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
October 6, 2026
Oct. 4, 2026 A meteor crater buried beneath Oklahoma has turned out to be nearly 100 million years younger than scientists thought. Zircon crystals show the Ames impact occurred about 370 million years ago, meaning it was not part of the mysterious Ordovician ...
Oct. 4, 2026 A 30-year forestry experiment in Australia found that heavily thinned mountain ash forests grew unusually large trees while recovering enough carbon to match or exceed untouched areas. The results suggest carefully managed thinning could support ...
Oct. 4, 2026 A new light-activated material can efficiently produce hydrogen from water without requiring an additional expensive metal catalyst. Researchers say its unusual sulfur-based chemistry could point toward cheaper and more practical ways to turn ...
Oct. 1, 2026 A new protective fabric boosted strawberry yields by as much as 3.56 times while blocking insects and still allowing sunlight, rain, and airflow to reach the plants. Originally inspired by research on military clothing, Plant Armor could also help ...
Sep. 30, 2026 Marine heatwaves may be only the most intense part of much longer warming events, with elevated temperatures sometimes lingering for months. Researchers found that conventional measurements underestimate total heat exposure by more than 150% on ...
Sep. 27, 2026 Scientists have streamlined a method for measuring DNA-bound phosphorus in soil, making it cheaper and easier while preserving its accuracy. The technique could reveal how soil microbes help recycle phosphorus and ultimately support more sustainable ...
Sep. 27, 2026 Scientists studying ancient Australian rocks uncovered more than 12,000 fossils from some of the oldest known eukaryotes on Earth. These early complex cells lived in settings ranging from coastal ...
Sep. 25, 2026 Scientists have captured a subduction zone off Vancouver Island in the process of tearing itself apart, revealing that these massive tectonic systems may die piece by piece rather than all at once. The discovery could help explain ancient plate ...
Sep. 24, 2026 Scientists discovered two tiny new snail species in Montenegro, showing that even Europe still holds animals unknown to science. One lives in the threatened Komarnica Canyon, where a proposed hydropower reservoir could destroy habitat before its ...
Sep. 23, 2026 The Cascadia subduction zone and northern San Andreas fault may sometimes rupture in rapid succession, according to evidence preserved in 3,100 years of ocean sediments. Researchers identified ...
Sep. 23, 2026 Some tropical trees have evolved a clever way to survive drought by taking in carbon dioxide at night, allowing them to keep their pores closed during the hot daytime and conserve water. By comparing three Clusia species, researchers discovered that ...
Sep. 23, 2026 The Arctic sea ice melt season is roughly 40 days longer than it was in 1979, yet its rapid expansion unexpectedly leveled off around 2010. Scientists say changing clouds and increasingly thin ice ...
Latest Headlines
updated 12:56 pm ET
Oct. 2, 2026 Researchers say stress on Southern California’s San Andreas and San Jacinto faults has reached some of the highest levels seen in a 1,000-year ...
Sep. 30, 2026 Mount Vesuvius’ famous 79 CE eruption has given scientists a remarkably precise benchmark for dating events deep in Earth’s past. The improved ...
Sep. 29, 2026 Scientists may have solved why the length of Earth’s day changes by a few milliseconds over decades. Subtle shifts in the inner core appear to tug ...
Sep. 26, 2026 Scientists have found that a famous 2-billion-year-old chemical signature, once thought to record a massive global change in Earth’s carbon cycle, may instead have been produced by local magma, ...
Sep. 23, 2026 Stonehenge’s six-ton Altar Stone may have been carried from Scotland to Dogger Bank by glaciers before prehistoric people transported it hundreds of kilometers to Salisbury Plain. The possible ...
Sep. 23, 2026 Scientists have found strong observational evidence that a key part of the Atlantic Meridional Overturning Circulation has been weakening across a ...
Sep. 22, 2026 Lake Powell has fallen to its lowest level on record after an exceptionally dry and warm winter left the Colorado River Basin with little mountain snow to melt. Lake Mead also reached record lows, ...
Sep. 22, 2026 Researchers have created a concrete mixture that is both stronger and capable of absorbing carbon dioxide. The best formula, combining zeolite with bamboo biochar, boosted compressive strength by ...
Sep. 22, 2026 An amateur astronomer searching satellite maps for a Quebec camping spot accidentally discovered a massive ancient impact crater. Scientists later ...
Sep. 22, 2026 A Yellowstone super-eruption would begin not with a sudden surprise, but with weeks of increasingly alarming warning signs such as migrating ...