Orals: Thu, 1 May | Room 0.11/12
The European Space Agency (ESA) through the Clean Space Office has approached the assessment of the environmental performance of its activities by applying Life Cycle Assessment (LCA) since the early 2010’s. ESA through its Green Agenda (EGA) has put sustainability as one of its key pillars aiming at reducing the environmental impacts of ESA projects. The assessments of the three traditional space, launch and ground segments have been instrumental in the creation of the ESA LCA Handbook and Database which are being applied systematically to its missions. Nevertheless, significant knowledge gaps remain, particularly in understanding the intricate interactions between launcher exhaust emissions and spacecraft demise with the upper layers of the atmosphere—critical steps in the life cycle assessment process. This work will present the growing necessity to better understand the potential environmental impacts at all altitudes, the current challenges of including atmospheric impacts into LCA thinking and ESA’s consolidated efforts to address key knowledge gaps. In addition to addressing areas of uncertainty, this paper will detail ongoing activities and outline how ESA plans to enhance awareness and implement measures to mitigate the environmental impacts of space activities.
How to cite: Affentranger, L., Mitchell, A., Tormena, E., Girardin, V., Morales Serrano, S., and Van den Eynde, J.: The European Space Agency’s approach towards environmental impact assessment in the atmosphere: Lessons learned, knowledge gaps and roadmap, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-21651, https://doi.org/10.5194/egusphere-egu25-21651, 2025.
The space sector has experienced significant growth in recent years, with rocket launch rates increasing by over 20% since 2019. In its 2022 Scientific Assessment of Ozone Depletion the World Meteorological Organization cautions that future increases in launch rates, the adoption of new propellants like hydrogen and methane, and emissions from reentering objects could significantly influence future ozone levels . Therefore, the creation and evaluation of emission inventories of space activities, which can be used in atmospheric chemistry modelling, is of particular importance. Here we present two open-source tools developed at the University of Stuttgart. 1) Launch Emission Assessment Tool (LEAT), and 2) Re-entry Emission Assessment Tool (REAT), and discuss the underlying models and assumptions. Furthermore, we compare results obtained with LEAT to previously published emission inventories.
LEAT enables the calculation of a launch trajectory based on basic launcher data and calculates emissions such as CO, H2O and NO either using emission indices or by calculating the engine and afterburning emissions. The model accounts for the different flight states and environmental conditions based on a chemical equilibrium model. This makes it possible to distinguish between emissions stemming from different fuel systems and those from different flight paths.
REAT enables the calculation of emissions from re-entering objects. The interaction with the atmosphere is simulated using emission indices or a chemical equilibrium model depending on atmospheric conditions.
Both tools enable us to create detailed high-resolution 3-D emission inventories, which can readily be used in chemistry-climate models in order to assess the atmospheric and climatic effects of launcher and re-entry emissions. Furthermore, by using existing emission inventories a comparison can be made with literature. We also assess and discuss underlying model assumptions and parameter and model uncertainties as well as measures required to reduce uncertainties related to the emission inventories.
How to cite: Fischer, J.-S., Fasoulas, S., Nützel, M., and Schmidt, A.: Development and assessment of space launch and re-entry emission inventories for atmospheric modelling, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15071, https://doi.org/10.5194/egusphere-egu25-15071, 2025.
In the last 5 years, the mass of human-made objects like satellites or rocket stages launched into orbit has strongly risen due to the implementation of satellite mega-constellations and generally increased space activity. Besides the well-known problems of on-orbit space debris and ground impacts, this means a strong increase of the human-made mass re-entering Earth’s atmosphere. Upon reentry, this space waste ablates in the atmosphere, injecting matter in form of aerosols and vapor. Murphy et al. (PNAS, 2023, Vol. 120, No. 43, e2313374120) detected remnants of such material in stratospheric aerosol particles. Thus, there is the concrete possibility of environmental effects due to space waste matter injection like ozone depletion or increased cloud nucleation (Mitchell et al., Understanding the Atmospheric Effects from Spacecraft Re-entry, Whitepaper, 2024). In order to understand what the exact effects on the atmosphere are, first, the amount and element-wise composition of the injected material has to be known. In this context, we present updated annual injection estimates compared to the first comprehensive estimation in Schulz and Glassmeier, 2021 (Advances in Space Research, 2021, 67 (3), 1002-1025) taking into account launch and re-entry databases, used spacecraft materials, as well as the observational data from the stratosphere. We present estimates of the overall injected mass as well as of specific elements. This data can serve as a baseline for modelling efforts and help steer towards the most promising future research.
