Climate is the long-term weather pattern in a region, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorological variables that are commonly measured are temperature, humidity, atmospheric pressure, wind, and precipitation. In a broader sense, climate is the state of the components of the climate system, including the atmosphere, hydrosphere, cryosphere, lithosphere and biosphere and the interactions between them. The climate of a location is affected by its latitude, longitude, terrain, altitude, land use and nearby water bodies and their currents.
The tropopause is the atmospheric boundary that demarcates the troposphere from the stratosphere, which are the lowest two of the five layers of the atmosphere of Earth. The tropopause is a thermodynamic gradient-stratification layer that marks the end of the troposphere, and is approximately 17 kilometres (11 mi) above the equatorial regions, and approximately 9 kilometres (5.6 mi) above the polar regions.
El Niño–Southern Oscillation (ENSO) is an irregular periodic variation in winds and sea surface temperatures over the tropical eastern Pacific Ocean, affecting the climate of much of the tropics and subtropics. The warming phase of the sea temperature is known as El Niño and the cooling phase as La Niña. The Southern Oscillation is the accompanying atmospheric component, coupled with the sea temperature change: El Niño is accompanied by high air surface pressure in the tropical western Pacific and La Niña with low air surface pressure there. The two periods last several months each and typically occur every few years with varying intensity per period.
Carl-Gustaf Arvid Rossby was a Swedish-born American meteorologist who first explained the large-scale motions of the atmosphere in terms of fluid mechanics. He identified and characterized both the jet stream and the long waves in the westerlies that were later named Rossby waves.
A derecho is a widespread, long-lived, straight-line wind storm that is associated with a fast-moving group of severe thunderstorms known as a mesoscale convective system.
A tornado outbreak is the occurrence of multiple tornadoes spawned by the same synoptic scale weather system. The number of tornadoes required to qualify as an outbreak typically are at least six to ten, with at least two rotational locations or at least two supercells producing multiple tornadoes.
James Louis Franklin is a former weather forecaster encompassing a 35-year career with National Oceanic and Atmospheric Administration (NOAA). He served as the first branch chief of the newly formed Hurricane Specialist Unit (HSU) before his retirement in 2017.
Tropical cyclogenesis is the development and strengthening of a tropical cyclone in the atmosphere. The mechanisms through which tropical cyclogenesis occurs are distinctly different from those through which temperate cyclogenesis occurs. Tropical cyclogenesis involves the development of a warm-core cyclone, due to significant convection in a favorable atmospheric environment.
A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depending on its location and strength, a tropical cyclone is referred to by different names, including hurricane, typhoon, tropical storm, cyclonic storm, tropical depression, or simply cyclone. A hurricane is a strong tropical cyclone that occurs in the Atlantic Ocean or northeastern Pacific Ocean, and a typhoon occurs in the northwestern Pacific Ocean. In the Indian Ocean and South Pacific, comparable storms are referred to as "tropical cyclones", and such storms in the Indian Ocean can also be called "severe cyclonic storms".
In meteorology and climatology, a mesonet, portmanteau of mesoscale network, is a network of automated weather and, often also including environmental monitoring stations, designed to observe mesoscale meteorological phenomena and/or microclimates.
Teleconnection in atmospheric science refers to climate anomalies being related to each other at large distances. The most emblematic teleconnection is that linking sea-level pressure at Tahiti and Darwin, Australia, which defines the Southern Oscillation. Another well-known teleconnection links the sea-level pressure over Iceland with the one over the Azores, traditionally defining the North Atlantic Oscillation (NAO).
On August 28, 1884, a tornado outbreak, including a family of least five strong tornadoes, affected portions of the Dakota Territory within present-day South Dakota. Among them was one of the first known tornadoes to have been photographed, an estimated F4 on the Fujita scale, that occurred near Howard and exhibited multiple vortices. Another violent tornado also occurred near Alexandria, and three other tornadoes were also reported. A sixth tornado also occurred in present-day Davison County. In all, the tornadoes killed at least seven people and injured at least two others. Contemporary records and survivors' recollections indicate that the storms were F3 or F4 on the Fujita scale, but cannot currently be verified, as official records begin in 1950.
The North American monsoon, variously known as the Southwest monsoon, the Mexican monsoon, the New Mexican monsoon, or the Arizona monsoon is a pattern of pronounced increase in thunderstorms and rainfall over large areas of the southwestern United States and northwestern Mexico, centered roughly on the Rio Grande Valley, and typically occurring between June and mid-September. During the monsoon, thunderstorms are fueled by daytime heating and build up during the late afternoon and early evening. Typically, these storms dissipate by late night, and the next day starts out fair, with the cycle repeating daily. The monsoon typically loses its energy by mid-September when much drier conditions are reestablished over the region. Geographically, the North American monsoon precipitation region is centered over the Sierra Madre Occidental in the Mexican states of Sinaloa, Durango, Sonora and Chihuahua.
Greenland's climate is a tundra climate on and near the coasts and an ice cap climate in inland areas. It typically has short, cool summers and long, moderately cold winters.
The microwave sounding unit (MSU) was the predecessor to the Advanced Microwave Sounding Unit (AMSU).
The highest temperature recorded on Earth has been measured in three major ways: air, ground, and via satellite observation. Air measurements are used as the standard measurement due to persistent issues with unreliable ground and satellite readings. Air measurements are noted by the World Meteorological Organization (WMO) and Guinness World Records among others as the standard to be used for determining the official record. The current official highest registered air temperature on Earth is 56.7 °C (134.1 °F), recorded on 10 July 1913 at Furnace Creek Ranch, in Death Valley in the United States. For ninety years, a former record that was measured in Libya had been in place, until it was decertified in 2012 based on evidence that it was an erroneous reading. This finding has since raised questions about the legitimacy of the 1913 record measured in Death Valley, with several meteorological experts asserting that there were similar irregularities. The WMO has stood by the record as official pending any future investigative results. If the current record were to be decertified then the holder would be a tie at 54.0 °C (129.2 °F), recorded both at Furnace Creek and in Kuwait.
Roland Aloysius Madden, an American meteorologist, was a staff scientist at the National Center for Atmospheric Research (NCAR) from 1967 to 2002. His research centers on diagnostic studies of the atmosphere. Madden is a fellow of the American Meteorological Society (AMS) and a recipient of the 2002 Jule G. Charney Award of the AMS.
Jenni L. Evans is a Professor of Meteorology and Atmospheric Science at Pennsylvania State University, Director of the Institute for CyberScience and President of the American Meteorological Society. She was elected a Fellow of the American Meteorological Society in 2010 and the American Association for the Advancement of Science in 2019.
Carl Wilhelm Max Dorno was a Prussian-born businessman and amateur meteorologist who settled in Davos, Switzerland for the recovery of his only daughter from tuberculosis. Interested in the effect of climate on health, he established a pioneering observatory, now known as the Physikalisch-Meteorologisches Observatorium Davos (PMOD), for the study of solar radiation. He pioneered a field that has been termed as physiological, medical or biological climatology. Ultraviolet radiation was at the time also referred to as "Dorno radiation". The observatory continues to function as the PMOD World Radiation Centre.
