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Arctic Methane Emissions
Arctic methane release is the release of methane from seas and soils in permafrost regions of the Arctic. While it is a long-term natural process, methane release is exacerbated by global warming. This results in a positive feedback cycle, as methane is itself a powerful greenhouse gas. The Arctic region is one of the many natural sources of the greenhouse gas methane. Global warming accelerates its release, due to both release of methane from existing stores, and from methanogenesis in rotting biomass. Large quantities of methane are stored in the Arctic in natural gas deposits, permafrost, and as undersea clathrates. Permafrost and clathrates degrade on warming, thus large releases of methane from these sources may arise as a result of global warming. Other sources of methane include submarine taliks, river transport, ice complex retreat, submarine permafrost and decaying gas hydrate deposits. Methane concentrations are 8–10% higher in the Arctic than in the Antarctic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methane
Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Earth makes it an economically attractive fuel, although capturing and storing it poses technical challenges due to its gaseous state under normal conditions for temperature and pressure. Naturally occurring methane is found both below ground and under the seafloor and is formed by both geological and biological processes. The largest reservoir of methane is under the seafloor in the form of methane clathrates. When methane reaches the surface and the atmosphere, it is known as atmospheric methane. The Earth's atmospheric methane concentration has increased by about 150% since 1750, and it accounts for 20% of the total radiative forcing from all of the long-lived and globally mixed greenhouse gases. It has also been detected on other plane ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parts Per Billion
In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they are pure numbers with no associated units of measurement. Commonly used are parts-per-million (ppm, ), parts-per-billion (ppb, ), parts-per-trillion (ppt, ) and parts-per-quadrillion (ppq, ). This notation is not part of the International System of Units (SI) system and its meaning is ambiguous. Overview Parts-per notation is often used describing dilute solutions in chemistry, for instance, the relative abundance of dissolved minerals or pollutants in water. The quantity "1 ppm" can be used for a mass fraction if a water-borne pollutant is present at one-millionth of a gram per gram of sample solution. When working with aqueous solutions, it is common to assume that the density of water is 1.00 g/mL. Therefore, it is common to equate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Ice
Sea ice arises as seawater freezes. Because ice is less dense than water, it floats on the ocean's surface (as does fresh water ice, which has an even lower density). Sea ice covers about 7% of the Earth's surface and about 12% of the world's oceans. Much of the world's sea ice is enclosed within the polar ice packs in the Earth's polar regions: the Arctic ice pack of the Arctic Ocean and the Antarctic ice pack of the Southern Ocean. Polar packs undergo a significant yearly cycling in surface extent, a natural process upon which depends the Arctic ecology, including the ocean's ecosystems. Due to the action of winds, currents and temperature fluctuations, sea ice is very dynamic, leading to a wide variety of ice types and features. Sea ice may be contrasted with icebergs, which are chunks of ice shelves or glaciers that calve into the ocean. Depending on location, sea ice expanses may also incorporate icebergs. General features and dynamics Sea ice does not simply grow and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctic Council
The Arctic Council is a high-level intergovernmental forum that addresses issues faced by the Arctic governments and the indigenous people of the Arctic. At present, eight countries exercise sovereignty over the lands within the Arctic Circle, and these constitute the member states of the council: Canada; Denmark; Finland; Iceland; Norway; Russia; Sweden; and the United States. Other countries or national groups can be admitted as observer states, while organizations representing the concerns of indigenous peoples can be admitted as indigenous permanent participants. History The first step towards the formation of the Council occurred in 1991 when the eight Arctic countries signed the Arctic Environmental Protection Strategy (AEPS). The 1996 Ottawa Declaration established the Arctic Council as a forum for promoting cooperation, coordination, and interaction among the Arctic states, with the involvement of the Arctic Indigenous communities and other Arctic inhabitants on issues ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gas Flare
A gas flare, alternatively known as a flare stack, flare boom, ground flare, or flare pit is a gas combustion device used in places such as petroleum refineries, chemical plants and natural gas processing plants, oil or gas extraction sites having oil wells, gas wells, offshore oil and gas rigs and landfills. In industrial plants, flare stacks are primarily used for burning off flammable gas released by safety valves during unplanned over-pressuring of plant equipment. (See Chapter 11, ''Flare Stack Plume Rise''). During plant or partial plant startups and shutdowns, they are also often used for the planned combustion of gases over relatively short periods. At oil and gas extraction sites, gas flares are similarly used for a variety of startup, maintenance, testing, safety, and emergency purposes. In a practice known as production flaring, they may also be used to dispose of large amounts of unwanted associated petroleum gas, possibly throughout the life of an oil well. 5 bar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ARPA-E