How to cite: Schulz, L., Glassmeier, K.-H., Mitchell, A., Murphy, D., Plane, J. M. C., and Plaschke, F.: An update of space waste matter injection into the atmosphere, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6252, https://doi.org/10.5194/egusphere-egu25-6252, 2025.
Rocket launches and space debris from reentries are the only direct anthropogenic emission sources above ~20 km in the atmosphere. Space launch activities, and consequently these emissions, are expected to grow by an order of magnitude in just the next decade. Modeling the impact of rocket emissions on the stratosphere requires accurate specification of exhaust composition profiles that depend on rocket propellant types (fuels) and operational and design parameters. Global models predict that black carbon (BC) is the most significant radiative forcing component in both kerosene (RP-1) and liquefied natural gas (LNG, methane) fueled rocket exhaust, although these emissions have never been measured from a rocket in flight. Validation of rocket combustion models, in turn, requires comprehensive in situ composition data from rocket plumes at stratospheric altitudes where near-field hot plume chemistry is expected to weaken.
In February 2023, the NOAA SABRE mission, using a NASA WB-57F aircraft, obtained in situ plume composition data (H2O, SO2, NO, NO2, NOy, HONO, CO, CO2, BC, particle concentration) just above the tropopause from a kerosene-fueled rocket launched from Cape Canaveral, FL. The nighttime plume (not visible to the aircrew) was intercepted twice using a predetermined search pattern flown by the WB-57F. Measured ratios of emissions constituents reveal potentially surprising clues about near-field exhaust chemistry and kerosene engine BC emission in the lowermost stratosphere. The plume data acquired here, while limited, demonstrate the utility of such measurements toward resolving key questions about rocket emissions, and the SABRE 2023 flight experience suggests ways to improve plume sampling (e.g., need for plume direction finding capability) for future stratospheric rocket emission studies.
How to cite: Thornberry, T., Schwarz, J., Rosenlof, K., Ross, M., Lyu, M., Waxman, E., Gurganus, C., Diskin, G., Novak, G., Ahern, A., Brock, C., Bui, P., Michailoudi, G., Poudyal, R., Robinson, M., and Rollins, D.: In situ observations of a kerosene-fueled rocket plume sampled during SABRE 2023, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14035, https://doi.org/10.5194/egusphere-egu25-14035, 2025.
Measurements of aerosol particles in the stratosphere show that metals that were vaporized during the reentry of rocket boosters and satellites accumulate in the stratosphere. These metals are incorporated into natural sulfuric acid particles in the stratosphere. With the rapidly increasing number of spacecraft reentry events, in the coming decades a majority of sulfuric acid particles in the stratosphere could contain novel metals from spacecraft in addition to the meteoric metals that are already present.
Over 20 elements from reentry were detected in stratospheric particles. We are able to quantify the relative amounts of a number of these metals, including lithium, aluminum, copper, and lead. For the EGU meeting we will also present results on several more metals such as titanium, niobium, molybdenum, silver, and tin. These atmospheric measurements can be compared to inventories of the elemental composition of spacecraft.
These metal-containing particles are found in the same air that contains the ozone layer. The addition of materials from spacecraft might affect heterogeneous chemistry in the ozone layer or change ice nucleation in polar stratospheric clouds.
How to cite: Murphy, D., Lawler, M., Schill, G., and Schulz, L.: Metals from spacecraft reentry in the stratosphere, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7114, https://doi.org/10.5194/egusphere-egu25-7114, 2025.
Every year, from 2000 to 8000 tons of natural extraterrestrial meteoroids are ablated in our atmosphere in the form of aerosols, estimated as a fraction of the total mass of incoming meteoroids. In 2019, the corresponding number for anthropogenic materials was estimated at about 263 tons, originating from launches and re-entries of rocket bodies, satellites, and space debris [1]. These injections of anthropogenic materials raise concerns about their effects on the Earth’s atmosphere such as ozone depletion, radiative forcing and other unknow effects [2], [3], [4]. Furthermore, the anthropogenic injections are expected to increase significantly due to the rapid increase in launch rates and number of mega-constellations planned for the coming years. Indeed, there have been more satellites launched in the last 6 years than between 1957 and 2018 [5] and these numbers are set to grow, especially in the low Earth orbit region located below 2000 km [6].
However, large uncertainties remain about the evolution of the proportion and origins of these injected anthropogenic particles. This work attempts to reduce these uncertainties by further exploring the compositions of stratospheric particles collected in situ by the NASA Cosmic Dust program over 40 years.
