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Journal ArticleDOI

The Anomalous 2019 Antarctic Ozone Hole in the GEOS Constituent Data Assimilation System With MLS Observations

About: This article is published in Journal of Geophysical Research.The article was published on 2020-09-27. It has received 41 citations till now. The article focuses on the topics: Ozone depletion & Stratosphere.
Citations
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01 Jan 2016
TL;DR: The aeronomy of the middle atmosphere is universally compatible with any devices to read and is available in the digital library an online access to it is set as public so you can get it instantly.
Abstract: Thank you for downloading aeronomy of the middle atmosphere. Maybe you have knowledge that, people have look numerous times for their favorite readings like this aeronomy of the middle atmosphere, but end up in harmful downloads. Rather than reading a good book with a cup of tea in the afternoon, instead they juggled with some malicious virus inside their computer. aeronomy of the middle atmosphere is available in our digital library an online access to it is set as public so you can get it instantly. Our digital library spans in multiple countries, allowing you to get the most less latency time to download any of our books like this one. Kindly say, the aeronomy of the middle atmosphere is universally compatible with any devices to read.

201 citations

Journal ArticleDOI
TL;DR: In this article, an overview of the low-frequency (i.e., monthly to seasonal) evolution, dynamics, predictability, and surface impacts of a rare Southern Hemisphere (SH) stratospheric warming that occurred in austral spring 2019.
Abstract: This study offers an overview of the low-frequency (i.e., monthly to seasonal) evolution, dynamics, predictability, and surface impacts of a rare Southern Hemisphere (SH) stratospheric warming that occurred in austral spring 2019. Between late August to mid-September 2019, the stratospheric circumpolar westerly jet weakened rapidly, and Antarctic stratospheric temperatures rose dramatically. The deceleration of the vortex at 10 hPa was as drastic as that of the first ever observed major sudden stratospheric warming in the SH during 2002, while the mean Antarctic warming over the course of spring 2019 broke the previous record of 2002 by ~50% in the mid-stratosphere. This event was preceded by a poleward shift of the SH polar night jet in the uppermost stratosphere in early winter, which was then followed by record-strong planetary wave-one activity propagating upward from the troposphere in August that acted to dramatically weaken the polar vortex throughout the depth of the stratosphere. The weakened vortex winds and elevated temperatures moved downward to the surface from mid-October to December, promoting a record strong swing of the Southern Annular Mode (SAM) to its negative phase. This record-negative SAM appeared to be a primary driver of the extreme hot and dry conditions over subtropical eastern Australia that accompanied the severe wildfires that occurred in late spring 2019. State-of-the-art dynamical seasonal forecast systems skilfully predicted the significant vortex weakening of spring 2019 and subsequent development of negative SAM from as early as late July.

