Jason-1 was a
satellite altimeter oceanography mission. It sought to monitor global
ocean circulation, study the ties between the
ocean
The ocean (also the sea or the world ocean) is the body of salt water that covers approximately 70.8% of the surface of Earth and contains 97% of Earth's water. An ocean can also refer to any of the large bodies of water into which the wo ...
and the
atmosphere
An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A s ...
, improve global
climate
Climate is the long-term weather pattern in an area, 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 meteorologic ...
forecasts and predictions, and monitor events such as
El Niño and ocean
eddies
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 beh ...
. Jason-1 was launched in 2001 and it was followed by
OSTM/Jason-2
OSTM/Jason-2, or Ocean Surface Topography Mission/Jason-2 satellite, was an international Earth observation satellite, Earth observation satellite altimeter joint mission for sea surface height measurements between NASA and CNES. It was the t ...
in 2008, and
Jason-3
Jason-3 is a satellite altimeter created by a partnership of the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) and National Aeronautic and Space Administration (NASA), and is an international cooperative mis ...
in 2016the
Jason satellite series
The Jason is a series of oceanographic altimeter satellites, including:
* TOPEX/Poseidon (1992–2006), a joint-venture between NASA and CNES, predecessor to the Jason satellites
* Jason-1 (2001–2013)
* Jason-2 (2008–2019)
* Jason-3 (from ...
. 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
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 Par ...
, 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
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'', ...
br>
https://web.archive.org/web/20140117162201/http://www.wmo-sat.info/oscar/satelliteprogrammes/view/8
History
Jason-1 is the successor to the
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. ...
mission, which measured
ocean surface topography from 1992 through 2005. Like its predecessor, Jason-1 is a joint project between the
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research.
NASA was established in 1958, succeeding t ...
(United States) and
CNES (France) space agencies. Jason-1's successor, the
Ocean Surface Topography Mission on the
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 st ...
satellite, was launched in June 2008. These satellites provide a unique global view of the oceans that is impossible to acquire using traditional ship-based sampling.
Jason-1 was built by
Thales Alenia Space
Thales Alenia Space () is a Franco-Italian aerospace manufacturer. A joint venture between the French technology corporation Thales Group (67%) and Italian defense conglomerate Leonardo (33%), the company is the largest satellite manufacture ...
using a
Proteus
In Greek mythology, Proteus (; Ancient Greek: Πρωτεύς, ''Prōteus'') is an early prophetic sea-god or god of rivers and oceanic bodies of water, one of several deities whom Homer calls the "Old Man of the Sea" ''(hálios gérôn)''. ...
platform, under a contract from
CNES, as well as the main Jason-1 instrument, the Poseidon-2 altimeter (successor to the Poseidon altimeter on-board TOPEX/Poseidon).
Jason-1 was designed to measure
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 E ...
through very precise millimeter-per-year measurements of global
sea level changes. As did TOPEX/Poseidon, Jason-1 uses an
altimeter to measure the hills and valleys of the ocean's surface. These measurements of
sea 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 exp ...
allow scientists to calculate the speed and direction of ocean currents and monitor global ocean circulation. The global ocean is Earth's primary storehouse of solar energy. Jason-1's measurements of sea surface height reveal where this heat is stored, how it moves around Earth by ocean currents, and how these processes affect weather and climate.
Jason-1 was launched on 7 December 2001 from
Vandenberg Air Force Base, in
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
, aboard a
Delta II
Delta II was an expendable launch system, originally designed and built by McDonnell Douglas. Delta II was part of the Delta rocket family and entered service in 1989. Delta II vehicles included the Delta 6000, and the two later Delta 7000 va ...
Launch vehicle
A launch vehicle or carrier rocket is a rocket designed to carry a payload (spacecraft or satellites) from the Earth's surface to outer space. Most launch vehicles operate from a launch pad, launch pads, supported by a missile launch contro ...
. During the first months Jason-1 shared an almost identical orbit to TOPEX/Poseidon, which allowed for cross calibration. At the end of this period, the older satellite was moved to a new orbit midway between each Jason
ground track. Jason had a repeat cycle of 10 days.
