Ozone layer ≈ Ozone layer
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UKESM1: Description and Evaluation of the U.K. Earth System Model Open
We document the development of the first version of the U.K. Earth System Model UKESM1. The model represents a major advance on its predecessor HadGEM2‐ES, with enhancements to all component models and new feedback mechanisms. These includ…
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Emergence of healing in the Antarctic ozone layer Open
Turning the corner The Antarctic ozone hole is finally showing signs of disappearing, nearly 30 years after the Montreal Protocol came into effect. The Montreal Protocol, an international treaty that phased out the production of many of th…
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The Chemistry Mechanism in the Community Earth System Model Version 2 (CESM2) Open
The Community Earth System Model version 2 (CESM2) includes a detailed representation of chemistry throughout the atmosphere in the Community Atmosphere Model with chemistry and Whole Atmosphere Community Climate Model configurations. Thes…
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Evidence for a continuous decline in lower stratospheric ozone offsetting ozone layer recovery Open
Ozone forms in the Earth's atmosphere from the photodissociation of molecular oxygen, primarily in the tropical stratosphere. It is then transported to the extratropics by the Brewer–Dobson circulation (BDC), forming a protective ozone lay…
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History of chemically and radiatively important atmospheric gases from the Advanced Global Atmospheric Gases Experiment (AGAGE) Open
We present the organization, instrumentation, datasets, data interpretation, modeling, and accomplishments of the multinational global atmospheric measurement program AGAGE (Advanced Global Atmospheric Gases Experiment). AGAGE is distingui…
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Description and evaluation of the UKCA stratosphere–troposphere chemistry scheme (StratTrop vn 1.0) implemented in UKESM1 Open
Here we present a description of the UKCA StratTrop chemical mechanism, which is used in the UKESM1 Earth system model for CMIP6. The StratTrop chemical mechanism is a merger of previously well-evaluated tropospheric and stratospheric mech…
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Tropospheric ozone in CMIP6 simulations Open
The evolution of tropospheric ozone from 1850 to 2100 has been studied using data from Phase 6 of the Coupled Model Intercomparison Project (CMIP6). We evaluate long-term changes using coupled atmosphere–ocean chemistry–climate models, foc…
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Radiative and Chemical Response to Interactive Stratospheric Sulfate Aerosols in Fully Coupled CESM1(WACCM) Open
We present new insights into the evolution and interactions of stratospheric aerosol using an updated version of the Whole Atmosphere Community Climate Model (WACCM). Improved horizontal resolution, dynamics, and chemistry now produce an i…
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Nitrous oxide emissions are enhanced in a warmer and wetter world Open
Significance N 2 O has 300 times the global warming potential of CO 2 on a 100-y timescale, and is of major importance for stratospheric ozone depletion. The climate sensitivity of N 2 O emissions is poorly known, which makes it difficult …
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Evaluation of the Ozone Fields in NASA’s MERRA-2 Reanalysis Open
The assimilated ozone product from the Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2), produced at NASA’s Global Modeling and Assimilation Office (GMAO) spanning the time period from 1980 to the presen…
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Record‐Low Arctic Stratospheric Ozone in 2020: MLS Observations of Chemical Processes and Comparisons With Previous Extreme Winters Open
Aura Microwave Limb Sounder (MLS) measurements show that chemical processing was critical to the observed record‐low Arctic stratospheric ozone in spring 2020. The 16‐year MLS record indicates more polar denitrification and dehydration in …
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Representation of the Community Earth System Model (CESM1) CAM4-chem within the Chemistry-Climate Model Initiative (CCMI) Open
The Community Earth System Model (CESM1) CAM4-chem has been used to perform the Chemistry Climate Model Initiative (CCMI) reference and sensitivity simulations. In this model, the Community Atmospheric Model version 4 (CAM4) is fully coupl…
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Trends in global tropospheric ozone inferred from a composite record of TOMS/OMI/MLS/OMPS satellite measurements and the MERRA-2 GMI simulation Open
Past studies have suggested that ozone in the troposphere has increased globally throughout much of the 20th century due to increases in anthropogenic emissions and transport. We show, by combining satellite measurements with a chemical tr…
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The Stratospheric Water and Ozone Satellite Homogenized (SWOOSH) database:a long-term database for climate studies Open
In this paper, we describe the construction of the Stratospheric Water and Ozone Satellite Homogenized (SWOOSH) database, which includes vertically resolved ozone and water vapor data from a subset of the limb profiling satellite instrumen…
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Total ozone trends from 1979 to 2016 derived from five merged observational datasets – the emergence into ozone recovery Open
We report on updated trends using different merged datasets from satellite and ground-based observations for the period from 1979 to 2016. Trends were determined by applying a multiple linear regression (MLR) to annual mean zonal mean data…
