Introduction
The International Ozone Commission (IO3C) facilitates the study of atmospheric ozone around the world. The IO3C was formally established in 1948 at the seventh International Union of Geodesy and Geophysics (IUGG) in Oslo, Norway. IUGG represents the entire community of geophysical scientists around the world, and IO3C is a special commission of the IUGG. In its early years, IO3C played a lead role in preparing for the International Geophysical Year in 1958, and since then it has remained on the cusp of the state of the art in ozone science. (For more information on the IO3C’s long history, visit the article “International Ozone Commission: History and activities.”)
As part of its work, IO3C organizes periodic symposia – which have been held quadrennially since 1964 – to update the community on the progress of processes affecting atmospheric ozone, its observations, photochemistry, impacts on air quality and human health, as well as the existential threat of ozone layer depletion resulting from chlorofluorocarbons (CFC) and halons.
The most recent of these meetings, the 2024 Quadrennial Ozone Symposium (QOS), took place July 15–19, 2024, in Boulder, CO. The University of Colorado, Boulder (CU) hosted the event. About 220 people attended in person at CU’s Glenn Miller Ballroom, with another 40 attending virtually from three-dozen countries – see Photo 1.
The IO3C collaborated on organizing the 2024 QOS with NASA, the National Oceanic and Atmospheric Administration (NOAA), CU Boulder’s Cooperative Institute for Research in Environmental Sciences (CIRES), and the National Center for Atmospheric Research (NCAR).
The proceedings from QOS (and other ozone-related meetings) contribute to the development of periodic United Nations Environment Programme (UNEP)/World Meteorological Organization (WMO) Ozone Scientific Assessment reports. These reports have been issued since 1985 and quadrennially since 1994. The objective of these reports is to provide information on the state of the ozone layer and ozone-depleting substances (ODS) in an accessible and concise way for policy makers and the general public. To continue this effort, the “20 Questions and Answers about the Ozone Layer” section has been included in the report since 2002. The next Ozone Assessment is scheduled for 2026 and was a topic of discussion at the meeting – see the section “2026 Ozone Assessment” of the current article for more details.
The remainder of this article summarizes the 2024 QOS. After beginning with a big-picture perspective on the meeting – which includes information on two awards presented during QOS and on election of leadership for 2024–2028 – the bulk of the report is organized around the key topics discussed during the symposium. Content has been intentionally kept generic. Those seeking specifics on the missions, models, and other details should review the abstracts and presentations available in the full 2024 QOS program.
Meeting Overview
During the opening ceremony of the 2024 QOS, the organizing committee and participants acknowledged that the CU Boulder campus is located on the traditional territories and ancestral homelands of the Cheyenne, Arapaho, Ute, and other Native American nations.
The oral and poster presentations were organized into six sessions that covered the following themes:
- Stratospheric Ozone Science;
- Tropospheric Ozone Science;
- Ozone, Climate, and Meteorology;
- Environmental and Human Health Effects of Atmospheric Ozone and Ultraviolet (UV) radiation;
- Ozone-depleting Gases and Related Substances; and
- Ozone Monitoring and Measurement Techniques.
Each day oral presentations were followed by poster sessions [Monday and Tuesday (Sessions 1–3) and Thursday and Friday (Sessions 4–6)].
Election of New IO3C Leadership
At any time, ~30 leading scientists in the study of atmospheric processes from around the world are members of the IO3C. Elections are held to determine the membership. Members typically serve for four years with the possibility of serving a second term. By way of history, the first president of the IO3C was Gordon Dobson [Oxford University], a famous scientist who was a pioneer in the study of atmospheric ozone. The Dobson Spectrophotometer, the first device for measuring ozone, was named for Dobson.
During the 2024 Symposium, the IO3C elected new leadership: Irina Petropavlovskikh [CIRES, Global Monitoring Laboratory] was elected president for 2024–2028; Nathaniel Livesey [NASA/Jet Propulsion Laboratory (JPL)] and Valerie Thouret [Aerologie-Observatoire Midi-Pyrenees (French Laboratory of Aerology)] were both elected vice president. Corinne Vigouroux [Institut Royal d’Aéronomie Spatiale de Belgique (Royal Belgian Institute for Space Aeronomy)] was elected as secretary. Sophie Godin-Beekmann [Centre National de la Recherche Scientifique (French National Center for Scientific Research)] and Paul Newman [NASA’s Goddard Space Flight Center (GSFC)], who have served as president and vice-president for two four-year terms, respectively, have stepped down.