On 16 March 2002, Jason-1 experienced a sudden attitude upset, accompanied by temporary fluctuations in the onboard electrical systems. Soon after this incident, two new small pieces of
space debris
Space debris (also known as space junk, space pollution, space waste, space trash, or space garbage) are defunct human-made objects in space—principally in Earth orbit—which no longer serve a useful function. These include derelict spacecr ...
were observed in orbits slightly lower than Jason-1's, and
spectroscopic analysis
Spectroscopy is the field of study that measures and interprets the electromagnetic spectra that result from the interaction between electromagnetic radiation and matter as a function of the wavelength or frequency of the radiation. Matter wav ...
eventually proved them to have originated from Jason-1. In 2011, it was determined that the pieces of debris had most likely been ejected from Jason-1 by an unidentified, small "high-speed particle" hitting one of the spacecraft's
solar panels
A solar cell panel, solar electric panel, photo-voltaic (PV) module, PV panel or solar panel is an assembly of photovoltaic solar cells mounted in a (usually rectangular) frame, and a neatly organised collection of PV panels is called a phot ...
.
Orbit maneuvers in 2009 put the Jason-1 satellite on the opposite side of
Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...
from the
OSTM/Jason-2
OSTM/Jason-2, or Ocean Surface Topography Mission/Jason-2 satellite, was an international Earth observation satellite, Earth observation satellite altimeter joint mission for sea surface height measurements between NASA and CNES. It was the t ...
satellite, which is operated by the United States and French weather agencies. At that time, Jason-1 flew over the same region of the ocean that OSTM/Jason-2 flew over five days earlier. Its ground tracks fell midway between those of OSTM/Jason-2, which are about apart at the
equator
The equator is a circle of latitude, about in circumference, that divides Earth into the Northern and Southern hemispheres. It is an imaginary line located at 0 degrees latitude, halfway between the North and South poles. The term can als ...
.
This interleaved tandem mission provided twice the number of measurements of the ocean's surface, bringing smaller features such as ocean eddies into view. The tandem mission also helped pave the way for a future ocean altimeter mission that would collect much more detailed data with its single instrument than the two Jason satellites now do together.
In early 2012, having helped cross-calibrate the OSTM/Jason-2 replacement mission, Jason-1 was maneuvered into its graveyard orbit and all remaining fuel was vented. The mission was still able to return science data, measuring Earth's gravity field over the ocean. On 21 June 2013, contact with Jason-1 was lost; multiple attempts to re-establish communication failed. It was determined that the last remaining transmitter on board the spacecraft had failed. Operators sent commands to the satellite to turn off remaining functioning components on 1 July 2013, rendering it decommissioned. It is estimated that the spacecraft will remain on orbit for at least 1,000 years.
The program is named after the Greek mythological hero
Jason.
Satellite instruments
Jason-1 has five 5 instruments:
* Poseidon 2 –
Nadir pointing
Radar altimeter using
C band and for measuring height above
sea
The sea, connected as the world ocean or simply the ocean, is the body of salty water that covers approximately 71% of the Earth's surface. The word sea is also used to denote second-order sections of the sea, such as the Mediterranean Sea, ...
surface.
* Jason
Microwave
Microwave is a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter corresponding to frequencies between 300 MHz and 300 GHz respectively. Different sources define different frequency ran ...
Radiometer
A radiometer or roentgenometer is a device for measuring the radiant flux (power) of electromagnetic radiation. Generally, a radiometer is an infrared radiation detector or an ultraviolet detector. Microwave radiometers operate in the microwave w ...
(JMR) – measures
water vapor
(99.9839 °C)
, -
, Boiling point
,
, -
, specific gas constant
, 461.5 J/( kg·K)
, -
, Heat of vaporization
, 2.27 MJ/kg
, -
, Heat capacity
, 1.864 kJ/(kg·K)
Water vapor, water vapour or aqueous vapor is the gaseous pha ...
along altimeter path to correct for pulse delay
*
DORIS (
Doppler Orbitography and Radiopositioning Integrated by
Satellite
A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioisotope ...
) for orbit determination to within 10 cm or less and
ionospheric
The ionosphere () is the ionized part of the upper atmosphere of Earth, from about to above sea level, a region that includes the thermosphere and parts of the mesosphere and exosphere. The ionosphere is ionized by solar radiation. It plays an im ...
correction data for Poseidon 2.
