Displays

Ground-based remote sensing of atmospheric properties complements satellite remote sensing from space. Hereby the well-defined solar background of ground-based samples offers data of higher accuracy, which help to constrain (needed) assumptions in global data-sets of satellite remote sensing and earth system modeling. With ground monitoring largely limited to land or island surfaces, efforts have been made to add at least a few reference data over oceans with atmospheric remote sensing activities during ship cruises of opportunity. This presentation reports on recent voyages with German Research vessels (i.e. SONNE, MERIAN, METEOR and POLARSTERN) and how samples on these voyages have contributed to a better representation of marine properties for aerosol, trace-gases and clouds. Aside from establishing references for satellite remote sensing and modeling, relationships among different atmospheric properties also offer observational constrains for parametrizations of atmospheric processes in modeling.  

How to cite: Kinne, S.: Atmospheric measurements over oceans on German research vessels, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1348, https://doi.org/10.5194/egusphere-egu2020-1348, 2020.

Three deployments involving the NASA P-3 and ER-2 aircraft in the ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) project in September 2016, August 2017 and October 2018 were designed to study the seasonal interactions of biomass burning (BB) aerosols emanating from Southern Africa with the semi-permanent subtropical stratocumulus (Sc) cloud deck over the South-East (SE) Atlantic. We provide a science overview of all deployments, describing novel approaches for coordinating the NASA aircraft with each other, with the Bae-146 aircraft during flights near Ascension Island in 2017, and with satellite overpasses. Based on various examples, we describe the requirements for spatiotemporal coordination and the scientific benefits gleaned from successful synergy of datasets thus obtained. We provide the current status of integrative work that addresses the overarching science questions regarding aerosol-radiation-climate interactions in the region. We conclude by linking the suborbital observations with overarching observational efforts, in particular NASA’s ACCP (Aerosols, Clouds, Convection, and Precipitation) Designated Observable study, which aims to define combinations of orbital and suborbital observing system concepts for addressing integrated aerosol-cloud-climate objectives as defined in the 2017 US Decadal Survey.

How to cite: Redemann, J. and the The ORACLES science team: The NASA ORACLES airborne flight projects – lessons learned for future multi-platform missions to study aerosol-cloud-climate interactions, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-10956, https://doi.org/10.5194/egusphere-egu2020-10956, 2020.

The North Atlantic is witnessing major changes during the Anthropocene. These include changes in the physical climate system: in ocean and atmosphere temperatures and circulation; in sea ice thickness and extent; and in atmospheric composition, where ozone, ozone precursors and aerosols have undergone significant changes over the last few decades. Changes in aerosols over the North Atlantic have been linked to changes in sea surface temperatures (SST) and North Atlantic climate variability. A long-term research project, The North Atlantic Climate System Integrated Study (ACSIS), involving data collection and interpretation, has begun to better understand the processes and composition-climate interactions associated with these changes. Here we report on one of the major observational components of the ACSIS programme which involves repeated measurements of the composition of the North Atlantic using the NERC FAAM BAe146. To date six campaigns have taken place including three which coincided with the NASA ATom campaigns (2-4). 

In this presentation we will discuss the rationale for the aircraft project and recent results including the observation of transport of biomass burning plumes into the North Atlantic that are estimated to have originated from fires sampled as part of the NASA FIREX campaigns during the summer of 2019. We will highlight results from an intercomparison with the NASA DC-8 during our second campaign and ATom 3, which reveal good agreement in measurements of O3, CO and NOx between the two aircraft but large differences in measurements of non-methane VOCs, and we will summarise our results to-date including the comparison against chemical transport models. 

How to cite: Archibald, A. and the The NERC ACSIS Team: Aircraft campaigns in support of the North Atlantic Climate System Integrated Studies (ACSIS), EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-3761, https://doi.org/10.5194/egusphere-egu2020-3761, 2020.

The EUREC4A (ElUcidating the RolE of Clouds-Circulation Coupling in Climate) field campaign takes place in the lower Atlantic trades, over the ocean east of Barbados from 20 January to 20 February 2020. During this campaign, for the first time, simultaneous measurements of surface turbulence, cloud microphysical properties, cloud radiative properties, convective activity and the large-scale environment in which clouds and convection are embedded (large-scale vertical motion, thermodynamic stratification, surface properties, turbulent and radiative sources or sinks of energy).

Our new Atmospheric Raman Temperature and Humidity Sounder (ARTHUS) observes temperature and moisture profiles over the ocean with turbulence resolution of up to 10 s and 7.5 m. By this, the thermodynamic properties as well as statistics of their turbulent fluctuations in the oceanic boundary layer can be investigated in detail including relative humidity, buoyancy, CAPE, and CIN. In addition, ARTHUS is also a aerosol Raman lidar and provides profiles of particle extinction and backscatter coefficient independently at 355 nm. Two Doppler lidars – one vertical pointing the second in scanning mode – measure horizontal wind profiles as well as profiles of vertical wind fluctuations, turbulent kinetic energy, and momentum flux. The combination of the three lidars will provide synergetic data products like latent and sensible heat flux profiles. Thus, this combination allows to investigate boundary-layer properties including cloud formation and aerosol-cloud interaction.

During the EGU General Assembly, we will show our first results from the campaign.

How to cite: Lange Vega, D., Behrendt, A., Späth, F., and Wulfmeyer, V.: Lidar-based Water Vapor, Temperature and Wind Measurements with Turbulence Resolution during the EUREC4A Field Campaign onboard RV Merian, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-12144, https://doi.org/10.5194/egusphere-egu2020-12144, 2020.

As a potential way to measure atmospheric variables with high vertical resolution and improved accuracy, the technique of Microwave and Infrared Occultation was studied. To monitor the atmospheric thermodynamic state variables (e.g., pressure, temperature, and humidity) and greenhouse gases (e.g., H2O, CO2, CH4, N2O, O3), a concept mission named Climate and Atmospheric Composition Exploring Satellites (CACES) that is based on the occultation technique of the Low Earth Orbit (LEO) satellites, was proposed to the Strategic Priority Research Program of Chinese Academy of Sciences (SPRPCAS). The mission has been approved in 2018 as a primary study to prove the possibility of observing the benchmark climate data. Designs of the constellation for the scientific objectives in climate and weather forecasts were simulated. The spatiotemporal distribution of simulated measurements was analyzed and evaluated for ensuring the desired performance. And the retrieval methods with bending angle and transmission amplitude of microwave and infrared-laser signals were studied.

How to cite: Wang, X., Wu, X., Zhang, Z., and Lyu, D.: Progress of the Climate and Atmospheric Composition Exploring Satellites Mission (CACES) in China, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-13183, https://doi.org/10.5194/egusphere-egu2020-13183, 2020.

