Reference Terms
from Wikipedia, the free encyclopedia
Ionosphere
The ionosphere is the part of the atmosphere that is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on the Earth. The lowest part of the Earth's atmosphere is called the troposphere and it extends from the surface up to about 10 km (6 miles). The atmosphere above 10 km is called the stratosphere, followed by the mesosphere. It is in the stratosphere that incoming solar radiation creates the ozone layer. At heights of above 80 km (50 miles), in the thermosphere, the atmosphere is so thin that free electrons can exist for short periods of time before they are captured by a nearby positive ion. The number of these free electrons is sufficient to affect radio propagation. This portion of the atmosphere is ionized and contains a plasma which is referred to as the ionosphere. In a plasma, the negative free electrons and the positive ions are attracted to each other by the electromagnetic force, but they are too energetic to stay fixed together in an electrically neutral molecule. The ionosphere has irregular patches of ionization.
Related Stories
1
2
Earth & Climate News
February 5, 2026
Feb. 4, 2026 Melting ice from West Antarctica once delivered huge amounts of iron to the Southern Ocean, but algae growth did not increase as expected. Researchers found the iron was in a form that marine life could not easily use. This means more melting ice ...
Feb. 3, 2026 Researchers have found that manganese, an abundant and inexpensive metal, can be used to efficiently convert carbon dioxide into formate, a potential hydrogen source for fuel cells. The key was a clever redesign that made the catalyst last far ...
Feb. 2, 2026 As demand for critical metals grows, scientists have taken a rare, close look at life on the deep Pacific seabed where mining may soon begin. Over five years and 160 days at sea, researchers documented nearly 800 species, many previously unknown. ...
Feb. 2, 2026 SAR11 bacteria dominate the world’s oceans by being incredibly efficient, shedding genes to survive in nutrient-poor waters. But that extreme streamlining appears to backfire when conditions change. Under stress, many cells keep copying their DNA ...
Jan. 29, 2026 Scientists studying ancient ocean fossils found that the Arabian Sea was better oxygenated 16 million years ago, even though the planet was warmer than today. Oxygen levels only plunged millions of years later, after the climate cooled, defying ...
Jan. 29, 2026 Small mammals are early warning systems for environmental damage, but many species look almost identical, making them hard to track. Scientists have developed a new footprint-based method that can tell apart nearly indistinguishable species with ...
Jan. 29, 2026 Scientists have created a device that captures carbon dioxide and transforms it into a useful chemical in a single step. The new electrode works with realistic exhaust gases rather than requiring purified CO2. It converts the captured gas into ...
Jan. 25, 2026 After analyzing 40 years of tree records across the Andes and Amazon, researchers found that climate change is reshaping tropical forests in uneven ways. Some regions are steadily losing tree species, especially where conditions are hotter and ...
Jan. 21, 2026 A new building material developed by engineers at Worcester Polytechnic Institute could change how the world builds. Made using an enzyme that turns carbon dioxide into solid minerals, the material cures in hours and locks away carbon instead of ...
Jan. 21, 2026 Mountain regions around the world are heating up faster than the lands below them, triggering dramatic shifts in snow, rain, and water supply that could affect over a billion people. A major global review finds that rising temperatures are turning ...
Jan. 19, 2026 Plastic-coated fertilizers used on farms are emerging as a major but hidden source of ocean microplastics. A new study found that only a tiny fraction reaches beaches through rivers, while direct drainage from fields to the sea sends far more ...
Jan. 17, 2026 Tiny plastic particles drifting through the oceans may be quietly weakening one of Earth’s most powerful climate defenses. New research suggests microplastics are disrupting marine life that helps oceans absorb carbon dioxide, while also releasing ...
Latest Headlines
updated 12:56 pm ET
Feb. 5, 2026 Deep inside Earth, two massive hot rock structures have been quietly shaping the planet’s magnetic field for millions of years. Using ancient magnetic records and advanced simulations, scientists ...
Feb. 1, 2026 Old Indian poems and folk songs are revealing a surprising truth about the land. Scientists found that descriptions of thorny trees and open grasslands in texts written as far back as the 1200s ...
Jan. 27, 2026 The Ediacara Biota are some of the strangest fossils ever found—soft-bodied organisms preserved in remarkable detail where preservation shouldn’t be possible. Scientists now think their survival ...
Jan. 23, 2026 Rare rocks buried deep in central Australia have revealed how a valuable niobium deposit formed during the breakup of an ancient supercontinent. More than 800 million years ago, tectonic rifting ...
Jan. 17, 2026 Scientists are uncovering a hidden and surprisingly complex earthquake zone beneath Northern California by tracking swarms of tiny earthquakes that are far too weak to feel. These faint tremors are ...
Jan. 16, 2026 Hydrogen cyanide, a toxic chemical, may have helped spark the chemistry that led to life. When frozen, it forms crystals with highly reactive surfaces that can drive unusual chemical reactions, even ...
Jan. 15, 2026 New research shows tropical forests can recover twice as fast after deforestation when their soils contain enough nitrogen. Scientists followed forest regrowth across Central America for decades and ...
Jan. 15, 2026 In the rapidly disappearing Atlantic Forest, mosquitoes are adapting to a human-dominated landscape. Scientists found that many species now prefer feeding on people rather than the forest’s diverse ...
Jan. 14, 2026 For thousands of years, wildfires on Alaska’s North Slope were rare. That changed sharply in the 20th century, when warming temperatures dried soils and fueled the spread of shrubs, setting the ...
Jan. 14, 2026 Scientists have identified a newly recognized threat lurking beneath the ocean’s surface: sudden episodes of underwater darkness that can last days or even months. Caused by storms, sediment ...