48 citations

Journal ArticleDOI
TL;DR: In this article, the Tropospheric Monitoring Instrument (TROPOMI) sensor on board the Sentinel-5 Precursor satellite showed abnormally low total ozone columns in the polar region of the Northern Hemisphere (Arctic) in spring 2020.
Abstract: . Ozone data derived from the Tropospheric Monitoring Instrument (TROPOMI) sensor on board the Sentinel-5 Precursor satellite show exceptionally low total ozone columns in the polar region of the Northern Hemisphere (Arctic) in spring 2020. Minimum total ozone column values around or below 220 Dobson units (DU) were seen over the Arctic for 5 weeks in March and early April 2020. Usually the persistence of such low total ozone column values in spring is only observed in the polar Southern Hemisphere (Antarctic) and not over the Arctic. These record low total ozone columns were caused by a particularly strong polar vortex in the stratosphere with a persistent cold stratosphere at higher latitudes, a prerequisite for ozone depletion through heterogeneous chemistry. Based on the ERA5, which is the fifth generation of the European Centre for Medium-Range Weather Forecasts (ECMWF) atmospheric reanalysis, the Northern Hemisphere winter 2019/2020 (from December to March) showed minimum polar cap temperatures consistently below 195 K around 20 km altitude, which enabled enhanced formation of polar stratospheric clouds. The special situation in spring 2020 is compared and discussed in context with two other Northern Hemisphere spring seasons, namely those in 1997 and 2011, which also displayed relatively low total ozone column values. However, during these years, total ozone columns below 220 DU over several consecutive days were not observed in spring. The similarities and differences of the atmospheric conditions of these three events and possible explanations for the observed features are presented and discussed. It becomes apparent that the monthly mean of the minimum total ozone column value for March 2020 (221 DU) was clearly below the respective values found in March 1997 (267 DU) and 2011 (252 DU), which highlights the special evolution of the polar stratospheric ozone layer in the Northern Hemisphere in spring 2020. A comparison with a typical ozone hole over the Antarctic (e.g., in 2016) indicates that although the Arctic spring 2020 situation is remarkable, with total ozone column values around or below 220 DU observed over a considerable area (up to 0.9 million km 2 ), the Antarctic ozone hole shows total ozone columns typically below 150 DU over a much larger area (of the order of 20 million km 2 ). Furthermore, total ozone columns below 220 DU are typically observed over the Antarctic for about 4 months.

38 citations


Cites background from "The Anomalous 2019 Antarctic Ozone ..."

  • ...In September 2019 the polar vortex was also significantly disturbed (Wargan et al., 2020; Lim et al., 2020; see purple lines in Figs....

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  • ...The minimum TOC values in the Antarctic were noticeably higher in 2019 than in previous years (Wargan et al., 2020; see the purple line in Fig....

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  • ...It becomes evident that in winter the zonal mean zonal winds (at 60◦ S, 10 hPa) are stronger (by about 30 m s−1), and the minimum temperatures (polar cap, 50 hPa) are much lower (about 10 K) than in the Arctic (see also Wargan et al., 2020)....

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Journal ArticleDOI
TL;DR: In early 2020, activity reductions due to the coronavirus disease 2019 pandemic led to unprecedented decreases in carbon dioxide (CO2) emissions, despite their record size as discussed by the authors.
Abstract: Activity reductions in early 2020 due to the coronavirus disease 2019 pandemic led to unprecedented decreases in carbon dioxide (CO2) emissions. Despite their record size, the resulting atmospheric...

24 citations

Posted Content
TL;DR: In this paper, the authors used data assimilation to ingest satellite observations of column average CO2 (XCO2) from NASA's Orbiting Carbon Observatory 2 (OCO-2) into the Goddard Earth Observing System (GEOS), an integrated Earth system model.
Abstract: Monitoring the global distribution of greenhouse gases using spaceborne observations and attributing regional anomalies of their surface fluxes to either climatic or human processes represents a new frontier in Earth system science. The reduction in economic activity in early 2020 due to the Coronavirus Disease 2019 (COVID-19) pandemic led to unprecedented decreases in monthly carbon dioxide (CO2) emissions from fossil fuel use. This paper shows, for the first time, that the regional impact of COVID-19 was observable from space. Our approach uses data assimilation to ingest satellite observations of column average CO2 (XCO2) from NASA's Orbiting Carbon Observatory 2 (OCO-2) into the Goddard Earth Observing System (GEOS), an integrated Earth system model.

22 citations

References
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Journal ArticleDOI
TL;DR: An overview of the MERRA-2 system and various performance metrics is provided, including the assimilation of aerosol observations, several improvements to the representation of the stratosphere including ozone, and improved representations of cryospheric processes.
Abstract: The Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2), is the latest atmospheric reanalysis of the modern satellite era produced by NASA’s Global Modeling and Assimilation Office (GMAO). MERRA-2 assimilates observation types not available to its predecessor, MERRA, and includes updates to the Goddard Earth Observing System (GEOS) model and analysis scheme so as to provide a viable ongoing climate analysis beyond MERRA’s terminus. While addressing known limitations of MERRA, MERRA-2 is also intended to be a development milestone for a future integrated Earth system analysis (IESA) currently under development at GMAO. This paper provides an overview of the MERRA-2 system and various performance metrics. Among the advances in MERRA-2 relevant to IESA are the assimilation of aerosol observations, several improvements to the representation of the stratosphere including ozone, and improved representations of cryospheric processes. Other improvements in the quality of M...

