To understand tropospheric air pollution at a regional/global scale, the SPIRIT airborne instrument (SPectromètre Infra-Rouge In situ Toute altitude) was developed in 2011 and used on aircraft to measure CO, an important indicator of air pollution, during the last decade. SPIRIT could provide high-quality CO measurements with 1σ precision of 0.3 ppbv at a time resolution of 1.6 s. It can be operated on different aircraft from DLR (Germany) and SAFIRE (CNRS-CNES-Météo France) such as Falcon-20 and ATR-42. With support from various projects, more than 200 flight hours measurements were conducted over three continents (Europe, Asia, Africa), including two inter-continental transect measurements (Europe-Asia and Europe-Africa). Levels of CO and its horizontal and vertical distribution are briefly discussed and compared between different regions/continents. A 3D trajectory mapped by CO level was plotted for each flight and presented in this study. The database containing all the raw data will be archived on the AERIS database (www.aeris-data.fr), the French national center for Earth observation dedicated to the atmosphere. The database can help to understand the horizontal and vertical distribution of CO over different regions and continents. Besides, it can help to validate model performance and satellite measurements. For instance, the database covers measurements at high-latitude regions (i.e., Kiruna, Sweden, 68˚N) where satellite measurements are still a challenge, and at low-latitude regions (West Africa and South-East Asia) where in situ data are scarce and satellites need more validation by airborne measurements.

How to cite: Catoire, V., Xue, C., Krysztofiak, G., Brocchi, V., Chevrier, S., Chartier, M., Jacquet, P., and Robert, C.: A Database of Aircraft Carbon Monoxide (CO) Measurements with High Temporal and Spatial Resolution during 2011 – 2021, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2960, https://doi.org/10.5194/egusphere-egu22-2960, 2022.

Tropospheric ozone (O₃) can adversely affect human health and environmental ecosystems and it is therefore vitally important to understand its formation pathways from both natural and anthropogenic precursors.  Wildfires are an important source of these precursors (both VOCs and NO_x) and it is likely that the prevalence of wildfires will increase in a warming climate. Wildfires have been shown to contribute to elevated O₃ at air quality monitoring sites, so it is therefore important to better understand the emissions, photochemistry and impacts of these fires. Instrumented research aircraft provide one of the best methods for studying emissions of VOCs and NOx from wildfires. Aircraft provide the flexibility to sample close to fires, allowing for calculation of emission factors, as well as further afield to study the chemical processing of fire plumes.

Here we present measurements of O₃ and its precursors taken from the UK large atmospheric research aircraft. Flights sampling wildfires in the Amazon rainforest in Brazil, scrublands in Senegal, wetlands in Uganda and moorland peat fires in the UK are reported, with measurements of O3, CO, NOx, CH4, CO2, C2H6 and a wide range of VOCs sampled directly in the plume and in more aged air up to 5 days from the source. Measurements of a range of O₃ enhancement ratios (DO3 / DCO) are observed, ranging from 0.05 when sampling within 1-2 hours transport time from all 4 types of fire, to 0.3 when sampling up to 100 hours away from the Senegalese fires. VOC composition of the plumes is also investigated. Ratios of different VOCs to CO are examined to derive emission ratios that are used to provide emission estimates of VOCs from wildfires. OH reactivity calculations in the plumes are used to assess the potential contribution of different VOCs to O₃ formation. In addition, measurements of aged air from fires in sub-Saharan Africa are compared against values calculated by the GEOS Composition Forecasting (GEOS-CF) system, a global atmospheric model with 25 km resolution, focusing on the model’s ability to capture ozone from biomass burning.

How to cite: Lee, J., Hopkins, J., Squires, F., and Wilde, S.: Use of a large aircraft to measure composition and chemistry of wildfires. , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7139, https://doi.org/10.5194/egusphere-egu22-7139, 2022.

