Wildfire smoke destroys stratospheric ozone

Science, Год журнала: 2022, Номер 375(6586), С. 1292 - 1295

Опубликована: Март 17, 2022

Large wildfires inject smoke and biomass-burning products into the mid-latitude stratosphere, where they destroy ozone, which protects us from ultraviolet radiation. The infrared spectrometer on Atmospheric Chemistry Experiment satellite measured spectra of particles "Black Summer" fires in Australia late 2019 early 2020, revealing that contain oxygenated organic functional groups water adsorption surfaces. These injected have produced unexpected extreme perturbations stratospheric gases beyond any seen previous 15 years measurements, including increases formaldehyde, chlorine nitrate, monoxide, hypochlorous acid decreases nitrogen dioxide, hydrochloric acid. composition potential to affect ozone chemistry ways.

Язык: Английский

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Chlorine activation and enhanced ozone depletion induced by wildfire aerosol

Nature, Год журнала: 2023, Номер 615(7951), С. 259 - 264

Опубликована: Март 8, 2023

Язык: Английский

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Stratospheric ozone, UV radiation, and climate interactions

Photochemical & Photobiological Sciences, Год журнала: 2023, Номер 22(5), С. 937 - 989

Опубликована: Апрель 21, 2023

This assessment provides a comprehensive update of the effects changes in stratospheric ozone and other factors (aerosols, surface reflectivity, solar activity, climate) on intensity ultraviolet (UV) radiation at Earth's surface. The is performed context Montreal Protocol Substances that Deplete Ozone Layer its Amendments Adjustments. Changes UV low- mid-latitudes (0-60°) during last 25 years have generally been small (e.g., typically less than 4% per decade, increasing some sites decreasing others) were mostly driven by cloud cover atmospheric aerosol content, caused partly climate change measures to control tropospheric pollution. Without Protocol, erythemal (sunburning) irradiance northern southern latitudes 50° would increased 10-20% between 1996 2020. For exceeding 50°, Index (UVI) surged 25% (year-round tip South America) more 100% (South Pole spring). Variability Antarctica was very large four years. In spring 2019, minimum historical (1991-2018) range Pole, while near record-high values observed 2020, which up 80% above mean. Arctic, highest irradiances record measured March April example monthly average UVI over site Canadian Arctic 70% higher (2005-2019) average, often this mean three standard deviations. Under presumption all countries will adhere future concentrations remain constant, (30-60°) projected decrease 2015 2090 2-5% north 4-6% south due recovering ozone. for tropics are ≤ 3%. However, industrial regions currently affected air pollution, increase as reduce pollutants gradually restore intensities those cleaner atmosphere. Since most substances controlled also greenhouse gases, phase-out these may avoided warming 0.5-1.0 °C mid-latitude continents, 1.0 Arctic; however, uncertainty calculations large. We assess climate, focusing poleward shift zones, discuss role Antarctic hole 2019 devastating "Black Summer" fires Australia. Additional topics include advances measuring modeling radiation; methods determining personal exposure; effect management (stratospheric injections) relevant plants; possible revisions vitamin D action spectrum, describes wavelength dependence synthesis previtamin

Язык: Английский

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Interactive effects of changes in UV radiation and climate on terrestrial ecosystems, biogeochemical cycles, and feedbacks to the climate system

Photochemical & Photobiological Sciences, Год журнала: 2023, Номер 22(5), С. 1049 - 1091

Опубликована: Фев. 1, 2023

Terrestrial organisms and ecosystems are being exposed to new rapidly changing combinations of solar UV radiation other environmental factors because ongoing changes in stratospheric ozone climate. In this Quadrennial Assessment, we examine the interactive effects ozone, climate on terrestrial biogeochemical cycles context Montreal Protocol. We specifically assess organisms, agriculture food supply, biodiversity, ecosystem services feedbacks system. Emphasis is placed role extreme events altering exposure potential biodiversity. also address responses plants increased temporal variability radiation, change (e.g. drought, temperature) crops, driving breakdown organic matter from dead plant material (i.e. litter) biocides (pesticides herbicides). Our assessment indicates that interact various ways affect structure function ecosystems, by protecting layer, Protocol continues play a vital maintaining healthy, diverse land sustain life Earth. Furthermore, its Kigali Amendment mitigating some negative consequences limiting emissions greenhouse gases carbon sequestration vegetation pool.

Язык: Английский

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Understanding the critical elements of the pyrocumulonimbus storm sparked by high-intensity wildland fire

Communications Earth & Environment, Год журнала: 2022, Номер 3(1)

Опубликована: Окт. 17, 2022

Abstract High-intensity wildland fires can produce extreme flaming and smoke emissions that develop into a fire-cloud chimney, reaching the upper troposphere or lower stratosphere. Termed pyrocumulonimbus, these storms are both conventional counterintuitive. They have been observed to lightning, hail, downdraft wind hazards, tornadoes as expected with severe convective storms, but counterintuitively, they not associated significant precipitation. Pyrocumulonimbus noticed outside wildfire expert circles following Australia’s Black Summer in 2019/20, since repeatedly made headlines United States. However, much is unknown about their behavior, energetics, history, impact on Earth/atmosphere system. We address several questions science challenges related unknowns. Our worldwide record of pyrocumulonimbus events from 2013 2021 shows phenomenon neither new nor rare. Despite high occurrences 2019 2021, data do support identification trend. Future studies require an expansive occurrence globally regionally, historically continuously forward time.

