An Observationally Constrained Evaluation of the Oxidative Capacity in the Tropical Western Pacific Troposphere

Hydroxyl radical (OH) is the main daytime oxidant in the troposphere and determines the atmospheric lifetimes of many compounds. We use aircraft measurements of O3, H2O, NO, and other species from the Convective Transport of Active Species in the Tropics (CONTRAST) field campaign, which occurred in the tropical western Pacific (TWP) during January–February 2014, to constrain a photochemical box model and estimate concentrations of OH throughout the troposphere. We find that tropospheric column OH (OHCOL) inferred from CONTRAST observations is 12 to 40% higher than found in chemical transport models (CTMs), including CAM-chem-SD run with 2014 meteorology as well as eight models that participated in POLMIP (2008 meteorology). Part of this discrepancy is due to a clear-sky sampling bias that affects CONTRAST observations; accounting for this bias and also for a small difference in chemical mechanism results in our empirically based value of OHCOL being 0 to 20% larger than found within global models. While these global models simulate observed O3 reasonably well, they underestimate NOx (NO + NO2) by a factor of two, resulting in OHCOL ~30% lower than box model simulations constrained by observed NO. Underestimations by CTMs of observed CH3CHO throughout the troposphere and of HCHO in the upper troposphere further contribute to differences between our constrained estimates of OH and those calculated by CTMs. Finally, our calculations do not support the prior suggestion of the existence of a tropospheric OH minimum in the TWP, because during January–February 2014 observed levels of O3 and NO were considerably larger than previously reported values in the TWP

The Multi-Scale Infrastructure for Chemistry and Aerosols (MUSICA)

To explore the various couplings across space and time and between ecosystems in a consistent manner, atmospheric modeling is moving away from the fractured limited-scale modeling strategy of the past toward a unification of the range of scales inherent in the Earth system. This paper describes the forward-looking Multi-Scale Infrastructure for Chemistry and Aerosols (MUSICA), which is intended to become the next-generation community infrastructure for research involving atmospheric chemistry and aerosols. MUSICA will be developed collaboratively by the National Center for Atmospheric Research (NCAR) and university and government researchers, with the goal of serving the international research and applications communities. The capability of unifying various spatiotemporal scales, coupling to other Earth system components, and process-level modularization will allow advances in both fundamental and applied research in atmospheric composition, air quality, and climate and is also envisioned to become a platform that addresses the needs of policy makers and stakeholders

Transport of tropospheric ozone and precursors to the Arctic: lessons from a multi-model evaluation using aircraft, satellite and surface data

International audienceChanges in abundances of short-lived climate pollutants such as tropospheric ozone and aerosol may have contributed significantly to observed rapid Arctic warming in recent decades. Ozone in the Arctic troposphere is influenced by long-range transport of polluted air from Europe, Asia and N. America, and in summer from boreal wildfires. Our understanding of how different sources contribute to Arctic tropospheric ozone is limited, and is reliant on sparse observations and models of atmospheric transport and chemistry. In particular, our confidence in future high latitude tropospheric ozone response to projected changes in mid-latitude emissions, and subsequent climate impacts, is informed by the ability of models to accurately simulate poleward export from source regions, long-range transport to high latitudes, and photochemical transformation of ozone and its precursors during such events

Quantifying the causes of differences in tropospheric OH within global models

International audienceThe hydroxyl radical (OH) is the primary daytime oxidant in the troposphere and provides the main loss mechanism for many pollutants and greenhouse gases, including methane (CH4). Global mean tropospheric OH differs by as much as 80% among various global models, for reasons that are not well understood. We use neural networks (NNs), trained using archived output from eight chemical transport models (CTMs) that participated in the Polar Study using Aircraft, Remote Sensing, Surface Measurements and Models, of Climate, Chemistry, Aerosols and Transport Model Intercomparison Project (POLMIP), to quantify the factors responsible for differences in tropospheric OH and resulting CH4 lifetime (τCH4) between these models. Annual average τCH4, for loss by OH only, ranges from 8.0 to 11.6 years for the eight POLMIP CTMs. The factors driving these differences were quantified by inputting 3-D chemical fields from one CTM into the trained NN of another CTM. Across all CTMs, the largest mean differences in τCH4 (ΔτCH4) result from variations in chemical mechanisms (ΔτCH4 = 0.46 years), the photolysis frequency (J) of O3 → O(1D) (0.31 years), local O3 (0.30 years), and CO (0.23 years). The ΔτCH4 due to CTM differences in NOx (NO + NO2) is relatively low (0.17 years), although large regional variation in OH between the CTMs is attributed to NOx. Differences in isoprene and J(NO2) have negligible overall effect on globally averaged tropospheric OH, although the extent of OH variations due to each factor depends on the model being examined. This study demonstrates that NNs can serve as a useful tool for quantifying why tropospheric OH varies between global models, provided that essential chemical fields are archived

