Soil moisture-sensing SMAP satellite could help farmers, Arctic builders

Farmers, crews building new roads in the melting Arctic and weather forecasters are among those who will soon be getting some extra help in predicting costly hazards — from space.

NASA's $1.1B satellite can divine water from space

NASA's Soil Moisture Active Passive (SMAP) mission will produce high-resolution global maps of soil moisture to track water availability around our planet. (NASA-JPL/Caltech)

Farmers, crews building new roads in the melting Arctic and weather forecasters are among those who will soon be getting some extra help in predicting costly hazards — from space.

NASA's Soil Moisture Active Passive (SMAP) mission is designed to monitor from space how wet the soil is around the world in an effort to improve forecasts of hazards such as droughts and floods.

The satellite launch on Saturday was the beginning of a planned three-year mission. (Bill Ingalls/NASA/Associated Press)

It launched successfully this past Saturday, to the relief of the Canadian scientists involved, including Alexandre Langlois at the University of Sherbrooke.

"We're happy it's up there. It's one of the main steps," Langlois said Monday.

Canadian scientists at universities and federal government departments across the country have been involved in the satellite mission, which will map the amount of soil moisture in the top five centimetres of soil worldwide using radar and detectors for radio waves. It will also be able to distinguish between soil that's frozen or thawed.

The Canadian Space Agency committed $1.1 million toward the $1.1-billion NASA project.

Paul Bullock, a professor in the department of soil science at the University of Manitoba who is part of the Canadian SMAP team, said the satellite will provide valuable information to farmers.

Not only does the level of soil moisture determine the yield of crops, but it can also provide early warning of conditions that might lead to an explosion of pests, such as the canola disease blackleg and some blights that affect grains.

Mapping risk

Soil moisture and temperature maps can be combined to create maps showing high-risk areas for certain crops.

A man stands on the cracked ground of the Atibainha dam reservoir as it dries up owing to a prolonged drought in Nazare Paulista in Brazil's Sao Paulo state in 2014. The new satellite aims to help forecast and map droughts from space. (Nacho Doce/Reuters)

"In some cases you can try to mitigate with some kind of fungicide or some other type of practice," said Bullock. "If you have these sorts of things to raise a flag and let them know … where they should be focusing their efforts, that can be useful."

The data can also be useful for insurance companies that are trying to figure out exactly where people have been hit by droughts or floods, in order to figure out whether to accept their claims, Bullock said.

In the future, the data may be used to help predict flooding, as waterlogged soils that can't take in any more moisture create more runoff.

The new satellite will also provide data about where the soil is frozen or thawed, a feature that Langlois has been working on.

As permafrost thaws, it can cause the ground to sink and erode, damaging infrastructure. The new satellite may be able to map areas that present a lower risk, to help infrastructure planners avoid costly damage.

The Arctic is warming because of climate change, and the soil in many areas that was permanently frozen is now melting.

Mapping the melt across the Arctic will be particularly useful for people building roads, buildings, pipelines and other infrastructure, Langlois said. Melting permafrost can cause the ground to sink, damaging infrastructure.

"But there's certain areas that would actually be less problematic in terms of freeze-thaw cycles, and those have yet to be identified," he said.

Pinpointing those areas could reduce infrastructure damage and save significant amounts of money, and could also reduce damage to the environment.

More worries

Langlois said even though the satellite has now launched, scientists will continue to worry until the satellite's antenna starts rotating and begins collecting data in about two weeks.

The satellite will begin its soil moisture mapping in earnest in about 70 days.

At that point, the Canadian team, Ramata Magagi at the University of Sherbrooke, will have to make sure that the data being provided by the satellite actually represents the soil moisture measured on the ground.

The wider goals of the three-year mission include helping scientists improve weather, climate, drought and flood forecasts, along with measuring how much carbon plants are taking in from the atmosphere.

SMAP is similar to the European Space Agency's Soil Moisture and Ocean Salinity satellite, launched in 2009. SMOS was designed for a five-year mission and is now at the end of its lifetime.

Like SMAP, the European agency's satellite looked for radio waves of particular wavelengths that are given off by soil. The intensity depends on how wet the soil is.

SMAP will have a much higher resolution, however, because it uses a radar in addition to its radio-wave sensor.


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