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On the Cause of Recent Variations in Lower Stratospheric Ozone Open
We use height‐resolved and total column satellite observations and 3‐D chemical transport model simulations to study stratospheric ozone variations during 1998–2017 as ozone‐depleting substances decline. In 2017 extrapolar lower stratosphe…
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Environmental effects of stratospheric ozone depletion, UV radiation, and interactions with climate change: UNEP Environmental Effects Assessment Panel, Update 2020 Open
This assessment by the Environmental Effects Assessment Panel (EEAP) of the United Nations Environment Programme (UNEP) provides the latest scientific update since our most recent comprehensive assessment (Photochemical and Photobiological…
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An update on ozone profile trends for the period 2000 to 2016 Open
Ozone profile trends over the period 2000 to 2016 from several merged satellite ozone data sets and from ground-based data measured by four techniques at stations of the Network for the Detection of Atmospheric Composition Change indicate …
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Estimates of ozone return dates from Chemistry-Climate Model Initiative simulations Open
>We analyse simulations performed for the Chemistry-Climate Model Initiative (CCMI) to estimate the return dates of the stratospheric ozone layer from depletion caused by anthropogenic stratospheric chlorine and bromine. We consider a tota…
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Near‐Complete Local Reduction of Arctic Stratospheric Ozone by Severe Chemical Loss in Spring 2020 Open
In the Antarctic ozone hole, ozone mixing ratios have been decreasing to extremely low values of 0.01–0.1 ppm in nearly all spring seasons since the late 1980s, corresponding to 95–99% local chemical loss. In contrast, Arctic ozone loss ha…
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Ground-based assessment of the bias and long-term stability of 14 limb and occultation ozone profile data records Open
The ozone profile records of a large number of limb and occultation satellite instruments are widely used to address several key questions in ozone research. Further progress in some domains depends on a more detailed understanding of thes…
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Stratospheric solar geoengineering without ozone loss Open
Significance The combination of emissions cuts and solar geoengineering could reduce climate risks in ways that cannot be achieved by emissions cuts alone: It could keep Earth under the 1.5-degree mark agreed at Paris, and it might stop se…
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The major stratospheric final warming in 2016: dispersal of vortex air and termination of Arctic chemical ozone loss Open
The 2015/16 Northern Hemisphere winter stratosphere appeared to have the greatest potential yet seen for record Arctic ozone loss. Temperatures in the Arctic lower stratosphere were at record lows from December 2015 through early February …
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Update on Ozone-Depleting Substances (ODSs) and Other Gases of Interest to the Montreal Protocol Open
This chapter concerns atmospheric changes in ozone-depleting substances (ODSs), such as chlorofluorocarbons (CFCs), halons, chlorinated solvents (e.g., CCl 4 and CH 3 CCl 3 ) and hydrochlorofluorocarbons (HCFCs), which are controlled under…
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COVID‐19 Crisis Reduces Free Tropospheric Ozone Across the Northern Hemisphere Open
Throughout spring and summer 2020, ozone stations in the northern extratropics recorded unusually low ozone in the free troposphere. From April to August, and from 1 to 8 kilometers altitude, ozone was on average 7% (≈4 nmol/mol) below the…
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Effective radiative forcing from emissions of reactive gases and aerosols – a multi-model comparison Open
This paper quantifies the pre-industrial (1850) to present-day (2014) effective radiative forcing (ERF) of anthropogenic emissions of NOX, volatile organic compounds (VOCs; including CO), SO2, NH3, black carbon, organic carbon, and concent…
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Recent Tropical Expansion: Natural Variability or Forced Response? Open
Previous studies have documented a poleward shift in the subsiding branches of Earth’s Hadley circulation since 1979 but have disagreed on the causes of these observed changes and the ability of global climate models to capture them. This …
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Evaluating stratospheric ozone and water vapour changes in CMIP6 models from 1850 to 2100 Open
Stratospheric ozone and water vapour are key components of the Earth system, and past and future changes to both have important impacts on global and regional climate. Here, we evaluate long-term changes in these species from the pre-indus…
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On the composite response of the MLT to major sudden stratospheric warming events with elevated stratopause Open
Based on a climate‐chemistry model (constrained by reanalyses below ~50 km), the zonal‐mean composite response of the mesosphere and lower thermosphere (MLT) to major sudden stratospheric warming events with elevated stratopauses demonstra…
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First Reprocessing of Southern Hemisphere Additional Ozonesondes (SHADOZ) Ozone Profiles (1998–2016): 2. Comparisons With Satellites and Ground‐Based Instruments Open
The Southern Hemisphere ADditional OZonesonde (SHADOZ) network was assembled to validate a new generation of ozone‐monitoring satellites and to better characterize the vertical structure of tropical ozone in the troposphere and stratospher…