Part Two II › Division II II › Section 223 223

Weather and Climate

Subject Outline

ACondensation of water in the atmosphere producing clouds, fogs, and precipitation
- 1Moisture in the atmosphere [see also 221.A.1.a. and 723.G.5.]
  - aHumidity indices: absolute, specific, and relative humidity; dew-point temperature
  - bClimatic aspects of atmospheric humidity [see E.1.e., below]
  - cEffects of atmospheric humidity on the life and health of humans and other life-forms [see E.4., below]
- 2Condensation of atmospheric water vapour
  - aConvection, air-mass convergence, and other processes that lead to condensation [see also 221.B.]
  - bCondensation nuclei: atmospheric ions, salt and dust particles
  - cDew
  - dFrost
- 3Clouds and fogs
  - aFormation and growth of clouds
  - bDescription and classification of clouds
  - cClouds and weather
  - dFog
  - eArtificial modification of clouds and fogs
- 4Precipitation [see also 222.D. and 723.G.5.]
  - aOrigin of precipitation in clouds, mechanisms of precipitation release [see also A.3.a., above]
  - bTypes of precipitation: drizzle, rain, freezing rain; snow; sleet, hail
  - cThe world distribution of rainfall
  - dEffects of precipitation
BWinds and storms [see also 221.B.]
- 1Development and distribution of cyclones and anticyclones
- 2Lightning and thunderstorms [see also 127.A. and B.]
- 3Tornadoes, hail, and other severe phenomena associated with organized storms or squall lines
- 4Tropical cyclones: hurricanes and typhoons
CWeather forecasting
- 1Synoptic weather data: the collection and correlation of meteorological observations
- 2Numerical weather prediction and numerical climate modeling
- 3Short-range forecasting
  - aNowcasting: predictions based on computer analyses of radar and satellite observations of local atmospheric conditions
  - bModel Output Statistics: extrapolation of weather conditions, using statistical relations , between numerical model forecasts and past weather phenomena
- 4Long-range forecasting
  - aEnhancing the reliability of extended-range prediction through systematic studies of atmosphere-ocean interactions; e.g., El Nino/Southern Oscillation (ENSO)
  - bLimits to predictability
DWeather lore
EClimate: the aggregate of weather [see also 133.B.5., 221, and 723.G.5.]
- 1Factors that generate climate
  - aSolar radiation
    - iVariability of incident radiation; the solar constant
    - iiEffects of the atmosphere: absorption by dust and gases, including the trapping of solar radiation of infrared wavelength (the so-called greenhouse effect)
    - iiiVariations in the Earth's albedo due to clouds and ice
  - bTemperature
  - cAtmospheric pressure
  - dThe world's oceans
  - eThe moisture cycle
- 2Climatic variation
  - aSeasonal changes resulting from the north-south migration of belts of cyclonic activity and other cyclic processes
  - bLocal effects: modification of climate by local terrain and surface conditions
  - cEffects of human activities on global climate; e.g., greenhouse warming induced by high concentrations of carbon dioxide (from the burning of fossil fuels) and other trace gases in the atmosphere [see also 241.B.5.and 737.C.1.J]
- 3Climatic types: the Koppen classification system, world climates and their distribution
- 4Influences of climate on terrestrial life
- 5Microclimates [see also 351.B.]
- 6Climatic change
  - aEvidence: e.g., landscape features associated with glaciations; fluctuations of lake and sea levels; pollen stratigraphy; archaeological and historical data