Atmospheres Research Articles

A New Regional Background Atmospheric Station in the Yangtze River Delta Region for Carbon Monoxide: Assessment of Spatiotemporal Characteristics and Regional Significance

A new meteorological station (DMS) was established at the Morning Glory summit in Zhejiang Province to provide regional background information on atmospheric composition in the Yangtze River Delta (YRD) region, China. This study investigated the first carbon monoxide (CO) records at DMS from September 2020 to January 2022. The annual average concentration of CO was 233.4 ± 3.8 ppb, which exceeded the measurements recorded at the other Asian background sites. The winter CO concentration remained elevated but peaked in March in the early spring due to the combined effect of regional emissions within the YRD and transportation impacts of North China and Southeast Asia sources. The diurnal cycle had a nocturnal peak and a morning valley but with a distinct afternoon climb, as the metropolis in the YRD contributed to a local concentration enhancement. The back trajectory analysis and the Weighted Potential Sources Contribution Function (WPSCF) maps highlighted emissions from Anhui, Jiangxi, Zhejiang, and Jiangsu provinces as significant sources. Due to well-mixed air conditions and fewer anthropogenic influences, DMS records closely aligned with the CO averages derived from the Copernicus Atmospheric Monitoring Service (CAMS) covering the YRD, confirming its representativeness for regional CO levels. This study underscored DMS as a valuable station for monitoring and understanding CO spatiotemporal characteristics in the YRD region.

Increased Surface Temperatures of Habitable White Dwarf Worlds Relative to Main-sequence Exoplanets

Abstract Discoveries of giant planet candidates orbiting white dwarf (WD) stars and the demonstrated capabilities of the James Webb Space Telescope bring the possibility of detecting rocky planets in the habitable zones (HZs) of WDs into pertinent focus. We present simulations of an aqua planet with an Earth-like atmospheric composition and incident stellar insolation orbiting in the HZ of two different types of stars—a 5000 K WD and main-sequence K-dwarf star Kepler-62 (K62) with a similar effective temperature—and identify the mechanisms responsible for the two differing planetary climates. The synchronously rotating WD planet's global mean surface temperature is 25 K higher than that of the synchronously rotating planet orbiting K62, due to its much faster (10 hr) rotation and orbital period. This ultrafast rotation generates strong zonal winds and meridional flux of zonal momentum, stretching out and homogenizing the scale of atmospheric circulation, and preventing an equivalent buildup of thick, liquid water clouds on the dayside of the planet compared to the synchronous planet orbiting K62, while also transporting heat equatorward from higher latitudes. White dwarfs may therefore present amenable environments for life on planets formed within or migrated to their HZs, generating warmer surface environments than those of planets with main-sequence hosts to compensate for an ever shrinking incident stellar flux.

Challenges and opportunities offered by geostationary space observations for air quality research and emission monitoring

Abstract Space-borne remote sensing of atmospheric chemical constituents is crucial for monitoring and better understanding global and regional air quality. Since the 1990s, the continuous development of instruments onboard low-Earth orbit (LEO) satellites has led to major advances in air quality research by providing daily global measurements of atmospheric chemical species. The next generation of atmospheric composition satellites measures from the geostationary Earth orbit (GEO) with hourly temporal resolution, allowing the observation of diurnal variations of air pollutants. The first two instruments of the GEO constellation coordinated by the Committee on Earth Observation Satellites (CEOS), the Geostationary Environment Monitoring Spectrometer (GEMS) for Asia and the Tropospheric Emissions: Monitoring of Pollution (TEMPO) for North America, were successfully launched in 2020 and 2023, respectively. The European component, Sentinel-4, is planned for launch in 2025. This work provides an overview of satellite missions for atmospheric composition monitoring and the state of the science in air quality research. We cover recent advances in retrieval algorithms, the modeling of emissions and atmospheric chemistry, data assimilation, and the application of machine learning based on satellite data. We discuss the challenges and opportunities in air quality research in the era of GEO satellites, and provide recommendations on research priorities for the near future.