In the frame of the science preparation activities for the upcoming German hyperspectral satellite mission EnMAP, an airborne survey took place in September 2019 with hyperspectral VNIR-SWIR-LWIR data using the HySpex sensor and the newly acquired Hyper-Cam LWIR camera from the GeoResearch Center Potsdam (GFZ) mounted on the airborne platform Cessna-T207A from the Free University Berlin (FUB). Although logistically complex conditions with several teams distributed in different locations, all the sites in central and northern Greece could be successfully acquired under clear sky conditions, and all data could be demilitarized providing 45 flight stripes covering a total area of 300 km².

This abstract is focusing on the Amyntaio soil site in northern Greece, an agricultural area of variable soil composition from carbonate rich to clay/silt content to organic carbon rich fields around the lignite mine south of the area, over which 11 flight stripes could be acquired. The science goals of the Amyntaio soil campaign were: (a) Simulation of hyperspectral satellite imagery and demonstration of the potential of upcoming spaceborne hyperspectral sensors (EnMAP, CHIME) for global soil mapping and monitoring; (b) Large test and validation for existing soil algorithms such as the HYSOMA / ENSOMAP software tools for the prediction of top-soil quantitative surface properties; (c) Data validation and comparison of soil products with recent relevant satellite sensors (e.g. S2, PRISMA, ECOSTRESS); (d) Enlargement of global soil spectral libraries with harmonised standards and testbed for their use as calibration-validation data for soil spectral models.

Simultaneous to the airborne survey, an intensive ground-based campaign took place in the area focusing on the acquisition of soil data, VNIR-SWIR and LWIR in-situ data with field spectroradiometers (PSR+, ASD FieldSpec3, MEMS, Handheld FTIR), fractional vegetation cover with RGB and UAV RGB data, soil moisture, infiltrometer and spectral data in undisturbed soil crust with the SoilPRO device, and Cal-Val data acquisition at the same time than the overflight (Temperature-loggers, ASD VNIR-SWIR, handheld FTIR) over bare soils and black/white thermal targets.

We present the project objectives, selected field, airborne, satellite data, with preliminary analyses that show the high data quality and the potential of multi hyperspectral airborne campaigns as a support for basic science developments and satellite mission preparations. The results represent how more sensor flexibility can bridge the gap from in-situ to satellite scale. Further airborne flights and carefully designed in situ campaigns will allow testing and iterative improvement of new observational modalities for soil monitoring based on the integrated information from satellite platforms with the one provided by in-situ systems on the ground and air.

How to cite: Chabrillat, S., Ruhtz, T., Zalidis, G., Ben-Dor, E., Brell, M., Tziolas, N., Milewski, R., Berger, D., Foerster, S., Kuester, T., Tsakiridis, N., Liakopoulos, V., Angelopoulou, T., Samarinas, N., Francos, N., Cawse-Nicholson, K., and Pignatti, S.: EnMAP airborne soil Greece campaign 2019, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-8988, https://doi.org/10.5194/egusphere-egu2020-8988, 2020.

The purpose of this study was to evaluate the realistic feasibility of using hyperspectral remote sensing airborne data for mapping asphalt road conditions. We constructed a real-life operational scenario, where the road's dynamic friction coefficient was modeled against the reflectance information extracted from the image. The asphalt pavement's dynamic friction coefficient was measured by a standardized technique, using a Dynatest friction-measuring system. The hyperspectral data were acquired by both the Specim AisaFENIX 1K and Telops Hyper-Cam airborne sensors at a selected study site, with roads characterized by different aging conditions. The spectral radiance data were processed to provide apparent surface reflectance and emissivity using ground calibration targets. Our final dataset was comprised of thousands of clean asphalt pixels coupled with geo-rectified in situ friction measurement points. We deployed a partial least squares regression model with the PARACUDA-II spectral data-mining engine, which uses an automated outlier-detection procedure and dual validation routines—a full cross-validation and an iterative internal validation based on a Latin hypercube sampling algorithm. Our results show prediction capabilities across the visible–near infrared–shortwave infrared (0.4–2.5 mm) spectral region of R² = 0.72 for the best available model in internal validation, and across the longwave infrared (7.6–11.4 mm) spectral region of R²=0.62  for the best available model in internal validation. Both spectral regions (optical and thermal) maintained high significant results with p < 0.0001. Using spectral assignment analysis, we located the spectral bands with the highest weight in the model, and discuss their possible physical and chemical assignments. The derived model was applied back on the hyperspectral images to predict and map the friction values of every road's pixels in the scene. We conclude that although a relatively strong prediction model can be achieved, the imaging spectroscopy technique from airborne platforms ) may open a new frontier in road safety and present a new capability for the promising airborne technology.

How to cite: Ben Dor, E. and Carmon, N.: Mapping the Friction Coefficient of Asphalt Roads Using Airborne Imaging Spectroscopy, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1660, https://doi.org/10.5194/egusphere-egu2020-1660, 2020.

Rhododendron (Rhododendron ponticum) has been identified as an invasive non-native species (INNS) in the UK and a potential carrier of Phytophthora ramorum and therefore needs management.  This study identified the presence and location of rhododendron from airborne hyperspectral data and compared the results with Random Forests classifications of Sentinel-2 and Pleiades satellite data. The multispectral satellite systems had two limitations. The first limitation was insufficient spectral resolution to identify individual understorey species in a deciduous woodland (e.g. rhododendron, cherry laurel and holly). In this instance the satellite systems were only able to identify the presence of ‘potential rhododendron’, rather than actual rhododendron, where the term ‘potential rhododendron’ included any understorey evergreen species in a deciduous woodland. The second was insufficient spatial resolution (10m and 2m, respectively) to discriminate individual understorey plants; which resulted in the understorey being represented by a majority of mixed pixels. In this situation no more than percentage estimates of ‘potential rhododendron’ in an area could be obtained.

The airborne data used in this study were collected using a HySpex hyperspectral VNIR sensor and Phase One (80MB) survey camera; these provided a spatial resolution of 0.32m and 0.07m, respectively. The HySpex VNIR sensor had 186 bands with a full-width-half-maximum of 4.5nm. This sensor combination was shown to have sufficient spectral and spatial resolution to identify individual understorey species. Discrimination of different understorey species was achieved using a combination of spectral analysis techniques, including spectral angle mapper (SAM), and object-based-image analysis (OBIA). Furthermore, overstorey and understorey canopies were separated through the inclusion of a separate airborne LiDAR dataset, collected earlier that year.

Remotely sensed optical data were collected in leaf-off conditions to minimise the influence of the overstorey vegetation canopy. However, this introduced specific issues relating to weak sunlight and low solar illumination angles; these influenced data quality, data analysis and validation of the final classification. Methods to mitigate these issues were developed (e.g. use of masks to remove long shadows cast by trees), but challenging obstacles remained (e.g. steep north-facing terrain casting large areas in shadow). Meanwhile, validation required botanical expertise, careful consideration of the relative dates when remotely sensed data and field validation data were collected, the geographical precision of field data and an awareness of any bias incurred by shadow.  As with other remote sensing studies, the number and distribution of validation samples and the selection of training data were major considerations. However, this multi-scale study demonstrates the advantages of using airborne hyperspectral systems for species mapping in complex environments. 

