5,021 articles
Longwave radiation
Longwave radiation is infrared radiation emitted by Earth's surface and atmosphere at wavelengths of roughly 3 to 100 micrometers, also called terrestrial or thermal radiation.
Loo (लू) (wind)
The Loo (लू) is a strong, hot, dry, dusty westerly summer wind across the northern plains of India and Pakistan, blowing in May and June before the monsoon.
Lopingian
The Lopingian is the youngest epoch of the Permian, from about 259.5 to 251.9 million years ago, ending at the Permian-Triassic boundary and divided into the Wuchiapingian and Changhsingian stages.
Losing stream
Losing stream, also called influent stream: a stream or reach that loses streamflow by infiltration into the ground, recharging the aquifer; in karst it may sink into fractures or a ponor, unlike a sinking stream at a swallet.
Loss and Damage Fund
The Loss and Damage Fund (FRLD) is a UN climate fund providing financial support to developing countries vulnerable to climate change, agreed at COP27 in 2022.
Loss on ignition
Loss on ignition (LOI) is a gravimetric method that heats a dried sample and reports the percentage of mass lost, indicating volatile content such as water and organic matter.
Louise Lear
Louise Lear is a British broadcast weather presenter who has presented BBC forecasts since 1998, appearing on BBC Breakfast, BBC News at Six, Radio 5 Live, and Countryfile.
Low-carbon cement
Low-carbon cement is cement that replaces much of Portland clinker, the most carbon-intensive component, with materials like calcined clay and limestone, cutting CO2 emissions by 30–40%.
Low-level jet (meteorology)
A low-level jet is a wind speed maximum in the lowest kilometer of the atmosphere, with wind speed rising to a core and falling sharply above it.
Low-pressure area
A low-pressure area, also called a low, depression, or cyclone, is a region of lower surface atmospheric pressure with converging rotating winds, generally bringing unsettled weather, cloud, wind, and precipitation.
Lowest temperature recorded on Earth
The lowest temperature recorded on Earth, also called the coldest temperature achieved on Earth, is −89.2 °C, recorded at Vostok Station in Antarctica on 21 July 1983.
Lucy Verasamy
Lucy Verasamy, born in 1980, is a British meteorologist and weather presenter who has fronted ITV's national forecasts since 2012, after five years at Sky News.
Luisa Neubauer
Luisa Neubauer (Luisa-Marie Neubauer), born 1996 in Hamburg, is a German climate activist co-organizing Fridays for Future Germany and lead plaintiff in Neubauer vs. Germany.
Lunar laser ranging
Lunar laser ranging (LLR) is a geodetic technique that times laser pulses fired at retroreflector arrays on the Moon, measuring the Earth-Moon distance to millimeter precision since 1969.
Lunar lava tubes
Lunar lava tubes are empty conduits beneath the Moon's surface left when lava flows drained away; orbital evidence confirms intact examples exist, potentially far larger than any cave on Earth.
Lunar mare basalt
Lunar mare basalt is the dark volcanic rock that fills the Moon's low-lying maria, plains early astronomers mistook for seas, erupted mostly between 3.8 and 3.2 billion years ago.
Lustre (mineralogy)
Lustre, also called mineral luster, is the way a mineral's fresh surface reflects light, described by terms such as metallic, vitreous, pearly, and adamantine, with vitreous the most common.
Lutetian
The Lutetian is the second of four Eocene stages, spanning about 47.8 to 41.2 million years ago and named after Lutetia, the Roman name for Paris.
Luvisols
Luvisols are a Reference Soil Group of the World Reference Base, in which clay has washed down to a base-rich subsurface horizon; they correspond to Alfisols in USDA Soil Taxonomy.
Lysimeter
A lysimeter is a device that isolates a column of soil, with or without vegetation, to measure percolation, leaching, and evapotranspiration; weighing types are the reference method for crop water use.
Maar
A maar is a broad, low-rimmed volcanic crater formed by explosive interaction of rising magma with groundwater, cutting below the pre-eruption surface and underlain by a funnel-shaped diatreme, with the type locality in Germany's Vulkaneifel.
Maastrichtian
The Maastrichtian is the youngest stage of the Upper Cretaceous, spanning 72.2 to 66 million years ago and ending at the mass extinction that killed the dinosaurs.
Macassa Mine
Macassa Mine is an underground gold mine in Kirkland Lake, northeastern Ontario, Canada, owned by Agnico Eagle and one of the world's highest-grade gold mines.
Machine learning earthquake detection
Machine learning earthquake detection uses trained neural networks to find earthquake signals in seismic recordings and pick P and S wave arrival times, replacing manual analysis.
Mackinawite
Mackinawite is a soft, black iron sulfide mineral, FeS, first described in 1964 from the Mackinaw mine in Washington and acting as the precursor to greigite and pyrite.
Madden–Julian oscillation
The Madden–Julian oscillation (MJO) is an eastward-moving disturbance of clouds, rainfall, and winds that circles the global tropics every 30 to 60 days and shapes tropical weather.
Maevarano Formation
Maevarano Formation: Late Cretaceous (Maastrichtian, 72.1-66 Ma) fossil-rich rock unit in Madagascar's Mahajanga Basin, near Berivotra; source of Majungasaurus, Rapetosaurus, Rahonavis, Beelzebufo; distinct from the Maevarano Suite granites.
Mafic
Mafic, also known as basic rock, describes dark-colored igneous rocks and minerals rich in magnesium and iron, such as basalt and gabbro, contrasting with felsic rocks.
Maghemite
Maghemite is a strongly ferrimagnetic iron oxide mineral, γ-Fe₂O₃, with magnetite's spinel structure and hematite's composition, formed by oxidation of magnetite, common in soils, and used in magnetic nanoparticles.
Magma
Magma is molten rock beneath the Earth's surface, made of silicate melt, mineral crystals, and dissolved gases, that rises through volcanic vents and is called lava once it erupts.