Quantifying the Causes of Differences in Tropospheric OH Within Global Models

The hydroxyl radical (OH) is the primary daytime oxidant in the troposphere and provides the main loss mechanism for many pollutants and greenhouse gases, including methane (CH4). Global mean tropospheric OH differs by as much as 80% among various global models, for reasons that are not well understood. We use neural networks (NNs), trained using archived output from eight chemical transport models (CTMs) that participated in the Polar Study using Aircraft, Remote Sensing, Surface Measurements and Models, of Climate, Chemistry, Aerosols and Transport Model Intercomparison Project (POLMIP), to quantify the factors responsible for differences in tropospheric OH and resulting CH4 lifetime (Tau CH4) between these models. Annual average Tau CH4, for loss by OH only, ranges from 8.0 to 11.6 years for the eight POLMIP CTMs. The factors driving these differences were quantified by inputting 3-D chemical fields from one CTM into the trained NN of another CTM. Across all CTMs, the largest mean differences in Tau CH4 (Delta Tau CH4) result from variations in chemical mechanisms (Delta Tau CH4 = 0.46 years), the photolysis frequency (J) of O3 yields O(D-1) (0.31 years), local O3 (0.30 years), and CO (0.23 years). The Delta Tau CH4 due to CTM differences in NO(x) (NO + NO2) is relatively low (0.17 years), although large regional variation in OH between the CTMs is attributed to NO(x). Differences in isoprene and J(NO2) have negligible overall effect on globally averaged tropospheric OH, although the extent of OH variations due to each factor depends on the model being examined. This study demonstrates that NNs can serve as a useful tool for quantifying why tropospheric OH varies between global models, provided that essential chemical fields are archived

2017 ESC focused update on dual antiplatelet therapy in coronary artery disease developed in collaboration with EACTS: The Task Force for dual antiplatelet therapy in coronary artery disease of the European Society of Cardiology (ESC) and of the European Association for Cardio-Thoracic Surgery (EACTS)