ARPA-E, or Advanced Research Projects Agency–Energy is a United States government agency tasked with promoting and funding research and development of advanced energy technologies. It is modeled after the Defense Advanced Research Projects Agency (DARPA). The current Acting Director is ARPA-E Deputy Director for Technology Jennifer Gerbi. History and mission Legislative history ARPA-E was initially conceived by a report by the National Academies entitled ''Rising Above the Gathering Storm: Energizing and Employing America for a Brighter Economic Future''. The report described a need for the US to stimulate innovation and develop clean, affordable, and reliable energy. ARPA-E was officially created by the America COMPETES Act , authored by Congressman Bart Gordon, within the United States Department of Energy (DOE) in 2007, though without a budget. The initial budget of about $400 million was a part of the economic stimulus bill of February 2009. In early January 2011, the Am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megagrams
The tonne ( or ; symbol: t) is a unit of mass equal to 1000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton to distinguish it from the non-metric units of the short ton ( United States customary units), and the long ton ( British imperial units). It is equivalent to approximately 2204.6 pounds, 1.102 short tons, and 0.984 long tons. The official SI unit is the megagram (symbol: Mg), a less common way to express the same mass. Symbol and abbreviations The BIPM symbol for the tonne is t, adopted at the same time as the unit in 1879.Table 6 . BIPM. Retrieved on 2011-07-10. Its use is also official for the metric ton in the United States, having been adopted by the United States |
Methanotrophs
Methanotrophs (sometimes called methanophiles) are prokaryotes that metabolize methane as their source of carbon and chemical energy. They are bacteria or archaea, can grow aerobically or anaerobically, and require single-carbon compounds to survive. Methanotrophs are especially common in or near environments where methane is produced, although some methanotrophs can oxidize atmospheric methane. Their habitats include wetlands, soils, marshes, rice paddies, landfills, aquatic systems (lakes, oceans, streams) and more. They are of special interest to researchers studying global warming, as they play a significant role in the global methane budget, by reducing the amount of methane emitted to the atmosphere. Methanotrophy is a special case of methylotrophy, using single-carbon compounds that are more reduced than carbon dioxide. Some methylotrophs, however, can also make use of multi-carbon compounds; this differentiates them from methanotrophs, which are usually fastidious metha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudomonadota
Pseudomonadota (synonym Proteobacteria) is a major phylum of Gram-negative bacteria. The renaming of phyla in 2021 remains controversial among microbiologists, many of whom continue to use the earlier names of long standing in the literature. The phylum Proteobacteria includes a wide variety of pathogenic genera, such as ''Escherichia'', '' Salmonella'', ''Vibrio'', ''Yersinia'', ''Legionella'', and many others.Slonczewski JL, Foster JW, Foster E. Microbiology: An Evolving Science 5th Ed. WW Norton & Company; 2020. Others are free-living (nonparasitic) and include many of the bacteria responsible for nitrogen fixation. Carl Woese established this grouping in 1987, calling it informally the "purple bacteria and their relatives". Because of the great diversity of forms found in this group, it was later informally named Proteobacteria, after Proteus, a Greek god of the sea capable of assuming many different shapes (not after the Proteobacteria genus ''Proteus''). In 2021 the Internat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Russell Glacier (Greenland)
Russell Glacier ( da, Russells Gletscher) is a glacier in the Qeqqata municipality in central-western Greenland. It flows from the Greenland ice sheet ( kl, Sermersuaq) in the western direction. The front of the glacier is located east of Kangerlussuaq. It is active, advancing every year, and, due to easy access from Kangerlussuaq, it remains a popular place for tourists to visit. Geography The ice sheet outflow ending in Russell Glacier is bounded on the north by the tundra highland of Isunngua and on the south by an exposed, barren, flattened ridge of Akuliarusiarsuk. Several meltwater outflow streams from the base of the glacier form the Akuliarusiarsuup Kuua river, which flows west-southwest towards Kangerlussuaq. The sandur basin of the outflow river forming the valley of the same name ( da, Sandflugtdalen) is very shallow; shallow enough to form quicksand fields several kilometers long. Directly to the west of the glacier is a large lake, the 2x10km Aajuitsup Tasia. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Methane
Atmospheric methane is the methane present in Earth's atmosphere. Atmospheric methane concentrations are of interest because it is one of the most potent greenhouse gases in Earth's atmosphere. Atmospheric methane is rising. The 20-year global warming potential of methane is 84. See Table 8.7. That is, over a 20-year period, it traps 84 times more heat per mass unit than carbon dioxide (CO2) and 105 times the effect when accounting for aerosol interactions. Global methane concentrations rose from 722 parts per billion (ppb) in pre-industrial times to 1895 ppb by 2021, an increase by a factor of 2.6 and the highest value in at least 800,000 years. Its concentration is higher in the Northern Hemisphere since most sources (both natural and human) are located on land and the Northern Hemisphere has more land mass. The concentrations vary seasonally, with, for example, a minimum in the northern tropics during April−May mainly due to removal by the hydroxyl radical. It rema ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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