Язык: Английский

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Radiative impacts of the Australian bushfires 2019–2020 – Part 1: Large-scale radiative forcing

Atmospheric chemistry and physics, Год журнала: 2022, Номер 22(14), С. 9299 - 9311

Опубликована: Июль 20, 2022

Abstract. As a consequence of extreme heat and drought, record-breaking wildfires developed ravaged south-eastern Australia during the fire season 2019–2020. The strength reached its paroxysmal phase at turn year During this phase, pyrocumulonimbus clouds (pyroCb) injected biomass burning aerosols gases into upper troposphere lower stratosphere (UTLS). UTLS aerosol layer was massively perturbed by these fires, with extinction increased factor 3 in visible spectral range Southern Hemisphere, respect to background atmosphere, stratospheric optical depth reaching values as large 0.015 February 2020. Using best available description event observations, we estimate radiative forcing (RF) such perturbations Hemispheric layer. We use offline transfer modelling driven observed information perturbation variability obtained from limb satellite measurements. Based on hypotheses absorptivity angular scattering properties layer, regional (at three latitude bands Hemisphere) clear-sky TOA (top-of-atmosphere) RF is found varying small positive relatively negative (up −2.0 W m−2), surface be consistently −4.5 m−2). argue that are unlikely for event, if ageing/mixing plume mirrored evolution properties. Our area-weighted global-equivalent -0.35±0.21 (TOA RF) -0.94±0.26 m−2 (surface RF), thus strongest documented comparable magnitude volcanic eruptions post-Pinatubo era. surplus surface, TOA, due absorption within has contributed generation ascending smoke vortices stratosphere. Highly reflective underlying surfaces, like clouds, can nevertheless swap RF, global average high +1.0 assuming highly absorbing particles.

Язык: Английский

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Climate Impacts and Potential Drivers of the Unprecedented Antarctic Ozone Holes of 2020 and 2021

Geophysical Research Letters, Год журнала: 2022, Номер 49(10)

Опубликована: Май 21, 2022

Abstract The latter months of 2020 and 2021 were marked by two the largest Antarctic ozone holes on record. That such large occurred despite ongoing recovery raises questions about their origins climate impacts. Here we provide novel evidence that supports hypothesis influenced distinct extraordinary events: Australian wildfires early eruption La Soufriere in 2021. We further reveal both associated with widespread changes Southern Hemisphere are consistent established impacts depletion, including a strengthening polar stratospheric vortex, enhanced surface westerlies over Ocean, temperature Antarctica Australia. results thus suggestive injections wildfire smoke volcanic emissions into stratosphere can lead to hemispheric‐scale climate.

Язык: Английский

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Can southern Australian rainfall decline be explained? A review of possible drivers

Wiley Interdisciplinary Reviews Climate Change, Год журнала: 2023, Номер 14(2)

Опубликована: Янв. 20, 2023

Abstract Southern Australia's rainfall is highly variable and influenced by factors across scales from synoptic weather to large‐scale circulation remote climate modes of variability. Anthropogenic change natural variability modulate these their interactions. However, studies often focus on changes in selected parts the system with less emphasis as a whole. As such, it difficult gain complete understanding how southern responds broad‐scale system. We step through existing literature long‐term synoptic‐to‐large‐scale atmospheric drivers form more story Australia. This process reveals that most robust observed winter decline consistent several changing climatic factors: decreasing systems, strengthening subtropical ridge, poleward shifts Hadley Cell Annular Mode, increasing frequency positive Indian Ocean Dipole events. In other seasons, particularly summer, may not agree changes, highlighting gaps our knowledge dynamics processes. Future work should research temporal‐ spatial‐scales, better jet interactions, influence stratospheric processes troposphere, instances contrasting trends Australian changes. article categorized under: Paleoclimates Current Trends > Modern Climate Change Detection Attribution Assessing Impacts Observed

Язык: Английский

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Rapid ozone depletion after humidification of the stratosphere by the Hunga Tonga Eruption

Science, Год журнала: 2023, Номер 382(6668)

Опубликована: Окт. 19, 2023

The eruption of the Hunga Tonga-Hunga Ha'apai volcano on 15 January 2022 offered a good opportunity to explore early impacts tropical volcanic eruptions stratospheric composition. Balloon-borne observations near Réunion Island revealed unprecedented amount water vapor injected by volcano. enhanced humidity, radiative cooling, and expanded aerosol surface area in plume created ideal conditions for swift ozone depletion 5% stratosphere just 1 week. decrease hydrogen chloride 0.4 parts per million volume (ppbv) increase chlorine monoxide ppbv provided compelling evidence activation within plume. This study enhances our understanding effect this unusual chemistry provides insights into possible changes that may occur changing climate.

Язык: Английский

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Stratospheric Climate Anomalies and Ozone Loss Caused by the Hunga Tonga‐Hunga Ha'apai Volcanic Eruption

Journal of Geophysical Research Atmospheres, Год журнала: 2023, Номер 128(22)

Опубликована: Ноя. 22, 2023

Abstract The Hunga Tonga‐Hunga Ha'apai (HTHH) volcanic eruption in January 2022 injected unprecedented amounts of water vapor (H 2 O) and a moderate amount the aerosol precursor sulfur dioxide (SO ) into Southern Hemisphere (SH) tropical stratosphere. H O perturbations have persisted during early 2023 dispersed throughout atmosphere. Observations show large‐scale SH stratospheric cooling, equatorward shift Antarctic polar vortex slowing Brewer‐Dobson circulation. Satellite observations substantial ozone reductions over winter midlatitudes that coincide with largest circulation anomalies. Chemistry‐climate model simulations forced by realistic HTHH inputs SO qualitatively reproduce observed evolution plumes first year, exhibits changes effects similar to behavior. agreement demonstrates are caused influences.

Язык: Английский

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