4,524 citations


"The Anomalous 2019 Antarctic Ozone ..." refers background in this paper

  • ...…zonal wind at 5, 10, and 70 hPa, and the ozone hole area from the Modern‐Era Retrospective Analysis for Research and Applications, Version 2 (MERRA‐2; Gelaro et al., 2017; GMAO, 2015a, 2015b) and a Global Earth Observing System (GEOS) assimilation discussed below, along with the 2005–2018 mean,…...

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Journal ArticleDOI
01 May 1985-Nature
TL;DR: In this article, it was shown that the very low temperatures which prevail from midwinter until several weeks after the spring equinox make the Antarctic stratosphere uniquely sensitive to growth of inorganic chlorine, ClX, primarily by the effect of this growth on the NO2/NO ratio.
Abstract: Recent attempts1,2 to consolidate assessments of the effect of human activities on stratospheric ozone (O3) using one-dimensional models for 30° N have suggested that perturbations of total O3 will remain small for at least the next decade. Results from such models are often accepted by default as global estimates3. The inadequacy of this approach is here made evident by observations that the spring values of total O3 in Antarctica have now fallen considerably. The circulation in the lower stratosphere is apparently unchanged, and possible chemical causes must be considered. We suggest that the very low temperatures which prevail from midwinter until several weeks after the spring equinox make the Antarctic stratosphere uniquely sensitive to growth of inorganic chlorine, ClX, primarily by the effect of this growth on the NO2/NO ratio. This, with the height distribution of UV irradiation peculiar to the polar stratosphere, could account for the O3 losses observed.

3,131 citations


"The Anomalous 2019 Antarctic Ozone ..." refers background in this paper

  • ...…defined as regions with total ozone column of 220 Dobson units (DU) or less, have formed over Antarctica every austral spring since the early 1980s (Farman et al., 1985; Komhyr et al., 1986; Stolarski et al., 1986) and constitute the most dramatic manifestation of the twentieth century…...

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Journal ArticleDOI
TL;DR: The Ozone Monitoring Instrument is a ultraviolet/visible nadir solar backscatter spectrometer, which provides nearly global coverage in one day with a spatial resolution of 13 km/spl times/24 km and will enable detection of air pollution on urban scale resolution.
Abstract: The Ozone Monitoring Instrument (OMI) flies on the National Aeronautics and Space Administration's Earth Observing System Aura satellite launched in July 2004. OMI is a ultraviolet/visible (UV/VIS) nadir solar backscatter spectrometer, which provides nearly global coverage in one day with a spatial resolution of 13 km/spl times/24 km. Trace gases measured include O/sub 3/, NO/sub 2/, SO/sub 2/, HCHO, BrO, and OClO. In addition, OMI will measure aerosol characteristics, cloud top heights, and UV irradiance at the surface. OMI's unique capabilities for measuring important trace gases with a small footprint and daily global coverage will be a major contribution to our understanding of stratospheric and tropospheric chemistry and climate change. OMI's high spatial resolution is unprecedented and will enable detection of air pollution on urban scale resolution. In this paper, the instrument and its performance will be discussed.

1,644 citations


"The Anomalous 2019 Antarctic Ozone ..." refers methods in this paper

  • ...Named, the Belgian Assimilation System for Chemical ObsErvations (BASCOE) Reanalysis of Aura MLS, WARGAN ET AL....

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  • ...We assimilate observed stratospheric profiles of ozone, HCl, N2O, water vapor, and HNO3 from the MLS instrument onboard NASA's Aura satellite....