1 January 2020 marked a major change in the legal sulphur content of shipping fuel – from 3.5% to 0.5% by mass outside of the Sulphur Emission Control Areas (SECAs). The anticipated effect of the new regulation is improvement of coastal air quality, supporting both environmental and human health. In addition, since sulphur is believed to be a negative climate forcer, removal of its substantial source might have positive influence on the global climate.
The Atmospheric Composition and Radiative forcing changes due to UN International Ship Emissions regulations (ACRUISE) project demonstrates the use of a large aircraft to measure emissions from ships and their impact on local air quality and cloud formation. The Facility for Airborne Atmospheric Measurements (FAAM) research aircraft was deployed first in July 2019 (before regulation change) in shipping lanes along the Portuguese coast, the English Channel SECA and the Celtic Sea. Over 100 ships were sampled, 15 specifically targeted for plume aging and cloud interaction. A large container ship showed significant reduction in apparent fuel sulphur content upon entering SECA. Bulk statistics in and out of extremely busy shipping lanes were collected. The second, post regulation change, part of the fieldwork was postponed by the COVID-19 pandemic until September 2021. Over 150 ships were measured in the shipping lanes of the Bay of Biscay, the English Channel SECA and Celtic Sea. This part of the work focussed more on targeting specific ships, than on bulk measurements due to lower density of ships in the region and improved sampling strategy.
This study presents a range of aspects of measurements. Onboard measurements of SO₂, CO₂, CH₄ and speciated PM provide emission factors and apparent fuel sulphur content for a variety of ships. Moreover, about 100 whole air samples were taken during each fieldwork and analysed for VOCs. The encountered vessels included container ships, bulk carriers, cruise ships, ferries, crude oil tankers and even elusive LNG tankers. Some ships were measured both in and out of SECA and a few ships were measured both in 2019 and 2021. 

How to cite: Pasternak, D., Lee, J., Hopkins, J., Bauguitte, S., Batten, S., Yang, M.-X., Bell, T., Coe, H., Bower, K., Andrews, S., Temple, L., Vallow, J., Matthews, E., Bannan, T., Marsden, N., Wu, H., and Thamban, N.: Airborne measurement of ship emissions in international waters and Sulphur Emission Control Area, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5355, https://doi.org/10.5194/egusphere-egu22-5355, 2022.

Hydrogen peroxide and higher organic hydroperoxides form an important reservoir for peroxy radicals (HO_x), which are key contributors to the self-cleaning processes of the atmosphere. The work gives an overview of airborne in-situ trace gas observations of hydrogen peroxide (H₂O₂), and methyl hydroperoxide (MHP) over Europe during the Chemistry of the Atmosphere – Field Experiments in Europe (CAFE-EU, also BLUESKY) aircraft campaign. The purpose of the campaign was to obtain an overview of the trace gas and aerosol distribution over Europe to analyze atmospheric chemistry under the conditions of the COVID-19 lock-down. The campaign anticipated to investigate the impact of reduced emissions from anthropogenic sources due to the COVID-19 pandemic on the chemistry and physics of the atmosphere. The rapid decrease of anthropogenic emissions established a unique opportunity for analysis of the changes in the atmosphere. The campaign took place in May/June 2020 over Central and Southern Europe and within the North Atlantic Flight Corridor. Airborne measurements were performed on the High Altitude and Long-range (HALO) research aircraft out of the base of operation in Oberpfaffenhofen (Germany). Average mixing ratios for H₂O₂ of 0.32 ± 0.25 ppb_v, 0.39 ± 0.23 ppb_v and 0.38 ± 0.21 ppb_v within the upper and middle troposphere and the boundary layer were measured over Europe, respectively. Vertical distribution of H₂O₂ reveals a significant decrease above the boundary layer in comparison with previous airborne observations, most likely due to cloud scavenging and subsequent rainout. The expected maximum hydrogen peroxide mixing ratios at 3 – 7 km were not found during BLUESKY in contrast to observations during previous studies over Europe, during the campaigns HOOVER and UTOPIHAN-ACT II/III. Simulations with the global chemistry-transport model EMAC reproduce partly the impact of cloud uptake and rainout loss of H₂O₂. A comparison of calculated deposition loss rates based on EMAC reveals an underestimation relative to the observations. A performed sensitivity study without H₂O₂ scavenging underlines the major impact of cloud processing and precipitation on the hydrogen peroxide budget. Differences between simulations and observations are most likely due to difficulties in the simulation of wet scavenging.

How to cite: Hamryszczak, Z., Pozzer, A., Obersteiner, F., Bohn, B., Steil, B., Lelieveld, J., and Fischer, H.: Distribution of hydrogen peroxide over Europe during the BLUESKY aircraft campaign, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10133, https://doi.org/10.5194/egusphere-egu22-10133, 2022.