* BlackJack
Global Positioning System
The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of the global navigation satellite sy ...
receiver provides precise
orbit
In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as a p ...
ephemeris
In astronomy and celestial navigation, an ephemeris (pl. ephemerides; ) is a book with tables that gives the trajectory of naturally occurring astronomical objects as well as artificial satellites in the sky, i.e., the position (and possibly vel ...
data
* Laser
retroreflector
A retroreflector (sometimes called a retroflector or cataphote) is a device or surface that reflects radiation (usually light) back to its source with minimum scattering. This works at a wide range of angle of incidence, unlike a planar mirror, ...
array works with ground stations to track the satellite and calibrate and verify altimeter measurements.
The Jason-1 satellite, its altimeter instrument and a position-tracking antenna were built in France. The radiometer, Global Positioning System receiver and laser retroreflector array were built in the United States.
Use of information
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. ...
and Jason-1 have led to major advances in the science of
physical oceanography
Physical oceanography is the study of physical conditions and physical processes within the ocean, especially the motions and physical properties of ocean waters.
Physical oceanography is one of several sub-domains into which oceanography is divi ...
and in climate studies. Their 15-year data record of ocean surface topography has provided the first opportunity to observe and understand the global change of ocean circulation and sea level. The results have improved the understanding of the role of the ocean in climate change and improved weather and climate predictions. Data from these missions are used to improve ocean models, forecast hurricane intensity, and identify and track large ocean/atmosphere phenomena such as
El Niño and
La Niña
La Niña (; ) is an oceanic and atmospheric phenomenon that is the colder counterpart of as part of the broader El Niño–Southern Oscillation (ENSO) climate pattern. The name ''La Niña'' originates from Spanish for "the girl", by an ...
. The data are also used every day in applications as diverse as routing ships, improving the safety and efficiency of offshore industry operations, managing fisheries, and tracking marine mammals. Their 15-year data record of ocean surface topography has provided the first opportunity to observe and understand the global change of ocean circulation and sea level. The results have improved the understanding of the role of the ocean in climate change and improved weather and climate predictions. Data from these missions are used to improve ocean models, forecast hurricane intensity, and identify and track large ocean/atmosphere phenomena such as El Niño and La Niña. The data are also used every day in applications as diverse as routing ships, improving the safety and efficiency of offshore industry operations, managing fisheries, and tracking marine mammals.
TOPEX/Poseidon and Jason-1 have made major contributions to the understanding of:
Ocean variability
The missions revealed the surprising variability of the ocean, how much it changes from season to season, year to year, decade to decade and on even longer time scales. They ended the traditional notion of a quasi-steady, large-scale pattern of global ocean circulation by proving that the ocean is changing rapidly on all scales, from huge features such as El Niño and La Niña, which can cover the entire equatorial Pacific, to tiny eddies swirling off the large Gulf Stream in the Atlantic.
Sea level change
Measurements by Jason-1 indicate that mean sea level has been rising at an average rate of 2.28 mm (0.09 inch) per year since 2001. This is somewhat less than the rate measured by the earlier
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. ...
mission, but over four times the rate measured by the later
Envisat
Envisat ("Environmental Satellite") is a large inactive Earth-observing satellite which is still in orbit and now considered space debris. Operated by the European Space Agency (ESA), it was the world's largest civilian Earth observation satell ...
mission. Mean sea level measurements from Jason-1 are continuously graphed at th
Centre National d'Études Spatialesweb site, on th
Aviso page A composite sea level graph, using data from several satellites, is also available o
that site
The data record from these altimetry missions has given scientists important insights into how global sea level is affected by natural climate variability, as well as by human activities.
Planetary Waves
TOPEX/Poseidon and Jason-1 made clear the importance of planetary-scale waves, such as
Rossby and
Kelvin
The kelvin, symbol K, is the primary unit of temperature in the International System of Units (SI), used alongside its prefixed forms and the degree Celsius. It is named after the Belfast-born and University of Glasgow-based engineer and phys ...
waves. No one had realized how widespread these waves are. Thousands of kilometers wide, these waves are driven by wind under the influence of Earth's rotation and are important mechanisms for transmitting climate signals across the large ocean basins. At high latitudes, they travel twice as fast as scientists believed previously, showing the ocean responds much more quickly to climate changes than was known before these missions.
Ocean tides
The precise measurements of TOPEX/Poseidon's and Jason-1 have brought knowledge of ocean tides to an unprecedented level. The change of water level due to tidal motion in the deep ocean is known everywhere on the globe to within 2.5 centimeters (1 inch). This new knowledge has revised notions about how tides dissipate. Instead of losing all their energy over shallow seas near the coasts, as previously believed, about one third of tidal energy is actually lost to the deep ocean. There, the energy is consumed by mixing water of different properties, a fundamental mechanism in the physics governing the general circulation of the ocean.
