troposphere

American  

[trop-uh-sfeer, troh-puh-] / ˈtrɒp əˌsfɪər, ˈtroʊ pə- /

noun

Meteorology.

1. the lowest layer of the atmosphere, 6 miles (10 km) high in some areas and as much as 12 miles (20 km) high in others, within which there is a steady drop in temperature with increasing altitude and within which nearly all cloud formations occur and weather conditions manifest themselves.

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troposphere British  

/ ˌtrɒpəˈsfɛrɪk, ˈtrɒpəˌsfɪə /

noun

1. the lowest atmospheric layer, about 18 kilometres (11 miles) thick at the equator to about 6 km (4 miles) at the Poles, in which air temperature decreases normally with height at about 6.5°C per km

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troposphere Scientific  

/ trō′pə-sfîr′,trŏp′ə- /

1. The lowest and densest region of the Earth's atmosphere, extending from the Earth's surface to the tropopause. The troposphere is characterized by temperatures that decrease with increasing altitude. At the top of this region, temperatures are close to −55°C (−67°F). The weather, major wind systems, and cloud formations occur mostly in the troposphere.

2. See also exosphere mesosphere stratosphere thermosphere See illustration at atmosphere

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troposphere Cultural  

1. The lowest layer of the atmosphere of the Earth, extending from ground level to an altitude of seven to ten miles.

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Other Word Forms

• tropospheric adjective

Etymology

Origin of troposphere

First recorded in 1905–10; tropo- + sphere

Compare meaning

How does troposphere compare to similar and commonly confused words? Explore the most common comparisons:

• troposphere vs. stratosphere

Explanation

Use the noun troposphere when you're talking about the part of the atmosphere that's closest to the surface of the Earth. The gases around our planet, which are affected by the Earth's gravity, make up the atmosphere. It is divided into three sections, the lowest of which is the troposphere. Our planet's weather is largely caused by whatever happens in the troposphere, which is known by scientists for its turbulent movement. The word troposphere comes from the Greek root tropos, "a turn or change."

Example Sentences

This increase promotes ice nucleation in clouds in the lower troposphere, weakening the efficiency of clouds to contain more liquid droplets and fewer ice crystals as the Arctic warms.

From Science Daily • Nov. 26, 2024

Jet streams travel in the tropopause—the area between the troposphere and the stratosphere—that hovers between five and nine miles above the Earth's surface.

From National Geographic • Jan. 26, 2024

They noted that their study was the first to officially discover airborne microplastics in cloud water both in the atmospheric boundary layer and in the free troposphere.

From Salon • Sep. 29, 2023

Those warm waters fuel convection, with hot, moisture-laden air rising and fueling rain until it hits the tropopause, where the lowest layer of the atmosphere, the troposphere, meets the stratosphere.

From Scientific American • Jun. 21, 2023

At 29,028 feet up in the troposphere, so little oxygen was reaching my brain that my mental capacity was that of a slow child.

From "Into Thin Air" by Jon Krakauer

Related Words

• atmosphere
• breeze
• wind