Exoplanets in reflected starlight with dual-field interferometry. A case for shorter wavelengths and a fifth Unit Telescope at VLTI/Paranal

The direct observation of cold and temperate planets within 1 to 10 AU would be extremely valuable for uncovering their atmospheric compositions but remains a formidable challenge with current astronomical methods. Ground-based optical interferometry, capable of high angular-resolution imaging, offers a promising avenue for studying these exoplanets. Our objective is to explore the fundamental limits of dual-field interferometry and assess its potential for characterising exoplanets in reflected light using the Very Large Telescope Interferometer (VLTI). We developed analytical expressions to describe the performance of dual-field interferometry and integrated these with simulations of atmospheric wavefronts corrected by extreme adaptive optics. An analytical solution for optimal phase apodization was formulated to enhance starlight rejection when injected into a single-mode fibre. This framework was applied to determine the detectability of known exoplanets in reflected light across various wavelength bands for both the current VLTI and a proposed extended version. Our results indicate that employing shorter wavelengths improves detectability, enabling at least seven Jupiter-mass exoplanets to be observed in the J band with current VLTI's baselines. Adding new baselines with lengths beyond 200 meters significantly enhances VLTI's capabilities, increasing the number of detectable exoplanets and revealing potential habitable zone candidates such as τ Ceti e and Proxima Centauri b. To substantially improve the VLTI's exoplanet characterisation capabilities, we recommend developing instrumentation at wavelengths shorter than 1$,μ$m, and increasing the baselines length by the addition of a fifth Unit Telescope (UT5).

H2 Chemistry and Protonation in the Dayside Venusian Upper Atmosphere

Abstract Although H2 is present in low concentrations, it critically controls the structure and composition of planetary upper atmospheres through protonation under solar extreme-ultraviolet and soft X-ray irradiation. Recent studies highlight the importance of protonation on Venus. As H2 concentrations in its upper atmosphere remain poorly constrained, we conduct a systematic model investigation of how the structure of the topside Venusian ionosphere responds to varying H2 distributions. Our model results suggest that protonated species could outnumber nonprotonated species in the topside ionosphere when ambient H2 concentrations exceed 5 ppm. Generally, increasing H2 concentrations enhances the degree of protonation, manifesting as elevated levels of most protonated species, while nonprotonated species are generally depleted due to rapid reactions with H2. These trends, however, are not universal; nonmonotonic variations among multiple species like OH+ and O 2 + emerge, driven by the complex chemical network that intricately links species distributions throughout the upper atmosphere. The results presented here provide a foundation for improved characterization of hydrogen escape on Venus during its evolutionary history.

Promise and Peril: Stellar Contamination and Strict Limits on the Atmosphere Composition of TRAPPIST-1 c from JWST NIRISS Transmission Spectra

Abstract Attempts to probe the atmospheres of rocky planets around M dwarfs present both promise and peril. While their favorable planet-to-star radius ratios enable searches for even thin secondary atmospheres, their high activity levels and high-energy outputs threaten atmosphere survival. Here we present the 0.6–2.85 μm transmission spectrum of the 1.1 R ⊕, ∼ 340 K rocky planet TRAPPIST-1 c obtained over two JWST NIRISS/SOSS transit observations. Each of the two spectra displays 100–500 ppm signatures of stellar contamination. Despite being separated by 367 days, the retrieved spot and facula properties are consistent between the two visits, resulting in nearly identical transmission spectra. Jointly retrieving for stellar contamination and a planetary atmosphere reveals that our spectrum can rule out hydrogen-dominated, ≲300× solar metallicity atmospheres with effective surface pressures down to 10 mbar at the 3σ level. For high mean molecular weight atmospheres, where O2 or N2 is the background gas, our spectrum disfavors partial pressures of more than ∼10 mbar for H2O, CO, NH3, and CH4 at the 2σ level. Similarly, under the assumption of a 100% H2O, NH3, CO, or CH4 atmosphere, our spectrum disfavors thick, >1-bar atmospheres at the 2σ level. These nondetections of spectral features are in line with predictions that even heavier, CO2-rich atmospheres would be efficiently lost on TRAPPIST-1 c given the cumulative high-energy irradiation experienced by the planet. Our results further stress the importance of robustly accounting for stellar contamination when analyzing JWST observations of exo-Earths around M dwarfs, as well as the need for high-fidelity stellar models to search for the potential signals of thin secondary atmospheres.