When validating atmospheric satellite observations, several error sources must be taken into account: the uncertainties of the satellite products, the uncertainties of the reference measurements, and the representativity of the latter with respect to the investigated satellite pixels. Compared to static ground-based reference measurements, airborne observations reduce the spatial component of the representativity error. Recent airborne campaigns indicate a remaining low-bias for TROPOMI tropospheric NO2 VCDs above polluted areas. This bias has been attributed in particular to wrong assumptions on the NO2 profiles in the satellite products. 

In the context of the RAMOS and SVANTE projects, we started regular continuous mapping of the NO2 tropospheric VCDs above Bucharest and Berlin, respectively. Both activities make use of compact whiskbroom imagers, namely SWING. In Bucharest, we also measure the profiles of NO2 and of aerosols from the aircraft and perform car-based DOAS measurements of tropospheric NO2 underneath the aircraft. We study the error budgets of the validation of the TROPOMI tropospheric NO2 VCD product in these two situations. We quantify the added values of the ancillary observations in Bucharest and assess the temporal component of the representativity error. Given the time duration of a scientific flight, several configurations are possible for our whiskbroom observations, and it may be useful to undersample satellite pixels to cover a large area. This work is therefore also useful to optimize the flight patterns and information content of future validation flights.

How to cite: Merlaud, A., Van Roozendael, M., Tack, F., Thomas, R., Ene, D., Calcan, A., Ardelean, M., Constantin, D., and Schuettemeyer, D.: Investigations of comparison uncertainties for airborne validation of air quality satellite products, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11594, https://doi.org/10.5194/egusphere-egu22-11594, 2022.

EUFAR (EUropean Facility for Airborne Research, https://www.eufar.net) was born out of the necessity to create a central network for the airborne research community in Europe with the principal aim of supporting scientists, by granting them access to research aircraft and instruments otherwise not accessible in their home countries. With time EUFAR has grown, introducing new activities and objectives to place itself as the unique network and portal of airborne research for the environmental and geosciences in Europe. From serving as an interactive and dynamic hub of information, to maintaining a central data archive, and developing tools and standards to collect, process and analyse data, EUFAR continues to improve the operational environment for conducting airborne research.

EUFAR's data archive activity seeks to improve access to and use of the data collected by instrumented aircraft in Europe, providing a unique portal to the data along with supporting metadata. AERIS, the French Data and Services Cluster for Atmosphere (https://en.aeris-data.fr) has implemented a new Data and Metadata Catalogue for EUFAR that in the longer term is intended to become a principal data portal for the European airborne science community.

All EUFAR datasets are following the FAIR principles. The main features of the catalogue, i.e. data and metadata discovery and download, have been improved. Advanced services have been implemented such as the discovery of external datasets from EUFAR partners starting with the French Research Airborne Data Portal SAFIRE+. This will be extended to other databases in 2022 such as DLR, NERC-ARF, FAAM, Met Office, etc. New advanced features are currently under development: discovery of datasets from other airborne Research Infrastructures (IAGOS, HEMERA, etc.); data visualization services; integration of the EUFAR products and services in EOSC (European Open Science Cloud); tools for the management of campaigns metadata, etc.

How to cite: Retornard, V., Boulanger, D., Garland, W., and Formenti, P.: New EUFAR flight finder, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8353, https://doi.org/10.5194/egusphere-egu22-8353, 2022.

The SAFIRE, a joint service unit of CNRS, Météo-France and CNES in charge of environment observation campaigns, aeronautical R&D projects, as well as preparation and validation of space missions, is striving to provide state of the art infrastructure and services to its Science Users. Hence, SAFIRE has always supported development of common standards and use of best practices for hosting Science Payloads in its airborne infrastructure.

In the recent years, airborne scientific operations have been significantly improved through digitalization. However, growing number of individual equipment embarked still leads to tedious work when attempting to integrate together acquisition, measurement and processing tools or to manage the experimental set up as a whole. To answer this challenge, SAFIRE has proposed to use MQTT protocol messaging to allow an easier flow of data between on board equipment.

Collaborating with the SAFIRE, ATMOSPHERE developed MQTT-based solutions aiming to provide automated storage of measurement data in specific formats, and live monitoring of data produced by various equipment. These solutions can be easily interfaced with other MQTT compliant equipment and allow more centralized data management and processing.

