Science terms starting with A

1,045 terms

  1. Area Wide Hydrologic Prediction System (AWHPS) A computer system which automatically ingests areal flash flood guidance values and WSR-88D products and displays this data and other hydrologic…
  2. Area-Capacity Curve A graph showing the relation between the surface area of the water in a reservoir, the corresponding volume, and elevation.
  3. Area-capacity table A table giving reservoir storage capacity, and sometimes surface areas, in terms of elevation increments.
  4. Areas of Critical Environmental Concern (ACEC) These areas are managed by the Bureau of Land Management and are defined by the Federal Land Policy and Management Act of 1976 as having significant…
  5. Argon A colorless, odorless inert gas sometimes used in the spaces between the panes in energy efficient windows.
  6. Arid A region that receives too little water to support agriculture without irrigation. Less than ten inches of rainfall a year is typically considered arid.
  7. ARINC Aeronautical Radio, Incorporated
  8. Arizona Water Banking Authority (AWBA) The AWBA was established in 1996 to increase utilization of the state's Colorado River entitlement and to develop long-term storage credits for the state.
  9. ARM Climate Research Facility (ACRF) A U.S. Department of Energy designated national user facility that provides a unique asset for the study of global change to the broader national and…
  10. ARM Mobile Facility See Mobile Facility.
  11. ARMG Abbreviation for antibiotic resistance marker gene.
  12. Armoring. See riprap.
  13. ARMS Automated Records Management System.
  14. ARND Around
  15. aromatic (A-ruh-MA-tik) Having an odor, which often is pleasant or spicy.
  16. ARP address resolution protocol.
  17. ARR Arrive/Arrival
  18. ARRA American Recovery and Reinvestment Act (can also be shortened to \"Recovery Act\").
  19. Array (Solar) Any number of solar photovoltaic modules or solar thermal collectors or reflectors connected together to provide electrical or thermal energy.
  20. Arrayed library Individual primary recombinant clones (hosted in phage, cosmid, YAC, or other vector) that are placed in two-dimensional arrays in microtiter dishes.
  21. Arrays See Photovoltaic (PV) array
  22. Arroyo A Spanish word for brook that refers to a dry river, creek, or stream bed that temporarily or seasonally fills and flows after sufficient rain.
  23. ARS Abbreviation for autonomous(ly) replicating segment (or sequence).
  24. ARSI Atmospheric Research System, Inc.
  25. ART The Automatic Radiotheodolite. A ground-based radio direction finder that automatically tracks a ballon-borne radiosonde.
  26. ARTCC Air Route Traffic Control Center
  27. Artesian water (artesian pressure) Groundwater that is under pressure when tapped by a well and is able to rise above the level at which it is first encountered.
  28. Artesian Well Water held under pressure in porous rock or soil confined by impermeable geologic formations. An artesian well is free flowing. See confined aquifer.
  29. Artifact An object produced or shaped by human beings and of archaeological or historical interest.
  30. Artificial Control A weir or other man-made structure which serves as the control for a stream-gaging station.
  31. Artificial drains Man-made or constructed drains.
  32. artificial inembryonation Non-surgical transfer of embryo(s) to a recipient female. As in vitro embryo technology develops, artificial inembryonation may replace artificial…
  33. artificial insemination (Abbreviation: AI). The deposition of semen, using a syringe, at the mouth of the uterus to make conception possible.
  34. artificial medium See: culture medium.
  35. Artificial recharge Addition of surface water to a ground water reservoir by human activity, such as putting surface water into spreading basins.
  36. artificial seed Encapsulated or coated somatic embryos that are planted and treated like seed.
  37. artificial selection The practice of choosing individuals from a population for reproduction, usually because these individuals possess one or more desirable traits.
  38. ARTS Automated Resources Training System.
  39. ARWRI American River Water Resources Investigation.
  40. AS assistant secretary.
  41. ASA Abbreviation for allele-specific amplification.
  42. ASAP as soon as possible.
  43. ASAPTRAN The software component of ASAP.
  44. ASB Aviation Support Branch
  45. ASC Administrative Service Center.
  46. ASCC Alaskan System Coordination Council (part of NERC).
  47. ASCE American Society of Civil Engineers.
  48. ASCII An acronym for American Standard Code that allocates a number to each key on the keyboard and that can be traded and read by most computer systems.
  49. ascites (uh-SY-teez) Abnormal buildup of fluid in the abdomen that may cause swelling. In late-stage cancer, tumor cells may be found in the fluid in the abdomen.
  50. ASCMP Administrative Support Career Management Program.
  51. ascospore One of the spores contained in the ascus of certain fungi.
  52. ASCS Agricultural Stabilization and Conservation Service.
  53. ascus (pl.: asci) Reproductive sac in the sexual stage of a type of fungi (Ascomycetes) in which ascospores are produced.
  54. aseptic Sterile, free of contaminating organisms (bacteria, fungi, algae but not generally including viruses, and particularly not internal symbionts ).
  55. asexual Reproduction not involving meiosis or the union of gametes.