How to cite: Llewellyn, G., Jaouen, L., Killeen, J., Barnes, C., Platts, L., Case, S., and Mothersdill, D.: Detection of rhododendron in a deciduous woodland using airborne hyperspectral remote sensing, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-19931, https://doi.org/10.5194/egusphere-egu2020-19931, 2020.

Airborne campaigns for the meteorological and environmental research have been conducted in regional and global scales. The aircraft is increasingly considered as one of the best platforms to get the atmospheric spatial information, especially over sea. National Institute of Meteorological Sciences (NIMS), Korea Meteorological Administration (KMA) has been utilizing an aircraft (Beechcraft King Air 350HW) equipped with 25 scientific mission instruments since 2018, in order to fill in observational gaps and observe the upper level of troposphere at higher temporal/spatial resolution and to test advanced observational and experimental techniques, resulting in enhancing meteorological technologies and research capabilities. Our airborne observation plans using the aircraft are designed over the Korean Peninsula; preceding observation of severe weather (e.g., tropical cyclone, heavy rainfall and snowfall), greenhouse gas monitoring, environmental meteorology monitoring (e.g., Asian dust), and cloud physics and cloud seeding. In particular, preceding observation of severe weather which mainly uses dropsondes focuses on characterizing generation/migration of severe weather phenomena and investigating meteorological precursors sensitive to severe weather and variations in its thermo-dynamical structures, and then improving predictability of numerical models with the data assimilation. Here, we discuss current status and future plan of our airborne measurement campaigns over the Korean Peninsula, with examples of data observed from the aircraft.

How to cite: Lee, C., Jung, S., Kim, J.-H., Yang, H., Ko, H., Yun, J., Kim, S., and Joo, S.: Airborne measurements over Korea using the KMA/NIMS atmospheric research aircraft (NARA), EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-18367, https://doi.org/10.5194/egusphere-egu2020-18367, 2020.

Launched on 13 October 2017, Sentinel 5 Precursor (S-5p) is the first mission of the Copernicus Programme dedicated to the monitoring of air quality, climate, ozone and UV radiation. The S-5p characteristics, in particular its fine spatial resolution of 3.5 x 5.5 km², introduce new opportunities for science and applications requiring to carefully assess the quality and validity of the generated data products by comparison with independent measurements and analyses.

While the routine validation and QA/QC of the S-5p operational products is performed within the ESA Mission Performance Center (MPC) based on a limited number of Fiducial Reference Measurements (FRM), additional validation activities including field campaigns are conducted in research mode as part of the S-5p Validation Team (S5PVT). The validation activities bring together various teams and instruments and provide a more in-depth, complete insight into the S-5p instrument performance and the fitness for purpose of its data products.

Here, we present observational deployments planned to take place in 2020-2021 in the context of the Sentinel 5p VAlidatioN and calibraTion Experiment (SVANTE). A first set of activities concentrates on the main S-5p UV-Vis tropospheric products (NO₂, HCHO and SO₂₎. Airborne measurements, including both in-situ spiral and remote sensing mapping flights, are planned over cities and industrial areas in Romania (Bucharest; Jiu valley), the German Ruhr area (Cologne; Duisburg; Dusseldorf) and Berlin, Belgium (Antwerp and Brussels), The Netherlands (Rotterdam and Cabauw), as well as the southern part of The Persian Gulf. These operations will be supported by ground-based measurements using Pandora, MAX-DOAS, car-DOAS, sun-photometer, ceilometer, lidar, etc. Over Berlin and Bucharest, the aim is to perform recurrent airborne observations with hyperspectral imagers in order to accumulate mapping data during approximately one full year, under variable meteorological and air quality conditions, as well as different satellite overpass configurations.

A second set of activities will focus on the validation of the SWIR data products (CO and CH₄). COCCON (COllaborative Carbon Column Observing Network) portable low-resolution EM27/SUN FTIR spectrometers will be deployed for an extended period at different sites in order to obtain a good coverage of geophysical parameters and different ground scenes.

Additionally, synergies will be created with large field campaigns, such as the Asian Summer Monsoon Chemical and Climate Impact Project (ACCLIP) and the 2020 HYTES Joint European Campaign, which will provide airborne measurements of NO₂, CO and CH₄ columns and vertical profiles.

The various airborne and ground-based measurements will produce a comprehensive ensemble of reference datasets. For each product, a core team will coordinate validation tasks, making use of data collected in all relevant instrumental deployments.

How to cite: Van Roozendael, M., Tack, F., Merlaud, A., Schuettemeyer, D., Hase, F., Richter, A., Meier, A., Sha, M. K., De Mazière, M., Apituley, A., Nicolae, D., Calcan, A., Ruhtz, T., Crévoisier, C., Roiger, A., Dehn, A., and Zehner, C.: The Sentinel-5 Precursor VAlidatioN and calibraTion Experiment (SVANTE), EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-18805, https://doi.org/10.5194/egusphere-egu2020-18805, 2020.

The scientific community is beginning to see how our environment reacts to changes on an unprecedented time and space scale with the utilization of small Unmanned Aircraft Systems or sUAS.  These new observation platforms can be utilized for flood forecasting, local weather forecasting, monitor wildlife, improve hurricane forecasts and this the tip of the iceberg. This technology is a new tool that will allow the scientific community to observe the environment on time and space scales that are unprecedented.  This particular talk will primarily address the future of these observing platforms as it relates to advancing the atmospheric sciences. UAS’s are rapidly becoming the new technology that can acquire low-level environment information more frequently, in support of higher-resolution model forecasts of severe thunderstorm and tornado potential, improvement in  Environmental Model Prediction, provide environmental  information to provide better support  the spread of wildfires and smoke, as well as wildfire imagery for Incident Command and more complete/accurate storm damage surveys.  One of the end goals would be to have  a nationwide network of sUAS providing near-continuous observations of thermodynamic parameters, NDVI, surface sensible heat and wind speed and direction. Most of these observations are being done on a regular basis and some will be attainable in the future as technology progresses and National Airspace becomes more accessible. 

How to cite: Baker, B., Dumas, E., Lee, T., and Buban, M.: The Present and Future Role for sUAS in Atmospheric Sciences, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-2753, https://doi.org/10.5194/egusphere-egu2020-2753, 2020.

iUAGS is an emerging UAV aerogeophysical integrated survey system ( magnetic & radiation) based on the rainbow series UAV(the CH-3),which has many advantages such as long-endurance,low altitude, all-day time work ability, high precision,low cost,etc.It’s leading researched and developed by Institute of Geophysical and Geochemical Exploration (IGGE) of China Geological Survey (CGS).Since 2013,more than 150,000 kilometers’ pretty good and high quality geophysical data have been acquired using iUAGS in Duobaoshan of Heilongjiang province , Karamay and Kashi area of Xinjiang province,YanCheng of Jiangsu province in china.And a new survey hosted by IGGE is now working for earth deep probe project in southern china.With the development of UAV and aerogeophysical technology，We believe that iUAGS will be widely and better used in more fields.  