Thunderstorms and their Influence on Meteorology and Atmospheric Composition Over Southern Peninsular India

The study examines the long-term (2011-2023) analysis of thunderstorm and lightning activities and their impacts on local meteorology and air pollutants over Bengaluru. The diurnal thunderstorm events occur mainly in the late evening hours (1900–2100 IST) and on monthly maximum in May while minimum in January. Annually, Bengaluru experiences an average of 41 thunderstorms and 157 lightning strikes, both of which have shown a statistically significant upward trend at a 95% confidence level. The rate of increase is 3.41% per year for thunderstorms and 3.3% per year for lightning events. Local temperatures coupled with abundant moisture supply from the southwest/northeast monsoon creates a favourable condition for the initiation of thunderstorms over the region. This study also focused on the trend analysis of meteorological parameters and atmospheric compositions, a rising trend were found in rainfall (1.44 mm year–1), RH (0.74% year–1) & pressure (0.03 hPa year–1) whereas a slight declining trends in temperature (0.06 0C year-1) & wind speed (-0.02 ms-1 year–1). As the availability of heat and humidity are two main prerequisites for the occurrence of thunderstorm and hence the probability of severe thunderstorms may increase in future. The AOD, NO2 & O3 showed a significant increasing trend while no trend for SO2. The Pearson correlations showed the AOD, NO2 & SO2 concentrations are significant negatively correlated with wind speed but positively correlated with atmospheric pressure. A further study indicated a significant impact of thunderstorm on the air pollutants has also been quantified and it was observed that PM2.5 concentration gradually decreases after the commencement of thunderstorm while quick increase response (less than 1 hour) was observed in O3 and delay response (after 2:30 hours) in NO2 which may linked to lightning activities. The results reveal that thunderstorms can affect both the local meteorology as well as atmospheric pollutants and vice-versa from regional to global.

Non-Stoichiometric BaxMn0.7Cu0.3O3 Perovskites as Catalysts for CO Oxidation: Optimizing the Ba Content

In this work, a series of BaxMn0.7Cu0.3O3 samples (x: 1, 0.9, 0.8, and 0.7, BxMC) was synthesized, characterized, and used as catalysts for CO oxidation reaction. All formulations were active for CO oxidation in the tested conditions. A correlation between the electrical conductivity, obtained by impedance spectroscopy, and the reducibility of the samples, obtained by H2-TPR, was observed. The Ba0.8Mn0.7Cu0.3O3 composition (B0.8MC) showed the best catalytic performance (comparable to that of the 1% Pt/Al2O3 reference sample) during tests conducted under conditions similar to those found in the exhaust gases of current gasoline engines. The characterization data suggest the simultaneous presence of a high Mn(IV)/Mn(III) surface ratio, oxygen vacancies, and reduced copper species, these two latter being key properties for ensuring a high CO conversion percentage as both are active sites for CO oxidation. The reaction temperature and the reactant atmosphere composition seem to be the most important factors for achieving a good catalytic performance, as they strongly determine the location and stability of the reduced copper species.

The Role of Atmospheric Composition in Defining the Habitable Zone Limits and Supporting E. coli Growth

The Role of Atmospheric Composition in Defining the Habitable Zone Limits and Supporting E. coli Growth

To what extent is the description of streets important in estimating local air quality: a case study over Paris

Abstract. Modeling atmospheric composition at street level is challenging because pollutant concentrations within street canyons depend on both local emissions and the transport of polluted air masses from remote areas. Therefore, regional-scale modeling and local applications must be combined to provide accurate simulations of the atmospheric composition at street locations. In our study, we compare two strategies: (i) a subgrid-scale approach embedded in the chemistry–transport model (denoted Subgrid) and (ii) the street-network model MUNICH (Model of Urban Network of Intersecting Canyons and Highways). In both cases, the regional-scale chemistry–transport model CHIMERE provides the urban background concentrations, and the meteorological model Weather Research and Forecasting (WRF), coupled with CHIMERE, is used to provide meteorological fields. Simulation results for NOx, NO2, and PM2.5 concentrations over the city of Paris from both modeling approaches are compared with in situ measurements from traffic air quality stations. At stations located in downtown areas, with low traffic emissions, the street-network model MUNICH exhibits superior performance compared to the Subgrid approach for NOx concentrations, while comparable results are obtained for NO2. However, significant discrepancies between the two methods are observed for all analyzed pollutants at stations heavily influenced by road traffic. These stations are typically located near highways, where the difference between the two approaches can reach 58 %. The ability of the Subgrid approach to estimate accurate emission data is limited, leading to potential underestimation or overestimation of gas and fine-particle concentrations based on the emission heterogeneity it handles. The performance of MUNICH appears to be highly sensitive to the friction velocity, a parameter influenced by the anthropogenic heat flux used in the WRF model. Street dimensions do contribute to the performance disparities observed between the two approaches, yet emissions remain the predominant factor.

