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Evaluation of the N 2O Rate of Change to Understand the Stratospheric Brewer-Dobson Circulation in a Chemistry-Climate Model. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2022; 127:e2021JD036390. [PMID: 36589523 PMCID: PMC9788151 DOI: 10.1029/2021jd036390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 10/20/2022] [Accepted: 10/28/2022] [Indexed: 06/17/2023]
Abstract
The Brewer-Dobson Circulation (BDC) determines the distribution of long-lived tracers in the stratosphere; therefore, their changes can be used to diagnose changes in the BDC. We evaluate decadal (2005-2018) trends of nitrous oxide (N2O) in two versions of the Whole Atmosphere Chemistry-Climate Model (WACCM) by comparing them with measurements from four Fourier transform infrared (FTIR) ground-based instruments, the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS), and with a chemistry-transport model (CTM) driven by four different reanalyses. The limited sensitivity of the FTIR instruments can hide negative N2O trends in the mid-stratosphere because of the large increase in the lowermost stratosphere. When applying ACE-FTS measurement sampling on model datasets, the reanalyses from the European Center for Medium Range Weather Forecast (ECMWF) compare best with ACE-FTS, but the N2O trends are consistently exaggerated. The N2O trends obtained with WACCM disagree with those obtained from ACE-FTS, but the new WACCM version performs better than the previous above the Southern Hemisphere in the stratosphere. Model sensitivity tests show that the decadal N2O trends reflect changes in the stratospheric transport. We further investigate the N2O Transformed Eulerian Mean (TEM) budget in WACCM and in the CTM simulation driven by the latest ECMWF reanalysis. The TEM analysis shows that enhanced advection affects the stratospheric N2O trends in the Tropics. While no ideal observational dataset currently exists, this model study of N2O trends still provides new insights about the BDC and its changes because of the contribution from relevant sensitivity tests and the TEM analysis.
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COVID-19 Crisis Reduces Free Tropospheric Ozone Across the Northern Hemisphere. GEOPHYSICAL RESEARCH LETTERS 2021; 48:e2020GL091987. [PMID: 33785974 PMCID: PMC7995013 DOI: 10.1029/2020gl091987] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 01/28/2021] [Accepted: 02/03/2021] [Indexed: 05/21/2023]
Abstract
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 2000-2020 climatological mean. Such low ozone, over several months, and at so many stations, has not been observed in any previous year since at least 2000. Atmospheric composition analyses from the Copernicus Atmosphere Monitoring Service and simulations from the NASA GMI model indicate that the large 2020 springtime ozone depletion in the Arctic stratosphere contributed less than one-quarter of the observed tropospheric anomaly. The observed anomaly is consistent with recent chemistry-climate model simulations, which assume emissions reductions similar to those caused by the COVID-19 crisis. COVID-19 related emissions reductions appear to be the major cause for the observed reduced free tropospheric ozone in 2020.
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Atmospheric implications of large C 2-C 5 alkane emissions from the U.S. oil and gas industry. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2019; 124:1148-1169. [PMID: 32832312 PMCID: PMC7433792 DOI: 10.1029/2018jd028955] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 12/18/2018] [Indexed: 06/10/2023]
Abstract
Emissions of C2-C5 alkanes from the U.S. oil and gas sector have changed rapidly over the last decade. We use a nested GEOS-Chem simulation driven by updated 2011NEI emissions with aircraft, surface and column observations to 1) examine spatial patterns in the emissions and observed atmospheric abundances of C2-C5 alkanes over the U.S., and 2) estimate the contribution of emissions from the U.S. oil and gas industry to these patterns. The oil and gas sector in the updated 2011NEI contributes over 80% of the total U.S. emissions of ethane (C2H6) and propane (C3H8), and emissions of these species are largest in the central U.S. Observed mixing ratios of C2-C5 alkanes show enhancements over the central U.S. below 2 km. A nested GEOS-Chem simulation underpredicts observed C3H8 mixing ratios in the boundary layer over several U.S. regions and the relative underprediction is not consistent, suggesting C3H8 emissions should receive more attention moving forward. Our decision to consider only C4-C5 alkane emissions as a single lumped species produces a geographic distribution similar to observations. Due to the increasing importance of oil and gas emissions in the U.S., we recommend continued support of existing long-term measurements of C2-C5 alkanes. We suggest additional monitoring of C2-C5 alkanes downwind of northeastern Colorado, Wyoming and western North Dakota to capture changes in these regions. The atmospheric chemistry modeling community should also evaluate whether chemical mechanisms that lump larger alkanes are sufficient to understand air quality issues in regions with large emissions of these species.