A complete list of current officers and members (2024–2028) is also available online.
Award Presentations
During each QOS event, IO3C presents the Dobson Award for an outstanding research paper led by a young scientist. Luke Western [University of Bristol, UK—Marie Curie Research Fellow] received the 2024 Dobson Award for his work on the global increase of ozone-depleting CFCs from 2010 to 2020.
IO3C also presents the Farman Award, which is given to scientists who create and/or maintain long-term measurements of atmospheric constituents related to the study of atmospheric ozone and surface UV radiation. Both Herman Smit [Forschungszentrum Jülich (Institute of Energy and Climate Research), Germany] and Philippe Nédélec [Federal University of Toulouse Midi-Pyrénées, France] received the 2024 Farman Award. Smit was awarded for his work on global ozonesonde network calibration and data quality assurance and Nédélec for producing high quality ozone record in the troposphere and lowermost stratosphere using in-situ observations onboard commercial aircraft [In-service Aircraft for a Global Observing System (IAGOS)] – see Photo 2.
Stratospheric Ozone
Since the late 1990s, the concentration of ODS in the stratosphere has declined due to the Montreal Protocol, which regulates their production and use. This reduction is expected to lead to significant ozone recovery. The symposium included reports on various ozone trends, including profile, total, and partial column ozone.
Observations indicate significant positive trends in upper stratospheric ozone of about 1–2% per decade – see Figure 1. Model simulations suggest these trends result from reduced ODS and upper stratospheric cooling linked to climate change from increased concentrations of greenhouse gases (GHG); however, total column ozone remains stable globally and does not show statistically significant positive trends. In addition, the stratospheric ozone column trend, derived from limb and occultation measurements, generally agrees with the total ozone column trend obtained from nadir instruments within their respective uncertainties.
By 2018, multiple studies noted the emergence of an Antarctic ozone recovery. In the past decade, the opening of the ozone hole has been delayed by 1–2 weeks. Ground-based observations at the Antarctic Davis Station also showed signs of recovery during key depletion periods. The 2019 Antarctic ozone hole was the smallest since 1983, although this was a result of strong stratospheric warming events. In contrast, ozone holes from 2020–2023 were the longest-lived on record, breaking up in late December (e.g., extending several weeks beyond the 1990–2019 average breakup date of December 9).
Several presenters during this session analyzed these unusual Antarctic seasons, reporting weaker meridional transport of ozone from mid-latitudes from 2020–2023 and unusually high UV radiation levels in November–December of each year. Some studies suggest increased stratospheric aerosol concentrations from the Australian bushfires in 2019–2020 and the 2022 Hunga Tonga–Hunga Haʻapa volcanic eruption for the delayed vortex breakup. Model simulations are needed to understand how these events and increased stratospheric aerosols and water vapor affect the vortex.
Other presenters in this session focused on the Arctic, where the total column ozone in March 2024 reached a record high of 478–60 DU, above the long-term mean. Stratospheric warmings between December 2023 and March 2024 are believed to have contributed to this high value – in contrast to the record depletion observed in Spring 2020. The reduction in ODS as a result of the Montreal Protocol also likely contributed to the 2024 Arctic record. Ozone remained at record levels throughout Summer 2024, reducing surface UV radiation over the northern mid-latitudes by about 8%.
Hunga Volcanic Eruption
This session focused on the impact of Hunga Tonga–Hunga Haʻapa (Hunga) underwater volcanic eruption in January 2022 on the Antarctic ozone hole. The Hunga eruption was intense and explosive, propelling volcanic plumes into the stratopause. The plume injected a relatively small amount of sulfur dioxide (SO₂) but a record high amount of water vapor (~150 Tg), increasing global stratospheric water content by about 10%. Many presenters showed results from studies focused on evaluating the volcanic plume, the effects of increased water vapor and stratospheric aerosol concentrations on chemistry and dynamics, and how both factors affected atmospheric ozone distribution.
During this session, speakers discussed analysis of Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) measurement taken following the Hunga eruption. [CALIOP flew on NASA’s Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) mission.] The results show that the aerosol optical depth of the volcanic plume clouds immediately after the Hunga eruption measured ~0.6 at 532 nm. The clouds rapidly descended several kilometers over the next few days due to intense radiative cooling, elongating and spreading zonally – see Figure 2.
