News Column

NASA's Aquarius returns global maps of soil moisture

July 24, 2014



By a News Reporter-Staff News Editor at Agriculture Week -- Soil moisture, the water contained within soil particles, is an important player in Earth's water cycle. It is essential for plant life and influences weather and climate. Satellite readings of soil moisture will help scientists better understand the climate system and have potential for a wide range of applications, from advancing climate models, weather forecasts, drought monitoring and flood prediction to informing water management decisions and aiding in predictions of agricultural productivity.

Launched June 10, 2011, aboard the Argentinian spacecraft Aquarius/Satelite de Aplicaciones Cientificas (SAC)-D, Aquarius was built to study the salt content of ocean surface waters. The new soil wetness measurements were not in the mission's primary science objectives, but a NASA-funded team led by U.S. Department of Agriculture (USDA) researchers has developed a method to retrieve soil moisture data from the instrument's microwave radiometer.

The Aquarius measurements are considerably coarser in spatial resolution than the measurements from the upcoming NASA Soil Moisture Active Passive (SMAP) mission, which was specifically designed to provide the highest quality soil moisture measurements available, including a spatial resolution 10 times that offered by Aquarius.

Soils naturally radiate microwaves and the Aquarius sensor can detect the microwave signal from the top 2 inches (5 centimeters) of the land, a signal that subtly varies with changes in the wetness of the soil. Aquarius takes eight days to complete each worldwide survey of soil moisture, although with gaps in mountainous or vegetated terrain where the microwave signal becomes difficult to interpret.

Tom Jackson, principal investigator for the Aquarius soil moisture measurements and a hydrologist with USDA, said that his agency uses soil wetness information to improve crop forecasts. These forecasts not only help farmers and markets adjust their prices according to worldwide production, but also allow relief agencies to plan for food emergency responses.

"There's a lot of precipitation data in our country, but outside the U.S. and Europe it gets pretty sparse," said Jackson. "By using soil moisture readings, we can better monitor the condition of soils."

Keywords for this news article include: USDA, Aerospace, Agriculture, NASA/Goddard Space Flight Center.

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


For more stories covering the world of technology, please see HispanicBusiness' Tech Channel



Source: Agriculture Week


Story Tools






HispanicBusiness.com Facebook Linkedin Twitter RSS Feed Email Alerts & Newsletters