Climatology Glossary

The proportion of incoming solar radiation reflected by a surface, expressed as a value between 0 (no reflection) and 1 (total reflection).

A proposed geological epoch marking the period when human activities began to have a significant global impact on Earth's geology, ecosystems, and climate.

A system of ocean currents that transports warm surface water northward in the Atlantic and returns cold deep water southward, playing a major role in global heat distribution.

The biogeochemical cycle by which carbon is exchanged among the atmosphere, oceans, terrestrial biosphere, and lithosphere.

A natural or artificial reservoir that absorbs and stores more carbon from the atmosphere than it releases, such as forests and oceans.

A process that amplifies (positive) or dampens (negative) the response of the climate system to an initial perturbation.

A mathematical representation of the climate system that uses equations to simulate interactions among the atmosphere, oceans, land surface, and ice.

The equilibrium change in global mean surface temperature resulting from a sustained doubling of atmospheric CO2 concentration.

The apparent deflection of moving objects caused by Earth's rotation, influencing the direction of winds and ocean currents.

The portions of Earth's surface where water is in solid form, including ice sheets, glaciers, sea ice, snow cover, and permafrost.

The scientific method of dating tree rings to analyze past climate conditions with annual resolution.

A periodic fluctuation in sea surface temperatures and air pressure across the equatorial Pacific Ocean that affects global weather patterns.

A complex computer simulation that represents the physical processes of the atmosphere, oceans, and land surface on a three-dimensional grid.

A gas in the atmosphere that absorbs and re-emits infrared radiation, contributing to the greenhouse effect, including CO2, CH4, N2O, and water vapor.

A large-scale tropical atmospheric circulation pattern in which warm air rises near the equator, flows poleward, descends around 30 degrees latitude, and returns as trade winds.

The amount of incoming solar radiation received by a given area on Earth's surface, varying with latitude, season, and time of day.

An international body established in 1988 that assesses the science related to climate change and provides policymakers with regular scientific assessments.

Variants of a chemical element with different numbers of neutrons. Oxygen and hydrogen isotope ratios in ice and sediment are used as proxies for past temperature.

Periodic variations in Earth's orbital eccentricity, axial tilt, and precession that influence the distribution of solar radiation and drive glacial-interglacial cycles.

The ongoing decrease in ocean pH caused by the uptake of atmospheric CO2, which forms carbonic acid in seawater.

The study of past climates over geological time using natural climate archives and proxy records.

A preserved natural archive, such as tree rings, ice cores, or sediment layers, that provides indirect evidence of past climate conditions.

The net change in the energy balance of the Earth system due to an imposed perturbation, measured in watts per square meter at the tropopause.

A climate linkage between weather changes occurring in widely separated regions of the globe, often spanning thousands of kilometers.

The global-scale ocean circulation driven by differences in water density arising from variations in temperature and salinity.