The paper will describe the benefits of the new SAFIRE airborne architecture and will review early results from latest measurements campaigns. It will also describe how the exploitation of data monitoring and processing tools using MQTT-based communication can benefit the scientific community.

How to cite: Vernizeau, T., Gallois, R., Gaubert, J. M., and Jiang, T.: Innovative airborne experiments tools for Science Users, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9814, https://doi.org/10.5194/egusphere-egu22-9814, 2022.

IAGOS (In-service Aircraft for a Global Observing System) is a European Research Infrastructure that aims to provide long-term, regular and spatially resolved in situ observations of the atmospheric composition.  IAGOS observation systems are deployed on a fleet of commercial aircraft and perform uninterrupted measurements, from take-off to landing, of aerosols, cloud particles, greenhouse gases, ozone, carbon monoxide, water vapor and nitrogen oxides, from the surface to the lower stratosphere. The IAGOS database is an essential part of the global atmospheric monitoring network.

The IAGOS Data Portal (via https://www.iagos.org) is managed by AERIS, the French Data and Services Cluster for Atmosphere (https://en.aeris-data.fr). The new portal offers improved discovery and access to all the IAGOS datasets from the observational data to the derived and elaborated data products. Thanks to the H2020 project ENVRI-FAIR, all data is now managed in accordance with the FAIR principles. Rich metadata and data files are available in standardized formats (NetCDF-CF, etc.). The portal also provides advanced web-processing services such as visualisation capabilities and machine actionable access.

Particular attention has been paid to the interoperability of IAGOS data with external data portals. Interoperability is currently being implemented with other airborne programs such as SAFIRE and EUFAR, with other Research Infrastructures from the Atmospheric domain and more generally from the Environmental domain in the frame of the ENVRI community.

In the frame of the European projects ATMO-ACCESS and RI-URBANS, IAGOS is currently developing new advanced services such as: statistical analysis tools, combination of products from different sources with satellite data and models, Jupyter notebooks for demonstration of IAGOS data usage, footprints calculation and homeless data service for datasets acquired on mobile platforms.

How to cite: Boulanger, D., Bouhouili, A., Bex-Chauvet, O., Wolff, P., Thouret, V., and Clark, H.: The new IAGOS Data Portal, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7775, https://doi.org/10.5194/egusphere-egu22-7775, 2022.

Dust in the Upper Stratosphere Tracking Experiment and Retrieval (DUSTER) aims to collect and characterize uncontaminated particles (<30μm) from the Earth stratosphere (30–40km). The upper stratosphere is populated by both terrestrial and extraterrestrial particles. However, it is richer in the extraterrestrial ones compared to lower altitudes [1]. The stratosphere is a reservoir for Interplanetary Dust Particles (IDPs) [2]: a selection effect would facilitate fragile materials that could not reach the ground [3].

In addition to DUSTER, only a few other attempts have been made for the collection of particles through balloons at altitude >30km [4,5]. The innovations brought by DUSTER include: (i) does not require sample manipulation after collection; (ii) guarantees low impact velocities between particles and the collector’s substrate; and (iii) a key factor, adopts a strict control protocol for the minimization of contamination [3,6]. On the collector (a holder with 13 TEM grids), directly exposed to the airflow, the particles remain stuck without the use of adhesive materials (dry collection). High-resolution images of the collector and the blank (similar to the collector but not exposed to the airflow) are acquired before and after the flight, to exclude from the count pre-existing particles [6,7].

Five DUSTER launch campaigns successfully collected stratospheric particles. The most recent ones took place at the ESRANGE, Kiruna (Sweden), in 2019 and 2021. DUSTER sampled the stratosphere at an altitude of ~33km for ~5 hours over Lapland, and its collector and blank are currently under analysis. Up to now, the identified particles range from 0.1 to 150µm (latest data to be published). Morphologically, they can be classified as mineral fragments and aggregates, spherules, fungal spores [10], and a type-I cosmic spherule. EDX analyses have shown the occurrence of minerals like plagioclase, silica, fassaite, but also carbonates, CaO – all mineralogic phases present in CI and CM carbonaceous chondrites, unequilibrated ordinary chondrites, and comets [8]. The occurrence of CaO and carbon nanoparticles has been suggested to be a result of condensation after disaggregation of carbonates of extraterrestrial origin [11]. 

