS data, the assimilation experiments with SPO data show significant improvements, in terms of the cold pool and gust front. The improvement of FSS in 10 mm hourly precipitation reached to 3% to 12%. Our findings indicate that high-resolution SPO data have the potential to enhance the forecasting capabilities of mesoscale convective system.

How to cite: Zhang, Q.: Smartphone Pressure Data: Statistical Characteristics, Bias Correction, and Applications in Weather Forecasting, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-661, https://doi.org/10.5194/ems2025-661, 2025.

Show EMS2025-661 recording (13min) recording
10:00–10:15
|
EMS2025-417
|
Online presentation
Ben Pickering

Accurate and timely observations remain fundamental to meteorological research and operational forecasting, yet many regions still rely on sparse or intermittent data. Whilst low-cost sensors are becoming increasingly abundant, their utility has been marred by lack of standardisation, calibration, and accuracy. This abstract introduces a concept for building a network of low-cost, crowdsource-able “all-sky” camera observation stations to address these coverage gaps and previous shortcomings. Each station would passively capture sky imagery at frequent intervals, analyse image features and upload the data to a central repository for use by the broader weather and climate community.

By integrating this imagery with existing meteorological datasets, it may be possible to resolve localised phenomena more precisely than current observing networks. Existing research suggests that ground-based visible images could enhance high-resolution numerical weather prediction (NWP) by offering near-real-time cloud fraction, cloud genus, and atmospheric motion vectors (AMVs) at unparalleled spatial granularity. Such data also hold promise for improving nowcasting systems designed to detect rapidly evolving weather features. Moreover, the resulting datasets would present novel opportunities for advanced AI/machine learning applications, such as training algorithms to classify cloud types, track convective development, monitor the climatic impact of contrails, or nowcast surface-level solar irradiance. The network could be designed such that over-the-air (OTA) software updates allow the ‘intelligence’ of the network in aggregate to improve over time or gain new abilities as they are discovered and developed.

While the station design and data-processing pipeline remain under early development, this presentation aims to share the concept, identify potential applications, and gather community input on technical and scientific challenges. In particular, the project welcomes feedback on topics such as image standardisation, data validation, and deployment strategies. Interested colleagues are encouraged to discuss potential collaborations or sign up for project updates, including an early-access waitlist for the first stations. By co-developing these capabilities with the meteorological community, we can create a robust, accessible network that extends and complements existing observational infrastructure—ultimately enhancing our collective ability to monitor and understand the atmosphere.

How to cite: Pickering, B.: Crowdsourced All-Sky Imagery for AI Nowcasting and Research, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-417, https://doi.org/10.5194/ems2025-417, 2025.

Show EMS2025-417 recording (13min) recording
10:15–10:30
|
EMS2025-142
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Onsite presentation
Niklas Blum, Paul Matteschk, Yann Fabel, Bijan Nouri, Roberto Roman, Juan Carlos Antuña-Sanchez, Luis F. Zarzalejo, and Stefan Wilbert

All-sky imagers (ASIs) have been used to provide accurate nowcasts of solar irradiance and to derive atmospheric measurements and cloud observations. ASI-based information enhances the understanding of atmospheric processes, serves as input for weather and climate models and can provide reference data for validating satellite-derived parameters. Additionally, ASIs have the potential for automating atmospheric observations. However, there are still manual tasks involved in the setup, calibration and operation of ASIs. This is where our contribution comes in.

The tasks mentioned above often require the reconstruction of the ‘world coordinates’ of observed points in the sky from their pixel positions in the ASI images. This necessitates a geometric calibration of each ASI regarding camera-intrinsic lens distortion parameters and the ASI’s external orientation. This task usually requires the manual placement of special checkerboard or other patterns at multiple positions above the camera. In general, existing calibration methods require a non-negligible amount of manual work.

We present the Python tool ‘SuMo’ which determines all parameters defining the lens distortion and external orientation only using regular ASI images depicting Sun and Moon. SuMo avoids a manual interference on-site, can be applied retrospectively and can also be used to continuously monitor an ASI’s geometric calibration. We recently published SuMo as part of an open-source package together with over 2 years of ASI images and irradiance measurements. This will support the method’s reproducibility and practical usability.

