Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Más filtros

Intervalo de año de publicación
Environ Sci Technol ; 55(24): 16573-16580, 2021 12 21.
Artículo en Inglés | MEDLINE | ID: mdl-34842427


Two years of satellite observations were used to quantify methane emissions from coal mines in Queensland, the largest coal-producing state in Australia. The six analyzed surface and underground coal mines are estimated to emit 570 ± 98 Gg a-1 in 2018-2019. Together, they account for 7% of the national coal production while emitting 55 ± 10% of the reported methane emission from coal mining in Australia. Our results indicate that for two of the three locations, our satellite-based estimates are significantly higher than reported to the Australian government. Most remarkably, 40% of the quantified emission came from a single surface mine (Hail Creek) located in a methane-rich coal basin. Our findings call for increased monitoring and investment in methane recovery technologies for both surface and underground mines.

Minas de Carbón , Metano , Australia , Carbón Mineral , Metano/análisis
Philos Trans A Math Phys Eng Sci ; 379(2210): 20210106, 2021 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-34565220


Surface observations have recorded large and incompletely understood changes to atmospheric methane (CH4) this century. However, their ability to reveal the responsible surface sources and sinks is limited by their geographical distribution, which is biased towards the northern midlatitudes. Data from Earth-orbiting satellites designed specifically to measure atmospheric CH4 have been available since 2009 with the launch of the Japanese Greenhouse gases Observing SATellite (GOSAT). We assess the added value of GOSAT to data collected by the US National Oceanic and Atmospheric Administration (NOAA), which have been the lynchpin for knowledge about atmospheric CH4 since the 1980s. To achieve that we use the GEOS-Chem atmospheric chemistry transport model and an inverse method to infer a posteriori flux estimates from the NOAA and GOSAT data using common a priori emission inventories. We find the main benefit of GOSAT data is from its additional coverage over the tropics where we report large increases since the 2014/2016 El Niño, driven by biomass burning, biogenic emissions and energy production. We use data from the European TROPOspheric Monitoring Instrument to show how better spatial coverage and resolution measurements allow us to quantify previously unattainable diffuse sources of CH4, thereby opening up a new research frontier. This article is part of a discussion meeting issue 'Rising methane: is warming feeding warming? (part 1)'.

Sci Adv ; 6(17): eaaz5120, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32494644


Using new satellite observations and atmospheric inverse modeling, we report methane emissions from the Permian Basin, which is among the world's most prolific oil-producing regions and accounts for >30% of total U.S. oil production. Based on satellite measurements from May 2018 to March 2019, Permian methane emissions from oil and natural gas production are estimated to be 2.7 ± 0.5 Tg a-1, representing the largest methane flux ever reported from a U.S. oil/gas-producing region and are more than two times higher than bottom-up inventory-based estimates. This magnitude of emissions is 3.7% of the gross gas extracted in the Permian, i.e., ~60% higher than the national average leakage rate. The high methane leakage rate is likely contributed by extensive venting and flaring, resulting from insufficient infrastructure to process and transport natural gas. This work demonstrates a high-resolution satellite data-based atmospheric inversion framework, providing a robust top-down analytical tool for quantifying and evaluating subregional methane emissions.

Rev. colomb. cardiol ; 26(6): 338-341, nov.-dic. 2019. tab
Artículo en Español | LILACS, COLNAL | ID: biblio-1115590


Resumen Por su elevada especificidad y sensibilidad, y a raíz de la tercera definición universal de infarto estas isoformas cardiacas han sido aceptadas en el ámbito internacional como los biomarcadaores de elección en la práctica clínica para el diagnóstico de síndrome coronario agudo, preferibles a la determinación de las enzimas creatina quinasa y su isoforma MB. Se presenta el caso de un varón de ochenta años, quien, de manera persistente, tuvo valores elevados de troponinas, pese a evolución clínica no compatible con síndrome coronario agudo ni otras causas de elevación de este biomarcador.

Abstract Due to its elevated specificity and sensitivity, and on being the third universal definition of myocardial infarction, these cardiac isoforms have been accepted internationally as the biomarkers of choice in clinical practice for the diagnosis of acute coronary syndrome, and are preferable to the determinations of creatine kinase and its MB isoform. A case is presented on an eighty year-old man, who persistently had elevated Troponin values, despite a clinical course that was incompatible with an acute coronary syndrome or any other causes of elevation of this biomarker.

Humanos , Masculino , Anciano de 80 o más Años , Biomarcadores , Angina de Pecho , Infarto del Miocardio , Troponina , Sensibilidad y Especificidad , Anticuerpos