How to cite: Lu, N., Xi, Y., Zheng, H., Liu, J., and Wu, S.: Applications of an UAV aerogeophysical integrated survey system(iUAGS) in china, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-17069, https://doi.org/10.5194/egusphere-egu2020-17069, 2020.

The forthcoming Upper-Air Instruments Intercomparaison (UAII2021) is organized under the auspices of the World Meteorological Organization (WMO) with the purpose to improve the quality of upper air observing systems and to develop the knowledge and expertise of national meteorological services (NMHS). The participating radiosonde systems (RS) are representative for those currently employed in the global observational network. A novelty with regard to previous RS intercomparison campaigns is to adopt principles and practices well established in the GCOS Reference Upper Air Network (GRUAN). This includes using GRUAN reference data products (GDPs) in the comparison of the RS. A distinguishing feature of a GDP is that the data are traceable to SI units. The data measured by a GDP are fully characterized in terms of their vertically-resolved uncertainty. This means that for each data point measured by the GDP at altitude z the obtained value V is represented as V(z) ± ΔV(z). Another novelty is the use of open source software for data analysis and visualization. The Data Visualization and Analysis Software (DVAS) is currently being developed and, as a basic feature, will use GDPs to establish the reference against which the performances of the participating RS are evaluated. This ensures a fair and transparent approach in the intercomparison of the RS. The DVAS uses a statistical combination of the available GDPs (two GDPs being the minimum number required) to act as a working standard (WS). Each data point measured by a GDP at the altitude z is assessed for consistency with the data points measured by the other GDPs and, if consistent, they are retained for calculation of the WS. In other words, the values V(z) ± ΔV(z) from the GDPs are evaluated and added together to yield the combined values for the measured parameter and its uncertainty. The evaluation of the values V(z) ± ΔV(z) consists of a consistency test, i.e. the values V(z) ± ΔV(z) should lie within the uncertainties of the other GDPs. The details of the consistency test, including the case when the test fails, will be provided in the presentation of the DVAS.

In addition to the evaluation of the RS performances in terms of their mean bias and variability, each RS is assessed for its ability to be fit for purpose with respect to different application areas based on the Observing Systems Capability Analysis and Review Tool (OSCAR table of requirements, https://www.wmo-sat.info/oscar/). For example, a RS can be affected by a too-large bias/ variability with respect to the reference WS for applications in the area of high-resolution numerical modelling, but can be fit for the purposes of global modelling.

How to cite: Martucci, G., Dirksen, R., Romanens, G., Haefele, A., Vogt, F. P. A., Sommer, M., Félix, C., Lehmann, V., Voemel, H., Edwards, D., Taylor, S., Gardiner, T., Ansari, M. I., Mahmoud, E. E., Oakley, T., Ruedi, I., Premec, K., Berger, F., and Calpini, B.: DVAS -Data Visualization and Analysis Software: processing and analysis of the radiosounding data for the next WMO Upper-Air Instruments Intercomparaison - UAII2021., EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-17779, https://doi.org/10.5194/egusphere-egu2020-17779, 2020.

The National Center for Atmospheric Research Earth Observing Laboratory (EOL) proposes to develop the LOwer Troposphere Observing System (LOTOS), a new integrated sensor network that offers the potential for transformative understanding of the lower atmosphere and its coupling to the Earth's surface. 

The LOTOS sensor network is designed to allow simultaneous and coordinated sampling both vertically, through the atmospheric planetary boundary layer, and horizontally, across the surrounding landscape, focusing on the land-atmosphere interface and its coupling with the overlying free troposphere. The core of LOTOS will be a portable integrated network of up to five nodes, each consisting of a profiling suite of instruments surrounded by up to fifteen flux measuring towers. LOTOS will provide an integrated set of measurements needed to address outstanding scientific challenges related to processes within the atmospheric surface layer, boundary layer, and lower troposphere. LOTOS will also enable novel quantification of exchanges of biogeochemical and climate-relevant gases from microscale up to regional scale. 

LOTOS’ uniqueness lies in its ability to simultaneously sample both horizontally and vertically as an integrated system, but also in its flexibility to be easily relocated as a portable field-deployable system suitable for addressing a wide range of research needs. LOTOS will provide real-time data quality control, combine measurements from a variety of sensors into integrated data products, and provide real-time data displays. It is envisioned that LOTOS will become part of the deployable NSF Lower Atmosphere Observing Facilities (LAOF) and thus be available to a broad base of NSF users from both observational and modeling communities. LOTOS offers the potential for transformative understanding of the Earth and its atmosphere as a coupled system. This presentation will describe the background, motivation, plan, and timeline for the LOTOS’ proposed development.

How to cite: Hock, T., Weckwerth, T., Oncley, S., Brown, W., Grubišić, V., and Lee, W.-C.: Planning for LOTOS: A New LOwer Troposphere Observing System, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-19600, https://doi.org/10.5194/egusphere-egu2020-19600, 2020.

How to cite: Smith, E. R., Mynard, A., McInnes, R. N., Hort, M. C., Agnew, P., Kent, J., Wilson, A., Tiddeman, D., Bowles, J., Langridge, J. M., Wivell, K., Szpek, K., Barrett, P. A., King, R., and Archibald, A. T.: A 12-month UK air quality aircraft campaign and model evaluation, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7041, https://doi.org/10.5194/egusphere-egu2020-7041, 2020.

Cyprus enters the space arena with the ‘EXCELSIOR’ project. ‘EXCELSIOR’ is expected to bring change in many aspects, including new opportunities for researchers, enhanced skills development for future experts in the Earth Observation and Geoinformation sector on a local, national, European and global level. Due to its geographical proximity, ‘EXCELSIOR’ can become a hub for partners in Middle Eastern and Northern African countries. Cyprus’s unique geostrategic position can support Earth Observation from satellites programmes in three continents and provide valuable services in the processes of satellite calibration and validation. The ERATOSTHENES Centre of Excellence (ECoE), with its expertise and infrastructure, could further complement the existing network of international ground stations. Cyprus is ideally located to host the ECoE, due to its climate, which is characterized by 300 days of sunshine a year, providing excellent weather conditions for cloud free satellite images.