We test the calibration on five camera types at three sites using datasets which represent different seasons, distinct ranges of turbidity and cloud cover, exposure times as well as sun/ moon elevation and azimuth angles. In each case, we evaluate how accurately Moon positions in a 1-year dataset are predicted. Also, we cross-validate SuMo with the semi-automatic star-based ORION calibration method developed by University of Valladolid.

First, we confirm the high accuracy of the SuMo method. Already a single month of images from either summer or winter yields an accurate calibration (root mean squared error, RMSE, 0.14°). Further, we analyze the influence of the above-mentioned atmospheric, site and hardware/ firmware parameters on the calibration accuracy. A comparable calibration accuracy (RMSE 0.14° – 0.38°) is achieved for all tested ASIs without modifying the method’s parameters. Image quality moderately influences the calibration accuracy. Similarly, extreme conditions such as high cloud cover (RMSE 0.38°) and high turbidity (RMSE 0.32°) can reduce the calibration accuracy compared to very clear conditions (RMSE 0.12°). Cross-validation with the ORION method further confirms the high accuracy of our method over the entire sky dome (mean absolute error 14°). Overall, our comprehensive experimental analysis attests the high accuracy and practical feasibility of a geometric calibration of ASIs relying only operationally recorded day- and nighttime sky images.

How to cite: Blum, N., Matteschk, P., Fabel, Y., Nouri, B., Roman, R., Antuña-Sanchez, J. C., Zarzalejo, L. F., and Wilbert, S.: Geometric Calibration of All-Sky Cameras Using Sun and Moon Positions: Achieving Sub-Degree-Accuracy without any Handwork, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-142, https://doi.org/10.5194/ems2025-142, 2025.

Orals Thu2: Thu, 11 Sep, 11:00–13:00 | Room M1

Chairpersons: Frank Beyrich, Jens Bange
Networks
11:00–11:30
|
EMS2025-700
|
solicited
|
Onsite presentation
Jasper Wijnands, Arnoud Apituley, Diego Alves Gouveia, Jan Willem Noteboom, Minhao Yan, Marijn de Haij, and Luca Trani

Following the growing use of AI/ML in atmospheric sciences, this presentation will address the use of machine learning techniques for product generation from atmospheric measurement data. Our Deep-Pathfinder algorithm uses solely ceilometer observations to extract the mixing layer height (MLH), indicating the change between vertical mixing of air near the surface and less turbulent air above. The concept is to represent the sensor data as an image and the MLH profile as a corresponding mask, and directly predict the mask using image segmentation techniques. This concept is generic and, in principle, it can be applied to various sensor types.

Deep-Pathfinder is based on a customised U-Net architecture with MobileNetV2 encoder for fast inference and a nighttime variable to indicate whether a stable or convective boundary layer can be expected. Model training used range-corrected signal data from Lufft CHM15k ceilometers in the Netherlands (2020–2022), supplemented with 50 days of high-resolution annotations. First, input samples were randomly cropped to 224x224 pixels, covering a 45-minute period and maximum altitude of 2240 meters. Then, the model was pre-trained on the Dutch National Supercomputer Snellius using 19.4 million samples of unlabelled data. Finally, the labelled data was used to fine-tune the model for the task of mask prediction. Performance on a test set was compared to MLH estimates from ceilometer manufacturer Lufft and the STRATfinder algorithm, showing Deep-Pathfinder followed short-term fluctuations more closely.

Existing path optimization algorithms have good temporal consistency but can typically only be evaluated after a full day of ceilometer data has been recorded. Deep-Pathfinder retains the advantages of temporal consistency by assessing MLH evolution in 45-minute samples, using the full 12 s x 10 m resolution of the ceilometer. KNMI’s MLOps team is implementing the Deep-Pathfinder algorithm to run it in near-real-time on observations of CHM15k ceilometers in the Netherlands. The upcoming monitoring phase will highlight areas where the model could be further improved, using a model lifecycle of enhancing annotations for identified shortcomings, retraining and deployment. Further, we are investigating extending our concept to a multi-class segmentation problem to create atmospheric feature masks. These developments exemplify how machine learning techniques can be deployed towards enhancing operational usage of sensor data.

How to cite: Wijnands, J., Apituley, A., Gouveia, D. A., Noteboom, J. W., Yan, M., de Haij, M., and Trani, L.: Deep-Pathfinder: Near-real-time detection of mixing layer height based on lidar remote sensing data and deep learning, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-700, https://doi.org/10.5194/ems2025-700, 2025.