The high-water content led to an unusual evolution of the Hunga plume in the two weeks following the eruption. Satellite measurements indicated unusually rapid sulfate (SO4) aerosol formation downstream of the plume. By the end of January, the conversion of SO₂ to SO4 aerosols was complete in the volcanic plume clouds. Sonde observations at La Réunion showed ozone decreased up to ~5% in the plume – suggesting possible chlorine activation and ozone destruction.
Other presenters during this session addressed the transport of water vapor injected by the Hunga volcano to the tropics, followed by movement to middle and polar latitudes over time. The results show that the excessive water vapor plume did not reach the southern polar regions in time to impact the 2022 Antarctic polar vortex and ozone depletion. By May–June 2023, the Hunga water plume reached the Antarctic and levels of stratospheric water vapor in high southern latitudes rose to record levels, leading to rapid formation of polar stratospheric clouds and early activation of ozone-depleting chlorine species in the middle and upper stratosphere. Starting in late June 2023, the concentration of water vapor declined sharply in the polar lower stratosphere due to seasonal dehydration (i.e., sedimentation of ice particles) with unprecedented amounts of water vapor removed. Dehydration and chlorine activation processes were completed by July–August. The amount of chlorine converted in May–June 2023 was much smaller than normally seen in August–September – which is typically the peak of Antarctic ozone depletion. Thus, the excess water vapor from the Hunga eruption had little overall effect on the 2023 Antarctic ozone hole. Model runs with and without the excessive water vapor showed a minor effect on ozone consistent with observations, and the models reproduced the record dehydration in 2023.
Ozone-depleting Substances
While the Montreal Protocol regulates the atmospheric concentrations of chlorine and bromine, the rate of decrease for certain ODSs (e.g., CFC-11) slowed from 2013–2017 due to unreported production but has since re-accelerated. The meeting presenters emphasized the importance of reconciling top-down and bottom-up inventory models for substances such as CFCs and hydrofluorocarbons (HFCs).
The Equivalent Effective Stratospheric Chlorine (EESC) provides a means to measure ozone depletion by active chlorine and bromine levels in the stratosphere. Based on the WMO/UNEP 2006 Ozone Assessment, the projected date for EESC to return to 1980 levels has been pushed back 17 years – from 2049 to 2066. While unexpected emissions of ODS have contributed to this delay, the primary factors include updated atmospheric lifetimes of ODS, underestimation of atmospheric release of carbon tetrachloride (CCl4), and revised bank calculations, which estimate the amount of ODS that has been produced and is contained in the equipment or product (e.g., air conditioning and refrigeration systems, thermo-isolating foams, or fire protection systems) but has not been released to the atmosphere yet. Some fraction of ODS will be gradually released during the equipment or product’s lifetime, and some will be released at or after the end-of-life of equipment or products. With an intervention particularly at the end of life, ODS may be collected, stored, and safely destroyed, preventing their release into the atmosphere. Capturing ODS releases from banks and reducing CCl4 emissions can be addressed in the future. Contributions of very short-lived species (VSLS), which are not regulated by the Montreal Protocol, remain uncertain.
Symposium participants discussed emerging concerns around ODS (e.g., brominated VSLS from coastal coal power generation) and the need for validated emissions inventories. For example, bromoform (CHBr3) is a contributor to stratospheric ozone depletion but due to its short lifetime and substantial natural sources, the compound is not regulated under the Montreal Protocol. Recent measurements from balloon and aircraft campaigns in the extratropical Northern Hemisphere indicate that CHBr3 concentrations are much higher than previously assumed natural levels. Anthropogenic (or human-made) sources (i.e., emissions from coastal power plant cooling systems, ship ballast, and desalination plants) contribute to these observed concentrations – see Figure 3.
A report about a new inventory of both anthropogenic and natural CHBr3 sources demonstrated a 31.5% global and a 70.5% Northern Hemisphere increase, primarily due to human activity. Anthropogenic emission concentrations are twice the concentration of natural sources in the Northern Hemisphere extratropics during boreal winter. Atmospheric bromine concentrations near the tropopause in the Northern Hemisphere have increased by 2.4 parts per trillion (ppt) in the new inventory – indicating significant anthropogenic contributions of CHBr3 to the lowermost stratosphere.
A New Potential Threat to the Ozone Layer
The number of satellite launches have increased four-fold in the last decade and are expected to continue to increase for the foreseeable future. Some presenters during this session highlighted the need to evaluate potential risks posed by the growing space industry to the ozone layer. Previous studies have shown that rocket ascent can lead to short-term ozone depletion, primarily due to the direct chlorine emissions from rocket motors. Additionally, rocket fuel contributes to higher concentrations of black carbon aerosols, which can impact stratospheric temperatures and dynamics – see Figure 4.