There are some distinct needs and opportunities that motivate the establishment of an Earth Observation Centre of Excellence in Cyprus. The needs include: i) to establish a Supersite for aerosol and cloud monitoring in the Eastern Mediterranean, Middle East and North Africa (EMMENA): strong demand for EO monitoring to provide data to evaluate the extent of pollution and climate change, especially in the EMMENA region; ii) to observe droughts and water shortages in the EMMENA region; iii) to adopt Rehabilitation programmes in EMMENA; iv) to reduce Disaster Risk and v) to create a Regional Digital Innovation Hub for Earth Observation in Cyprus. The foreseen opportunities include: i) the ECoE has the potential to become a catalyst for facilitating and enabling Regional, European and International cooperation; ii) the Eco E can capitalise on the favourable environmental, weather and climatic conditions of Cyprus to conduct cutting-edge research with impact in various sectors, including climate change, marine, solar energy, etc.; iii) the development of the Cyprus Space Strategy, which can be exploited for further Earth observation research and applications; iv) create a unique European capacity in Cyprus by mobilizing internal national assets and consolidating European EO capabilities in Cyprus to serve EMMENA. The ECoE will procure and develop the European Satellite Ground Stations covering the EMMENA region; v) accessing funding instruments for Earth Observation at the national and European Level and vi) the development of Big Data management and analytics.                              

The EXCELSIOR project has received funding from the European Union’s Horizon 2020 research and innovation programme under Grant Agreement No 857510 and from the Government of the Republic of Cyprus through the Directorate General for the European Programmes, Coordination and Development.

How to cite: Themistocleous, K., Hadjimitsis, D., Schreier, G., Kontoes, H., Ansmann, A., Komodromos, G., Michaelides, S., Neocleous, K., Papoutsa, C., Mamouri, R., Schwarz, E., Papoutsis, I., Bühl, J., Nisantzi, A., Mettas, C., Danezis, C., and Tzouvaras, M.: Cyprus enters the space arena with "Excelsior " H2020 Teaming project and the Eratosthenes Centre of Excellence: Why Cyprus? Why Excelsior? What are the needs and opportunities?, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-21801, https://doi.org/10.5194/egusphere-egu2020-21801, 2020.

About 60% of global methane (CH₄) emissions are due to human activities. Since the Paris Agreement was signed in 2016, an increasing effort has been devoted to accelerate the greenhouse-gas-emissions mitigation. Afore in 2014, the Oil and Gas Climate Initiative (OGCI) formed, which is an international industry-led organization including 13 member companies from the oil and gas industry, representing 1/3 of the global operated oil and gas production. The Environmental Defense Fund (EDF) and United Nations Environment Programme (UNEP) funded project METHANE-To-Go aims to focus on trace gas emissions from the natural gas and oil operations in the Persian/Arabian Gulf region, a wealthy region which contains about 50% of the world´s oil reserves. The project is coordinated by the Deutsches Zentrum für Luft- und Raumfahrt (DLR) and envisages to carry out airborne in-situ measurements with the German Deutsches Zentrum für Luft- und Raumfahrt (DLR) Falcon-20 in autumn 2020 in cooperation with local OGCI partners.

The flaring, venting and combustion processes produce large amounts of CH₄, a greenhouse gas that is ~84 times more potent than CO₂ (measured over a 20-year period) and in focus of current mitigation strategies trying to reduce global warming. However, there is a huge lack of detailed CH₄ measurements worldwide and especially from the Gulf region. The contribution from this region to the global CH₄ mass balance is presently unknown. Furthermore, recently a first global satellite-derived SO₂ emissions inventory was established based on measurements with the Ozone Monitoring Instrument (OMI) on the NASA Aura satellite showing a number of SO₂ hot spots in the Persian/Arabian Gulf region. The Middle East region was high-lighted as the region with the most missing SO₂ sources compared to reported sources in the global emission inventories. The petroleum industry operations are mainly responsible for these emissions, since high amounts of H₂S are trapped in oil and gas deposits and released during extraction. In recent years, the air quality in this region has worsened dramatically and concurrently global warming is especially strong.  

The DLR Institute of Atmospheric Physics plan the performance of airborne in-situ measurements to probe the isolated, outstanding emission plumes from the different CH₄ and SO₂ sources in the southern part of the Gulf region as mentioned above. A novel dual Quantum Cascade Laser (QCL) instrument based on laser absorption spectroscopy will be deployed to measure CH₄ and CO, and related trace gases as CO₂ and C₂H₆, which can be used to distinguish between different CH₄ sources (flaring, venting and combustion). An ion-trap chemical ionization mass spectrometer (IT-CIMS) is foreseen for the measurements of SO₂. Both instruments operate with a high precision/accuracy and a temporal resolution of 0.5 to 1s, which covers a horizontal distance of roughly 50-200 m during the flight. Measurements of further trace species are also foreseen (e.g. NO, NO_y, and aerosols) and simulations with particle dispersion models for flight planning and post analyses (HYSPLIT and the EMAC related model MECO(n)). Furthermore, satellite validation is envisaged with the TROPOMI instrument on Sentinel-5P (focus on CH₄ and SO₂).

How to cite: Huntrieser, H., Roiger, A., Sauer, D., Schlager, H., Mertens, M., and Schwietzke, S.: Emissions from natural gas and oil operations: The airborne METHANE-To-Go field campaign in the Persian/Arabian Gulf region , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-13490, https://doi.org/10.5194/egusphere-egu2020-13490, 2020.

We analyzed seasonality and interannual variability of tropospheric HCN column amounts in densely populated eastern China for the first time. The results were derived from solar absorption spectra recorded with ground-based high spectral resolution Fourier transform infrared (FTIR) spectrometer at Hefei (117°10′E, 31°54′N) between 2015 and 2018. The tropospheric HCN columns over Hefei, China showed significant seasonal variations with three monthly mean peaks throughout the year. The magnitude of the tropospheric HCN column peak in May > September > December. The tropospheric HCN column reached a maximum of (9.8 ± 0.78) × 10¹⁵ molecules/cm² in May and a minimum of (7.16 ± 0.75) × 10¹⁵ molecules/cm² in November. In most cases, the tropospheric HCN columns at Hefei (32°N) are higher than the FTIR observations at Ny Alesund (79°N), Kiruna (68°N), Bremen (53°N), Jungfraujoch (47°N), Toronto (44°N), Rikubetsu (43°N), Izana (28°N), Mauna Loa (20°N), La Reunion Maido (21°S), Lauder (45°S), and Arrival Heights (78°S) that are affiliated with the Network for Detection of Atmospheric Composition Change (NDACC). Enhancements of the tropospheric HCN columns were observed between September 2015 and July 2016 compared to the counterpart measurements in other years. The magnitude of the enhancement ranges from 5 to 46% with an average of 22%. Enhancement of tropospheric HCN (ΔHCN) is correlated with the coincident enhancement of tropospheric CO (ΔCO), indicating that enhancements of tropospheric CO and HCN were due to the same sources. The GEOS-Chem tagged CO simulation, the global fire maps and the PSCFs (Potential Source Contribution Function) calculated using back trajectories revealed that the seasonal maxima in May is largely due to the influence of biomass burning in South Eastern Asia (SEAS) (41 ± 13.1%), Europe and Boreal Asia (EUBA) (21 ± 9.3%) and Africa (AF) (22 ± 4.7%). The seasonal maxima in September is largely due to the influence of biomass burnings in EUBA (38 ± 11.3%), AF (26 ± 6.7%), SEAS (14 ± 3.3%), and Northern America (NA) (13.8 ± 8.4%). For the seasonal maxima in December, dominant contributions are from AF (36 ± 7.1%), EUBA (21 ± 5.2%), and NA (18.7 ± 5.2%).The tropospheric HCN enhancement between September 2015 and July 2016 at Hefei (32°N) were attributed to an elevated influence of biomass burnings in SEAS, EUBA, and Oceania (OCE) in this period. Particularly, an elevated fire number in OCE in the second half of 2015 dominated the tropospheric HCN enhancement in September – December 2015. An elevated fire number in SEAS in the first half of 2016 dominated the tropospheric HCN enhancement in January – July 2016.