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  • ...Additionally, the system assimilates total ozone column observations from the OMI instrument also onboard Aura (Levelt et al., 2006, 2018) in the same way as it is done in MERRA‐2 (Wargan et al., 2017)....

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Journal ArticleDOI
TL;DR: The Earth Observing System Microwave Limb Sounder measures several atmospheric chemical species to improve the authors' understanding of stratospheric ozone chemistry, the interaction of composition and climate, and pollution in the upper troposphere.
Abstract: The Earth Observing System Microwave Limb Sounder measures several atmospheric chemical species (OH, HO/sub 2/, H/sub 2/O, O/sub 3/, HCl, ClO, HOCl, BrO, HNO/sub 3/, N/sub 2/O, CO, HCN, CH/sub 3/CN, volcanic SO/sub 2/), cloud ice, temperature, and geopotential height to improve our understanding of stratospheric ozone chemistry, the interaction of composition and climate, and pollution in the upper troposphere. All measurements are made simultaneously and continuously, during both day and night. The instrument uses heterodyne radiometers that observe thermal emission from the atmospheric limb in broad spectral regions centered near 118, 190, 240, and 640 GHz, and 2.5 THz. It was launched July 15, 2004 on the National Aeronautics and Space Administration's Aura satellite and started full-up science operations on August 13, 2004. An atmospheric limb scan and radiometric calibration for all bands are performed routinely every 25 s. Vertical profiles are retrieved every 165 km along the suborbital track, covering 82/spl deg/S to 82/spl deg/N latitudes on each orbit. Instrument performance to date has been excellent; data have been made publicly available; and initial science results have been obtained.

1,191 citations


"The Anomalous 2019 Antarctic Ozone ..." refers background in this paper

  • ...MLS (Waters et al., 2006) measures thermal radiation in a broad spectrum of microwave bands allowing high‐quality retrievals of temperature and stratospheric concentrations of a wide variety of constituents....

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Journal ArticleDOI
TL;DR: In this paper, all major midwinter stratospheric warming events are identified and classified, in both the NCEP-NCAR and 40-yr ECMWF Re-Analysis (ERA-40) datasets.
Abstract: Stratospheric sudden warmings are the clearest and strongest manifestation of dynamical coupling in the stratosphere–troposphere system. While many sudden warmings have been individually documented in the literature, this study aims at constructing a comprehensive climatology: all major midwinter warming events are identified and classified, in both the NCEP–NCAR and 40-yr ECMWF Re-Analysis (ERA-40) datasets. To accomplish this a new, objective identification algorithm is developed. This algorithm identifies sudden warmings based on the zonal mean zonal wind at 60°N and 10 hPa, and classifies them into events that do and do not split the stratospheric polar vortex. Major midwinter stratospheric sudden warmings are found to occur with a frequency of approximately six events per decade, and 46% of warming events lead to a splitting of the stratospheric polar vortex. The dynamics of vortex splitting events is contrasted to that of events where the vortex is merely displaced off the pole. In the stratosphere, the two types of events are found to be dynamically distinct: vortex splitting events occur after a clear preconditioning of the polar vortex, and their influence on middle-stratospheric temperatures lasts for up to 20 days longer than vortex displacement events. In contrast, the influence of sudden warmings on the tropospheric state is found to be largely insensitive to the event type. Finally, a table of dynamical benchmarks for major stratospheric sudden warming events is compiled. These benchmarks are used in a companion study to evaluate current numerical model simulations of the stratosphere.

922 citations


"The Anomalous 2019 Antarctic Ozone ..." refers background in this paper

  • ...…major sudden stratospheric warmings (SSWs), defined as reversal events of the 60°S/60°N zonal mean zonal winds at 10 hPa (e.g., Butler et al., 2017; Charlton & Polvani, 2007), are common in the Northern Hemisphere (NH), only one major SSW in the SH occurred since at least the late 1950s (e.g.,…...

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