The ambitious goal of DUSTER is to become a reference collection for uncontaminated extraterrestrial particles available for scientific research – a unique and barely explored reservoir complementary to (micro)meteorites and IDPs available at the Earth’s surface. 

In general, the properties of solid and condensed dust in the upper stratosphere remain poorly known. Complete morphological and chemical characterization of particles collected at altitudes >30 km remains incidental with few exceptions, DUSTER will provide a record of the amount of solid aerosols, their size, shapes and chemical properties in the upper stratosphere, including particles less than 3 microns in size.

Acknowledgement – ASI-INAF “Rosetta GIADA”,I/024/12/0 and 2019-33-HH.0; PRIN2015/MIUR; European Union's Horizon 2020 research and Innovation programme,No.730970.

References – [1]Flynn, 1997. Nature,387, 248. [2]Brownlee 1985. Annu.Rev.Earth Planet.Sci., 13(1),147-173. [3]Della Corte & Rotundi, 2021. Elsevier,269-293. [4]Testa et al., 1990. Earth Planet.Sci.Lett., 98,287-302. [5]Wainwright et al., 2003. FEMS Microbiol.Lett., 218,161-165. [6]Della Corte et al., 2012. SpaceSci.Rev, 169,159-180. [7]Palumbo et al., 2008. Mem.Soc.Astron.Ital., 79,853. [8]Rietmeijer et al., 2016. Icarus, 266,217-234. [10]Della Corte et al., 2014. Astrobiology, 14(8),694-705. [11]Della Corte et al., 2013. TellusB: Chem.Phys.Meteorol.,65(1),1-12. 

How to cite: Musolino, A., Della Corte, V., Rotundi, A., Dionnet, Z., Folco, L., Liuzzi, V., and Ferretti, S.: Dust in the Upper Stratosphere Tracking Experiment and Retrieval: Exploring the Dust Reservoir of the Upper Stratosphere through Balloons , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12838, https://doi.org/10.5194/egusphere-egu22-12838, 2022.

Water vapor (H₂O) is the strongest greenhouse gas in our atmosphere, and it plays a key role in multiple processes that affect weather and climate. Particularly, H₂O in the upper troposphere - lower stratosphere (UTLS) is of great importance to the Earth's radiative balance, yet accurate measurements of H₂O in this region are notoriously difficult, and significant discrepancies were found in the past between different techniques (both in-situ and remote sensing). Currently, cryogenic frostpoint hygrometry (CFH) is considered as the reference method for balloon-borne measurements of UTLS H₂O [1]. However, the ongoing phasing-out of the cooling agent required by CFH (freon R23) urges the need of an alternative solution to maintain the monitoring of UTLS H₂O in long-term global observing networks, such as the GCOS Reference Upper Air Network (GRUAN).

As an alternative method, we developed a compact instrument based on mid-IR quantum-cascade laser absorption spectroscopy (QCLAS) [2]. The spectrometer incorporates a specially designed segmented circular multipass cell to extend the optical path length to 6 m within a small footprint [3], while meeting the stringent requirements in terms of mass, size, and temperature resilience, posed by the balloon platform and by the harsh environmental conditions of the UTLS. Two successful test flights performed in December 2019, in collaboration with the German Meteorological Service (DWD), demonstrated the instrument's outstanding capabilities under real atmospheric conditions up to 28 km altitude.

The accuracy and precision of QCLAS at UTLS-relevant conditions were validated by a dedicated laboratory campaign conducted at the Swiss Federal Institute of Metrology (METAS). Using a dynamic-gravimetric permeation method, we generated SI-traceable reference gas mixtures with H₂O amount fractions as low as 2.5 ppmv and 1.5 % uncertainty in synthetic air. All measurements by QCLAS were found within ± 1.5 % of the reference value, corresponding to a maximum absolute deviation of 210 ppbv, and with an absolute precision better than 30 ppbv at 1 s resolution. This represents an unprecedented level of accuracy and precision for a balloon-borne hygrometer. Further in-flight validation campaigns from Lindenberg (Germany) are currently in preparation.

[1] Brunamonti et al., J. Geophys. Res. Atmos., 2019, 124, 13, 7053-7068.

[2] Graf et al., Atmos. Meas. Tech., 2021, 14, 1365-1378.