Since 1981, the NASA Johnson Space Center (JSC) has been collecting dust particles from the lower stratosphere with airborne collectors during specific campaigns and published ~5500 preliminary analyses in the “Cosmic Dust Catalogs”. Each preliminary analysis is based on Scanning Electron Microscopy (SEM) images, some morphological characteristics and X-ray Energy-Dispersive Spectrometry (EDS) composition. The particles are then classified into four main groups: Cosmic, Terrestrial Contaminant Natural, Terrestrial Contaminant Artificial and Aluminum Oxide Sphere. Nevertheless, at least 20% of them remain ambiguously classified. The recent digitalization of all the published catalogs gives us the opportunity to explore their composition using multivariate analysis techniques such as Principal Component Analysis, and automatic clustering of the EDS spectra for classification. Nonlinear projected maps of the EDS composition can help visualize the classification of the particles [7]. The compositional clusters obtained can be used to identify the origin of each particle and constrain the atmospheric injection of each material. The temporal variations of the different compositions injected will be assessed and additional EDS data taken on meteorites and natural minerals will be included in the analysis to define natural material references.
In the future, this work will be complemented with new EDS spectra, SEM images and Raman spectroscopy of selected old samples and post-2020 collected samples curated at NASA JSC in Houston.
[1] Schulz and Glassmeier, Advances in Space Research, 2021. DOI: 10.1016/j.asr.2020.10.036
[2] Ferreira et al., Geophysical Research Letters, 2024. DOI: 10.1029/2024GL109280
[3] Jones et al., Journal of Geophysical Research, 1995. DOI: 10.1029/95JD01539
[4] Ross and Sheaffer, Earth’s Future, 2014. DOI: 10.1002/2013EF000160
[5] McDowell, « Jonathan’s Space Report », Accessed: Jan. 2025. https://planet4589.org/space/log/launch.html
[6] Gaston et al., Frontiers in Ecology and the Environment, 2023. DOI: 10.1002/fee.2624
[7] Lasue et al., Meteoritics & Planetary Science, 2010. DOI: 10.1111/j.1945-5100.2010.01059.x
How to cite: Taupin, Q., Lasue, J., Määttänen, A., and Zolensky, M.: Origins of stratospheric particles through an updated automated classification: revisiting the 1981-2020 period of the NASA Cosmic Dust Collections, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4490, https://doi.org/10.5194/egusphere-egu25-4490, 2025.
The frequency of space launches has increased dramatically as costs plummet and demand rises with the advent of use cases (such as mega constellations or larger-scale exploration). This increase in launch cadence is enabled by reusable launchers, whose technology is progressing in Europe. They provide enhanced material efficiency while adding complexity to flight paths, burn patterns and more. There is, however, a notable gap in observational evidence regarding emissions and their subsequent atmospheric effects, especially for liquid or hybrid solid/liquid propellants.
We present ongoing work within the ESA project FIREWALL (Facilitate Inquiry of Rocket Emission impact With Atmosphere Lower Layers) that aims to design a mission concept for measuring emission and plume properties during the takeoff and return of current or near-future launch vehicles. It leverages expertise in the fields of ground observations at the launch site, airborne in-situ measurements with different available platforms like aircraft, balloons or sounding rockets, satellite remote sensing of contrails or trace gases, as well as plume and global atmospheric modelling. Thereby the major atmospheric burn events of a modern launcher shall be captured in unprecedented extent and detail to better quantify their atmospheric effects.
This innovative atmospheric science mission brings together experts from the fields of atmospheric measurements with space launch system operators and airspace authorities. Additionally, input will be provided by experts in plume thermodynamics and chemistry modelling, trajectory and dispersion modelling as well as weather forecasting. The gathered mission concept devises a recipe to operate a comprehensive suite of measurement platforms and instruments at a scheduled rocket launch event, including a list of objectives and requirements as well as a comprehensive risk assessment.
How to cite: Marsing, A., Voigt, C., Roiger, A., Nützel, M., Yamashita, H., Schmidt, A., Bräuer, T., Hardi, J., Lober, L., Karl, S., Duperray, M., and Girardin, V.: Designing a mission concept for atmospheric plume measurements during a rocket launch event, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18151, https://doi.org/10.5194/egusphere-egu25-18151, 2025.