Show EMS2025-700 recording (26min) recording
11:30–11:45
|
EMS2025-130
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Onsite presentation
Eric Sauvageat, Rolf Rüfenacht, Maxime Hervo, Myles Turp, Augustin Mortier, Volker Lehmann, Ina Mattis, Domenico Cimini, and Alexander Haefele

The EUMETNET E-Profile programme collects, processes and disseminates atmospheric profiles of wind, aerosols, clouds, temperature, and humidity. It aims to promote the usability of vertical profiles for operational meteorology and bring support and expertise to data providers and end users. E-Profile offers centralized data processing and extensive quality monitoring for different ground-based remote sensing instrument including radar wind profilers (RWP), automatic lidars and ceilometers (ALC), Doppler wind lidars (DWL), and microwave radiometers (MWR). The current phase (2024-2028) of the programme aims to consolidate the existing networks, improve the data quality, and develop new products.

First, we started processing and distributing DWL measurements in November 2024, providing near real-time wind profiles in the atmospheric boundary layer (ABL) at a high spatial and temporal resolution. The retrieval uses an open-source code developed at the Deutscher Wetterdienst (DWD) to obtain 10 minutes averaged wind profiles. Currently BUFR messages from 14 instruments are distributed on the Global Telecommunication System (GTS) with a timeliness of around 20 min and data availability over 90% of the time.

Second, the network composed of ground-based microwave radiometers (MWR) for thermodynamic profiling is being setup. Since early 2024, a pilot network is running with a centralized processing which enables the retrieval of temperature profiles and humidity from the MWR brightness temperatures in the K- and V-bands. Operational, near real-time MWR data distribution on the GTS is planned for the second half of 2025.

Finally, following the growing interest to assimilate ALC measurements to improve atmospheric composition models, new developments have been implemented in the centralized processing chain to improve the ALC data quality. This includes an improved calibration scheme and better correction for the overlap on a significant portion of the ALC instruments (over 150 of the 470 instruments currently included in the network).

In this contribution, we present an overview of the E-Profile networks focusing on these new developments, their current status and expected benefits. We highlight the challenges associated with setting up harmonized real-time processing pipelines and discuss the remaining work and improvements.

How to cite: Sauvageat, E., Rüfenacht, R., Hervo, M., Turp, M., Mortier, A., Lehmann, V., Mattis, I., Cimini, D., and Haefele, A.: E-Profile: real-time vertical profiling of wind, aerosols, temperature, and humidity at the European scale, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-130, https://doi.org/10.5194/ems2025-130, 2025.

11:45–12:00
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EMS2025-612
|
Onsite presentation
Ewan O'Connor, Simo Tukiainen, Tuomas Siipola, Lukas Pfitzenmaier, Nathan Feuillard, Matheus Tolentino da Silva, and Juan Antonio Bravo Aranda

The number of ground-based cloud profiling stations incorporating a cloud radar, ceilometer and multi-channel microwave radiometer have rapidly increased in recent years, with more than 20 stations now operating within the ACTRIS cloud profiling network and at least 5 more associated with the wider Cloudnet network. The majority of the cloud profiling stations are now providing data within about two hours with full product generation for these stations within a few minutes from receiving the data (meeting the requirement for real-real-time data delivery, RRT, which is within 3 hours of measurement). Decade or longer time series are available from at least 8 sites and comprehensive quality control and calibration procedures are applied across the network.

Two satellite calibration and validation pilots were performed during the EU H2020 project ATMO-ACCESS, which demonstrated that the increase in number of stations, the quality control applied and the reliable RRT operational capability of the ACTRIS network, were of significant benefit for the two users, EUMETSAT and ESA.

One pilot was dedicated to EUMETSAT cloud products obtained from both polar orbiters and geostationary satellites; here, the priority was to deliver consistent products from across the network with RRT provision for operational evaluation and over a long time-frame for statistical reliability.

For the second pilot, the task was to evaluate the ESA / JAXA satellite Cloud, Aerosol and Radiation Explorer (EarthCARE) which is the first Doppler cloud radar in space. The Doppler radar observations enable better characterization of cloud and precipitation processes, classification of hydrometeor types and investigation of cloud dynamics and, given that this is the first observation of in-cloud Doppler velocities from a spaceborne radar, extensive validation of these satellite observed Doppler velocities using ground-based Doppler velocities from the ACTRIS-Cloudnet cloud profiling network is under way.