The novel threat for the ozone layer comes from ever-increasing satellite atmospheric re-entries. At the end of their operational lives, satellites burn up during atmospheric re-entry, producing aluminum oxides that may contribute to ozone depletion. It is estimated that about 10% of stratospheric aerosols contain species originating from rocket stage and satellite ablation. The environmental effects of this anthropogenic impact are not well understood. Considering the explosive growth of satellite launches, there is an urgent need to better understand the effects of increased space activity on stratospheric composition, transport, and ozone chemistry.
Modeling Ozone Atmospheric Distribution
Chemistry Climate Model (CCM) simulations are crucial to understand present ozone distribution in response to the impact of unusual events (e.g., volcanic eruptions and wildfires) and ODS. CCMs are also used to predict changes in response to the Montreal Protocol, and the evolving climate conditions caused by increasing GHG concentrations in the atmosphere. The projections from these models are influenced by three sources of uncertainty: scenario uncertainties, structural differences, and internal model variability. Scenario uncertainties include factors such as the lifetime and evolution of chlorine and bromine species, the contribution of VSLS ODS, and unexpected increases in concentrations of certain ODS chemicals, such as CFC-11. Structural differences among CCMs arise from variations in model configurations, which affect ozone recovery predictions. Finally, internal model variability is related to short-term variations in model simulated ozone, not dependent on long-term change driven by ODSs and GHGs, which can be mitigated by running multi-ensemble simulations for each CCM.
CCM predictions indicate the rising concentrations of GHGs lead to warmer sea surface temperatures, which increase convection, intensify tropical waves, and accelerate the Brewer–Dobson circulation. GHG forcing in CCM simulations also suggest the Quasi-Biennial Oscillation period tends to decrease from 28 months to ~12 months. Accurate representation of chemical processes in CCMs (e.g., denitrification) is crucial. (More nitrogen dioxide (NO2) results in less chlorine activation and weaker ozone depletion.) CCMs predict that ozone recovery in the Arctic will occur sooner than in the Antarctic. The increased lifetimes of some of ODS shifts the estimation of the recovery from 2053 in the 2006 Ozone Assessment to 2067 in the 2022 Ozone Assessment – see Figure 5. Given these developments, it may be time to conduct another model assessment.
Ozone, Climate, and Meteorology
Presenters in this session focused on ozone–climate coupling and the influence of stratospheric ozone on surface temperature, the branches of the Brewer–Dobson circulation, and the uncertainties surrounding radiative forcing from halocarbons. The rate of ozone recovery is coupled to changes in the stratospheric circulation that can be inferred from atmospheric observations of some trace gases, such as N2O. One study illustrated how slower circulation in the Northern Hemisphere compared to the Southern Hemisphere during the last two decades contributed to somewhat faster ozone recovery in the Southern Hemisphere.
Other presenters addressed the influence of Antarctic ozone recovery on the Southern Annular Mode (SAM) climate oscillation. A reversal in SAM behavior after 2000 was attributed to downstream effects of the slow healing of the Antarctic ozone hole. While stratospheric–tropospheric coupling is stronger during the period of ozone depletion, the model predicts a significant weakening as the Antarctic ozone recovers. Symposium participants encouraged further research on ozone recovery, particularly in the Arctic lower stratosphere, and the impact of stratospheric cooling from GHG on Arctic polar vortex evolution.
Anthropogenic activity influences the composition of the stratosphere on an annual basis within the Asian Summer Monsoon (ASM), when surface pollutants – including VSLS – are lofted into the lower stratosphere. Observations from the 2022 Asian Summer Monsoon Chemical and Climate Impact Project (ACCLIP) show an unprecedented abundance of chlorinated VSLS above the tropopause during the monsoon that affects stratospheric chemistry and ozone layer – see Figure 6. Two high-altitude aircrafts – the NSF NCAR Gulfstream V (GV) and the NASA WB-57 – participated in the ACCLIP field campaign.
Tropospheric Ozone: Pollution, Observations, and Trends
Presenters during this session addressed tropospheric ozone observations and science. Unlike the stratosphere, tropospheric ozone is a harmful pollutant that is detrimental to human and vegetation health and is a climate-forcing gas.
