Soil Moisture and Ocean Salinity (SMOS) is a

satellite A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scient ...

which forms part of ESA's Living Planet Programme. It is intended to provide new insights into Earth's

water cycle The water cycle (or hydrologic cycle or hydrological cycle) is a biogeochemical cycle that involves the continuous movement of water on, above and below the surface of the Earth across different reservoirs. The mass of water on Earth remains fai ...

and

climate 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 meteoro ...

. In addition, it is intended to provide improved

weather forecasting Weather forecasting or weather prediction is the application of science and technology forecasting, to predict the conditions of the Earth's atmosphere, atmosphere for a given location and time. People have attempted to predict the weather info ...

and monitoring of snow and ice accumulation.ESA's water mission SMOS
European Space AgencySMOS Project Team
The Soil Moisture and Ocean Salinity (SMOS) Mission
European Space AgencySMOS Special Issue of ESA Bulleti

Special Issue 137, February 2009''SMOS: The Challenging Sea Surface Salinity Measurement from Space'', J. Font, A. Camps, A. Borges, M. Martin-Neira, J. Boutin, N. Reul, Y. Kerr, A. Hahne and S. Mecklenburg,

Proceedings of the IEEE The ''Proceedings of the IEEE'' is a monthly peer-reviewed scientific journal published by the Institute of Electrical and Electronics Engineers (IEEE). The journal focuses on electrical engineering and computer science. According to the ''Journa ...

, vol. 98, no. 5, May 2010, pp. 649-665

History

The project was proposed in November 1998; in 2004 the project passed ESA-phase "C/D" and,The Living Planet Program Soil Moisture and Ocean Salinity (MIRAS on RAMSES)
Mission SMOS at Centre d'Etudes Spatailes de la BIOsphere (CESBIO) after several delays, it was launched on 2 November 2009 from

Plesetsk Cosmodrome Plesetsk Cosmodrome () is a Russian spaceport located in Mirny, Arkhangelsk Oblast, near the town of Plesetsk, from which it takes its name. Until 2025 and the commissioning of the Andøya Space, Andøya base in Norway, it was the only operati ...

on a

Rockot Rokot ( meaning ''Rumble'' or ''Boom''), also transliterated Rockot, was a Soviet Union (later Russian) space launch vehicle that was capable of launching a payload of into a Earth orbit with 63° inclination. It was based on the UR-100N (S ...

rocket. The first data from the

MIRAS Miras is a village and a former municipality in the Korçë County, southeastern Albania. At the 2015 local government reform it became a subdivision of the municipality Devoll, Korçë, Devoll. The population at the 2011 census was 6,577.

(

Microwave Microwave is a form of electromagnetic radiation with wavelengths shorter than other radio waves but longer than infrared waves. Its wavelength ranges from about one meter to one millimeter, corresponding to frequency, frequencies between 300&n ...

Imaging

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 micro ...

using

Aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

Synthesis) instrument was received on 20 November 2009. The SMOS programme cost is about €315 million ($465 million; £280 million). It is led by ESA but with significant input from French and Spanish interests. The satellite is part of ESA's Earth Explorer programme – satellite missions that are performing innovative science in obtaining data on issues of pressing environmental concern. The first is already complete – a mission called

GOCE The Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) was the first of European Space Agency, ESA's Living Planet Programme satellite, heavy satellites intended to map in unprecedented detail the Earth's gravity field. The spacecr ...

, which mapped variations in the pull of

gravity In physics, gravity (), also known as gravitation or a gravitational interaction, is a fundamental interaction, a mutual attraction between all massive particles. On Earth, gravity takes a slightly different meaning: the observed force b ...

across the Earth's surface. SMOS was the second Explorer to launch; and was followed by CryoSat-2 (the first CryoSat failed on launch),

Swarm (spacecraft) Swarm is a European Space Agency (ESA) mission to study the Earth's magnetic field. High-precision and high-resolution measurements of the strength, direction and variations of the Earth's magnetic field, complemented by precise navigation, acc ...

, and ADM-Aeolus.

Launcher

The satellite was launched on 2 November 2009 (04:50 (01:50 GMT)) to a nearly circular orbit of 763 km aboard a

Rokot Rokot ( meaning ''Rumble'' or ''Boom''), also transliterated Rockot, was a Soviet Union (later Russian) space launch vehicle that was capable of launching a payload of into a Earth orbit with 63° inclination. It was based on the UR-100N ( ...

, a modified

Russian Russian(s) may refer to: *Russians (), an ethnic group of the East Slavic peoples, primarily living in Russia and neighboring countries *A citizen of Russia *Russian language, the most widely spoken of the Slavic languages *''The Russians'', a b ...

Intercontinental Ballistic Missile An intercontinental ballistic missile (ICBM) is a ballistic missile with a range (aeronautics), range greater than , primarily designed for nuclear weapons delivery (delivering one or more Thermonuclear weapon, thermonuclear warheads). Conven ...

(ICBM)

SS-19 The UR-100N, also known as RS-18A, is an intercontinental ballistic missile in service with Soviet and Russian Strategic Missile Troops. The missile was given the NATO reporting name SS-19 Stiletto and carries the industry designation 15A30. De ...

launched from a decommissioned SS-19 launcher from Northern Russia's

. The SMOS satellite was launched together with the Proba-2, a technology demonstration satellite.