How to cite: Sun, Y., Dai, P., and Yin, H.: FTIR time series of tropospheric HCN in eastern China and source attribution, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-2294, https://doi.org/10.5194/egusphere-egu2020-2294, 2020.

Korea Meteorological Administration/National Institute of Meteorological Sciences (KMA/NIMS) has adopted KMA/NIMS Atmospheric Research Aircraft (NARA) since the beginning of 2018. NARA has performed year-round airborne measurement of Sea surface Wind Speed (SWS) using Stepped Frequency Microwave Radiometer (SFMR) during 2018-2019. Total 84 flights of SFMR SWS measurements during this period were analyzed by comparing to concurrent measurements of KMA marine buoy. SFMR SWS around the Korean peninsula during the same period was 6.34±4.95 m s^-1. SFMR SWS was appeared to be 12.3% larger than those of KMA marine buoy and mean Bias Difference (BD) was 0.69 m s^-1. However, SFMR SWS and KMA marine buoy were correlated well to each other (R²~0.80). The BD was decreased with increasing SWS, this agreed well with results of previous studies (Klotz et al., 2014), however, SFMR SWS measurement showed still reliable even in low SWS environment (< 15 m s^-1). For more accurate measurement of SFMR SWS, parameters such as the flight altitude (swath area) and pre-input values (sea surface temperature, salinity) should also be considered. Also, this result can be a comparison reference for those of satellite-borne sensors, as well.

How to cite: Kim, J.-H., Lee, C., Yang, H., Jung, S., Ko, H., Yun, J., Hong, S., Kim, S., and Joo, S.: Validation of year-round Stepped Frequency Microwave Radiometer (SFMR) measurement of sea surface wind speed around the Korean Peninsula during 2018-2019, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-18175, https://doi.org/10.5194/egusphere-egu2020-18175, 2020.

The Synnyr alkaline massif is a concentrically zoned body located in the Baikal Vitim folded area, Holodninskiy graben. It is controlled by the deep-seated Precambrian Baikal-Synnyr fault, while major rock types of the massif were dated as 230-350 Ma (Kostuk et al., 1990; Mitrofanova 2009). However, there were no young strike-slip faults or thrusts identified throughout the massif. Studying the area is compounded by the climate and landscape conditions, which makes the airborne geophysical survey a very cost-effective mapping tool. Main geological investigations of the Synnyr massif were made in the 1960s and in the 1980s. In those times, an airborne geophysical survey was not as accurate as it was required and didn’t bring up any significant results.

The next stage of Synnyr massif exploration began in 2016. The first airborne magnetic survey based on unnamed aerial vehicles (UAV) was made in 2018 and increased our knowledge about the geological situation in the studying area. Main goals of the UAV magnetic survey were tracing highly magnetic foidal gabbroids named shonkinites, which are located in the central part of the ore zone, and mapping major faults.

The airborne geophysical complex included a multirotor aerial vehicle and quantum magnetometer with a rubidium magnetic field sensor that was placed in the special gondola and attached to the UAV. The study area was surveyed at 20 meters height with detailed terrain following and accuracy of magnetic field measurements comparable with the ground magnetic survey.

As a result, airborne magnetic data helped to clarify geological structure and tectonics in the areas covered with glacier or without any outcrops. Furthermore, magnetic field measurements allowed to locate faults and lineaments which were not traced in previous geological studies of the Synnyr massif and to make an assumption about the neotectonic activity of Baikal-Synnyr fault system.

Due to cost-efficiency, informativeness and high accuracy of geophysical surveys based on UAV, we are planning to continue research and extend the studying area.

References:

Mitrofanova N.N. Report for Aldan-Transbaikal geological maps, 2009

Kostuk V.P., Panina L.I., Zhidkov A. Y., Orlova M.P., Bazarova T.Y. Potassium alkaline magmatism in Baikal-Stanovoi rift system, 1990

How to cite: Maev, I., Karaman, A., and Kajukov, A.: UAV magnetic survey for geological exploration: A case study of the Synnyr Massif, Buryatia, Russia, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-725, https://doi.org/10.5194/egusphere-egu2020-725, 2020.

In this paper, we focus on UAVs (Unmanned Aerial Vehicles) positioning in GPS-denied environments and proposes a navigation mode of “track reckoning + relative ranging + heading constraint”. Internal sensors (gyros, accelerometer, barometer, etc.) measure the self-motion to obtain the flight path and attitude, and the external sensors identify and measure the relative ranging to achieve peer-to-peer constraint for UAVs. In order to guide the swarm to the intended destination when GPS is denied, the ground anchor nodes are set to provide relative heading constraints to the UAVs for target and trajectory guidance. We propose a hybrid centralized-distributed scheme including 20 UAVs, as well as its dynamic motion model and measurement model. To improve the ranging accuracy in the actual RSSI measurement, we analyze the influence of antenna pattern inhomogeneity and channel variation, respectively. The former mainly determines an antenna radiation function related to the yaw angle and relative position between the two measuring UAVs. The latter uses overlapping Allan variance to analyze and identify the measurement noises from outfield tests, that is, quantization noise, flicker noise, random walk noise and Gaussian white noise, which to some extent bridges the difference between the theoretical model and the practical measurement of RSSI. In this way, an improved extended Kalman filter is to predict and correct the colored noise by adaptively integrating the current peer-to-peer radio ranging performance and its Allan variance. To prove the effectiveness of this approach, simulation results base on practical noise modeling are demonstrated.

How to cite: Xiaofeng, O., Daqian, L., and Tianbao, D.: Cooperative Navigation of UAVs in GPS-denied area using an extended Kalman filter with colored RSSI measurements, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-4508, https://doi.org/10.5194/egusphere-egu2020-4508, 2020.

In this study, we present a hyper-spectral imaging (HSI) system that focuses on the spectral window 470-970 nm and meets the demands of static sampling and remote sensing when mounted on an Unmanned Aerial System (UAS).

The system comprises two HS cameras, a compact industrial PC and a battery pack. It has a total weight of <1.8kg, including the bracket for mounting to an active DJI Ronin gimbal. A labview interface was also developed to collect, process and analyse the images from the two HS cameras. The software has the ability to set the parameters for the cameras’ exposure times and capture frequency, while it can provide the digital counts at a single point of the image or the averaged counts over a rectangular area of the image. For the purposes of aerial applications, the program provides the ability of delayed start and sequentially image capture.