[3] Graf, Emmenegger and Tuzson, Opt. Lett., 2018, 43, 2434-2437.

How to cite: Brunamonti, S., Graf, M., Emmenegger, L., and Tuzson, B.: Quantum-cascade laser absorption spectrometer (QCLAS) for balloon-borne measurements of UTLS water vapor , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5728, https://doi.org/10.5194/egusphere-egu22-5728, 2022.

Static Fourier Transform spectrometers are traditionally realized with reflecting diffractive gratings. The positive aspects of these instruments, wide field of view and the absence of moving parts, are tested on an optical configuration in which the diffractive-reflective gratings are replaced with refractive-reflective prisms (Littrow prisms).

Beside the reduction in the resolution power, especially in the near IR, due to the dispersive power of the glasses, the optical quality of Littrow prisms can provide low noise instruments at low price.

The application to a sounding balloon flight on the Hemera project is presented. The flight took place in October 2021 at the CNES "Centre d'Opérations Ballons" at Aire sur l’Adour, France.

This work has been supported by ASI, Agenzia Spaziale Italiana, Agreement n. 2019-33-HH.0. for the payload realization and the flight opportunity has been provided by the European Commission in the frame of the INFRAIA grant 730790-HEMERA.

How to cite: Frassetto, F., Cocola, L., Claudi, R., Da Deppo, V., Zuppella, P., and Poletto, L.: Refractive static Fourier transform spectrometer: a balloon borne application, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11428, https://doi.org/10.5194/egusphere-egu22-11428, 2022.

The TWIN - Hemera stratospheric balloon flight took place on 12 - 13-Aug-2021 from the Esrange Space Center near Kiruna, Sweden (67°N).The project was supported by Hemera (www.hemera-h2020.eu) via the first call of proposals, and the flight was managed by the CNES (Centre national d'Etudes Spatiales) and SSC (Swedish Space Corporation). The scientific payload was developed in collaboration by several institutions from the Netherlands, Germany and France.

The main objectives were: (1) to characterize the vertical structure of COS mole fraction and isotopic composition; (2) to characterize the CFCs, other ozone depleting substances and climate relevant trace gases in the present atmosphere, linked to their change over the past decade; and (3) to compare and evaluate several instruments and sampling techniques.

The payload included several AirCores (U. Frankfurt, CIO and FZJ), two Pico-SDLA mid-infrared in-situ diode laser spectrometers (GSMA/DT-INSU), and devices for taking large whole air samples of stratospheric air for subsequent laboratory measurements: the BONBON whole-air cryosampler (U. Frankfurt) and LISA (CIO). IMAU is involved for the analysis of isotopic composition and mole fractions of samplers from the cryo-sampler. This approach allows obtaining a comprehensive dataset covering a range of spatial resolutions: from the multitude of gas species to be measured in the high-volume samples, to the subset of gases at higher vertical resolution from AirCores, and finally to the continuous in-situ CO₂ and CH₄ data from tunable diode laser spectroscopy. We expect this dataset to lead to novel and important knowledge on the trace gases in the stratosphere.

In this presentation we will describe the overall setup of the scientific payload, the flight characteristics, and we will give an overview of the already performed and planned measurements.

How to cite: Popa, M. E., Engel, A., Chen, H., Ghysels-Dubois, M., Laube, J. C., Amarouche, N., van Heuven, S., Baartman, S., Schuck, T., Wagenhäuser, T., Zanchetta, A., Durry, G., Keber, T., Richter, A., Sitnikow, A., Frerot, F., and Samake, J. C.: The TWIN - Hemera stratospheric balloon flight: sulfur, halogens and tracers in the stratosphere, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12470, https://doi.org/10.5194/egusphere-egu22-12470, 2022.