Rocket emissions damage the stratospheric ozone layer, which protects life from harmful solar radiation. To understand if significant ozone losses could occur as the launch industry grows, we examine two scenarios of industry aspirations. Our ‘ambitious’ scenario (2,040 launches/year) leads to a -0.29% depletion in annual-mean, near-global total column ozone, relative to a simulation with no rocket launches. Antarctic springtime ozone decreases by 3.9%. Our ‘conservative’ scenario (884 launches/year) leads to a -0.17% annual depletion; current licensing rates suggest this scenario may be exceeded sooner than 2030. Ozone losses are mostly driven by the reactive chlorine produced from solid rocket motor propellant, and black carbon which is emitted from most propellants in contemporary use. The ozone layer is slowly healing from the effects of anthropogenic CFCs, yet ozone abundances are still 2% lower than those measured prior to the onset of CFC-induced ozone depletion. Our results demonstrate that ongoing and frequent rocket launches could delay ozone recovery. Action is needed now to ensure that future growth of the launch industry and ozone protection are mutually sustainable.
How to cite: Revell, L., Bannister, M., Brown, T., Sukhodolov, T., Vattioni, S., Dykema, J., Frame, D., Cater, J., Chiodo, G., and Rozanov, E.: Near-future rocket launches could slow ozone recovery, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1201, https://doi.org/10.5194/egusphere-egu25-1201, 2025.
Around 10% of Junge layer sulphuric acid droplets have been measured to contain metals from ablated space debris. Some metals – Al, Li, Cu, Ni, Mn etc. – already exceed natural background levels from cosmic dust that has ablated in the mesopause region. The effect of these metals on the stratosphere is not yet known, and space debris input has been projected to increase by more than an order of magnitude in the next 15 years. It is therefore vitally important to determine the level of re-entering space debris that will cause significant changes to atmospheric aerosols and stratospheric chemistry, in particular to the ozone layer. Our calculations predict that the primary component of space debris particles (SDPs) will be aluminium hydroxide (Al(OH)3), which is expected to polymerise rapidly to form nano-particles and react with atmospheric HCl. The resulting complex is predicted to have a photolysis rate ~10 000 times faster than that of gas-phase HCl, and so Cl concentrations and therefore destruction of ozone by chlorine radicals are expected to increase.
Here we present preliminary results of a modelling study using a sectional aerosol model within an Earth system model (Whole Atmosphere Community Climate Model with the Community Aerosol and Radiation Model for Atmospheres, WACCM-CARMA). We simulate the transport of SDPs and meteoric smoke particles (MSPs) produced by condensation of Fe and Mg silicates from ablated cosmic dust. The particles grow by coagulation and deposition of sulphuric acid through 28 size bins (0.34 nm to 1.6 µm radius). The SDPs and MSPs are initially injected in concentrations consistent with current models and observations (7.9 t d-1 MSPs and 0.96 t d-1 SDPs) to assess the transport and lifetimes of the particles in the atmosphere. The effect of increasing the mass of SDPs in line with future increases in space travel is also simulated. The maximum possible impact of SDPs on stratospheric chemistry is then estimated from the available SDP surface area and assuming upper limits for unmeasured physico-chemical parameters.
How to cite: Egan, J., Feng, W., Marsh, D., and Plane, J.: Modelling impacts of ablated space debris on atmospheric aerosols , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4460, https://doi.org/10.5194/egusphere-egu25-4460, 2025.
The German Aerospace Center (DLR) has launched the S3D initiative, aimed at advancing the assessment and enhancement of sustainability in space activities. While recent years have seen growing attention to the environmental impacts of spacecraft and launch vehicles, S3D seeks to extend this perspective by integrating economic and social dimensions, transitioning from traditional Life Cycle Assessment (LCA) to a more comprehensive Life Cycle Sustainability Assessment (LCSA). A practice that is already established in other industries.
In addition to developing an LCSA process tailored for space activities, this initiative places particular emphasis on the impact of launch vehicle emissions in the upper atmosphere. This focus is driven by significant knowledge gaps and the potential for these emissions to be a major contributor to the climate impact of space transport activities. Substantial uncertainties remain with regard to the exact chemical composition of the exhaust, the post-combustion processes within the plume as well as the formation of particles such as black carbon. Moreover, there is a critical lack of data on the atmospheric effects of these gas and particle emissions at higher altitudes. To address these challenges, S3D will leverage the expertise of specialized DLR institutes in space systems, aerothermodynamics, propulsion, and atmospheric sciences to better characterize launch emissions and their atmospheric impacts.
This presentation will introduce the S3D initiative, outline the methodological approaches under development, and present initial findings on the exhaust profiles of various launch vehicle designs, along with progress toward creating a comprehensive exhaust inventory for 2024.
How to cite: Wilken, J., Herberhold, M., Maiwald, V., Nützel, M., Schmidt, A., and Sippel, M.: DLR Initiative S3D: Advancing Space Sustainability and Sustainable Development, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9526, https://doi.org/10.5194/egusphere-egu25-9526, 2025.
