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Jason 1
Jason-1 was a satellite altimeter oceanography mission. It sought to monitor global ocean circulation, study the ties between the ocean and the atmosphere, improve global climate forecasts and predictions, and monitor events such as El Niño and ocean Eddy (fluid dynamics), eddies. Jason-1 was launched in 2001 and it was followed by OSTM/Jason-2 in 2008, and Jason-3 in 2016the Jason satellite series. Jason-1 was launched alongside the TIMED spacecraft. Naming The lineage of the name begins with the JASO1 meeting (JASO=Journées Altimétriques Satellitaires pour l'Océanographie) in Toulouse, France to study the problems of assimilating altimeter data in models. Jason as an acronym also stands for "Joint Altimetry Satellite Oceanography Network". Additionally, it is used to reference the mythical quest for knowledge of Jason and the Argonauts]https://web.archive.org/web/20140117162201/http://www.wmo-sat.info/oscar/satelliteprogrammes/view/8 History Jason-1 is the successor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program, aeronautics research, and outer space, space research. NASA was National Aeronautics and Space Act, established in 1958, succeeding the National Advisory Committee for Aeronautics (NACA), to give the U.S. space development effort a distinctly civilian orientation, emphasizing peaceful applications in space science. NASA has since led most American space exploration, including Project Mercury, Project Gemini, the 1968-1972 Apollo program, Apollo Moon landing missions, the Skylab space station, and the Space Shuttle. NASA supports the International Space Station and oversees the development of the Orion (spacecraft), Orion spacecraft and the Space Launch System for the crewed lunar Artemis program, Commercial Crew Program, Commercial Crew ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eddy (fluid Dynamics)
In fluid dynamics, an eddy is the swirling of a fluid and the reverse current created when the fluid is in a turbulent flow regime. The moving fluid creates a space devoid of downstream-flowing fluid on the downstream side of the object. Fluid behind the obstacle flows into the void creating a swirl of fluid on each edge of the obstacle, followed by a short reverse flow of fluid behind the obstacle flowing upstream, toward the back of the obstacle. This phenomenon is naturally observed behind large emergent rocks in swift-flowing rivers. An eddy is a movement of fluid that deviates from the general flow of the fluid. An example for an eddy is a vortex which produces such deviation. However, there are other types of eddies that are not simple vortices. For example, a Rossby wave is an eddy which is an undulation that is a deviation from mean flow, but doesn't have the local closed streamlines of a vortex. Swirl and eddies in engineering The propensity of a fluid to swirl is use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Level Change
Globally, sea levels are rising due to human-caused climate change. Between 1901 and 2018, the globally averaged sea level rose by , or 1–2 mm per year on average.IPCC, 2019Summary for Policymakers InIPCC Special Report on the Ocean and Cryosphere in a Changing Climate .-O. Pörtner, D.C. Roberts, V. Masson-Delmotte, P. Zhai, M. Tignor, E. Poloczanska, K. Mintenbeck, A. Alegría, M. Nicolai, A. Okem, J. Petzold, B. Rama, N.M. Weyer (eds.) Cambridge University Press, Cambridge, UK and New York, NY, USA. https://doi.org/10.1017/9781009157964.001. This rate is accelerating, with sea levels now rising by 3.7 mm per year. Climate scientists expect further acceleration during the 21st century. Climate change heats (and therefore expands) the ocean and melts land-based ice sheets and glaciers. Between 1993 and 2018, the thermal expansion of water contributed 42% to sea level rise; melting of temperate glaciers, 21%; Greenland, 15%; and Antarctica, 8%. Over the next 2000 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Climate Change
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to Earth's climate. The current rise in global average temperature is more rapid than previous changes, and is primarily caused by humans burning fossil fuels. Fossil fuel use, deforestation, and some agricultural and industrial practices increase greenhouse gases, notably carbon dioxide and methane. Greenhouse gases absorb some of the heat that the Earth radiates after it warms from sunlight. Larger amounts of these gases trap more heat in Earth's lower atmosphere, causing global warming. Due to climate change, deserts are expanding, while heat waves and wildfires are becoming more common. Increased warming in the Arctic has contributed to melting permafrost, glacial retreat and sea ice loss. Higher temperatures are also causing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ocean Surface Topography Mission/Jason-2
OSTM/Jason-2, or Ocean Surface Topography Mission/Jason-2 satellite, was an international Earth observation satellite altimeter joint mission for sea surface height measurements between NASA and CNES. It was the third satellite in a series started in 1992 by the NASA/CNES TOPEX/Poseidon mission and continued by the NASA/CNES Jason-1 mission launched in 2001. History Like its two predecessors, OSTM/Jason-2 used high-precision ocean altimetry to measure the distance between the satellite and the ocean surface to within a few centimeters. These very accurate observations of variations in sea surface height — also known as ocean topography — provide information about global sea level, the speed and direction of ocean currents, and heat stored in the ocean. Jason-2 was built by Thales Alenia Space using a Proteus platform, under a contract from CNES, as well as the main Jason-2 instrument, the Poseidon-3 altimeter (successor to the Poseidon and Poseidon 2 altimeter on-boar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ocean Surface Topography Mission
OSTM/Jason-2, or Ocean Surface Topography Mission/Jason-2 satellite, was an international Earth observation satellite altimeter joint mission for sea surface height measurements between NASA and CNES. It was the third satellite in a series started in 1992 by the NASA/CNES TOPEX/Poseidon mission and continued by the NASA/CNES Jason-1 mission launched in 2001. History Like its two predecessors, OSTM/Jason-2 used high-precision ocean altimetry to measure the distance between the satellite and the ocean surface to within a few centimeters. These very accurate observations of variations in sea surface height — also known as ocean topography — provide information about global sea level, the speed and direction of ocean currents, and heat stored in the ocean. Jason-2 was built by Thales Alenia Space using a Proteus platform, under a contract from CNES, as well as the main Jason-2 instrument, the Poseidon-3 altimeter (successor to the Poseidon and Poseidon 2 altimeter on-boa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ocean Surface Topography