Measurements of halogenated trace gases such as CFCs, halons, HCFCs, HFCs, and PFCs are highly relevant due to their impact on the stratospheric ozone layer as well as their high Global Warming Potentials. Yet in situ profiles of the abundances of many of these species in the stratosphere have been increasingly rare in the last two decades, especially above the altitude range accessible by aircraft (i.e. up to 20 km). More recently, the AirCore technique, which was initially utilized for measurements of more abundant trace gases such as carbon dioxide and methane (Karion et al., 2010), has been demonstrated to also enable stratospheric mixing ratio determination for six halogenated species (Laube et al., 2020). However, a direct measurement comparison of AirCore-based air samples with those collected via a more established technique has been missing so far for such low-abundant species. We here present results from a large balloon flight in Esrange, Sweden (67.8877°N, 21.0838°E) in August 2021. An established cryogenic whole-air sampler (Engel et al., 2009) was flown on the same gondola as a so-called “MegaAirCore”, which has, at ~15 liters, a much larger internal volume than common AirCores (~1-1.5 liters). The air collected between ~32 km and ~5 km by this “MegaAirCore”  was transferred into 51 sub-samples immediately after the flight, and these were subsequently analysed for their content of >30 halogenated trace gases. The 13 larger air samples collected by the cryosampler were also measured on the same mass spectrometry-based instrument.Results compare well for many species, which represents an independent verification of AirCore-based measurements of halogenated trace gases at mixing ratios of parts per trillion levels or below – while at the same time demonstrating the viability of stratospheric air sampling at a much higher vertical resolution than previously possible. This opens up new possibilities for studying stratospheric chemistry and dynamics as well as for improvements of the independent validation of remote sensing-based observations. 

References

Engel et al., Nat. Geosci., 2, 28–31, 2009

Karion et al., J. Atmos. Ocean. Technol., 27(11), 1839–1853, 2010

Laube, et al., Atmos. Chem. Phys., 20, 9771–9782, 2020, https://doi.org/10.5194/acp-20-9771-2020

How to cite: Laube, J., Richter, A., Sitnikow, A., Keber, T., Popa, E., Schuck, T., Wagenhäuser, T., and Engel, A.: High resolution vertical information of halogenated trace gas abundances in the polar stratosphere: First flight of the „MegaAirCore“ in summer 2021, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7587, https://doi.org/10.5194/egusphere-egu22-7587, 2022.

GLORIA (Gimballed Limb Observer for Radiance Imaging of the Atmosphere) is a limb-imaging Fourier-Transform spectrometer (iFTS) providing radiances of the thermal infrared emission of atmospheric species. The nominal wavelength range is from 780 to1400 cm^-1 with a spectral sampling of 0.0625 cm^-1. GLORIA-B is an adaption of the airborne GLORIA instrument to stratospheric balloon platforms. It has performed its first flight from ESRANGE/Northern Sweden in August 2021 during the KLIMAT 2021 campaign in the framework of the EU Research Infrastructure HEMERA.

The maiden flight of GLORIA-B has proven its technical qualification and has provided a first imaging hyperspectral limb-emission dataset from 5 to 36 km altitude. Scientific objectives are, amongst others, the observation of the evolution of the upper tropospheric and stratospheric chlorine and nitrogen budget/family partitioning in a changing climate in combination with the set of 20 MIPAS-B (Michelson Interferometer for Passive Atmospheric sounding-balloon) flights since the mid-1990ies, the observation of photochemically active trace gases during sunset and sunrise, as well as the quantification of pollution of the Arctic upper troposphere/lower stratosphere, e.g. through forest fires.

In this contribution we will demonstrate the performance of GLORIA-B with regard to level-1 (calibrated spectra) as well as level-2 data, consisting of retrieved altitude profiles of a variety of trace gases. These retrievals will be thoroughly characterized as well as compared to externally available datasets (e.g. from simultaneous AirCore observations).

How to cite: Höpfner, M., Wetzel, G., Friedl-Vallon, F., Gulde, T., Kleinert, A., Kretschmer, E., Laube, J. C., Maucher, G., Neubert, T., Nordmeyer, H., Piesch, C., Preusse, P., and Ungermann, J.: First flight of the mid-infrared limb-imaging interferometer GLORIA on a stratospheric balloon, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5557, https://doi.org/10.5194/egusphere-egu22-5557, 2022.

Spectroscopic remote sensing in solar occultation geometry offers an important tool for determining atmospheric trace gas concentrations in the middle atmosphere. Monitoring ozone-depleting substances such as halogen oxides is essential to watch the ozone layer throughout a changing climate. The new TotalBrO instrument consists of an active solar tracker (LxWxH ~ 0.40 x 0.40 x 0.50 m, weight ~ 12 kg) and a spectrometer unit (LxWxH ~ 0.45 x 0.40 x 0.40 m, weight ~ 25 kg) with two temperature-stabilized grating spectrometers for the UV/visible spectral range. The instrument is compact and designed to measure bromine and iodine monoxide  (BrO and IO) in addition to other gases such as ozone (O₃) and nitrogen dioxide (NO₂) by means of Differential Optical Absorption Spectroscopy (DOAS). Sets of spectra collected during balloon ascent, sunset and sunrise allow for inferring vertical profiles of the gases.