For the calibration of the raw HS images, an offline workflow is developed to derive absolute reflectance values. The processing chain includes dark and vignetting correction, spectral response characterization, digital number to reflectance conversion and hyperspectral data cube reconstruction.

The system has been already deployed in several in house studies: detection of dothistroma in Scots pine needles, starch detection in apples and bananas, and avocados maturity indication, while aerial imagery was also acquired during field campaigns in the UK and China aiming to create a tree species distribution map and to early identify tree health issues.

The development of the system is dynamic as technology is moving forward and the demand for light-weighted multi-sensor UAS surveys is increased during the last decade. Furthermore, the calibration processes and data analysis techniques are constantly updated to meet international requirements and push the accuracy of the products to the highest standards.

How to cite: Zempila, M. M., Hamilton, M., and Mortimer, H.: Hyper-Spectral Imaging for Earth Observation Applications, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-19251, https://doi.org/10.5194/egusphere-egu2020-19251, 2020.

Artificial light at night (ALAN) has become a major concern in recent years due to its impact on the health of human beings and the ecosystems. As a result, there is a surge of light pollution research not only on night sky brightness, but also on assessments of impacts on both ecology and society.

We have set up an interdisciplinary project in Hungary since September 2017, to not only study the impacts of change in lighting technology on patterns of ALAN (with emphasis on the areas within and around national parks in Hungary), but also facilitate national and international cooperations in light pollution research. We refer to this project as Living Environmental Laboratory for Lighting (LELL). Specifically, the project covers the following areas:

1. Development of new techniques for night sky radiometry and spectrometry
We are developing techniques for night sky multispectral measurements using commercially available cameras with interchangeable lens, calibrated by high sensitivity spectroradiometer, in order to quantify night sky condition and identify sources of artificial light at high resolution not achieveable by systems based on panchromatic sensors or fisheye lenses. In addition, we will compare the results from our ground-based measurements with satellite-based observations.

2. Modeling of night sky patterns in national parks of Hungary
We have developed a Monte-Carlo method of modeling light pollution, which can also be used for investigating effects of aerosols and clouds on the propagation of artificial light.

3. Impact assessments of ALAN through measurements
The public lighting was remodeled to LED-based systems in two areas close to national parks, one of which in the Zselic region in Southwestern Hungary, and another in Bükk in Northern Hungary. Using the techniques above, we are monitoring the change in night sky brightness and color, as well as the impact on flora and fauna.

4. Recommendations on future assessments and mitigations of light pollution
With our experience gain within the duration of this project, we will inform the light pollution research community of standardizing methodologies for monitoring light pollution, as well as giving recommendations for managing public lighting assets to reduce the impacts of light pollution.

Acknowledgement
This project is supported by the European Union and co-financed by the
European Social Fund (Grant no. EFOP–3.6.2–16–201–00014: Development of
international research environment for light pollution studies)

How to cite: Tong, K. P. and Kolláth, Z.: Living Environmental Laboratory for Lighting — A comprehensive study of interactions of artificial lighting and wildlifes, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-6065, https://doi.org/10.5194/egusphere-egu2020-6065, 2020.

The recent surge in the development of small satellite platforms could offer the opportunity to significantly decrease the overall cost of science missions, if suitable instruments can be operated from such platforms. PICASSO is a CubeSat demonstration mission initiated by the Belgian Institute for Space Aeronomy and implemented by the European Space Agency (ESA). Its objective is to assess the ability of very low-cost satellites to carry out atmospheric measurements. PICASSO focuses on retrieving the ozone distribution in the stratosphere, the temperature profile up to the mesosphere, and the electronic density and temperature in the ionosphere.

Following its launch on a VEGA rocket in March 2020, PICASSO will fly for two years. The overall demonstration mission includes the end-to-end development of the satellite, launch, operation, and analysis of the scientific data. PICASSO follows a polar orbit at an altitude ranging from 475 to 500 km and an inclination of 98°. Its payload consists of a miniaturised hyper-spectral imager (VISION) and a four needle-like Sweeping Langmuir Probe (SLP). It utilizes four deployable solar panels with an average power generation of 8.7W, two on-board computers (OBC and PLC), and a high-performance ADCS with a pointing accuracy of around 1°.

The scientific objectives of VISION are to demonstrate the retrieval of polar and mid-latitude stratospheric ozone vertical profiles from multispectral transmittances observed in solar occultations. For SLP, the main goals are to study the ionosphere-plasmasphere coupling and aurora structures, and to monitor the density irregularities in the polar cap ionosphere.

How to cite: Baker, N., Anciaux, M., Dekemper, E., Demoulin, P., Fussen, D., Pieroux, D., and Ranvier, S.: PICASSO: a PICo-satellite for Atmospheric and Space Science Observations, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7512, https://doi.org/10.5194/egusphere-egu2020-7512, 2020.

An increasing number of remote sensing instruments measure the polarization state of electromagnetic radiation. The polarization state contains all the information about the sensing object that is available to optical measurement methods. Taking into account the polarization during the radiative transfer simulation leads to a redistribution of energy between the components of the Stokes vector, thereby introducing a correction to the scalar approximation, the value of which may be significant. This information potentially can be used to improve algorithms for removal of surface glint, underwater visibility, to improve radiative transfer retrieval methods if the polarization-sensitive sensors are employed.

A Monte Carlo polarized radiative transfer model termed MCPOLART for the ocean-atmosphere system that is able to predict the total and the polarized signals has been developed.  Since the ocean surface is not smooth, the radiation model must take into account waves that occur under the influence of wind. The Cox-Munk ocean wave slope distribution model is used in calculation of the reflection matrix of a wind-ruffled ocean surface. Sensitivity studies are conducted for various ocean-surface and atmospheric conditions, geometric schemes of lighting and observation.  

This work was supported by the Russian Science Foundation (project No. 19-77-10022).

How to cite: Russkova, T. and Shmirko, K.: Monte Carlo simulation of polarized radiative transfer over the ocean surface, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-10377, https://doi.org/10.5194/egusphere-egu2020-10377, 2020.

