Soil Moisture and Ocean Salinity (SMOS) is a

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 radioiso ...

which forms part of ESA's

Living Planet Programme The Living Planet Programme (LPP) is a programme within the European Space Agency which is managed by the Earth Observation Programmes Directorate. LPP consists of two classes of Earth observation missions (listed below) including research missio ...

. It is intended to provide new insights into Earth's

water cycle The water cycle, also known as the hydrologic cycle or the hydrological cycle, is a biogeochemical cycle that describes the continuous movement of water on, above and below the surface of the Earth. The mass of water on Earth remains fairly co ...

and

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 meteorologi ...

. In addition, it is intended to provide improved

weather forecasting Weather forecasting is the application of science and technology to predict the conditions of the atmosphere for a given location and time. People have attempted to predict the weather informally for millennia and formally since the 19th cen ...

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 ''Jou ...

, 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 ( rus, Космодром «Плесецк», r=Kosmodrom "Plesetsk", p=kəsmɐˈdrom plʲɪˈsʲet͡sk) is a Russian spaceport located in Mirny, Arkhangelsk Oblast, about 800 km north of Moscow and approximately 200 ...

on a Rockot 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. The population at the 2011 census was 6,577.

(

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 ra ...

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 microwave ...

using

Aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An ...

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

environment Environment most often refers to: __NOTOC__ * Natural environment, all living and non-living things occurring naturally * Biophysical environment, the physical and biological factors along with their chemical interactions that affect an organism or ...

al concern. The first is already complete – a mission called GOCE, which mapped variations in the pull of

gravity In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stro ...

across the Earth's surface. SMOS was the second Explorer to launch; and was followed by

CryoSat-2 CryoSat-2 is a European Space Agency (ESA) Earth Explorer Mission that launched on April 8th 2010. CryoSat-2 is dedicated to measuring polar sea ice thickness and monitoring changes in ice sheets. Its primary objective is to measure the thinnin ...

(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, acce ...

, 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 (russian: Рокот meaning ''Rumble'' or ''Boom''), also transliterated Rockot, was a 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 (SS- ...

, a modified Russian

Intercontinental Ballistic Missile An intercontinental ballistic missile (ICBM) is a ballistic missile with a range greater than , primarily designed for nuclear weapons delivery (delivering one or more thermonuclear warheads). Conventional, chemical, and biological weapo ...

(ICBM) SS-19 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 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 resolut ...

). This aspect is managed by the HYDROS project. Project Aquarius will attempt to monitor sea surface salinity 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 (resolved) against what happens. For example, a company might estimate their revenue in the next year, then compare it against the actual ...

. 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 the federal executive department responsible for developing and executing federal laws related to farming, forestry, rural economic development, and food. It aims to meet the needs of comme ...

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 c ...

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

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 ...

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 circulation that is driven by global density gradients created by surface heat and freshwater fluxes. The adjective ''thermohaline'' derives from '' thermo-'' referring to temp ...

. 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 the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth. Carbon is the main component of biological compounds as well as a major compon ...

. 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 Hurricane Florence was a powerful and long-lived Cape Verde hurricane that caused catastrophic damage in the Carolinas in September 2018, primarily as a result of freshwater flooding due to torrential rain. The sixth named storm, third h ...

Typhoon Mangkhut Typhoon Mangkhut (), known in the Philippines as Typhoon Ompong, was a powerful and catastrophic tropical cyclone that caused extensive damage in Guam, the Philippines and South China in September 2018. It was the strongest typhoon to strik ...

, and Typhoon Jebi.

Instrumentation

The SMOS satellite carries a new type of instrument called Microwave Imaging Radiometer with Aperture Synthesis (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 ranging from about one meter to one millimeter corresponding to frequencies between 300 MHz and 300 GHz respectively. Different sources define different frequency ra ...

L-band The L band is the Institute of Electrical and Electronics Engineers (IEEE) designation for the range of 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 the lowe ...

(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 The (CNES; French: ''Centre national d'études spatiales'') is the French government space agency (administratively, a "public administration with industrial and commercial purpose"). Its headquarters are located in central Paris and it is und ...

Satellite Operations

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

will operate 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 radio band, band of the electromagnetic spectrum covering frequency, frequencies from 2 to 4 gigahertz (GHz). Thus it c ...

facility located in

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

Sweden Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic countries, Nordic c ...

. The Data Processing Ground Segment ( CDTI, Villafranca, Spain) will process SMOS data through the

X-band The X band is the designation for a band of frequencies in the microwave radio region of the electromagnetic spectrum. In some cases, such as in communication engineering, the frequency range of the X band is rather indefinitely set at approxi ...

. Higher level processing of information will be done by scientists globally.

History

Launcher

Science

Instrumentation

Operations and ground segment

See also

References

External links