Meteopedia — Weather glossary

Weather encyclopedia with 342 terms

Browse detailed definitions of atmospheric phenomena, cloud types, measurement instruments, regional winds, meteorological scales, climatology and more.

342 Meteopedia 16 categories
All (342) Atmospheric phenomena (50) Instruments (30) Scales and measurements (10) Clouds (36) Wind (34) Precipitation (24) Temperature (15) Cyclones and severe storms (14) Atmospheric optics (16) Meteorological astronomy (5) Climatology (34) Marine meteorology (15) Air quality (10) Agrometeorology (10) Hazards and safety (10) General (29)
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A

Airborne pollen

Pollen grains suspended in air from plants, trees, and grasses, the main cause of seasonal respiratory allergies such as hay fever and allergic asthma.

Air quality

Atmospheric aerosol

Solid or liquid particles suspended in air, of natural (dust, sea salt, pollen) or anthropogenic (combustion, industry) origin, affecting climate and air quality.

Air quality

C

Carbon monoxide

Toxic, odourless gas (CO) produced by incomplete combustion of fuels, reducing the blood's ability to carry oxygen.

Air quality

M

Mixing layer

Lowest atmospheric layer where pollutants are dispersed by turbulence, varying in height from 100 m on stable nights to 2–3 km on convective afternoons.

Air quality

N

Nitrogen dioxide

Pollutant gas (NO₂) emitted mainly by traffic and combustion, irritating airways and contributing to tropospheric ozone and fine particle formation.

Air quality

P

Photochemical smog

Mixture of secondary pollutants formed by exhaust gases reacting with sunlight, producing a visible brown haze over cities with heavy traffic and intense sunshine.

Air quality

PM10

Airborne particles smaller than 10 micrometres, from dust, construction, traffic, and industry, penetrating the upper respiratory system.

Air quality

PM2.5

Airborne particles smaller than 2.5 micrometres, able to penetrate lung alveoli and the bloodstream, considered the most harmful pollutant for health.

Air quality

S

Sulphur dioxide

Pollutant gas (SO₂) emitted by power plants, refineries, and volcanoes, a precursor of acid rain and fine sulphate particles.

Air quality

T

Tropospheric ozone

Ozone in the lower atmosphere, a secondary pollutant formed by photochemical reactions between nitrogen oxides and volatile organic compounds under intense solar radiation.

Air quality