Here, we report on the first deployment of TotalBrO on a stratospheric balloon launched from Kiruna, Sweden, during the Klimat campaign in August 2021. The solar tracker was able to track the sun once the balloon gondola was azimuthally stabilized above altitudes of about 25 km. TotalBrO collected UV/visible absorption spectra throughout solar occultation during sunset and sunrise on August 21/22, 2021. For the solar occultation periods, the tracking deviation with respect to the center of the solar disk was in the targeted regime of < 0.05°, and the solar tracker was able to catch the sun down to solar zenith angles (SZA) of around 95°, corresponding to tangent heights of about 10 km. We show preliminary results for profile retrievals of O₃ and NO₂ and for DOAS analyses of BrO and IO. The latter currently suffer from an unexplained oscillatory spectral pattern, for which we report on extensive sensitivity studies.

How to cite: Holzbeck, P., Voss, K., Kleinschek, R., Nordmeyer, H., Pfeilsticker, K., and Butz, A.: TotalBrO: First results of a small solar occultation instrument for the stratosphere, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3803, https://doi.org/10.5194/egusphere-egu22-3803, 2022.

The Oxygen Spectrometer for Atmospheric Science on a Balloon (OSAS-B) is dedicated to the remote sounding of atomic oxygen in the mesosphere and lower thermosphere (MLT) region of Earth's atmosphere, where atomic oxygen is the dominant species. OSAS-B is a heterodyne receiver for the thermally excited ground state transition of atomic oxygen at 4.75 THz. Due to water absorption, this line can only be observed from high-altitude platforms such as a balloon. A combined Helium/nitrogen dewar comprises the detector of the instrument, a hot-electron bolometer mixer, as well as a quantum-cascade laser, which serves as the local oscillator for heterodyning. A turning mirror allows for measurements at different vertical inclinations and for radiometric calibration against two blackbody sources. The first flight will take place in autumn 2022 within the HEMERA2020 program. We will present the instrument design and results of the laboratory evaluation of the instrument.

How to cite: Wienold, M., Semenov, A., Richter, H., Dietz, E., Frohmann, S., and Hübers, H.-W.: Instrument design and laboratory evaluation of the OSAS-B heterodyne spectrometer for sounding atomic oxygen in the MLT, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8004, https://doi.org/10.5194/egusphere-egu22-8004, 2022.

Stratospheric long-duration balloons (LDBs) are a cheap and easy way to access the near space, allowing geophysical and cosmological observations.

A common issue for LDBs  is the high bit rate data transferring. Just few hours after launch balloons are nor reachable with direct radio link, and satellite links are, simply, too expensive.  For this reason the satellite link is used only for house keeping and remote control, and scientific  data are recorded on board.   This makes  mandatory to recover the payload to get the observation’s results, a difficult task operating in polar areas, impossible  during the polar winter.

The aim of the project is to provide an autonomous glider capable of physically carrying data and samples from the stratospheric platform to a recovery point on the ground. The glider itself  can also transport instruments and can make measurements during the flight. We estimate that an electrical motorglider released in the stratosphere can fly for several hundreds kilometres.

The glider  is installed on the balloon payload through a remotely controlled release system (which provides its own direct radio link  and satellite communications), and connected to the main computer to receive data and geographic coordinates of the recovery point. The glider trajectory can be monitored with Iridium SBD, and remotely controlled using Iridium too.

The glider is a carbon fiber reinforced foam structure, a compact and robust design, self-stable, which has been shown to steer correctly in the lower stratosphere.

Several test have been conducted with motorized and non motorized gliders,   showing  that the presence of the engine helps the aircraft to get into flight attitude, at around 20 km of altitude, compared to 10 km achieved in non-motorized flights.

How to cite: Romeo, G., Iarocci, A., Spinelli, G., Di Stefano, G., Lepore, A., Adobbato, P., Masi, S., and Bacci, S.: HERMES: HEmera Returning MESsenger, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12083, https://doi.org/10.5194/egusphere-egu22-12083, 2022.