Atmospheric Science Vocabulary Quiz

The troposphere is the lowest layer of Earth's atmosphere, extending from the surface to approximately 8–15 km altitude. It contains about 75% of the atmosphere's mass and almost all water vapour. Temperature decreases with altitude in the troposphere, which is the layer in which all weather — clouds, rain, snow and thunderstorms — occurs.

The stratosphere lies above the troposphere at altitudes of approximately 12–50 km. Unlike the troposphere, temperature increases with altitude here because the ozone layer absorbs ultraviolet radiation from the Sun. The ozone layer is crucial for life on Earth as it filters out most harmful UV-B and UV-C radiation.

An aerosol is a suspension of tiny solid or liquid particles in the air. Aerosols can be natural (sea salt, dust, pollen, volcanic ash) or human-made (soot, industrial particles). They affect climate by scattering or absorbing sunlight and by acting as cloud condensation nuclei. Some aerosols cool the climate by reflecting sunlight; others warm it by absorbing it.

Convection is the transfer of heat through the movement of air. When air near the surface is heated, it becomes less dense and rises, while cooler air sinks to replace it. This drives the formation of clouds, thunderstorms and large-scale atmospheric circulation. Convection is a key mechanism in the development of cumulonimbus clouds.

The jet stream is a fast-flowing, narrow band of air moving west to east at high altitudes in the upper troposphere. There are typically four jet streams globally. The polar jet stream in the Northern Hemisphere has a major influence on weather patterns in Europe and North America, directing storms and separating cold polar air from warmer subtropical air.

Albedo is the proportion of incoming solar radiation reflected by a surface, expressed as a fraction between 0 and 1. Fresh snow has a very high albedo (around 0.9), while the ocean has a low albedo (around 0.06). The melting of Arctic sea ice reduces albedo, causing the ocean to absorb more solar energy and accelerating warming.

Insolation (incoming solar radiation) is the amount of solar energy received per unit area at a given location. It varies with latitude, season, time of day and cloud cover. The unequal distribution of insolation between the tropics and poles drives atmospheric and oceanic circulation, creating winds, currents and weather patterns.

Barometric pressure is the force per unit area exerted by the atmosphere on the Earth's surface. Standard sea-level pressure is approximately 1013 hPa. High pressure generally brings settled, fair weather, while low pressure is associated with cloud, wind and precipitation.

Precipitation is any form of water — liquid or solid — that falls from clouds and reaches the Earth's surface, including rain, snow, sleet and hail. It forms when water droplets or ice crystals in clouds grow large enough to fall under gravity. It is a crucial part of the hydrological cycle, replenishing rivers, lakes and groundwater.

Humidity is the amount of water vapour in the air, commonly expressed as relative humidity — a percentage of the maximum amount the air could hold at that temperature. When relative humidity reaches 100%, condensation occurs, forming dew, fog or clouds. High humidity makes warm temperatures feel hotter because perspiration evaporates more slowly.