  56. asexual embryogenesis See: somatic cell embryogenesis.
  57. asexual propagation Vegetative, somatic, non-sexual reproduction of a plant without fertilization.
  58. Asexual reproduction Nonsexual means of reproduction which can include grafting and budding.
  59. Ash The non-combustible residue of a combusted substance composed primarily of alkali and metal oxides.
  60. ASHRAE Abbreviation for the American Society of Heating, Refrigeration, and Air-Conditioning Engineers.
  61. ASL Above Sea Level
  62. ASOS The ASOS program is a joint effort of the National Weather Service (NWS), the Federal Aviation Administration (FAA), and the Department of Defense (DOD).
  63. Asphalt A dark-brown-to-black cement-like material containing bitumen as the predominant constituent. It is obtained by petroleum processing.
  64. ASR Alkali-silica reaction.
  65. ASR-9 Airport Surveillance Radar (FAA)
  66. assay (AS-say) A laboratory test to find and measure the amount of a specific substance.
  67. ASSE American Society of Safety Engineers.
  68. Assembly Putting sequenced fragments of DNA into their correct chromosomal positions.
  69. Associated facility A term used by Reclamation to describe those facilities examined by the respective regional or area office.
  70. ASSOCIATED PRINCIPAL USER A Principal User with dedicated communications to a WSR-88D unit.
  71. Association of Boards of Certification (ABC) An international organization representing over 150 boards which certify the operators of waterworks and waste water facilities.
  72. assortative mating Mating in which the partners are chosen on the basis of phenotypic similarity.
  73. assortment See: segregation.
  74. ASSR alkali-silicate/silica reaction.
  75. ASTM Abbreviation for the American Society for Testing and Materials, which is responsible for the issue of many standard methods used in the energy industry.
  76. Astrocyte (AS-troh-site) A star-shaped cell that helps nerve cells in the brain and spinal cord work the way they should. An astrocyte is a type of glial cell.
  77. Astronomical Dawn The time at which the sun is 18 degrees below the horizon in the morning. Astronomical dawn is that point in time at which the sun starts lightening the…
  78. Astronomical Dusk This is the time at which the sun is 18 degrees below the horizon in the evening. At this time the sun no longer illuminates the sky.
  79. Astronomical Unit (abbrev. AU)- The mean earth-sun distance, equal to 1.496x1013 cm, or 214.94 solar radii.
  80. ASTS above ground storage tanks.
  81. Asymmetric Not similar in size, shape, form or arrangement of parts on opposite sides of a line, point or plane.
  82. asymmetric hybrid A hybrid formed, usually via protoplast fusion, between two donors, where the chromosome complement of one of the donors is incomplete.
  83. asynapsis The failure or partial failure in the pairing of homologous chromosomes during the first meiotic prophase.
  84. Asynchronous Generator A type of electric generator that produces alternating current that matches an existing power source.
  85. At-rest earth pressure The value of the earth pressure when the soil mass is in its natural state without having been permitted to yield or without having been compressed.
  86. ataxia-telangiectasia A rare, inherited, progressive, degenerative disease of childhood that causes loss of muscle control, a weakened immune system, and an increased risk of…
  87. ATC Air Traffic Control
  88. ATDTDCS Automated Tone Dial Telephone Data Collection System - Data collection system where cooperative observers collect precipitation, stage, and temperature…
  89. ATF Austin Field Office (Austin, TX).
  90. Atlatl A wood or bone shaft implement, held in one hand, and used to throw a spear. The tool functions as a lever, giving greater thrust and distance.
  91. Atmosphere The gaseous envelope surrounding the Earth, which consists almost entirely of nitrogen (78.1% volume mixing ratio) and oxygen (20.
  92. Atmospheric absorption Attenuation of sound during its passage through air, during which its sound energy is gradually converted into heat by a number of molecular processes in…
  93. Atmospheric Boundary Layer Same as Boundary Layer - in general, a layer of air adjacent to a bounding surface.
  94. Atmospheric circulation Atmospheric circulation System of atmospheric motions over the Earth on the scale of the whole globe (general atmospheric circulation), or over a certain…
  95. Atmospheric Circulation Model A mathematical model for quantitatively describing, simulating, and analyzing the structure of the circulation in the atmosphere and the underlying causes.
  96. Atmospheric Imaging Assembly (AIA) an EUV Instrument onboard SDO.
  97. Atmospheric Lifetime The lifetime of a greenhouse gas refers to the approximate amount of time it would take for the anthropogenic increment to an atmospheric pollutant…
  98. atmospheric moisture The moisture content of the air as indicated by several measurements including relative humidity, specific humidity, dewpoint, vapor pressure, water vapor…
  99. Atmospheric phenomenon Atmospheric phenomenon (phenomena) As commonly used in weather observing practice, an observable occurrence of particular physical significance within the…
  100. Atmospheric Pressure The pressure of the air at sea level; one standard atmosphere at zero degrees centigrade is equal to 14.695 pounds per square inch (1.