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Case report: successful treatment of membranous lupus nephritis with belimumab in an African female immigrant. Clin Rheumatol 2015; 35:1649-53. [DOI: 10.1007/s10067-015-3153-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 12/13/2015] [Accepted: 12/15/2015] [Indexed: 11/28/2022]
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Recent Northern Hemisphere stratospheric HCl increase due to atmospheric circulation changes. Nature 2014; 515:104-7. [DOI: 10.1038/nature13857] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 09/10/2014] [Indexed: 11/09/2022]
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Process-evaluation of tropospheric humidity simulated by general circulation models using water vapor isotopologues: 1. Comparison between models and observations. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jd016621] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Extracorporeal dialysis: techniques and adequacy. Clin Kidney J 2011. [DOI: 10.1093/ndtplus/4.s2.37] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Hydrogen fluoride total and partial column time series above the Jungfraujoch from long-term FTIR measurements: Impact of the line-shape model, characterization of the error budget and seasonal cycle, and comparison with satellite and model data. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2010jd014677] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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First ground-based infrared solar absorption measurements of free tropospheric methanol (CH3OH): Multidecade infrared time series from Kitt Peak (31.9°N 111.6°W): Trend, seasonal cycle, and comparison with previous measurements. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jd011003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Observations of long-lived anthropogenic halocarbons at the high-Alpine site of Jungfraujoch (Switzerland) for assessment of trends and European sources. THE SCIENCE OF THE TOTAL ENVIRONMENT 2008; 391:224-231. [PMID: 18036636 DOI: 10.1016/j.scitotenv.2007.10.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Anthropogenic halocarbons, such as chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), bromocarbons (halons) and long-lived chlorinated solvents have been measured continuously at the high-Alpine site of Jungfraujoch (Switzerland) since January 2000. Chloro- and bromo-containing halocarbons are responsible for the stratospheric ozone depletion and will be globally banned from usage within the next years. With the exception of the stable CFC-12 (CF2 Cl2), all major CFCs and chlorinated solvents show a negative trend in recent years in their background concentrations at Jungfraujoch. HCFCs, as their first-generation substitute, are still increasing with a few percent per year. However, the frequency and the strength of HCFCs pollution events, which are caused by regional European emissions, are already declining. This can be seen as a sign of the impending ban of these gases within the next years in Europe. On the other hand, HFCs as the second-generation substitutes, are increasing with relative rates of at least 10% per year (e.g. almost 5 ppt per year for HFC-134a). An allocation of European sources was attempted by combining measured concentrations with trajectories of air masses reaching the Jungfraujoch during pollution events. Potential source regions could be detected in Italy, France, Spain and Germany.
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Our changing atmosphere: evidence based on long-term infrared solar observations at the Jungfraujoch since 1950. THE SCIENCE OF THE TOTAL ENVIRONMENT 2008; 391:184-195. [PMID: 18067951 DOI: 10.1016/j.scitotenv.2007.10.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The Institute of Astrophysics of the University of Liège has been present at the High Altitude Research Station Jungfraujoch, Switzerland, since the late 1940s, to perform spectrometric solar observations under dry and weakly polluted high-mountain conditions. Several solar atlases of photometric quality, extending altogether from the near-ultra-violet to the middle-infrared, were produced between 1956 and 1994, first with grating spectrometers then with Fourier transform instruments. During the early 1970s, scientific concerns emerged about atmospheric composition changes likely to set in as a consequence of the growing usage of nitrogen-containing agricultural fertilisers and the industrial production of chlorine-bearing compounds such as the chlorofluorocarbons and hydro-chlorofluorocarbons. Resulting releases to the atmosphere with ensuing photolysis in the stratosphere and catalytic depletion of the protective ozone layer prompted a worldwide consortium of chemical manufacturing companies to solicit the Liège group to help in clarifying these concerns by undertaking specific observations with its existing Jungfraujoch instrumentation. The following pages evoke the main steps that led from quasi full sun-oriented studies to priority investigations of the Earth's atmosphere, in support of both the Montreal and the Kyoto Protocols.
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Evolution of a dozen non-CO2 greenhouse gases above central Europe since the mid-1980s. ACTA ACUST UNITED AC 2007. [DOI: 10.1080/15693430500397152] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Atmospheric Trace Molecule Spectroscopy (ATMOS) Experiment Version 3 data retrievals. APPLIED OPTICS 2002; 41:6968-6979. [PMID: 12463241 DOI: 10.1364/ao.41.006968] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Version 3 of the Atmospheric Trace Molecule Spectroscopy (ATMOS) experiment data set for some 30 trace and minor gas profiles is available. From the IR solar-absorption spectra measured during four Space Shuttle missions (in 1985, 1992, 1993, and 1994), profiles from more than 350 occultations were retrieved from the upper troposphere to the lower mesosphere. Previous results were unreliable for tropospheric retrievals, but with a new global-fitting algorithm profiles are reliably returned down to altitudes as low as 6.5 km (clouds permitting) and include notably improved retrievals of H2O, CO, and other species. Results for stratospheric water are more consistent across the ATMOS spectral filters and do not indicate a net consumption of H2 in the upper stratosphere. A new sulfuric-acid aerosol product is described. An overview of ATMOS Version 3 processing is presented with a discussion of estimated uncertainties. Differences between these Version 3 and previously reported Version 2 ATMOS results are discussed. Retrievals are available at http://atmos.jpl.nasa.gov/atmos.