Posters on site: Fri, 2 May, 10:45–12:30 | Hall X5
There have been long concerns on the potential environmental impact of aviation, which is the second biggest source of transport greenhouse gas emissions after road transport. Direct emissions from aviation accounted 3.8% of total CO2 emissions, which is estimated to contribute ~3.5% to the anthropogenic effective radiative forcing of climate (IPCC). The environmental impact of emissions from space launches is currently receiving much attention due to the space industry being one of the fastest growing global economic sectors. Since the first assessment of the impact of rocket emissions by Cicerone and Stedman (1974), there have been many developments in rockets and modelling. Rocket emissions can inject significant quantities of gases and particles into the atmosphere (including chlorine compounds HCl, H2O, CO2, NOx, H2, Al2O3 and black carbon), potentially affecting ozone depletion, the dynamics of the atmosphere, and climate change. Feng et al. (2023) have investigated stratospheric ozone depletion due to the presence of small satellites (e.g., CubeSats) with an iodine propulsion system to keep them in orbit. They have shown that an increase in the number of small satellite launches could cause substantial ozone depletion in the Antarctic.
In this work, we have incorporated the up-to-date aviation emission inventories (Teoh et al., 2024) and rocket emissions (Brown et al., 2023) into a state-of-the-art global chemistry-climate model (NCAR’s Community Earth System Model, CESM2) to explore how aviation and rocket emissions affect the stratospheric ozone layer and climate once the gases and particulates are injected into the atmosphere. The model includes dynamics, transport, aerosol microphysics, photochemistry, radiation, emissions, and their influences on stratospheric ozone depletion. We have carried out many model experiments in CEMS2 using different configurations (free running, specific-dynamic versions of Whole Atmosphere Community Climate Model) with different chemistry and NOx emissions scenarios from aircraft and rocket emissions (from zero NOx emissions, released NOx emission inventories and up to 100 times NOx emissions) to assess the atmospheric changes induced by these emissions under historical and future scenarios.
How to cite: Feng, W., Li, Y., Chipperfield, M., Plane, J., Marsh, D., Egan, J., Chang, S., Rap, A., Zhang, W., Archibald, A., Brown, T., Revell, L., Saiz López, A., Booth, J.-P., and Kinnison, D.: Atmospheric and climate effects of NOx emissions from Aviation and Rocket launches, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20347, https://doi.org/10.5194/egusphere-egu25-20347, 2025.
Emissions from the space industry are rapidly increasing due to surges in rocket launches and the amount of mass re-entering the Earth’s atmosphere. Satellite megaconstellations (SMCs) are a key contributor to this growth, representing a fifth of rocket launches and a quarter of object re-entries in 2020-2022. These activities release air pollutant emissions throughout the atmosphere, including in upper atmospheric layers where turnover rates are very slow. This results in extremely effective stratospheric ozone depletion and radiative forcing. Of the approximately 7500 satellites in low-Earth orbit (LEO), 75% belong to satellite megaconstellations, with 60,000 additional SMC satellites expected to be launched in the next decade. Despite this anticipated growth, the environmental impacts of SMC emissions lack characterization and are under regulated. Here we implement a recently published 3-D, global inventory of space industry emissions into a computational model to determine the impacts on stratospheric composition and radiative forcing from a decade of SMC missions. The inventory comprises emissions up to 80 km from all SMC and non-SMC rocket launches and spacecraft re-entries during the onset of the megaconstellation era (2020-2022). The emission species include gaseous nitrogen oxides (NOx≡NO), water vapour (H2O), carbon monoxide (CO), and chlorine species (Cly≡HCl+Cl2+Cl), and particulate black carbon (BC) and alumina (Al2O3). We project the emissions to 2029 based on linear growth in SMC and non-SMC launch propellant consumption and re-entry mass. We use the GEOS-Chem 3-D model of atmospheric composition coupled to a radiative transfer model to simulate the response of atmospheric composition and radiative forcing to these emissions. We include a standard GEOS-Chem simulation of externally mixed aerosols and an updated simulation where BC and Al2O3 undergo prompt uptake to abundant stratospheric sulfate aerosols (SSA), as evidenced by observations from a recent aircraft campaign. We find a global stratospheric ozone loss of 0.03% (0.072 DU) from launch and re-entry emissions at the end of the decade. This is much smaller than stratospheric ozone loss attributable to surface sources (~2% in 2022). Depletion due mostly to Cly from solid rocket motors is concentrated in the northern midlatitude upper stratosphere. SMC missions are responsible for 13% of this ozone depletion, as solid fuel represents <1% of rocket fuel used by SMC missions from 2020-2022. Uptake of aerosol emissions to SSA results in nearly complete removal of wintertime stratospheric BC and Al2O3 concentrations and a summertime peak. This process greatly reduces the positive radiative forcing by stratospheric BC, resulting in stratospheric ozone depletion as the dominant forcing process and an overall negative forcing. Space industry emissions from all mission types result in radiative forcing of -3.38 mW m-2 at the top of the atmosphere in summer 2029, with -0.59 mW m-2 from SMC missions. At the tropopause, there is a net negative radiative flux from all missions (-1.64 mW m-2) and SMC missions (-0.35 mW m-2). Current work includes conducting sensitivity simulations to quantify the impact of uncertainties in properties and chemical pathways of aerosol emissions on our results to inform future field and experimental studies.