We wil present results from both of these calibration/validation activities, and describe some of the improvements made to the ground-based network operations to enable these.

How to cite: O'Connor, E., Tukiainen, S., Siipola, T., Pfitzenmaier, L., Feuillard, N., Tolentino da Silva, M., and Bravo Aranda, J. A.: Validating satellite observations of clouds with the ground-based ACTRIS cloud profiling network, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-612, https://doi.org/10.5194/ems2025-612, 2025.

12:00–12:15
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EMS2025-568
|
Onsite presentation
Chris Fiebrich, Alyssa Avery, Tyler Bell, Matthew Cann, Mark Fox, James Hocker, Jamey Jacob, Cynthia Luttrell, Steven Piltz, Elizabeth Smith, and John Walker

The University of Oklahoma, Oklahoma State University, the US National Severe Storms Lab, and various US National Weather Service Forecast Offices have been actively engaged in enhancing the capabilities and applications of a 3D Mesonet system. This presentation will overview the extensive activities and advancements in Mesonet operations, focusing on the integration of uncrewed aircraft systems (UAS) for atmospheric profiling. The Oklahoma Mesonet system, comprised of 120 surface stations across the state, plays a crucial foundational role in real-time weather monitoring and data collection.

Through numerous experiments and field campaigns since 2014, we have deployed UAS for high-resolution vertical measurements of atmospheric parameters such as pressure, temperature, humidity, wind speed, and direction. These measurements are key for understanding the atmospheric boundary layer (ABL) and improving weather forecasting, agricultural decision-making, wildland fire management, wind energy optimization, and climate monitoring. Additionally, 3D Mesonet data have shown great promise in nowcasting, particularly in identifying low-level inversions that impact pesticide application and predicting fire behavior and smoke dispersal.

The integration of UAS with Mesonet infrastructure will allow for simultaneous data collection at multiple sites, providing new insights into the spatial heterogeneity of the ABL. This presentation will also discusses ongoing projects, including an initiative with WeatherHive and collaborations with the US National Weather Service (NWS) to enhance severe weather forecasting through real-time data ingest and analysis.

Furthermore, this presentation will highlight the need to develop robust and reliable UAV systems equipped with precision landing, automatic charging, and risk mitigation measures for unattended operations. A prototype built by the Advanced Radar Research Center at the University of Oklahoma demonstrated the capability to detect aircraft within a geofenced area, ensuring safe and efficient data collection.

Overall, the advancements in 3D Mesonet technology and its applications underscore the importance of continuous innovation in atmospheric research and its practical implications for various sectors.

 

How to cite: Fiebrich, C., Avery, A., Bell, T., Cann, M., Fox, M., Hocker, J., Jacob, J., Luttrell, C., Piltz, S., Smith, E., and Walker, J.: Transforming Weather Monitoring: Oklahoma's Advances in 3D Mesonet Systems, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-568, https://doi.org/10.5194/ems2025-568, 2025.

Show EMS2025-568 recording (13min) recording
12:15–12:30
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EMS2025-140
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Onsite presentation
Moritz Löffler, Christine Knist, Bernhard Pospichal, Antje Claußnitzer, and Ulrich Löhnert

Ground based microwave radiometers (MWR) are currently in the focus of meteorological agencies which intend to deploy MWR in network setups. The centralized processing of MWR data products within ACTRIS and the imminent integration of MWR into the EUMETNET E-PROFILE network are two prominent examples for this development.

Assimilation experiments with clear-sky MWR brightness temperatures (TB) at DWD show a positive impact on the numerical weather prediction. However, cloudy-sky conditions involve large random differences between model and observation and therefore, the most frequent reason for rejecting data from data assimilation is the suspected presence of clouds. A balanced detection of clouds and artificial sky-clearing are possible strategies to mitigate this effect.

We present the resulting effect of a neural network (NN) based liquid water cloud detection on observation minus background (O-B, ICON-D2) statistics and compare it to established cloud detection schemes. The NN relies solely on the observed TB and is trained with TB computed with a line-by-line radiative transfer model (Rosenkranz 2022, non-scattering) from ERA5 reanalysis data.

