Fingerprinting the recovery of Antarctic ozone

Nature, Journal Year: 2025, Volume and Issue: unknown

Published: March 5, 2025

Language: Английский

---

Environmental consequences of interacting effects of changes in stratospheric ozone, ultraviolet radiation, and climate: UNEP Environmental Effects Assessment Panel, Update 2024

Photochemical & Photobiological Sciences, Journal Year: 2025, Volume and Issue: unknown

Published: March 17, 2025

Abstract This Assessment Update by the Environmental Effects Panel (EEAP) of United Nations Environment Programme (UNEP) addresses interacting effects changes in stratospheric ozone, solar ultraviolet (UV) radiation, and climate on environment human health. These include new modelling studies that confirm benefits Montreal Protocol protecting ozone layer its role maintaining a stable climate, both at low high latitudes. We also provide an update projected levels UV-radiation during twenty-first century. Potential environmental consequences intervention scenarios are briefly discussed, illustrating large uncertainties of, for example, Stratospheric Aerosol Injection (SAI). Modelling predict that, although SAI would cool Earth’s surface, other factors be affected, including depletion precipitation patterns. The contribution to global warming replacements ozone-depleting substances (ODS) assessed. With respect breakdown products chemicals under purview Protocol, risks ecosystem health from formation trifluoroacetic acid (TFA) as degradation product ODS currently de minimis . change continue have complex interactive due largely activities. UV-radiation, weathering factors, microbial action contribute significantly plastic waste environment, affecting transport, fate, toxicity plastics terrestrial aquatic ecosystems, atmosphere. Sustainability demands drive industry innovations mitigate use disposal plastic-containing materials. Terrestrial ecosystems alpine polar environments increasingly being exposed enhanced earlier seasonal snow ice melt because extended periods depletion. Solar contributes decomposition dead plant material, which affects nutrient cycling, carbon storage, emission greenhouse gases, soil fertility. In loss cover is increasing area oceans with possible negative phytoplankton productivity. However, Arctic Ocean circulation suggests circulating progressively deeper ocean layers less UV irradiation. Human modified behaviour patterns, resulting exposure harmful or beneficial depending conditions skin type. For incidence melanoma has been associated increased air temperature, time spent outdoors thus UV-radiation. Overall, implementation Amendments mitigated deleterious

Language: Английский

---

The Influence of Stratospheric Hydration From the Hunga Eruption on Chemical Processing in the 2023 Antarctic Vortex

Journal of Geophysical Research Atmospheres, Journal Year: 2024, Volume and Issue: 129(16)

Published: Aug. 20, 2024

Abstract We use measurements of trace gases from the Microwave Limb Sounder and polar stratospheric clouds (PSCs) Cloud‐Aerosol Lidar with Orthogonal Polarization to investigate how extraordinary water vapor enhancement 2022 Hunga eruption affected processing during 2023 Antarctic winter. Although dynamical characteristics vortex itself were generally unexceptional, excess moisture initially raised PSC formation threshold temperatures above typical values. Cold conditions, especially in early July, prompted ice unusually severe irreversible dehydration at higher levels (500–700 K), while atypical hydration occurred lower (380–460 K). Heterogeneous chemical was more extensive, both vertically (up 750–800 K) temporally (earlier season), than prior winters. The resultant HCl depletion ClO redefined their previously observed ranges 600 K. Albeit unmatched satellite record, early‐winter upper‐level chlorine activation insufficient induce substantial ozone loss. Chlorine activation, denitrification, processes ran completion by July/August, gas evolution mostly following climatological mean thereafter, but deactivation starting slightly later usual. While cumulative losses 410–550 K relatively large, probably because delayed deactivation, they not unprecedented. Thus, unremarkable throughout stratosphere. enhanced winter, saturation dehydration, (as is Antarctic) prevented an exceptionally hole 2023.

Language: Английский

---

The Evolution of the Hunga Hydration in a Moistening Stratosphere

Geophysical Research Letters, Journal Year: 2024, Volume and Issue: 51(19)

Published: Sept. 28, 2024

Abstract The 2022 Hunga eruption caused unprecedented stratospheric hydration. Aura Microwave Limb Sounder (MLS) measurements show that the water vapor mass remains essentially unchanged as of early 2024 and hydration occurred atop a robust (possibly accelerating) moistening trend in stratosphere. Enhanced by excess vapor, dehydration via polar cloud sedimentation 2023 Antarctic vortex exceeded climatological values 50%. Simple projections based on modeled exponential decay illustrate timing return to humidity levels would have been expected absent depends ongoing trend. With compounding an underlying trend, stratosphere could remain anomalously humid for extended period.