How to cite: Barker, C., Marais, E., and Eastham, S.: Defining the environmental impacts of satellite megaconstellation missions in a rapidly growing space sector, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17301, https://doi.org/10.5194/egusphere-egu25-17301, 2025.
Atmospheric reentry impact on the atmosphere is an increasingly important topic today as the number of objects entering the atmosphere continues to rise (e.g. nanosats, cubesats, missiles, …) Modelling the way those artificial objects both enter the atmosphere and disaggregate requires precise knowledge of the medium conditions (e.g. temperature, density, …) However,current atmospheric models like MSIS 2.0 or ERA-5 reanalyses have been proven to lack accuracy at higher altitudes, limiting their use for this application. Therefore, this study aims at proposing an updated middle-atmospheric climatology using the NDACC and our Rayleigh LIDAR. We evaluate the bias between LIDAR observations and models (MSIS 2.0 and ERA 5), and explore the impact of mesospheric events on the temperature climatology. We also demonstrate how both the general daily variability and the input of some extreme events can influence the density and temperature at those altitudes. Climatologies were developed using 40 years of Lidar data, then compared to a climatology obtained with the calling of models. MSIS 2.0, while reliable in terms of seasonal trends, is less accurate daily: it shows high biases with the lidar at high altitudes (1.25% at 60 km, up to 6% at 80km). The European Climate and Weather Forecast model ERA-5 agrees with the lidar at 98.9% in the upper stratosphere but shows a larger statistical bias of 7 to 10% in the mesosphere. We removed extreme events such as Sudden Stratospheric Warmings (SSWs), Mesospheric Inversion Layers (MILs) and Double Stratopause (DSs) to create a “Steady-State” Climatology at different lidar stations. Observing the densities corresponding to the temperature profiles, we could evaluate the annual mean density in the OHP and the impact of those different events on the mean density profile. Density disturbances caused by SSWs and MILs were quantified, revealing deviations of up to 12% and 25%, respectively, from MSIS density profiles, with impacts spanning 10–20 km in altitude. Our study provided important basis for the study of atmospheric reentry. Re-actualisation of temperature and density above lidar station and expected bias for the most commonly used middle-atmosphere model will help set the ground for future evaluation of heating, ablation and trajectory computation in this medium.
How to cite: Tufel, N., Keckhut, P., and Hauchecorne, A.: Middle Atmosphere Climatology using LIDAR for the evaluation of atmospheric conditions during man-made object reentry, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1262, https://doi.org/10.5194/egusphere-egu25-1262, 2025.
Space debris is a major issue for space safety. In this context, there is a growing norm of disposal of orbital debris through atmospheric re-entry. The few existing studies, including our own modelling, agree that the projected exponential growth of satellites in Low-Earth Orbits (LEO) may come at the expense of damaging the integrity of the middle and upper atmosphere, with potentially unforeseeable consequences. We argue that sustainable LEO management requires overcoming what we call 'atmosphere-blindness': the limited understanding of the connections between space and the Earth system through orbital disposal practices and their impacts on the atmosphere. In our view, it is thus crucially important to undertake more interdisciplinary research on the issue of de-orbiting, as it is not merely a technical environmental problem, but also an inherently political matter of environmental justice on a planetary scale.
How to cite: Schaefer-Rolffs, U., Flamm, P., Lambach, D., Stolle, C., and Braun, V.: Space sustainability through atmosphere pollution? De-orbiting, atmosphere-blindness and planetary environmental injustice, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2816, https://doi.org/10.5194/egusphere-egu25-2816, 2025.