We will also present O-B statistics with artificially cleared TB observations. The spectral signature of the liquid water is subtracted from the observed TB spectrum using a NN trained on ERA5. The cloud detection and sky clearing allow a thorough discussion of 2-years O-B statistics, which provides some insights on the model performance and monitoring instrument errors. The presented progress on sky clearing of TB also provide a possible way forward to profit even more from assimilation of MWR TB in numerical weather prediction models.

How to cite: Löffler, M., Knist, C., Pospichal, B., Claußnitzer, A., and Löhnert, U.: Ground based microwave radiometer – cloud detection, sky-clearing and O-B statistics, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-140, https://doi.org/10.5194/ems2025-140, 2025.

12:30–12:45
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EMS2025-501
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Onsite presentation
Renato R. Colucci

The Alpine-Adriatic Meteorological Society (A-AMS), in collaboration with various organizations and institutions active in the Alpe-Adria region, has launched the 'Julian Alps Meteo-Lab' project with the aim of advancing scientific knowledge of this distinctive sector of the Alps. To this end, A-AMS promotes and supports studies related to the meteorology, climate, paleoclimate, and cryosphere of the area.
The Julian Alps and Prealps — parts of which lie within the Julian Prealps Natural Park (Italy), designated a UNESCO MAB Reserve in 2019, and the Triglav National Park (Slovenia) — constitute the Alpine region with the highest mean annual precipitation. Moreover, the intensity of individual rain or snow events is often significantly greater than the average severity of similar events across Europe.
Furthermore, in the Julian Alps, several small glacial bodies remain active at much lower elevations than in other parts of the Alps due to a combination of local and regional factors. Moreover, the area is affected by pronounced karst development, which predisposes the region to a high density of subsurface cavities, many of which host perennial ice deposits.
These observation sites, along with others planned for the future, will be made available online to enable systematic monitoring of the area's meteorological and climatic conditions. Particular emphasis will be placed on making data accessible to the public, not only for scientific purposes but also to support tourism and the local economy. Additionally, the Julian Alps Meteo-Lab was established with an educational mission aimed at promoting courses, seminars, summer schools, and training events to engage both enthusiasts and non-specialists in the scientific activities related to the project.

How to cite: Colucci, R. R.: Julian Alps Meteo-Lab: A Scientific and Educational Network for Alpine Climate and Cryosphere Studies, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-501, https://doi.org/10.5194/ems2025-501, 2025.

Show EMS2025-501 recording (14min) recording
12:45–13:00

Posters: Thu, 11 Sep, 16:00–17:15 | Grand Hall

Display time: Wed, 10 Sep, 08:00–Fri, 12 Sep, 13:00
Chairpersons: Mariska Koning, Jens Bange
P80
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EMS2025-255
A boundary layer height estimation algorithm from Doppler LiDAR data
(withdrawn)
Byung Hyuk Kwon, Sangjin Kim, Kyunghoon Lee, Hyeokjin Bae, Ziwoo Seo, and Yujung Koo
P82
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EMS2025-359
Christoph Feichtinger, Rene Hörschinger, Thomas Lumesberger, Daniel Stanka, and Manfred Dorninger

Understanding three-dimensional wind patterns and turbulence in complex terrain remains a significant challenge in atmospheric sciences due to the variability and unpredictability of airflow in such environments. This study introduces and explores the innovative application of newly developed, low-cost sensors designed for very high-frequency three-dimensional wind measurements. A particular emphasis is placed on the Windpuls sensor technology, which represents a significant advancement in the field due to its affordability, portability, and precision.

The research highlights the ability of these compact sensors to accurately capture fine-scale wind dynamics in highly complex terrains, offering an unprecedented combination of spatial and temporal resolution. Traditionally, acquiring such detailed wind data has required expensive and stationary equipment, often impractical in rugged landscapes. In contrast, the Windpuls system enables flexible deployment, including on moving platforms such as vehicles and gondolas, allowing for dynamic wind profiling across varied terrains. This flexibility significantly broadens the scope of observational possibilities, especially in remote or difficult-to-access areas.

Preliminary findings from a unique experimental setup using gondola-mounted sensors in the Alpine region are presented. These initial results reveal valuable insights into vertical wind profiles, gust structures, and turbulence characteristics in mountainous areas, which are critical for applications such as aviation safety, renewable energy planning, and climate modeling. Although the current study focuses on Alpine regions, the sensor technology has broad application potential in coastal zones, urban canyons, and forested landscapes.