Language: Английский

---

Large Ozone Hole in 2023 and the Hunga Tonga Volcanic Eruption

Pure and Applied Geophysics, Journal Year: 2024, Volume and Issue: 181(8), P. 2391 - 2402

Published: July 31, 2024

Abstract Polar stratospheric chemistry is highly sensitive to changes in water vapor content and temperature. We identified an unusual behavior of temperature the southern polar winter stratosphere 2023. The relationships between Hunga-Tonga eruption injection (detected tropics) its transport SH high latitudes, ozone anomalies at latitudes are discussed, as well roles zonal wind meridional flux mean momentum. These parameters exhibit a consistent pattern anomalous year In 2023 Southern Hemisphere, unexpected decrease levels emergence excessive hole were observed. This event marked one deepest Antarctic holes with largest area since 2011. appears be associated Hunga Tonga injection. study highlights importance for evolution stratosphere.

Language: Английский

---

In Situ Aerosol Size Spectra Measurements in the Austral Polar Vortex Before and After the Hunga Tonga‐Hunga Ha'apai Volcanic Eruption

Geophysical Research Letters, Journal Year: 2024, Volume and Issue: 51(22)

Published: Nov. 13, 2024

Abstract Aerosol from the Hunga Tonga‐Hunga Ha'apai (HT‐HH) volcanic eruption (20.6°S) in January 2022 were not incorporated into austral polar vortex until following year, March 2023. Within situ profiles of aerosol size spectra completed autumns 2019 and 2023, McMurdo Station, Antarctica (78˚S), 30 months prior to 15 after HT‐HH eruption. The measurements indicate that impact on was primarily confined particles with diameters >0.5 μm leading differences mass, surface area, extinction factors 2–4 at layer's peak below 20 km, increasing ratios 5–10 above km. Effective radius, radiative microphysical implications, increased ∼0.2 ∼0.3 μm. An Earth system model a modal package compares favorably impact.

Language: Английский

---

Fingerprinting the Robust Recovery of Antarctic Ozone

Research Square (Research Square), Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 20, 2024

The Antarctic ozone “hole” was discovered in 1985¹, and its primary cause is man-made ozone-depleting substances (ODS)². Following reductions of ODSs under the Montreal Protocol³, signs recovery have been reported, based largely on observations broad yet compelling model-data comparisons⁴. While such approaches are highly valuable, they do not establish levels overall confidence that account for temporal spatial structure trends as well uncertainties internal climate variability. Here, we rely trend pattern information a function month height to separate anthropogenically forced responses from variability, using pattern-based detection attribution (D&A) methods employed change studies^5–11. The analysis uses satellite together with both single-model multi-model ensemble simulations identify quantify month-height “fingerprint”¹². We demonstrate data show remarkable agreement fingerprint response decreasing ODS forcing since 2005. also has enhanced variability during austral spring, influencing their time emergence. Our results provide robust statistical physical evidence actions taken Protocol reduce indeed resulting recovery.

Language: Английский

---

Contrasting Chlorine Chemistry on Volcanic and Wildfire Aerosols in the Southern Mid‐Latitude Lower Stratosphere

Geophysical Research Letters, Journal Year: 2024, Volume and Issue: 51(18)

Published: Sept. 11, 2024

Abstract Volcanic eruptions and wildfires can impact stratospheric chemistry. We apply tracer‐tracer correlations to satellite data from Atmospheric Chemistry Experiment—Fourier Transform Spectrometer the Halogen Occultation Experiment at 68 hPa consistently compare chemical on HCl after multiple volcanic of different magnitudes. The 2020 Australian New Year (ANY) fire displayed an order magnitude less aerosol extinction than 1991 Pinatubo eruption, but showed similar large changes in mid‐latitude lower stratosphere HCl. While loadings 2015 Calbuco 2022 Hunga were ANY fire, little occurred. 2009 Black Saturday 2021 smoke remaining yield small changes, edge detection method. These observed contrasts across events highlight greater reactivity for versus aerosols warm temperatures.

Language: Английский

---