In 1973, the launch of Skylab created a ~50% depletion in the daytime ionosphere over the N. Atlantic Ocean that lasted for hours. This effect was discovered in the data being routinely gathered by radio receivers monitoring the Total Electron Content (TEC) using the Faraday rotation of a signal from the ATS-3 geostationary satellite. This “ionospheric hole” was created by the H2O and H2 in the rocket exhaust reacting with the ambient O+ in the F region. This reaction is ~2 orders of magnitude faster than the “normal” reaction between O+ and the ambient O2. Subsequent rocket launches were studied to confirm this process. Dedicated rocket launches were also used to create steep density gradients to study ionospheric instabilities near the magnetic equator. Today, rockets are being launched at an ever increasing rate (~2 launches/week), some of them causing ionospheric holes. The launches of Starlink group 6 from Florida de-orbit over the McDonald Observatory where Boston University has an All-sky Imager (ASI) dedicated to observing the optical emissions from the ionosphere. The de-orbit burns release H2O and CO2, both of which create an ionospheric hole with a concurrent burst of 630.0nm airglow. This airglow is bright enough (~ 10kR) to be seen with the unaided eye, and has been documented by citizen scientists. The resulting hole is also seen on GPS TEC maps of the region. Several examples of the de-orbit burns observed with the ASI at McDonald are shown.
How to cite: Mendillo, M., Baumgardner, J., Wroten, J., and Martinis, C.: Recent Observations of Rocket Exhaust Effects on the Ionosphere, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3801, https://doi.org/10.5194/egusphere-egu25-3801, 2025.
The recent uptick in rocket launch rates, as well as the proposal of large low earth orbit satellite constellations (LLC’s) has renewed interest into how space traffic might impact Earth’s climate. One issue, the potential atmospheric response to a significant increase in aerosols released into the lower mesosphere/upper stratosphere during satellite reentry, remains under studied. It is predicted that if all proposed LLC’s are implemented, the total number of satellites in low earth orbit (LEO) will balloon from ~5,000 to over 60,000 individual satellites by as early as 2040. The corresponding annual emissions of metallic aerosol from satellite reentry is also expected to increase and approach 10 Gg/year. This reentry emission source would be on the same scale as the naturally occurring meteoric mass flux which is estimated to fall between 8 Gg and 20 Gg per year. Little is currently known about what type of exotic aerosols may be released during satellite ablation, but a significant portion of the aerosol population may be aluminum. Reentering LEO satellites are expected to completely vaporize in the mesosphere, and the subsequent vapor cloud will cool and coalesce into metallic aerosol roughly between 60km and 70km. As a result, aluminum aerosol could be rapidly transported into the stratosphere by atmospheric circulation and oxidize into aluminum oxide (Al2O3). Past studies have shown how Al2O3 released by solid rocket motors in the stratosphere can impact heterogeneous chemistry and thus ozone. Additionally, not much work looking at the radiative impact from Al2O3 aerosols in the stratosphere has been conducted. Here we present results from a study which focuses on the radiative impacts and atmospheric transport of hypothetical Al2O3 emissions from satellite reentry. The WACCM6 global model coupled with the CARMA sectional model was run with a 10 Gg/year mass flux of Al2O3 between 60 km and 70 km. We simulate multiple reentry patterns and aerosol size distributions. Our results show that reentry Al2O3 begins to accumulate in the polar region of both hemispheres on a time frame of months to two years, depending on the reentry location and aerosol size. Additionally, anomalous longwave cooling near the stratopause may lead to as large as 1.5 K temperature anomalies in the high latitude stratosphere and perturb the strength of the stratospheric polar vortex by as much as 10%. Due to modeling limitations, the work presented here does not consider important interactions between metallic reentry aerosol and stratospheric chemistry, but our results provide a first order approximation of the potential atmospheric response to an increased influx of satellite reentry aerosol.
How to cite: Maloney, C., Portmann, R., Ross, M., and Rosenlof, K.: Modeling the atmospheric transport and possible radiative impact of alumina aerosols emitted from the projected increase in annual satellite reentry emissions., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3866, https://doi.org/10.5194/egusphere-egu25-3866, 2025.