Ionospheric Conductances at the Giant Planets of the Solar System: A Comparative Study of Ionization Sources and the Impact of Meteoric Ions

AbstractThe dynamics of giant planet magnetospheres is controlled by a complex interplay between their fast rotation, their interaction with the solar wind, and their diverse internal plasma and momentum sources. In the ionosphere, the Hall and Pedersen conductances are two key parameters that regulate the intensity of currents coupling the magnetosphere and the ionosphere, and the rate of angular momentum transfer and power carried by these currents. We perform a comparative study of Hall and Pedersen conductivities and conductances in the four giant planets of our Solar System ‐ Jupiter, Saturn, Uranus and Neptune. We use a generic ionospheric model (restraining the studied ions to , , and meteoric ions) to study the dependence of conductances on the structure and composition of these planets' upper atmospheres and on the main ionization sources (photoionization, ionization by precipitating electrons, and meteoroid ablation). After checking that our model reproduces the conclusions of Nakamura et al. (2022), https://doi.org/10.1029/2022ja030312 at Jupiter, that is, the contribution of meteoric ions to the height‐integrated conductances is non‐negligible, we show that this contribution could also be non‐negligible at Saturn, Uranus and Neptune, compared with ionization processes caused by precipitating electrons of energies lower than a few keV (typical energies on these planets). However, because of their weaker magnetic field, the conductive layer of these planets is higher than the layer where meteoric ions are mainly produced, limiting their role in magnetosphere‐ionosphere coupling.

Comparison of long-term trends and interannual variations of the NO₂ content in the atmosphere according to satellite (OMI) and ground-based spectrometric measurements at NDACC stations

Results of analysis of long-term trends and interannual variations of the NO₂ content in the atmosphere according to measurements with the Ozone Monitoring Instrument (OMI) aboard the EOS-Aura satellite in 2004–2020 are compared to the results of a similar analysis of the NO₂ content derived from independent spectrometric twilight NO₂ measurements by zenith-scattered solar radiation at stations of the Network for the Detection of Atmospheric Composition Change (NDACC)). According to both the data, seasonally dependent estimates of linear NO₂ trends and variations of the NO₂ content under the influence of the 11-year cycle of solar activity and large-scale circulation factors such as the Arctic and Antarctic Oscillations, variations in ocean surface temperature in the Niño 3.4 zone, and the quasi-biennial oscillation in zonal wind in the equatorial stratosphere have been obtained. In general, a good qualitative and, in some cases, quantitative correspondence between estimates of interannual variations of NO₂ has been obtained. For interannual variations of stratospheric NO₂, not a bad correspondence between estimates based on satellite and ground-based data has been obtained on average for all stations, but the correspondence between trend estimates is noticeably worse. The best correspondence between the analysis results has been obtained for Zvenigorod station. For stratospheric NO₂, it was noted in 80–90% of cases, and the correspondence for tropospheric NO₂ is practically 100%.

Volatile-rich Sub-Neptunes as Hydrothermal Worlds: The Case of K2-18 b

Abstract Temperate exoplanets between the sizes of Earth and Neptune, known as “sub-Neptunes,” have emerged as intriguing targets for astrobiology. It is unknown whether these planets resemble Earth-like terrestrial worlds with a habitable surface, Neptune-like giant planets with deep atmospheres and no habitable surface, or something exotic in between. Recent JWST transmission spectroscopy observations of the canonical sub-Neptune, K2-18 b, revealed ~1% CH4, ~1% CO2, and a nondetection of CO in the atmosphere. While previous studies proposed that the observed atmospheric composition could help constrain the lower atmosphere's conditions and determine the interior structure of sub-Neptunes like K2-18 b, the possible interactions between the atmosphere and a hot, supercritical water ocean at its base remain unexplored. In this work, we investigate whether a global supercritical water ocean, resembling a planetary-scale hydrothermal system, can explain these observations on K2-18 b–like sub-Neptunes through equilibrium aqueous geochemical calculations. We find that the observed atmospheric CH4/CO2 ratio implies a minimum ocean temperature of ~710 K, whereas the corresponding CO/CO2 ratio allows ocean temperatures up to ~1070 K. These results indicate that a global supercritical water ocean on K2-18 b is plausible. While life cannot survive in such an ocean, this work represents the first step toward understanding how a global supercritical water ocean may influence observable atmospheric characteristics on volatile-rich sub-Neptunes. Future observations with better-constrained CO and NH3 mixing ratios could further help distinguish between possible interior compositions of K2-18 b.

