NASA satellite will map soil moisture

NASA satellite will map soil moisture

NASA has launched new satellite to collect data on the topmost layer of Earth's soils

A satellite that will help scientists understand earth's water, energy and carbon cycles through soil moisture data was launched Jan. 31.

NASA said the satellite mission, Soil Moisture Active Passive, will return the "most accurate, highest-resolution global maps ever obtained from space" of the moisture present in the top 2 inches of Earth's soils.

Related: Could NASA Satellites Predict Agricultural Yields in the Future?

It also will detect and map whether the ground is frozen or thawed. NASA said this data will be used to enhance scientists' understanding of the processes that link Earth's water, energy and carbon cycles.

New satellite launched Jan. 31 to collect data on the topmost layer of Earth's soils

The data will also be used to see how soil moisture impacts floods, droughts and crop yield forecasts, said Christine Bonniksen, NASA Soil Moisture Active Passive program executive.

"SMAP's global soil moisture measurements will provide a new capability to improve our understanding of Earth's climate," she said.

Globally, the volume of soil moisture varies between 3-5% in desert and arid regions, to between 40-50% in saturated soils. In general, the amount depends on such factors as precipitation patterns, topography, vegetation cover and soil composition.

There are not enough sensors in the ground to map the variability in global soil moisture at the level of detail needed by scientists and decision makers, so SMAP will produce global maps with 6-mile (10-kilometer) resolution every two to three days.

Measuring moisture for crop growth
Researchers want to measure soil moisture and its freeze/thaw state better for numerous reasons. Plants and crops draw water from the soil through their roots to grow. If soil moisture is inadequate, plants fail to grow, which over time can lead to reduced crop yields.

Also, energy from the sun evaporates moisture in the soil, thereby cooling surface temperatures and also increasing moisture in the atmosphere, allowing clouds and precipitation to form more readily. In this way, soil moisture has a significant effect on both short-term regional weather and longer-term global climate.

Continue reading after the jump >>


In summer, plants in Earth's high northern latitudes take in carbon dioxide from the air and use it to grow, but lay dormant during the winter freeze period. All other factors being equal, the longer the growing season, the more carbon plants take in and the more effective forests are in removing carbon dioxide from the air.

Since the start of the growing season is marked by the thawing and refreezing of water in soils, mapping the freeze/thaw state of soils with SMAP will help scientists more accurately account for how much carbon plants are removing from the atmosphere each year.

This information will lead to better estimates of the carbon budget in the atmosphere and, hence, better assessments of future global warming, NASA said.

Read more about the SMAP project on the NASA website.

Editors note: This story originally appeared on Jan. 12, 2015. It was updated Feb. 6, 2015 to include launch date and information.

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.