Defining Climatology Terminology
Glossary of Terms Used to Understand Climate Change and Predictions
Feb 6, 2008
Explore the terms climatologists use to describe the climate and methods of measurement. Some of the most frequent terms used in climate studies and research are identified here.
Climate Change
The Climate Prediction Center states that climate change is "a non-random change". The EPA describes climate change as “any significant change in measures of climate (such as temperature, precipitation, or wind) lasting for an extended period (decades or longer)”.
Three factors produce climate change:
- Natural factors such as the sun’s intensity and the Earth’s orbit
- Natural processes – ocean circulations
- Human activities – Human activities produce changes in the atmosphere due to burning fuels and pollution and land surface changes dues to deforestation, urbanization, etc.
Climate Model
From simple to complex, climatologists use climate models to show interactions between atmosphere, ocean, land and ice, in a quantitative manner. Climate models are used to determine and analyze climate projections or predictions.
Climate Normal
The climate normal does not mean what the normal weather for a location is but rather it describes the average weather for a specific location. Given a 30-year period of climate data, it defines the normal.
Climate System
Climatologists study five climate system components and the interaction between them.
- Atmosphere – gases that surround the Earth, which are almost entirely nitrogen, at 78% and oxygen 21%. Water vapor is also contained in the atmosphere.
- Hydrosphere – comprised of liquid surfaces and water – ocean, sea, river, lakes and underground water
- Cryosphere – frozen water – snow, permafrost, floating ice and glaciers. Changes in the cryosphere can impact atmosphere and biosphere directly.
- Lithosphere – the solid part of the earth made of the crust and the upper mantle.
- Biosphere – comprised of the ecosystems of Earth and all living organisms in the atmosphere, on land or in oceans. The biosphere includes dead organic matter such as in soil.
Ice Core
Ice cores are the section of ice removed from an ice sheet or glacier, used to study climate patterns. Climatologists study the air trapped in the ice sample, estimating carbon dioxide and other gas amounts in atmosphere over long periods of time. Any small changes will present themselves in ice cores.
Ozone
Ozone is made up of three oxygen atoms, also called the triatomic form of oxygen, and its reaction with ultraviolet radiation. The ozone layer lies between 15 km and 50 km above Earth. The ozone layer shields the Earth from the sun’s ultraviolet radiation. The stratospheric ozone layer occurs at 25 km. This layer varies in concentration due to seasonal changes, and natural events, such as volcanoes and solar flares. Ozone depleting substances also cause changes in ozone concentration.
Hydrologic Cycle
The hydrologic cycle involves the process of evaporation, condensation, precipitation and flow of water from land to ocean. This cycle has a major role in climate. The hydrologic cycle is responsible for transporting heat from the equator to the polar areas.
References:
National Climatic Data Center
U.S. Environmental Protection Agency
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