In this presentation, we detail the sensor’s technical specifications, calibration and validation procedures, and share key findings from our initial field campaigns. The results demonstrate that this innovative sensor system offers a transformative approach to atmospheric monitoring and has the potential to significantly enhance our understanding of microscale wind phenomena in a wide range of complex environments.

How to cite: Feichtinger, C., Hörschinger, R., Lumesberger, T., Stanka, D., and Dorninger, M.: Very High Frequency 3D Wind Measurements from New Low-Cost Sensors, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-359, https://doi.org/10.5194/ems2025-359, 2025.

P83
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EMS2025-459
Cesar Azorin-Molina, Amir Pirooz, Nicholas Kay, and Jose Gomez-Reyes

In the framework of the ThinkInAzul programme, the WIND-COAST project is a joint collaboration between the CSIC, NIWA and UOA aimed at designing and developing a new inexpensive “Meteodrone” for monitoring weather data across the low and mid-levels of the troposphere (up to 5,000-7,000 m a.s.l.). The Meteodrone is based on a DJI Matrice 350 RTK drone, equipped with the LI-550 TriSonica Mini Wind & Weather Sensor as its size and weight make it perfect for Unmanned Aerial Vehicle (UAV). The Meteodrone reports wind speed, direction, air temperature, humidity, pressure, tilt, and compass data.

The prototype has already been tested and calibrated in the wind tunnel of UOA to correct motion errors and  evaluate its performance in different conditions of wind and turbulence. Field campaigns already started in September 2024 in New Zealand and Spain, first by flying the Meteodrone near a 10-m weather station from NIWA. The Meteodrone has potential to be the substitute of existing operational radiosonde systems such as sounding balloons, which are very expensive and have relatively high environmental impact. The use of Meteodrones will lead to better real-time monitoring and forecasting of extreme weather events, in a more sustainable and less costly way. Its ability to monitor wind storms is very useful for multiple socioeconomic ane environmental sectors. For example, the Meteodrone could have a wide range of potential applications, such as supporting firefighting and emergency management efforts by the Department of Forest Fire Prevention in Valencia.

Key words: UAV, meteodrone, weather data, upper air observations

Acknowledgements: This study forms part of the ThinkInAzul programme and was supported by MCIN with funding from European Union NextGenerationEU (PRTR-C17.I1) and by Generalitat Valenciana (THINKINAZUL/2021/018).

How to cite: Azorin-Molina, C., Pirooz, A., Kay, N., and Gomez-Reyes, J.: A new low-cost Unmanned Aerial Vehicle (Meteodrone) for monitoring upper air weather data, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-459, https://doi.org/10.5194/ems2025-459, 2025.

P84
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EMS2025-536
Sven Kabus

Motivated by recent severe weather events Deutscher Wetterdienst (DWD) plans to expand its operational network by adding vertical profile measurements of wind and later also of humidity. The underlying aim is to spatially and temporally refine the observation base. As a consequence, short-term forecast and warning capabilities are expected to improve, in particular in case of extreme precipitation events.
In this context, a network of Doppler lidar systems will be installed at 13 automatic weather stations across Germany within the next two years. The sites have been selected in order to complement the existing DWD network of radiosonde stations, radar wind profilers and AMDAR measurements in the proximity of major airports. Doppler lidar systems are capable of estimating the three-dimensional wind vector in near real-time within the atmospheric boundary layer and (under appropriate conditions) up to a height of 12 km above ground level.
For a period of a few months, up to four of those future systems (WindCube 100S from Vaisala) are tested side-by-side on our test site in Hamburg, Germany. A StreamLine system (HALO Photonics by Lumibird) is added for cross-checking purposes.
Data from the instruments are used for detailed evaluation and comparison. This includes (1) the evaluation of potential alignment inaccuracies during on-site installation, (2) the variation among the instruments (regarding wind measurements and data availability), and (3) the evaluation and potential optimization of certain scan protocols. First results indicate an inter-instrument variation of considerably less than 2.0 m/s for the wind speed and of less than 10 degrees for the wind direction.

How to cite: Kabus, S.: Expanding the DWD network by Doppler lidar systems: evaluation of vertical wind profile measurements, EMS Annual Meeting 2025, Ljubljana, Slovenia, 7–12 Sep 2025, EMS2025-536, https://doi.org/10.5194/ems2025-536, 2025.