The discussions that ensued addressed new techniques to model ozone pollution events more accurately. Others reported on recent field campaigns (e.g., Airborne and Satellite Investigation of Asian Air Quality). In other presentations, speakers gave updates on tropospheric ozone products from multiple satellite instruments. The discussions examined data products from several NASA instruments, including the Ozone Monitoring Instrument (OMI) and combined OMI/Microwave Limb Sounder on the Earth Observing System (EOS) Aura platform, the Atmospheric Infrared Sounder on the EOS Aqua platform, and the Tropospheric Emissions: Monitoring of Pollution (TEMPO) mission. The discussions also addressed the Cross-track Infrared Sounder on the joint NASA–NOAA Suomi National Polar-orbiting Platform (Suomi NPP), NOAA-20, and -21, as well as several international instruments, including the Infrared Atmospheric Sounding Interferometer on the European Operational weather satellites, the TROPOspheric Monitoring Instrument on the European Copernicus Sentinel-5 Precursor mission, and the South Korean Geostationary Environment Monitoring Spectrometer on the GEO-COMPSAT 2B satellite. With data from all of these sources – and more to come – ozone measurements now span the entire globe across multiple decades.
These satellite instruments detected anomalously low tropospheric ozone in spring–summer over the northern hemisphere midlatitudes. This was initially a result of the COVID-19 pandemic lockdowns but has been sustained for more than three consecutive years. The low ozone concentration is likely a combination of reduced anthropogenic pollution and a decrease in stratospheric ozone transport in recent years.
Other presenters in this session focused on new results from ground-based networks of instruments (e.g., ozonesondes, lidar, Fourier Transform Infrared Spectroscopy, IAGOS aircraft). These data were compiled under the Tropospheric Ozone Assessment Report Phase 2 (TOAR-II) Harmonization and Evaluation of Ground Based Instruments for Free Tropospheric Ozone Measurements (HEGIFTOM) Focus Working Group. Data from these ground-based sources are used to validate the satellite tropospheric ozone measurements and model simulations and are used to calculate long-term trends. The ground-based measurements show little overall ozone pollution change in the past two decades in the tropics, with some decreases over North America and Europe where emissions of ozone pollution precursors have sharply declined – see Figure 7. Significant positive ozone trends are found in Southeast Asia – which are associated with intense seasonal biomass burning and the largest increases in anthropogenic emissions. These data fall in general agreement with satellite trend estimates. The presentations also addressed the need to rectify any differences among satellite and model ozone products and their comparisons with ground-based instruments, which is a primary task for TOAR-II.
Ozone Monitoring and Measurement Techniques
The participants discussed the latest advances and challenges in ozone monitoring, highlighting the importance of continuous observations for tracking global ozone trends and informing those developing climate policy. Recent unusual events affecting ozone recovery (e.g., the 2019 sudden stratospheric warming, the Australian wildfires, and the Hunga eruption) underscored the role of the data from the Aura MLS in understanding these phenomena.
The planned 2026 termination of NASA’s Aura mission will reduce the community’s capability to understand ozone-related chemistry and transport. The Canadian Atmospheric Chemistry Experiment–Fourier Transform Spectrometer (ACE–FTS) instrument (launched in 2002), NASA’s Stratospheric Aerosol and Gas Experiment (SAGE III), and ESA’s upcoming Atmospheric Limb Tracker for Investigation of the Upcoming Stratosphere (ALTIUS) – expected launch in 2026 – can partially address gaps in stratospheric measurements of some trace gases and reactive species, although with limited spatial and temporal resolution. While ozone observations will continue with the Ozone Mapping and Profiler Suites (OMPS) on the Suomi-NPP, NOAA-20, and -21, OMPS only samples the sunlit portion of the Earth, leaving gaps during polar nights. These data will increase reliance on limited ground-based, airborne, and balloon-borne observations.
First results from the NASA’s new TEMPO geostationary instrument were demonstrated at the Symposium. TEMPO was launched in April 2023 and provides hourly observations of ozone and other trace gases, such as NO2, SO2, and formaldehyde, over North America with unprecedented spatial resolution [about 2 x 4.75 km (1.24 x 3 mi)].
The consistency of ozonesonde measurements has improved due to the adoption of best operational practices and updates to calibration functions from the Assessment of Standard Operating Procedures for OzoneSondes. An ozonesonde was launched as a demonstration on July 15 for attendees during the symposium – see Photo 3.
The implementation of new ozone absorption cross-sections, along with the switch to climatological temperatures for processing data from Brewer and Dobson instruments, has significantly reduced observed seasonal biases against satellite measurements at some stations, from 3–4% to less than 2%.
