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Cloud Condensation Nuclei
Cloud condensation nuclei (CCNs), also known as cloud seeds, are small particles typically 0.2 μm, or one hundredth the size of a cloud droplet. CCNs are a unique subset of aerosols in the atmosphere on which water vapour condenses. This can affect the radiative properties of clouds and the overall atmosphere. Water vapour requires a non- gaseous surface to make the transition to a liquid; this process is called condensation. In the atmosphere of Earth, this surface presents itself as tiny solid or liquid particles called CCNs. When no CCNs are present, water vapour can be supercooled at about for 5–6 hours before droplets spontaneously form. This is the basis of the cloud chamber for detecting subatomic particles. The concept of CCN (must associate to a supersaturation ratio) is used in cloud seeding, which tries to encourage rainfall by seeding the air with condensation nuclei (CN, which does not associate to supersaturation ratio). It has further been suggested that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Particulate
Particulate matter (PM) or particulates are microscopic particles of solid or liquid matter suspended in the air. An ''aerosol'' is a mixture of particulates and air, as opposed to the particulate matter alone, though it is sometimes defined as a subset of aerosol terminology. Sources of particulate matter can be natural or anthropogenic. Particulates have impacts on climate and precipitation that adversely affect human health. Types of atmospheric particles include suspended particulate matter; thoracic and respirable particles; inhalable coarse particles, designated PM, which are coarse particles with a diameter of 10 micrometers (μm) or less; fine particles, designated PM, with a diameter of 2.5 μm or less; ultrafine particles, with a diameter of 100 nm or less; and soot. Airborne particulate matter is a Group 1 carcinogen. Particulates are the most harmful form of air pollution as they can penetrate deep into the lungs and brain from blood streams, cau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marcia Baker
Marcia Baker is a retired professor known for her research on cloud physics which informs global climate models and defines the processes leading to the formation of lightning from clouds. She is the mother of Nobel laureate David Baker. Education and career Baker graduated in 1955 from Urbana High School in Illinois. She earned a scholarship on the basis of "scholastic achievement and promise of effective participation and leadership" to attend Cornell University from which she earned a B.S. in 1959. She earned an M.S. from Stanford University in 1960 and a Ph.D. in physics in 1971 from the University of Washington. She remained at the University of Washington following her Ph.D., initially as a research associate. She was promoted to professor of geophysics and atmospheric sciences in 1988. She retired in 2004 Research Baker's research on cloud physics informs climate change models. Her early research examined how atmospheric particles absorb energy and the formation of dro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Climate Change
Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in a broader sense also includes previous long-term changes to Earth's climate. The current rise in global temperatures is Scientific consensus on climate change, driven by human activities, especially fossil fuel burning since the Industrial Revolution. Fossil fuel use, Deforestation and climate change, deforestation, and some Greenhouse gas emissions from agriculture, agricultural and Environmental impact of concrete, industrial practices release greenhouse gases. These gases greenhouse effect, absorb some of the heat that the Earth Thermal radiation, radiates after it warms from sunlight, warming the lower atmosphere. Carbon dioxide, the primary gas driving global warming, Carbon dioxide in Earth's atmosphere, has increased in concentratio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice Nuclei
An ice nucleus, also known as an ice nucleating particle (INP), is a particle which acts as the nucleus for the formation of an ice crystal in the atmosphere. Ice nucleation mechanisms There are a number of mechanisms of ice nucleation in the atmosphere through which ice nuclei can catalyse the formation of ice particles. In the upper troposphere, water vapor can deposit directly onto solid particles. In clouds warmer than about where liquid water can persist in a supercooled state, ice nuclei can trigger droplets to freeze. Contact nucleation can occur if an ice nucleus collides with a supercooled droplet, but the more important mechanism of freezing is when an ice nucleus becomes immersed in a supercooled water droplet and then triggers freezing. In the absence of an ice nucleating particle, pure water droplets can persist in a supercooled state to temperatures approaching where they freeze homogeneously. There are several research groups that study ice nucleating properties ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hygroscopic
Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption (chemistry), absorption or adsorption from the surrounding Natural environment, environment, which is usually at normal or room temperature. If water molecules become suspended among the substance's molecules, adsorbing substances can become physically changed, e.g. changing in volume, boiling point, viscosity or some other physical characteristic or property of the substance. For example, a finely dispersed hygroscopic powder, such as a salt, may become clumpy over time due to collection of moisture from the surrounding environment. ''Deliquescent'' materials are sufficiently hygroscopic that they dissolve in the water they absorb, forming an aqueous solution. Hygroscopy is essential for many plant and animal species' attainment of hydration, nutrition, reproduction and/or seed dispersal. Biological evolution created hygroscopic solutions for water harvesting, filament tensile strength, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volatile Organic Compounds
