Megacryometeor

Last updated

A megacryometeor is a very large chunk of ice which, despite sharing many textural, hydro-chemical, and isotopic features found in large hailstones, is formed under unusual atmospheric conditions which clearly differ from those of the cumulonimbus cloud scenario (i.e. clear-sky conditions). They are sometimes called huge hailstones, but do not need to form under thunderstorm conditions unlike hailstorms. Jesús Martínez-Frías, a planetary geologist and astrobiologist at Institute of Geosciences (Spanish : Instituto de Geociencias, IGEO) in the Spanish National Research Council (Spanish : Consejo Superior de Investigaciones Científicas, CSIC) [1] in Madrid, pioneered research into megacryometeors in January 2000 after ice chunks weighing up to 6.6 pounds (3.0 kg) rained on Spain out of cloudless skies for ten consecutive days.

Contents

Mass and size

More than 50 megacryometeors have been recorded since the year 2000. They vary in mass between 0.5 kilograms (1.1 lb) to several tens of kilograms. One in Brazil weighed in at more than 50 kilograms (110 lb). [2] Chunks about 2 m (6 ft 7 in) in size also fell in Scotland on 13 August 1849. [3]

Formation

The process that creates megacryometeors is not completely understood yet, mainly with respect to the atmospheric dynamics necessary to produce them. They may have a similar mechanism of formation that leads to the production of hailstones. [4] Scientific studies show that their composition matches normal tropospheric rainwater for the areas in which they fall. In addition, megacryometeors also display textural variations of the ice surface and hydro-chemical and isotopic heterogeneity in its composition, which gives potential evidence to a complex formation process in the lower atmosphere. [5] [6] [7] It is known that they do not form from airplane toilet leakage because the large chunks of ice that occasionally do fall from airliners are distinctly blue due to the disinfectant used by them (hence their common name of "blue ice").

Some have speculated that these ice chunks must have fallen from aircraft fuselages [4] after plain water ice accumulating on those aircraft through normal atmospheric conditions has simply broken loose. However, similar events also occurred prior to the invention of aircraft. [8] [9] Studies indicate that metrological fluctuations in tropopause, associated with hydration of the lower stratosphere and stratospheric cooling, can be related to their formation. [5] A detailed micro-Raman spectroscopic study made it possible to place the formation of the megacryometeors within a particular range of temperatures: −10 to −20 °C (14 to −4 °F). [10] They are sometimes confused with meteors because they can leave small impact craters, though they form in the atmosphere and not from outer space.

Related Research Articles

<span class="mw-page-title-main">Eocene</span> Second epoch of the Paleogene Period

The Eocene Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name Eocene comes from the Ancient Greek ἠώς and καινός and refers to the "dawn" of modern ('new') fauna that appeared during the epoch.

<span class="mw-page-title-main">Hail</span> Form of solid precipitation

Hail is a form of solid precipitation. It is distinct from ice pellets, though the two are often confused. It consists of balls or irregular lumps of ice, each of which is called a hailstone. Ice pellets generally fall in cold weather, while hail growth is greatly inhibited during cold surface temperatures.

<span class="mw-page-title-main">Ice</span> Frozen water: the solid state of water

Ice is water frozen into a solid state, typically forming at or below temperatures of 0 degrees Celsius or 32 °F Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaque bluish-white color.

<span class="mw-page-title-main">Water vapor</span> Gaseous phase of water

Water vapor, water vapour or aqueous vapor is the gaseous phase of water. It is one state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. Water vapor is transparent, like most constituents of the atmosphere. Under typical atmospheric conditions, water vapor is continuously generated by evaporation and removed by condensation. It is less dense than most of the other constituents of air and triggers convection currents that can lead to clouds.

<span class="mw-page-title-main">Mushroom cloud</span> Cloud of debris and smoke from a large explosion

A mushroom cloud is a distinctive mushroom-shaped flammagenitus cloud of debris, smoke and usually condensed water vapor resulting from a large explosion. The effect is most commonly associated with a nuclear explosion, but any sufficiently energetic detonation or deflagration will produce the same effect. They can be caused by powerful conventional weapons, like thermobaric weapons, including the ATBIP and GBU-43/B Massive Ordnance Air Blast. Some volcanic eruptions and impact events can produce natural mushroom clouds.

<span class="mw-page-title-main">Cloud physics</span> Study of the physical processes in atmospheric clouds

Cloud physics is the study of the physical processes that lead to the formation, growth and precipitation of atmospheric clouds. These aerosols are found in the troposphere, stratosphere, and mesosphere, which collectively make up the greatest part of the homosphere. Clouds consist of microscopic droplets of liquid water, tiny crystals of ice, or both. Cloud droplets initially form by the condensation of water vapor onto condensation nuclei when the supersaturation of air exceeds a critical value according to Köhler theory. Cloud condensation nuclei are necessary for cloud droplets formation because of the Kelvin effect, which describes the change in saturation vapor pressure due to a curved surface. At small radii, the amount of supersaturation needed for condensation to occur is so large, that it does not happen naturally. Raoult's law describes how the vapor pressure is dependent on the amount of solute in a solution. At high concentrations, when the cloud droplets are small, the supersaturation required is smaller than without the presence of a nucleus.