Climate change and its impact on children and adolescents sleep.

This review discusses the impact of climate change on sleep, anxiety, and eating in the pediatric population. This is a nonsystematic literature review based on a search using PubMed and MeSH terms in titles and abstracts with these keywords: climate change, sleep, greenhouse effect, children, and adolescents. Climate change events are associated with human intervention in the ecosystem, having a strong impact on cognitive functions, physical and mental health, as well as subjective well-being, particularly in youth. Climate change is caused by human activity with changes in the composition of the global atmosphere caused by emissions of gases, such as carbon dioxide, which increase the greenhouse effect. This review discusses the impact of climate change on sleep, anxiety, and feeding in the pediatric population. Early detection of vulnerability conditions, along with adaptation strategies is necessary to address climate stressors with a focus on healthy sleep and eco-anxiety. Pediatrics has an important role to play in protecting healthy sleep in children.

The HUSTLE Program: The UV to Near-infrared HST WFC3/UVIS G280 Transmission Spectrum of WASP-127b

Ultraviolet wavelengths offer unique insights into aerosols in exoplanetary atmospheres. However, only a handful of exoplanets have been observed in the ultraviolet to date. Here, we present the ultraviolet-visible transmission spectrum of the inflated hot Jupiter WASP-127b. We observed one transit of WASP-127b with WFC3/UVIS G280 as part of the Hubble Ultraviolet-optical Survey of Transiting Legacy Exoplanets, obtaining a transmission spectrum from 200 to 800 nm. Our reductions yielded a broadband transit depth precision of 91 ppm and a median precision of 240 ppm across 59 spectral channels. Our observations are suggestive of a high-altitude cloud layer with forward modeling showing they are composed of submicron particles and retrievals indicating a high-opacity patchy cloud. While our UVIS/G280 data only offer weak evidence for Na, adding archival Hubble Space Telescope (HST) WFC3/IR and STIS observations raises the overall Na detection significance to 4.1σ. Our work demonstrates the capabilities of HST WFC3/UVIS G280 observations to probe the aerosols and atmospheric composition of transiting hot Jupiters with comparable precision to HST STIS.

Impacts of Climate Change on Health: A Current Assessment

Climate change refers to an accelerated change in climate that is directly or indirectly attributed to human activities, altering the composition of the global atmosphere and occurring in addition to the natural climate variability observed over comparable periods. This change is one of the most critical global challenges of the 21st century, creating impacts in many environmental, social and economic dimensions. Its impacts on human health seem to be much more significant and devastating. However, despite this, studies on its direct and indirect impacts on human health are relatively few. In this review, In the scientific literature, emphasis has been placed on publications examining the different health effects that climate change may cause on human health. The data obtained within this scope was searched on databases between June and July 2024 and was eliminated and synthesized according to the current literature. Through electronic databases, local and foreign theses, reports of national and international studies, articles, and gray literature were evaluated. The subject was examined under 6 main headings: ‘the effects of extreme hot and cold weather events on health’, ‘the effects of ultraviolet radiation’, ‘the effects of changes in air quality’, ‘the effects of food and water-related health problems’, ‘health problems associated with vectors’ and ‘mental problems’. To better understand the effects on health and to evaluate them as a whole, 45 of the literature reached as a result of the systematic literature review was included in the review prepared within the scope of the study.

Advective Transport Between the Stratosphere and Mesosphere

AbstractThe Brewer‐Dobson circulation (BDC) characterizes the large‐scale meridional overturning mass circulation influencing the composition of the whole middle atmosphere. The BDC consists of two separate parts—a shallow branch in the lower stratosphere and a deep branch higher in the middle atmosphere. Climate models robustly project the advective BDC part to accelerate due to greenhouse gas‐induced climate change and this acceleration strongly influences middle atmospheric chemistry and physics in the projections. A prominent quantity that is being studied as a proxy for advective BDC changes is the net tropical upwelling across pressure levels, particularly in the lower stratosphere. The upper branch of the BDC has received considerably less research attention than its shallow part, although, together with the mean mesospheric pole‐to‐pole circulation, it couples the stratosphere and mesosphere and is responsible for a large portion of the interhemispheric transport in the middle atmosphere. Aiming to fill this gap, we here study climatology and trends in advective mass transport across the stratopause. Results based on the analysis of seven CCMI models include quantification of the climatological cross‐stratopause advective transport, characterization of its interannual variability and long‐term trend as well as detailed analysis of inter‐model differences using a novel decomposition methodology. Our results demonstrate that the changes in circulation speed as well as changes in horizontal and vertical structure in the upper stratosphere and mesosphere jointly shape the projected increasing advective mass flux across the stratopause due to increasing greenhouse‐gas emissions.