Ocean surface topography or sea surface topography, also called ocean dynamic topography, are highs and lows on the ocean surface, similar to the hills and valleys of Earth's land surface depicted on a topographic map. These variations are expressed in terms of average sea surface height (SSH) relative to Earth's geoid. The main purpose of measuring ocean surface topography is to understand the large-scale ocean circulation. Time variations Unaveraged or instantaneous sea surface height (SSH) is most obviously affected by the tidal forces of the Moon and the Sun acting on Earth. Over longer timescales, SSH is influenced by ocean circulation. Typically, SSH anomalies resulting from these forces differ from the mean by less than ± at the global scale. Other influences include temperature, salinity, tides, waves, and the loading of atmospheric pressure. The slowest and largest variations are due to changes in Earth's gravitational field (geoid) due to the rearrangement of contin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TOPEX/Poseidon
TOPEX/Poseidon was a joint satellite altimeter mission between NASA, the U.S. space agency; and CNES, the French space agency, to map ocean surface topography. Launched on August 10, 1992, it was the first major oceanographic research satellite. TOPEX/Poseidon helped revolutionize oceanography by providing data previously impossible to obtain. Oceanographer Walter Munk described TOPEX/Poseidon as "the most successful ocean experiment of all time." A malfunction ended normal satellite operations in January 2006. Description Before TOPEX/Poseidon, scientists had only a brief glimpse of Earth's ocean as a whole from the pioneering but short-lived Seasat satellite. TOPEX/Poseidon's radar altimeter provided the first continuous global coverage of the surface topography of the oceans. From orbit 1,330 kilometers above Earth, TOPEX/Poseidon provided measurements of the surface height of 95 percent of the ice-free ocean to an accuracy of 3.3 centimeters. The satellite's measurements of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argonauts
The Argonauts (; Ancient Greek: ) were a band of heroes in Greek mythology, who in the years before the Trojan War (around 1300 BC) accompanied Jason to Colchis in his quest to find the Golden Fleece. Their name comes from their ship, ''Argo'', named after its builder, Argus. They were sometimes called Minyans, after a prehistoric tribe in the area. Mythology The Golden Fleece After the death of King Cretheus, the Aeolian Pelias usurped the throne from his half-brother Aeson and became king of Iolcus in Thessaly (near the modern city of Volos). Because of this unlawful act, an oracle warned him that a descendant of Aeolus would seek revenge. Pelias put to death every prominent descendant of Aeolus he could, but spared Aeson because of the pleas of their mother Tyro. Instead, Pelias kept Aeson prisoner and forced him to renounce his inheritance. Aeson married Alcimede, who bore him a son named Jason. Pelias intended to kill the baby at once, but Alcimede summoned her ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jason
Jason ( ; ) was an ancient Greek mythological hero and leader of the Argonauts, whose quest for the Golden Fleece featured in Greek literature. He was the son of Aeson, the rightful king of Iolcos. He was married to the sorceress Medea. He was also the great-grandson of the messenger god Hermes, through his mother's side. Jason appeared in various literary works in the classical world of Greece and Rome, including the epic poem ''Argonautica'' and the tragedy ''Medea''. In the modern world, Jason has emerged as a character in various adaptations of his myths, such as the 1963 film '' Jason and the Argonauts'' and the 2000 TV miniseries of the same name. Persecution by Pelias Pelias (Aeson's half-brother) was power-hungry and sought to gain dominion over all of Thessaly. Pelias was the progeny of a union between their shared mother, Tyro ("high born Tyro"), the daughter of Salmoneus, and the sea god Poseidon. In a bitter feud, he overthrew Aeson (the rightful king), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toulouse
Toulouse ( , ; oc, Tolosa ) is the prefecture of the French department of Haute-Garonne and of the larger region of Occitania. The city is on the banks of the River Garonne, from the Mediterranean Sea, from the Atlantic Ocean and from Paris. It is the fourth-largest city in France after Paris, Marseille and Lyon, with 493,465 inhabitants within its municipal boundaries (2019 census); its metropolitan area has a population of 1,454,158 inhabitants (2019 census). Toulouse is the central city of one of the 20 French Métropoles, with one of the three strongest demographic growth (2013-2019). Toulouse is the centre of the European aerospace industry, with the headquarters of Airbus, the SPOT satellite system, ATR and the Aerospace Valley. It hosts the CNES's Toulouse Space Centre (CST) which is the largest national space centre in Europe, but also, on the military side, the newly created NATO space centre of excellence and the French Space Command and Space Academy. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TIMED
timed (time daemon) is an operating system program that maintains the system time in synchronization with time servers using the Time Synchronization Protocol (TSP) developed by Riccardo Gusella and Stefano Zatti. Gusella and Zatti had done earlier related work on their TEMPO algorithm. The Time Synchronization Protocol specification refers an election algorithm and a synchronization mechanism specified in other technical reports listed as "to appear". With the release of macOS High Sierra in 2017, timed in macOS has subsumed all time synchronization responsibilities including those of the former ntpd and timed. See also * Network Time Protocol The Network Time Protocol (NTP) is a networking protocol for clock synchronization between computer systems over packet-switched, variable- latency data networks. In operation since before 1985, NTP is one of the oldest Internet protocols in ... (NTP) * Precision Time Protocol (IEEE 1588 PTP) References External links timed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