Presentations at the symposium also described the Small Mobile Ozone Lidar instrument (SMOL-X), a new, compact, affordable, and automated ozone lidar system, the design of which is based upon the SMOL but with extended capability for stratospheric ozone monitoring – see Photo 3. SMOL-X can measure vertical profiles of ozone and temperature throughout the upper troposphere and lower stratosphere, up to the mid stratosphere [about 4–40 km (2–25 mi)], with a precision better than 10% and a time resolution of a few hours. The 299/316 nm wavelength pair used by SMOL-X is better suited for measurements in the upper troposphere and lower stratosphere than the traditional, more absorbing 289/299 nm pair used by SMOL for tropospheric ozone. Unlike the traditional stratospheric ozone lidars, which are nighttime-only instruments, SMOL-X can make observations during twilight conditions down to a solar zenith angle of 88° – extending its measurement capacity to polar latitudes through early austral spring (up to mid-October, which is a crucial period for seasonal ozone depletion in Antarctica). The SMOL-X system will be deployed at the Antarctic Arrival Heights station in late 2025 or early 2026. The automated lidar measurements can potentially enhance coverage of ground-based ozone observations in the Southern Hemisphere and tropics.
Effect of Atmospheric Ozone and UV on Environmental and Human Health
Presenters in this session discussed the variability in surface UV levels due to ozone, aerosols, and clouds, and the dual nature of UV exposure – i.e., it has both harmful (e.g., cancer risk) and beneficial (e.g., vitamin D production) aspects. For example, the Antarctic ozone holes in recent years have lasted longer than average, which allows increased UV radiation to reach the surface during marine animal breeding seasons in mid- to late-austral spring; however, the Montreal Protocol is estimated to have prevented over 40 million cases of human skin cancer and countless cases of cataracts through its protection of the ozone layer and overall reduction of surface UV levels.
Other presenters focused on the effects of tropospheric ozone uptake by plant stomata, stressing the importance of understanding ozone’s role in air quality and crop productivity – see Figure 8. In the U.S. alone, economic damages from reduced crop productivity due to ozone pollution reach billions of dollars per year. Recent and future measurement campaigns will require more measurements of ozone uptake by vegetation to determine how policies aimed at improving air quality and ozone pollution are affecting crop yields.
Preparing for the 2026 Ozone Assessment
Presenters at the symposium covered topics that will be included in the upcoming 2026 UNEP/WMO Ozone Scientific Assessment and Panel (SAP). During the IO3C meeting, the new SAP co chairs – Lucy Carpenter [University of York, U.K.] and Ken Jucks [NASA’s Upper Atmosphere Research Program] – were announced. Carpenter and Jucks will replace Paul Newman and John Pyle [University of Cambridge, U.K.].
Published every four years, the Ozone Assessments aim to provide information on the state of the ozone layer and ozone depleting substances in an accessible and concise way for policy makers and the general public. The 2026 Ozone Assessment will include discussion of the potential risks posed by stratospheric aerosol injection as a climate intervention and the importance of early identification of substances that can be a cause of concern for ozone chemistry, both of which were topics of discussion at the 2024 QOS. The deliberations at the 2024 QOS will influence the development of the 2026 Ozone Assessment.
Conclusion.
The 2024 QOS in Boulder, CO, offered an excellent opportunity for scientists, technicians, and engineers involved in various aspects of ozone studies to come together and exchange their findings and ideas. This event marked the first in-person symposium in eight years, following the 2016 QOS held in Edinburgh, UK. The previous event, hosted in 2021 in Seoul, South Korea, was held virtually due to the COVID-19 pandemic.
The symposium provided a valuable venue to reconnect with long-time colleagues and collaborators while also welcoming new members of the community. The ozone research community comprises specialists with diverse expertise, including:
- instrument scientists and engineers developing the next-generation ozone measurement sensors;
- chemists conducting laboratory research;
- technicians operating ozone instruments, often in extreme environments, such as Arctic and Antarctic stations;
- modelers simulating ozone distribution under various conditions;
- data analysts processing and interpreting measurement results; and
- experts summarizing research findings and communicating them to policymakers.
The symposium serves as a unique platform to foster collaboration among these groups, united by a shared mission: protecting Earth’s ozone layer. This year’s meeting was highly productive, and we look forward to the announcement of the next symposium’s location, planned for 2028. Stay tuned.
Natalya A. Kramarova
NASA’s Goddard Space Flight Center
natalya.a.kramarova@nasa.gov
Ryan M. Stauffer
NASA’s Goddard Space Flight Center
ryan.m.stauffer@nasa.gov