<span class="mw-page-title-main">Proxy (climate)</span> Preserved physical characteristics allowing reconstruction of past climatic conditions

In the study of past climates ("paleoclimatology"), climate proxies are preserved physical characteristics of the past that stand in for direct meteorological measurements and enable scientists to reconstruct the climatic conditions over a longer fraction of the Earth's history. Reliable global records of climate only began in the 1880s, and proxies provide the only means for scientists to determine climatic patterns before record-keeping began.

<span class="mw-page-title-main">Polar stratospheric cloud</span> Clouds occurring in the stratosphere in high-latitude regions

Polar stratospheric clouds (PSCs) are clouds in the winter polar stratosphere at altitudes of 15,000–25,000 m (49,000–82,000 ft). They are best observed during civil twilight, when the Sun is between 1 and 6 degrees below the horizon, as well as in winter and in more northerly latitudes. One main type of PSC is made up mostly of supercooled droplets of water and nitric acid and is implicated in the formation of ozone holes. The other main type consists only of ice crystals which are not harmful. This type of PSC is also referred to as nacreous.

Mass-independent isotope fractionation or Non-mass-dependent fractionation (NMD), refers to any chemical or physical process that acts to separate isotopes, where the amount of separation does not scale in proportion with the difference in the masses of the isotopes. Most isotopic fractionations are caused by the effects of the mass of an isotope on atomic or molecular velocities, diffusivities or bond strengths. Mass-independent fractionation processes are less common, occurring mainly in photochemical and spin-forbidden reactions. Observation of mass-independently fractionated materials can therefore be used to trace these types of reactions in nature and in laboratory experiments.

<span class="mw-page-title-main">Cosmic dust</span> Dust floating in space

Cosmic dust, also called extraterrestrial dust or space dust, is dust which exists in outer space, or has fallen on Earth. Most cosmic dust particles measure between a few molecules and 0.1 mm. Larger particles are called meteoroids. Cosmic dust can be further distinguished by its astronomical location: intergalactic dust, interstellar dust, interplanetary dust and circumplanetary dust. There are several methods to obtain space dust measurement.

<span class="mw-page-title-main">Max Planck Institute for Chemistry</span>

The Max Planck Institute for Chemistry is a non-university research institute under the auspices of the Max Planck Society in Mainz. It was created as a Kaiser Wilhelm Institute in 1911.

The Arthur L. Day Prize and Lectureship is awarded by the U.S. National Academy of Sciences "to a scientist making new contributions to the physics of the Earth whose four to six lectures would prove a solid, timely, and useful addition to the knowledge and literature in the field." The prize was established by the physicist Arthur L. Day.

<span class="mw-page-title-main">Atmospheric convection</span> Atmospheric phenomenon

Atmospheric convection is the result of a parcel-environment instability, or temperature difference layer in the atmosphere. Different lapse rates within dry and moist air masses lead to instability. Mixing of air during the day which expands the height of the planetary boundary layer leads to increased winds, cumulus cloud development, and decreased surface dew points. Moist convection leads to thunderstorm development, which is often responsible for severe weather throughout the world. Special threats from thunderstorms include hail, downbursts, and tornadoes.

<span class="mw-page-title-main">Atmosphere of Titan</span> Only thick atmosphere of any moon in the Solar System

The atmosphere of Titan is the dense layer of gases surrounding Titan, the largest moon of Saturn. It is the only thick atmosphere of a natural satellite in the Solar System. Titan's lower atmosphere is primarily composed of nitrogen (94.2%), methane (5.65%), and hydrogen (0.099%). There are trace amounts of other hydrocarbons, such as ethane, diacetylene, methylacetylene, acetylene, propane, PAHs and of other gases, such as cyanoacetylene, hydrogen cyanide, carbon dioxide, carbon monoxide, cyanogen, acetonitrile, argon and helium. The isotopic study of nitrogen isotopes ratio also suggest acetonitrile may be present in quantities exceeding hydrogen cyanide and cyanoacetylene. The surface pressure is about 50% higher than on Earth at 1.5 bars which is near the triple point of methane and allows there to be gaseous methane in the atmosphere and liquid methane on the surface. The orange color as seen from space is produced by other more complex chemicals in small quantities, possibly tholins, tar-like organic precipitates.

<span class="mw-page-title-main">Cloud iridescence</span> Optical phenomenon

Cloud iridescence or irisation is a colorful optical phenomenon that occurs in a cloud and appears in the general proximity of the Sun or Moon. The colors resemble those seen in soap bubbles and oil on a water surface. It is a type of photometeor. This fairly common phenomenon is most often observed in altocumulus, cirrocumulus, lenticular, and cirrus clouds. They sometimes appear as bands parallel to the edge of the clouds. Iridescence is also seen in the much rarer polar stratospheric clouds, also called nacreous clouds.