Ocean models
TOPEX/Poseidon and Jason-1 observations provided the first global data for improving the performance of the numerical ocean models that are a key component of climate prediction models. TOPEX/Poseidon and Jason-1 data are available at the University of Colorado Center for Astrodynamics Research, NASA's Physical Oceanography Distributed Active Archive Center, and the French data archive center AVISO.
Benefits to society
Altimetry data have a wide variety of uses from basic scientific research on climate to ship routing. Applications include:
*
Climate Research: altimetry data are incorporated into computer models to understand and predict changes in the distribution of heat in the ocean, a key element of climate.
*
El Niño and
La Niña
La Niña (; ) is an oceanic and atmospheric phenomenon that is the colder counterpart of as part of the broader El Niño–Southern Oscillation (ENSO) climate pattern. The name ''La Niña'' originates from Spanish for "the girl", by an ...
Forecasting: understanding the pattern and effects of climate cycles such as El Niño helps predict and mitigate the disastrous effects of floods and drought.
*
Hurricane
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. Depend ...
Forecasting: altimeter data and satellite ocean wind data are incorporated into atmospheric models for hurricane season forecasting and individual storm severity.
* Ship Routing: maps of
ocean currents
An ocean current is a continuous, directed movement of sea water generated by a number of forces acting upon the water, including wind, the Coriolis effect, breaking waves, cabbeling, and temperature and salinity differences. Depth contours, s ...
, eddies, and vector winds are used in commercial shipping and recreational yachting to optimize routes.
* Offshore Industries: cable-laying vessels and offshore oil operations require accurate knowledge of ocean circulation patterns to minimize impacts from strong currents.
*
Marine Mammal
Marine mammals are aquatic mammals that rely on the ocean and other marine ecosystems for their existence. They include animals such as seals, whales, manatees, sea otters and polar bears. They are an informal group, unified only by their reli ...
Research: sperm whales, fur seals, and other marine mammals can be tracked, and therefore studied, around ocean eddies where nutrients and plankton are abundant.
*
Fisheries
Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life; or more commonly, the site where such enterprise takes place ( a.k.a. fishing ground). Commercial fisheries include wild fisheries and fish farms, both ...
Management: satellite data identify ocean eddies which bring an increase in organisms that comprise the marine food web, attracting fish and fishermen.
*
Coral Reef
A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups.
Co ...
Research: remotely sensed data are used to monitor and assess coral reef ecosystems, which are sensitive to changes in ocean temperature.
*
Marine Debris
Marine debris, also known as marine litter, is human-created waste that has deliberately or accidentally been released in a sea or ocean. Floating oceanic debris tends to accumulate at the center of gyres and on coastlines, frequently washing ...
Tracking: the amount of floating and partially submerged material, including nets, timber and ship debris, is increasing with human population. Altimetry can help locate these hazardous materials.
See also
*
Argo
In Greek mythology the ''Argo'' (; in Greek: ) was a ship built with the help of the gods that Jason and the Argonauts sailed from Iolcos to Colchis to retrieve the Golden Fleece. The ship has gone on to be used as a motif in a variety of sour ...
- a project to measure the temperature and
salinity
Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal ...
of the upper 2 km of the water column
*
Seasat - an early radar altimeter satellite
*
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. ...
- the immediate predecessor to Jason-1
*
Ocean Surface Topography Mission/Jason-2 – the immediate successor to Jason-1
*
2004 Indian Ocean earthquake
An earthquake and a tsunami, known as the Boxing Day Tsunami and, by the scientific community, the Sumatra–Andaman earthquake, occurred at 07:58:53 local time (UTC+7) on 26 December 2004, with an epicentre off the west coast of northern Suma ...
- Energy of the earthquake
*
French space program
References
External links
Jason 1 and 2 site at CNES (in French)TOPEX/Jason site at NASADEOS: the Radar Altimeter Database System (RADS)NASA Jason-1 mission page
{{Orbital launches in 2001
Earth observation satellites of the United States
Earth observation satellites of France
2001 in France
Spacecraft launched in 2001
Spacecraft launched by Delta II rockets
Physical oceanography
Earth satellite radar altimeters
NASA satellites orbiting Earth
Jason satellite series