ESA SMOS Earth Monitoring satellite - Five Years in Orbit - Video

ESA’s SMOS satellite has clocked up more than one billion kilometres orbiting Earth to improve our understanding of our planet’s water cycle.

Marking its fifth birthday, all the data collected over land and ocean have been drawn together to show how moisture in the soil and salinity in the ocean change over the year.

The Earth Explorer SMOS mission was launched on 2 November 2009 from Plesetsk in Russia.

Carrying a novel sensor, it captures images of ‘brightness temperature’. These images correspond to microwave radiation emitted from Earth’s surface and can be related to soil moisture and ocean salinity, two key variables in Earth’s water cycle.

The animation above uses five years of SMOS data to show how, on average, moisture in the soil changes with the seasons around the world.

It illustrates how change is more pronounced at higher latitudes, but monsoon dynamics in the Indian subcontinent are also clearly visible.

The ‘Sahel transition’ region in Africa is well depicted and seasonal flooding in regions such as La Plata in Argentina and the Orinoco Basin in Veneuzela can also be seen.



Over oceans, measurements from SMOS, the longest continuous record from space, show monthly differences in sea-surface salinity with respect to the average salinity, and show large deviations in the tropical Pacific Ocean and in the Indian Ocean.

This is linked to the occurrence of La Niña, which is associated with cooler than normal sea-surface temperatures in the eastern Pacific, and the Indian Ocean Dipole, which describes sea-surface temperature differences between the eastern and western equatorial Indian Ocean.

While these results are of interest to understanding aspects of the water cycle, information from SMOS is being used for a number of practical applications.

In fact, 18 TB of SMOS data are distributed every year, of which around 13 TB are used by scientists and around 5 TB for near-realtime applications by operational users.

For example, integrating these accurate near-realtime observations into the European Centre for Medium-Range Weather Forecasts’ (ECMWF) system is helping to improve air temperature and humidity forecasts near the surface.

In addition, the inclusion of SMOS observations are helping to improve the prediction of rain.

ESA’s SMOS satellite: Five Years of Soil Moisture and Sea Salinity Measurements

ESA’s SMOS satellite has clocked up more than one billion kilometres orbiting Earth to improve our understanding of our planet’s water cycle.

Marking its fifth birthday, all the data collected over land and ocean have been drawn together to show how moisture in the soil and salinity in the ocean change over the year.

The Earth Explorer SMOS satellite mission was launched on 2 November 2009 from Plesetsk in Russia.

Carrying a novel sensor, it captures images of ‘brightness temperature’.

These images correspond to microwave radiation emitted from Earth’s surface and can be related to soil moisture and ocean salinity, two key variables in Earth’s water cycle.

The animation above uses five years of SMOS data to show how, on average, moisture in the soil changes with the seasons around the world.

It illustrates how change is more pronounced at higher latitudes, but monsoon dynamics in the Indian subcontinent are also clearly visible.

The ‘Sahel transition’ region in Africa is well depicted and seasonal flooding in regions such as La Plata in Argentina and the Orinoco Basin in Veneuzela can also be seen.


Over oceans, measurements from SMOS, the longest continuous record from space, show monthly differences in sea-surface salinity with respect to the average salinity, and show large deviations in the tropical Pacific Ocean and in the Indian Ocean.

This is linked to the occurrence of La Niña, which is associated with cooler than normal sea-surface temperatures in the eastern Pacific, and the Indian Ocean Dipole, which describes sea-surface temperature differences between the eastern and western equatorial Indian Ocean.

While these results are of interest to understanding aspects of the water cycle, information from SMOS is being used for a number of practical applications.

In fact, 18 TB of SMOS data are distributed every year, of which around 13 TB are used by scientists and around 5 TB for near-realtime applications by operational users.

For example, integrating these accurate near-realtime observations into the European Centre for Medium-Range Weather Forecasts’ (ECMWF) system is helping to improve air temperature and humidity forecasts near the surface. In addition, the inclusion of SMOS observations are helping to improve the prediction of rain.

ESA SMOS: Water mission boosts food security

The SMOS mission makes global observations of soil moisture over Earth's landmasses and salinity over the oceans. 

Variations in soil moisture and ocean salinity are a consequence of the continuous exchange of water between the oceans, the atmosphere and the land - Earth's water cycle.

ESA's Soil Moisture and Ocean Salinity mission has gone beyond its original scientific brief of delivering critical information for understanding the water cycle - this versatile satellite is now being used to predict drought and improve crop yield in regions prone to famine.

The US Department of Agriculture use satellite images and soil moisture data to help identify abnormal weather that may affect the production and yield of crops.

Using this information, they publish monthly estimates of world production, supply and distribution.

As well as offering traders and commodity markets a source of unbiased information, these estimates provide decision-makers with critical information for countries that may need food aid as a result of severe droughts.

Identifying when and where there may be a risk of famine involves measuring soil moisture in the 'root-zone' during the growing season, and detecting the onset and severity of drought.

Analysts use information linked to drought from a range of observing systems to compile these crop production forecasts.

In the past, the amount of moisture in the soil available to plants was estimated by integrating daily observations of rainfall and temperatures into computer models of soil-water balance. However, this approach only works reliably in areas where high-quality observations are available.

In large areas of the world, such as southern Africa, there are little or no such data.

Turning to space, the US Department of Agriculture (USDA) Foreign Agricultural Service has started to incorporate data from ESA's Soil Moisture and Ocean Salinity (SMOS) satellite into their forecasting system.

Carrying a novel sensor, SMOS captures images of 'brightness temperature'. These images correspond to microwave radiation emitted from Earth's surface and can be related to soil moisture and ocean salinity - two key variables in Earth's water cycle.

Through SMOS, the US service obtains timely information on soil moisture patterns, which help to predict how the health of plants will change and, therefore, how productive they will be.

Testing the SMOS readings for this purpose, they received very positive feedback from analysts in southern Africa. This is a challenging area because there are very few working rain gauges.

The new product is available on the Crop Explorer website.