Land plants, sediment composition, granitic magma compositions and environments of formation

Earth’s biosphere and lithosphere continually interact, and life’s metabolic processes influence atmospheric composition, the weathering of rocks and how rivers deliver sediments to ocean and intracontinental basins. Recently, other authors noted a correlation between the oxygen isotopic compositions and crustal residencies of arc magmatic rocks. This correlation appeared at about 430 Ma and is attributed to the rise of deep-rooted land plants, which increased clay-mineral production and input to ocean basins, by slowing sediment transfer across continents, stabilising soils, and thereby enhancing weathering time and promoting clay formation. Granites, which form much of the continental crust, contain components derived through partial melting of sediments that can have varying chemical maturity, and the major-element chemical features and isotopic compositions of the granites reflects this. In a global dataset of granite compositions, dating from 500 Ma, major-element markers that reflect original source clay content do not reveal the stepwise increase in sediment clay content inferred for the sources of arc magmas at 430 Ma, and only increase consistently from approximately 200 Ma. This demonstrates that although granite compositions reflect the plant influence, they are not principally formed through subduction processes in magmatic arcs but rather in back-arc environments, and do not receive the immediate transcontinental sediment input that characterises ocean basins. The lag in the granite response occurs because there is commonly a substantial time gap between arc magmatism and granite genesis. This is because a subsequent orogeny is generally required to partially melt older back-arc rocks, including sediments, to produce granitic magmas.

European Soil NOx Emissions Derived From Satellite NO2 Observations

AbstractWe introduce an innovative method to distinguish soil nitrogen oxides (NOx = NO + NO2) emissions from satellite‐based total NOx emissions. To evaluate the approach, we compare the deviation between the tropospheric NO2 concentration observed by satellite and two atmospheric composition model simulations driven by the newly estimated soil NOx emissions and the Copernicus Atmosphere Monitoring Service (CAMS) inventory. The estimated average soil NOx emissions in Europe are 1.7 kg N ha−1 yr−1 in 2019, and the annual soil NOx emissions are approximately 1.7 times larger than that of the CAMS inventory. The discrepancy originates mainly from the forests, which would mean that the soil NOx emissions over forest areas in Europe are currently underestimated by the CAMS inventory. The model evaluation indicates that the simulations driven by DECSO‐soil emissions performed significantly better than using CAMS‐soil. Overall, the simulated RMSE% of DECSO‐soil is lower than that of CAMS‐soil, approximately 6% lower in spring and 2% lower in autumn. Our method can easily be extended to other regions in the world despite having monthly variations that are very different from those in Europe.

CRIRES+ and ESPRESSO Reveal an Atmosphere Enriched in Volatiles Relative to Refractories on the Ultrahot Jupiter WASP-121b

One of the outstanding goals of the planetary science community is to measure the present-day atmospheric composition of planets and link this back to formation. As giant planets are formed by accreting gas, ices, and rocks, constraining the relative amounts of these components is critical to understand their formation and evolution. For most known planets, including the solar system giants, this is difficult as they reside in a temperature regime where only volatile elements (e.g., C, O) can be measured, while refractories (e.g., Fe, Ni) are condensed to deep layers of the atmosphere where they cannot be remotely probed. With temperatures allowing for even rock-forming elements to be in the gas phase, ultrahot Jupiter atmospheres provide a unique opportunity to simultaneously probe the volatile and refractory content of giant planets. Here, we directly measure and obtain bounded constraints on the abundances of volatile C and O as well as refractory Fe and Ni on the ultrahot giant exoplanet WASP-121b. We find that ice-forming elements are comparatively enriched relative to rock-forming elements, potentially indicating that WASP-121b formed in a volatile-rich environment much farther away from the star than where it is currently located. The simultaneous constraint of ice and rock elements in the atmosphere of WASP-121b provides insights into the composition of giant planets otherwise unattainable from solar system observations.