<span class="mw-page-title-main">Allende meteorite</span>

The Allende meteorite is the largest carbonaceous chondrite ever found on Earth. The fireball was witnessed at 01:05 on February 8, 1969, falling over the Mexican state of Chihuahua. After it broke up in the atmosphere, an extensive search for pieces was conducted and over 2 tonnes were recovered. The availability of large quantities of samples of the scientifically-important chondrite class has enabled numerous investigations by many scientists; it is often described as "the best-studied meteorite in history." The Allende meteorite has abundant, large calcium–aluminium-rich inclusions (CAI), which are among the oldest objects formed in the Solar System.

<span class="mw-page-title-main">Stratospheric sulfur aerosols</span>

Stratospheric sulfur aerosols are sulfur-rich particles which exist in the stratosphere region of the Earth's atmosphere. The layer of the atmosphere in which they exist is known as the Junge layer, or simply the stratospheric aerosol layer. These particles consist of a mixture of sulfuric acid and water. They are created naturally, such as by photochemical decomposition of sulfur-containing gases, e.g. carbonyl sulfide. When present in high levels, e.g. after a strong volcanic eruption such as Mount Pinatubo, they produce a cooling effect, by reflecting sunlight, and by modifying clouds as they fall out of the stratosphere. This cooling may persist for a few years before the particles fall out.

The Late Ordovician glaciation, also known as the Hirnantian glaciation or end-Ordovician glaciation, is the first part of the Andean-Saharan glaciation. It was centered on the Sahara region in late Ordovician, about 440–460 Ma. The major glaciation during this period is widely considered to be the leading cause of the Ordovician-Silurian extinction event. Evidence of this glaciation can be seen in places such as Morocco, South Africa, Libya, and Wyoming. More evidence derived from isotopic data is that during the Late Ordovician, tropical ocean temperatures were about 5 °C cooler than present day; this would have been a major factor that aided in the glaciation process.

Kristie Ann Boering is a Professor of Earth and Planetary Science and the Lieselotte and David Templeton Professor of Chemistry at University of California, Berkeley. She studies atmospheric chemistry and mass transport in the extraterrestrial atmosphere using kinetics and photochemistry. Boering was elected a member of the National Academy of Sciences in 2018.

<span class="mw-page-title-main">Mark H. Thiemens</span> US scientist and academic

Mark Howard Thiemens is a Distinguished Professor and the Chancellors Associates Chair in the Department of Chemistry and Biochemistry at the University of California San Diego. He is best known for the discovery of a new physical chemical phenomena termed the mass independent isotope effect.

References

  1. "Ficha de Jesús Martínez Frías en el Directorio del IGEO de CSIC, 30 de enero de 2021".
  2. Gelo caindo do céu assusta moradores Archived 2007-09-27 at the Wayback Machine (in Portuguese).
  3. Peter T. Bobrowsky; Hans Rickman (2007). Comet/asteroid impacts and human society: an interdisciplinary approach. Springer. pp. 343–. ISBN   978-3-540-32709-7 . Retrieved 2 February 2012.
  4. 1 2 The Peculiar Phenomenon of Megacryometeors by Alan Bellows.
  5. 1 2 Martinez-FrÍas, J.; Delgado, A.; MillÁn, M.; Reyes, E.; Rull, F.; Travis, D.; Garcia, R.; LÓpez-Vera, F.; et al. (2005). "Oxygen and Hydrogen Isotopic Signatures of Large Atmospheric Ice Conglomerations". Journal of Atmospheric Chemistry. 52 (2): 185. Bibcode:2005JAtC...52..185M. doi:10.1007/s10874-005-2007-7.
  6. Martinez-Frias, Jesus; Delgado Huertas, Antonio (2006). "Megacryometeors: Distribution on Earth and Current Research". Ambio: A Journal of the Human Environment. 35 (6): 314. doi:10.1579/06-S-187.1. hdl: 10261/36014 .
  7. Orellana, Francisco Alamilla; Alegre, José Ma Ramiro; Cordero Pérez, José Carlos; Martín Redondo, Ma Paz; Delgado Huertas, Antonio; Fernández Sampedro, Ma Teresa; Menor-Salván, César; Ruiz-Bermejo, Marta; et al. (2008). "Monitoring the fall of large atmospheric ice conglomerations: a multianalytical approach to the study of the Mejorada del Campo megacryometeor" (PDF). Journal of Environmental Monitoring. 10 (4): 570–4. doi:10.1039/b718785h. hdl: 10261/36027 . PMID   18385879.
  8. William R. Corliss (1983). Tornados, dark days, anomalous precipitation, and related weather phenomena: a catalog of geophysical anomalies. Sourcebook Project. ISBN   978-0-915554-10-2.
  9. Riesgos Naturales, by Olcina Santos, J. and Ayala-Carcedo, J.
  10. Rull, F.; Delgado, A.; Martinez-Frias, J. (2010). "Micro-Raman spectroscopic study of extremely large atmospheric ice conglomerations (megacryometeors)". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 368 (1922): 3145–52. Bibcode:2010RSPTA.368.3145R. doi: 10.1098/rsta.2010.0103 . PMID   20529951.