none107siNon presentemixedValgimigli, Marco*; Bueno, Héctor; Byrne, Robert A.; Collet, Jean-Philippe; Costa, Francesco; Jeppsson, Anders; Kastrati, Adnan; Kolh, Philippe; Mauri, Laura; Montalescot, Gilles; Neumann, Franz-Josef; Petricevic, Mate; Roffi, Marco; Steg, Philippe Gabriel; Zamorano, Jose Luis; Levine, Glenn N.; Badimon, Lina; Vranckx, Pascal; Agewall, Stefan; Andreotti, Felicita; Antman, Elliott; Barbato, Emanuele; Bassand, Jean-Pierre; Bugiardini, Raffaele; Cikirikcioglu, Mustafa; Cuisset, Thomas; De Bonis, Michele; Delgado, Victora; Fitzsimons, Donna; Galiè, Nazzareno; Gilard, Martine; Hamm, Christian W.; Ibanez, Borja; James, Stefan; Knuuti, Juhani; Landmesser, Ulf; Leclercq, Christophe; Lettino, Maddalena; Lip, Gregory; Piepoli, Massimo Francesco; Pierard, Luc; Schwerzmann, Markus; Sechtem, Udo; Simpson, Iain A.; Uva, Miguel Sousa; Stabile, Eugenio; Storey, Robert F.; Tendera, Michal; Van De Werf, Frans; Verheugt, Freek; Aboyans, Victor; Windecker, Stephan; Coca, Antonio; Coman, Ioan Mircea; Dean, Veronica; Delgado, Victoria; Gaemperli, Oliver; Hindricks, Gerhard; Iung, Bernard; Jüni, Peter; Katus, Hugo A.; Lancellotti, Patrizio; McDonagh, Theresa; Ponikowski, Piotr; Richter, DImitrios J.; Shlyakhto, Evgeny; Roithinger, Franz Xaver; Aliyev, Farid; Stelmashok, Valeriy; Desmet, Walter; Postadzhiyan, Arman; Georghiou, Georgios P.; Motovska, Zuzana; Grove, Erik Lerkevang; Marandi, Toomas; Kiviniemi, Tuomas; Kedev, Sasko; Massberg, Steffen; Alexopoulos, DImitrios; Kiss, Robert Gabor; Gudmundsdottir, Ingibjorg Jona; McFadden, Eugène P.; Lev, Eli; De Luca, Leonardo; Sugraliyev, Akhmetzhan; Haliti, Edmond; Mirrakhimov, Erkin; Latkovskis, Gustavs; Petrauskiene, Birute; Huijnen, Steve; Magri, Caroline Jane; Cherradi, Rhizlan; Ten Berg, Jurrien M.; Eritsland, Jan; Budaj, Andrzej; Aguiar, Carlos Tavares; Duplyakov, Dmitry; Zavatta, Marco; Antonijevic, Nebojsa M.; Fras, Zlatko; Montoliu, Antonio Tello; Varenhorst, Christoph; Tsakiris, DImitri; Addad, Faouzi; Aydogdu, Sinan; Parkhomenko, Alexander; Kinnaird, TimValgimigli, Marco*; Bueno, Héctor; Byrne, Robert A.; Collet, Jean-Philippe; Costa, Francesco; Jeppsson, Anders; Kastrati, Adnan; Kolh, Philippe; Mauri, Laura; Montalescot, Gilles; Neumann, Franz-Josef; Petricevic, Mate; Roffi, Marco; Steg, Philippe Gabriel; Zamorano, Jose Luis; Levine, Glenn N.; Badimon, Lina; Vranckx, Pascal; Agewall, Stefan; Andreotti, Felicita; Antman, Elliott; Barbato, Emanuele; Bassand, Jean-Pierre; Bugiardini, Raffaele; Cikirikcioglu, Mustafa; Cuisset, Thomas; De Bonis, Michele; Delgado, Victora; Fitzsimons, Donna; Galiè, Nazzareno; Gilard, Martine; Hamm, Christian W.; Ibanez, Borja; James, Stefan; Knuuti, Juhani; Landmesser, Ulf; Leclercq, Christophe; Lettino, Maddalena; Lip, Gregory; Piepoli, Massimo Francesco; Pierard, Luc; Schwerzmann, Markus; Sechtem, Udo; Simpson, Iain A.; Uva, Miguel Sousa; Stabile, Eugenio; Storey, Robert F.; Tendera, Michal; Van De Werf, Frans; Verheugt, Freek; Aboyans, Victor; Windecker, Stephan; Coca, Antonio; Coman, Ioan Mircea; Dean, Veronica; Delgado, Victoria; Gaemperli, Oliver; Hindricks, Gerhard; Iung, Bernard; Jüni, Peter; Katus, Hugo A.; Lancellotti, Patrizio; McDonagh, Theresa; Ponikowski, Piotr; Richter, DImitrios J.; Shlyakhto, Evgeny; Roithinger, Franz Xaver; Aliyev, Farid; Stelmashok, Valeriy; Desmet, Walter; Postadzhiyan, Arman; Georghiou, Georgios P.; Motovska, Zuzana; Grove, Erik Lerkevang; Marandi, Toomas; Kiviniemi, Tuomas; Kedev, Sasko; Massberg, Steffen; Alexopoulos, DImitrios; Kiss, Robert Gabor; Gudmundsdottir, Ingibjorg Jona; McFadden, Eugène P.; Lev, Eli; De Luca, Leonardo; Sugraliyev, Akhmetzhan; Haliti, Edmond; Mirrakhimov, Erkin; Latkovskis, Gustavs; Petrauskiene, Birute; Huijnen, Steve; Magri, Caroline Jane; Cherradi, Rhizlan; Ten Berg, Jurrien M.; Eritsland, Jan; Budaj, Andrzej; Aguiar, Carlos Tavares; Duplyakov, Dmitry; Zavatta, Marco; Antonijevic, Nebojsa M.; Fras, Zlatko; Montoliu, Antonio Tello; Varenhorst, Christoph; Tsakiris, DImitri; Addad, Faouzi; Aydogdu, Sinan; Parkhomenko, Alexander; Kinnaird, Ti

2019 ESC Guidelines for the diagnosis and management of acute pulmonary embolism developed in collaboration with the European respiratory society (ERS) : The Task Force for the diagnosis and management of acute pulmonary embolism of the European Society of Cardiology (ESC)

Guidelines summarize and evaluate available evidence with the aim of assisting health professionals in proposing the best management strategies for an individual patient with a given condition. Guidelines and their recommendations should facilitate decision making of health professionals in their daily practice. However, the final decisions concerning an individual patient must be made by the responsible health professional(s) in consultation with the patient and caregiver as appropriate

2019 ESC Guidelines for the diagnosis and management of acute pulmonary embolism developed in collaboration with the European Respiratory Society (ERS).

Guidelines summarize and evaluate available evidence with the aim of assisting health professionals in proposing the best management strategies for an individual patient with a given condition. Guidelines and their recommendations should facilitate decision making of health professionals in their daily practice. However, the final decisions concerning an individual patient must be made by the responsible health professional(s) in consultation with the patient and caregiver as appropriate

2019 ESC guidelines for the dignosis and management of acute pulmonary embolism developed in collaboration with the european respiratory society (ERS)

Guidelines summarize and evaluate available evidence with the aim of assisting health professionals in proposing the best management strategies for an individual patient with a given condition. Guidelines and their recommendations should facilitate decision making of health professionals in their daily practice. However, the final decisions concerning an individual patient must be made by the responsible health professional(s) in consultation with the patient and caregiver as appropriate