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Free tropospheric CO, C2H6, and HCN above central Europe: Recent measurements from the Jungfraujoch station including the detection of elevated columns during 1998. ACTA ACUST UNITED AC 2000. [DOI: 10.1029/2000jd900371] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Correlation relationships of stratospheric molecular constituents from high spectral resolution, ground-based infrared solar absorption spectra. ACTA ACUST UNITED AC 2000. [DOI: 10.1029/2000jd900139] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Polar stratospheric descent of NOyand CO and Arctic denitrification during winter 1992-1993. ACTA ACUST UNITED AC 1999. [DOI: 10.1029/1998jd100034] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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18
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Northern and southern hemisphere ground-based infrared spectroscopic measurements of tropospheric carbon monoxide and ethane. ACTA ACUST UNITED AC 1998. [DOI: 10.1029/98jd02515] [Citation(s) in RCA: 209] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Ground-based infrared solar spectroscopic measurements of carbon monoxide during 1994 Measurement of Air Pollution From Space flights. ACTA ACUST UNITED AC 1998. [DOI: 10.1029/97jd02889] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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ClONO2total vertical column abundances above the Jungfraujoch Station, 1986-1994: Long-term trend and winter-spring enhancements. ACTA ACUST UNITED AC 1996. [DOI: 10.1029/95jd03349] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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April 1993 Arctic profiles of stratospheric HCl, ClONO2, and CCl2F2from atmospheric trace molecule spectroscopy/ATLAS 2 infrared solar occultation spectra. ACTA ACUST UNITED AC 1995. [DOI: 10.1029/95jd01047] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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[What should be the duration of a treatment with antidepressive agents?]. LA REVUE DU PRATICIEN 1994; 44:2302-5. [PMID: 7984936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The main clinical factors involved in deciding the length of an antidepressant treatment are briefly reviewed in the framework of current classifications of affective disorders. History of previous episodes and the polarity of depressive illness have a major role in such a process. Current definitions of remission, relapse and recurrence are given. In the context of a single depressive episode, treatment must be continued for at least 4 months after the start of clinical improvement in order to prevent a relapse. In case of recurrent depressive episode, the indications of a long-term treatment must be discussed. Some issues unsettled as to the adequate dosage of such a treatment, as well as to the length of treatment in other types of depressive states.
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Monitoring of the atmospheric burdens of CH4, N 2O, CO, CHCIF 2 and CF 2Cl 2 above Central Europe during the last decade. ENVIRONMENTAL MONITORING AND ASSESSMENT 1994; 31:203-209. [PMID: 24213907 DOI: 10.1007/bf00547198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Based on high spectral resolution infrared solar observations made at the International Scientific Station of the Jungfraujoch, Switzerland, total vertical column abundances of 18 atmospheric gases have been monitored routinely since 1984. The observed temporal evolutions in the columns of CH4, N2O, CO, CHClF2 (HCFC-22) and CF2Cl2 (CFC-12) are reported here as typical examples of this monitoring effort which is conducted within the frame of "Global Change" and "Network for the Detection of Stratospheric Change" programs.
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Heterogeneous conversion of N2O5to HNO3in the post-Mount Pinatubo eruption stratosphere. ACTA ACUST UNITED AC 1994. [DOI: 10.1029/93jd03469] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Secular trend and seasonal variability of the column abundance of N2O above the Jungfraujoch station determined from IR solar spectra. ACTA ACUST UNITED AC 1994. [DOI: 10.1029/94jd01030] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Increase of carbonyl fluoride (COF2) in the stratosphere and its contribution to the 1992 budget of inorganic fluorine in the upper stratosphere. ACTA ACUST UNITED AC 1994. [DOI: 10.1029/94jd01029] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Profiles of stratospheric chlorine nitrate (ClONO2) from atmospheric trace molecule spectroscopy/ATLAS 1 infrared solar occultation spectra. ACTA ACUST UNITED AC 1994. [DOI: 10.1029/94jd01520] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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ATMOS/ATLAS 1 measurements of sulfur hexafluoride (SF6) in the lower stratosphere and upper troposphere. ACTA ACUST UNITED AC 1993. [DOI: 10.1029/93jd02258] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Ground-based infrared measurements of carbonyl sulfide total column abundances: Long-term trends and variability. ACTA ACUST UNITED AC 1992. [DOI: 10.1029/92jd00040] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
Cannibalism is a provocative interpretation put forth repeatedly for practices at various prehistoric sites, yet it has been so poorly supported by objective evidence that later, more critical reviews almost invariably reject the proposal. The basic data essential to a rigorous assessment of a cannibalism hypothesis include precise contextual information, analysis of postcranial and cranial remains of humans and animals, and detailed bone modification studies. Such data are available from the Neolithic levels of the Fontbrégoua Cave (southeastern France) where several clusters of human and animal bones have been excavated. The analysis of these bones strongly suggests that humans were butchered, processed, and probably eaten in a manner that closely parallels the treatment of wild and domestic animals at Fontbrbégoua.
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