Science

The goal of the SMOS mission is to monitor surface

soil moisture Soil moisture is the water content of the soil. It can be expressed in terms of volume or weight. Soil moisture measurement can be based on ''in situ'' probes (e.g., capacitance probes, neutron probes) or remote sensing methods. Water that enters ...

with an accuracy of 4% (at 35–50 km

spatial resolution In physics and geosciences, the term spatial resolution refers to distance between independent measurements, or the physical dimension that represents a pixel of the image. While in some instruments, like cameras and telescopes, spatial resoluti ...

). This aspect is managed by the HYDROS project. Project Aquarius will attempt to monitor sea surface

salinity Salinity () is the saltiness or amount of salt (chemistry), 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 dimensio ...

with an accuracy of 0.1 psu (10- to 30-day average and a spatial resolution of 200 km x 200 km).Mecklenburg S, Kerr Y, Font J and Hahne A
''The Soil Moisture and Ocean Salinity (SMOS) Mission - An overview''
Geophysical Research Abstracts, Vol. 10, 2008, SMOS2010

Soil moisture is an important aspect of climate, and therefore

forecasting Forecasting is the process of making predictions based on past and present data. Later these can be compared with what actually happens. For example, a company might Estimation, estimate their revenue in the next year, then compare it against the ...

. Plants transpire water from depths lower than 1 meter in many places and satellites like SMOS can only provide moisture content down to a few centimeters, but using repeated measurements in a day, the satellite can extrapolate soil moisture. The SMOS team of ESA hope to work with farmers around the world, including the

United States Department of Agriculture The United States Department of Agriculture (USDA) is an executive department of the United States federal government that aims to meet the needs of commercial farming and livestock food production, promotes agricultural trade and producti ...

to use as ground-based calibration for models determining soil moisture, as it may help to better understand

crop yield In agriculture, the yield is a measurement of the amount of a crop grown, or product such as wool, meat or milk produced, per unit area of land. The seed ratio is another way of calculating yields. Innovations, such as the use of fertilizer, the ...

s over wide regions.How Dry We Are: European Space Agency To Test Earth's Soil Moisture Via Satellite
Science News, Science Daily Ocean

is crucial to the understanding of the role of the ocean in climate through the global

. Salinity in combination with temperature determine ocean circulation by defining its density and hence

thermohaline circulation Thermohaline circulation (THC) is a part of the large-scale Ocean current, ocean circulation driven by global density gradients formed by surface heat and freshwater fluxes. The name ''thermohaline'' is derived from ''wikt:thermo-, thermo-'', r ...

. Additionally, ocean salinity is one of the variables that regulate CO₂ uptake and release and therefore has an effect on the oceanic

carbon cycle The carbon cycle is a part of the biogeochemical cycle where carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of Earth. Other major biogeochemical cycles include the nitrogen cycle and the water cycl ...

. Information from SMOS is expected to help improve short and medium-term weather forecasts, and also have practical applications in areas such as agriculture and water resource management. In addition, climate models should benefit from having a more precise picture of the scale and speed of movement of water in the different components of the hydrological cycle. SMOS has been used to improve hurricane forecasting by collecting hurricane surface-level wind speed data using its novel microwave imaging radiometer, which can penetrate the thick clouds surrounding a cyclone. Hurricanes that have been studied by SMOS include Hurricane Florence, Typhoon Mangkhut, and Typhoon Jebi.

Instrumentation

The SMOS satellite carries a new type of instrument called

Microwave Imaging Radiometer with Aperture Synthesis Microwave Imaging Radiometer with Aperture Synthesis (MIRAS) is the major instrument on the Soil Moisture and Ocean Salinity satellite (SMOS). MIRAS employs a planar antenna composed of a central body (the so-called hub) and three telescoping, de ...

(MIRAS). Some eight metres across, it has the look of helicopter rotor blades; the instrument creates images of radiation emitted in the

microwave Microwave is a form of electromagnetic radiation with wavelengths shorter than other radio waves but longer than infrared waves. Its wavelength ranges from about one meter to one millimeter, corresponding to frequency, frequencies between 300&n ...

L-band The L band is the Institute of Electrical and Electronics Engineers (IEEE) designation for the range of Frequency, frequencies in the radio spectrum from 1 to 2 gigahertz (GHz). This is at the top end of the ultra high frequency (UHF) band, at t ...

(1.4 GHz). MIRAS will measure changes in the wetness of the land and in the salinity of seawater by observing variations in the natural microwave emission coming up off the surface of the planet.

Operations and ground segment

The

CNES CNES () is the French national space agency. Headquartered in central Paris, the agency is overseen by the ministries of the Armed Forces, Economy and Finance and Higher Education, Research and Innovation. It operates from the Toulouse Spac ...

Satellite Operations

Ground Segment A ground segment consists of all the ground-based elements of a spaceflight, space system used by operators and support personnel, as opposed to the Satellite space segment, space segment and user segment. The ground segment enables management of ...

operates the spacecraft with telecommunications from ESA's

S-band The S band is a designation by the Institute of Electrical and Electronics Engineers (IEEE) for a part of the microwave band of the electromagnetic spectrum covering frequencies from 2 to 4 gigahertz (GHz). Thus it crosses the convention ...

facility located in

Kiruna (; ; ; ) is the northernmost Stad (Sweden), city in Sweden, situated in the province of Lapland, Sweden, Lapland. It had 17,002 inhabitants in 2016 and is the seat of Kiruna Municipality (population: 23,167 in 2016) in Norrbotten County. The c ...

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

. The Data Processing Ground Segment is located in ESAC, Villafranca del Castillo, Spain. Higher level processing of information is done by scientists globally.

History

Launcher

Science

Instrumentation

Operations and ground segment

See also

References

External links