The space industry is currently growing more rapidly than during any earlier time period since the beginning of the space age. Large low Earth orbit (LEO) satellite constellations and reusable liquid natural gas (LNG) fueled launch vehicles will change the scope and character of spaceflight. Satellite launches have increased four-fold in the past decade and are projected to grow even more quickly in coming decades. Given this explosive growth of the space industry, we need to understand combustion emissions from rockets and vaporization emissions from reentering space debris and how they will impact the global atmosphere. In particular, there may be changes to the stratospheric ozone chemistry as a result of space industry emissions into the middle atmosphere. At present, impacts are small, but evidence of metals that can only come from rocket stages and satellites have been detected in stratospheric aerosols, with an estimate that 10% of stratospheric aerosols contain species that can only originate from rocket stage/satellite ablation. Current rates of reentry particles are a few Gg/yr, but are projected to be over 10 Gg/year by 2030. Although modeled heating rates produced by reentry aluminum particles are small, they are statistically significant, and, as the number of objects in LEO are projected to increase, that impact will grow with time. Future work will attempt to estimate the impact of heterogeneous chemistry on reentry particles. Well quantifying impacts will require information on reentry scenarios, rocket plume chemistry and reentry vaporization debris characterization. Measurements, via laboratory experiments, remote sensing of launches and reentry, and in situ sampling are all needed to fully characterize space industry impacts on the atmosphere. This presentation will give an overview on what has been accomplished so far, and address what is needed to better characterize the impacts (and uncertainties) on the ozone layer from a growing space industry.
How to cite: Rosenlof, K.: Rocket Launches and Satellite Re-Entry: Potential Issues and the Need for Additional Modeling and Measurements , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4564, https://doi.org/10.5194/egusphere-egu25-4564, 2025.
A large number of low earth orbit satellites are projected in the coming decades, which has led to concerns about environmental impacts of demised spacecraft. The current flux of anthropogenic aluminium vapours entering the Earth’s atmosphere is estimated to be already 10 times larger than the natural flux from meteoroids.
Metals ablated from meteoroids between 80 and 110 km react with atmospheric constituents in the mesosphere forming meteor smoke particles, which are transported by the global circulation to the stratosphere, where they entrain sulfuric acid aerosols and modify their properties. Metals ablated from demised spacecraft at ~60 km have a similar fate: Recent aircraft-based measurements show that 10% of stratospheric aerosols contain metals from re-entering satellites and rocket stages.
In this presentation I will give an overview of what we know about the gas-phase chemistry of spacecraft-relevant metals in the lower mesosphere-stratosphere. Based on this incomplete knowledge, I will speculate about the possible pathways of anthropogenic metals towards stratospheric aerosol and I will highlight uncertainties and experimental/theoretical work that needs to be carried out in order to address them. In particular, I will discuss preliminary results obtained with a modified version of the Meteor Ablation Simulator on the ablation of aluminium particles and the subsequent gas-phase chemistry of aluminium.
How to cite: Gomez Martin, J. C., Ocaña, A. J., Plane, J., and Carrillo-Sanchez, J. D.: What do we know about the chemistry of spacecraft constituent metals in the Lower Mesospehere-Upper Stratosphere?, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6158, https://doi.org/10.5194/egusphere-egu25-6158, 2025.
Increasing rocket launch rates in the last decade have prompted concerns over their environmental impacts. Launch vehicles are unique among anthropogenic pollution sources for directly emitting pollutants at all levels of the atmosphere. These high-altitude emissions have distinct – and poorly understood – consequences; emissions such as water vapor and black carbon aerosols have longer lifetimes in the stratosphere and thus a longer window for climate and ozone impacts.
Accurately estimating launch emissions is an outstanding problem in launch vehicle research, complicated further by diverse combustion products which vary according to propellant type. We create unique emissions profiles for representative launches with equivalent payloads to LEO for three different propellants: RP1/LOx, CH4/LOx, and LH2/LOx. Using the GEOS-Chem High-Performance (GCHP) chemical transport model, we simulate an array of launch scenarios reflecting different choices of launch site, propellant, and launch season in a global three-dimensional atmosphere.
We evaluate the impact of launch hemisphere by comparing launches at the same latitude in the Northern and Southern hemispheres, and show a greater ozone impact in southern-hemisphere launches. We simulate a range of launch sites across the northern hemisphere and show substantial variance in high-altitude ozone formation as a function of latitude. We show a several percent larger increase in stratospheric ozone for summer launches than in winter. Finally, we see net ozone column increase with RP1 and CH4 fuelled launches but net decrease with LH2, which we posit suggests black carbon is the dominant force in high-altitude ozone formation as a response to rocket launches.
Using these results, we synthesize a variety of impact mitigation strategies for a given rocket launch and estimate the potential harm reduction across a variety of metrics: global ozone column changes, radiative forcing, surface air quality, and population exposure to fine particulate matter. These findings could be used to inform future developments in the launch industry, from selecting and researching fuel types for future launch vehicles, to choosing locations for future launch sites, and even optimal utilization rates for existing launch sites.
How to cite: McDonald, H., Eastham, S., and Speth, R.: Reducing the Environmental Impacts of Rocket Launch Emissions through Launch Parameter Variations, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13478, https://doi.org/10.5194/egusphere-egu25-13478, 2025.