Volatile organic compounds (VOCs) are organic compounds that have a high vapor pressure at room temperature. They are common and exist in a variety of settings and products, not limited to house mold, upholstered furniture, arts and crafts supplies, dry cleaned clothing, and cleaning supplies. VOCs are responsible for the odor of scents and perfumes as well as pollutants. They play an important role in communication between animals and plants, such as attractants for pollinators, protection from predation, and even inter-plant interactions. Some VOCs are dangerous to human health or cause harm to the environment, often despite the odor being perceived as pleasant, such as " new car smell". Anthropogenic VOCs are regulated by law, especially indoors, where concentrations are the highest. Most VOCs are not acutely toxic, but may have long-term chronic health effects. Some VOCs have been used in pharmaceutical settings, while others are the target of administrative controls ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfur Dioxide
Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a colorless gas with a pungent smell that is responsible for the odor of burnt matches. It is released naturally by volcanic activity and is produced as a by-product of metals refining and the burning of Sour gas, sulfur-Sour crude oil, bearing fossil fuels. Sulfur dioxide is somewhat toxic to humans, although only when inhaled in relatively large quantities for a period of several minutes or more. It was known to medieval alchemy, alchemists as "volatile spirit of sulfur". Structure and bonding SO2 is a bent molecule with ''C''2v Point groups in three dimensions, symmetry point group. A valence bond theory approach considering just ''s'' and ''p'' orbitals would describe the bonding in terms of resonance (chemistry), resonance between two resonance structures. The sulfur–oxygen bond has a bond order of 1.5. There is support f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phytoplankton
Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater Aquatic ecosystem, ecosystems. The name comes from the Greek language, Greek words (), meaning 'plant', and (), meaning 'wanderer' or 'drifter'. Phytoplankton obtain their energy through photosynthesis, as trees and other plants do on land. This means phytoplankton must have light from the sun, so they live in the well-lit surface layers (euphotic zone) of oceans and lakes. In comparison with terrestrial plants, phytoplankton are distributed over a larger surface area, are exposed to less seasonal variation and have markedly faster turnover rates than trees (days versus decades). As a result, phytoplankton respond rapidly on a global scale to climate variations. Phytoplankton form the base of marine and freshwater food webs and are key players in the global carbon cycle. They account for about half of global photosynthetic activity and at least half o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic
A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and because most of Earth's plate boundaries are underwater, most volcanoes are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes resulting from divergent tectonic activity are usually non-explosive whereas those resulting from convergent tectonic activity cause violent eruptions."Mid-ocean ridge tectonics, volcanism and geomorphology." Geology 26, no. 455 (2001): 458. https://macdonald.faculty.geol.ucsb.edu/papers/Macdonald%20Mid-Ocean%20Ridge%20Tectonics.pdf Volcanoes can also form where there is stretching a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfate
The sulfate or sulphate ion is a polyatomic anion with the empirical formula . Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salts of sulfuric acid and many are prepared from that acid. Spelling "Sulfate" is the spelling recommended by IUPAC, but "sulphate" was traditionally used in British English. Structure The sulfate anion consists of a central sulfur atom surrounded by four equivalent oxygen atoms in a tetrahedral arrangement. The symmetry of the isolated anion is the same as that of methane. The sulfur atom is in the +6 oxidation state while the four oxygen atoms are each in the −2 state. The sulfate ion carries an overall charge of −2 and it is the conjugate base of the bisulfate (or hydrogensulfate) ion, , which is in turn the conjugate base of , sulfuric acid. Organic sulfate esters, such as dimethyl sulfate, are covalent compounds and esters of sulfuric acid. The tetrahedral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Carbon
Black carbon (BC) is the light-absorbing refractory form of Chemical_element, elemental carbon remaining after pyrolysis (e.g., charcoal) or produced by incomplete combustion (e.g., soot). Tihomir Novakov originated the term black carbon in the 1970s, after identifying black carbon as fine Particulates, particulate matter (PM ≤ 2.5 μm aerodynamic diameter) in aerosols. Aerosol black carbon occurs in several linked forms. Formed through the incomplete combustion of fossil fuels, biofuel, and biomass, black carbon is one of the main types of soot particle in both human impact on the environment, anthropogenic and naturally occurring soot. As soot, black carbon causes disease and premature death. Because of these human health impacts, many countries have worked to reduce their emissions. In climatology, aerosol black carbon is a climate forcing agent contributing to Climate change, global warming. Black carbon warms the Earth by absorbing sunlight and heating the atmosp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