The influence of aerosol on the various aspects of the atmospheric properties as well as on the energetic balance is widely recognised in the scientific community and this issue is currently subject to worldwide intense investigations. Among the multiple ways aerosol particles are impacting the atmospheric environment, their interference with the phase transformations of the atmospheric water is of particular importance. Cloud microphysics, on the other hand, is one of the key components in weather forecast and, therefore, in pursuing daily domestic activities ranging from agriculture to energy harvesting and aviation. The micro-physical processes taking place in clouds are strongly influenced by the spatiotemporal variation of the size distribution of the cloud droplets. In this context, as in situ investigations of clouds seem appropriate, one of the most useful types of instruments is casted into the generic name of Cloud and Aerosol Spectrometer (CAS) that can be mounted on specialized research aircraft. The CAS working principle relies basically on measuring the forward scattering cross section (FWSCS) of light with a certain wavelength on a cloud particle and comparing it to the FWSCS computed for pure water spheres. The eventual matching of these values leads to assigning a certain value for the measured particle’s diameter. The light wavelength is usually chosen in a range where pure water has virtually no absorption. However, atmospheric aerosol frequently mixes up with cloud droplets (starting even from the nucleation processes) and alters their optical properties. By increasing absorption and/or refractivity with respect to those of pure water, one can easily show that the FWSCS-diameter diagram changes drastically by becoming smoother and with an overall significant decrease in absolute values. This means that a CAS will systematically count “contaminated” cloud droplets in a lower range of diameters, thus distorting their real size distribution. This effect is inherently degrading the objectivity of CAS measurements and should be more pronounced when levels of sub-micrometer sized aerosol increase at the cloud altitude. The present study aims at pointing out such correlation in order to estimate the reliability of size distributions (and of the ensuing cloud microphysical properties) obtained by CAS.

How to cite: Moacă, D. E., Vâjâiac, S. N., Calcan, A., and Filip, V.: Post-flight analysis of the aerosol impact on size distributions of warm clouds’ droplets, as determined in situ by cloud and aerosol spectrometers, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-13576, https://doi.org/10.5194/egusphere-egu2020-13576, 2020.

The prediction of tornado trajectories has always been a crucial yet difficult problem in meteorology. In this research, an original and effective tornado simulator was designed and produced to study the travel trajectory characteristics of tornadoes through geoscience instrumentation and theoretical analysis.

First, tornado simulators designed by senior scientists were researched, and they all have one defect in common, which is failing to move freely. As a result, those tornado simulators cannot be used for studying the travel law of the tornado. Based on pioneers’ experience and real tornadoes’ features, an innovative tornado simulator that can move freely has been completed in this research. A stable wind field which bascially has the necessary characteristics of a tornado can be produced by it upon observing the wind field of the simulator.

Second, in order to research the tornadoes’ behavior in a stable external wind field, the simulator was placed floating on the water in a wind tunnel during the experiments. The experimental parameters such as the velocity of the simulator’s flow, and the velocity of the flow in the wind tunnel were carefully arranged, in order to systematically simulate different wind field conditions and observe the trajectory of the tornado simulator. Meanwhile, a tornado trajectory prediction model was made according to fluid dynamics including the Bernoulli Principle and the Precession Principle. The dynamics analyses of both real tornadoes and the simulator were carried out through formula derivation and numerical methods.

Third, by analyzing data of the trajectory of the simulator in detail through MATLAB, it was found that the offset degree was positively correlated to the rotation velocity of the tornado simulator, and negatively correlated to the wind velocity of the incoming flow, therefore verifying and enriching our model.

Fourth, the general flow function of the flow field of the simulator and tornadoes were respectively created by superposition of a flow around the symmetric cylinder function and a vortex flow function, perfecting the theoretical model. The “asymmetric flow around a cylinder” model for formula derivation in this research has been established, obtaining the numerical relationship of the velocity of the incoming flow and the simulator’s flow regarding the offset degree. The field data of the simulator and tornadoes demonstrated the validity of the theoretical assumption.

In conclusion, the Bernoulli Effect, precession effect and asymmetric flow of the tornado simulator were studied through experiments and theoretical modelling, which provided new insight and methods into the study of the trajectory of tornadoes. The experimental results conform to the theoretical assumption. This research is trail-blazing and inspiring as using mechanical devices in a wind tunnel to study the trajectory of tornadoes is unprecedented. It provides experience of how to combine engineering and geoscience in researches. The findings can help to predict the path of the tornado by monitoring the wind field of the area where the tornadoes occur, providing guidance for rescue operations.

How to cite: Zeng, Y., Fu, Y., and Lyu, C.: Establishing a Cyclone Generator to Study the Rotation and Advance Characteristics of Tornadoes, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-2372, https://doi.org/10.5194/egusphere-egu2020-2372, 2020.

In the last decades, large particle-physics experiments have shown that muon rate variations detected in underground laboratories are sensitive to regional, middle-atmosphere temperature variations. Therefore, muon measurements may be used to study middle-atmosphere dynamics, including short-term phenomena such as Sudden Stratospheric Warmings. In this work we use a portable muon detector conceived for geosciences applications. We study seasonal and short-term variations in the middle-atmosphere’s temperature by analyzing a year of continuous muon measurements at the Mont Terri underground rock laboratory. This site is located in the Jura Mountains in north-western Switzerland, at a depth of ~300 meters below the Earth's surface. We observe a direct correlation between middle‐atmosphere seasonal temperature variations and muon rate. Muon rate variations are also sensitive to the abnormal atmosphere heating in January-February 2017, associated to a major Sudden Stratospheric Warming that in a few days increased the zonal mean temperature in the polar region by more than 20 K. We estimate the effective temperature coefficient for our particular case and found that it agrees with theoretical models and with those calculated from large neutrino experiments under comparable conditions. Finally, we discuss the implications of our observations for the Atmospheric Sciences community.

How to cite: Tramontini, M., Rosas-Carbajal, M., Nussbaum, C., Gibert, D., and Marteau, J.: Study of seasonal and short-term temperature variations in the middle atmosphere using cosmic muons, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-9194, https://doi.org/10.5194/egusphere-egu2020-9194, 2020.

Beaches are not only one of the most beautiful natural entities the world coasts, they are also habitat for various species of living creatures, barrier against coastal hazards. Their conservation is crucially important, yet the efforts seem deficient. Geographic information systems are great tools towards this aim by incorporating coastal data and visually representing them. In this study, a database for all the beaches along the Black Sea coastline is created to help the efforts on marine conservation and coastal management. 1553 beaches have been digitized as polygons using satellite images between 2013 and 2016 covering the entire Black Sea coast. Geometric properties such as area, perimeter, width, central coordinates, UTM zone, shoreline length, and bound orientation are obtained through different data collection techniques. Information related to natural properties such as estuaries, coastal structures, and settlement densities have been gathered. Results indicated that Black Sea beaches are relatively narrow. Most of them are either experienced erosion or have a vulnerability to erosion. Among all 1553 beaches, only 28 beaches have an average width wider than 100 m. In the basin, the average width of the beaches is 26.04 m, the average beach area is 70384.2 m² and the total beach shoreline length is 2116.12 km, which covers 43% of the Black Sea coastline. The mean slope values of the beaches with a maximum width of greater than 100 m are calculated using ASTER Digital Elevation Model v2. According to this analysis, the mean slope of these 164 beaches is 7.28 degrees. An additional analysis is performed by creating a different layer for the South-western part of the basin, from approximately 5 years older satellite images. This analysis showed that, even in the short-term, beaches can experience significant area loss reaching up to 50% in a relatively high wave climate such as exists in the South-western part.

How to cite: Görmüş, T., Ayat, B., and Aydoğan, B.: A database of Black Sea beaches, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-579, https://doi.org/10.5194/egusphere-egu2020-579, 2020.