NASA Observatory Sends Back First Images of Earth’s Soil Moisture

The SMAP observatory is designed to help scientists better understand, predict and monitor natural hazards like droughts and floods


A NASA satellite designed to measure Earth's soil moisture sent back its first global map images this month as part of a mission that could help scientists better predict natural hazards like floods and drought.

The array of bright colors displayed in the images released this week show low soil moisture or lack of vegetation with blue colors. Red colors indicate dense vegetation and higher soil moisture levels, such as those seen in the Amazon and Congo rain forests.

The Soil Moisture Active Passive (SMAP) observatory also acquires data over ocean and sea ice, but uses a different color scale to depict temperature variations and the effects of wind.

The images are part of a test of SMAP's instruments before full operations begin in May. The imagery  comes nearly three months after launch from Vandenberg Air Base northwest of Santa Barbara.

SMAP works by bouncing microwave pulses off Earth, then measuring the strength of those signals. Water in soil responds differently to the microwaves than dry soil, allowing scientists to provide the data visualizations with vibrant colors.

The mission, based at Southern California's Jet Propulsion Laboratory, will help scientists understand links between Earth's energy and carbon cycles and reduce uncertainties when it comes to weather and climate forecasting, according to a statement from JPL. The data also will help researchers monitor and predict floods and droughts.

Currently, drought maps and flash flood guidance issued by the federal government are based on computer modeling. SMAP will take real-time measurements that can be incorporated into forecasts.

California is in a fourth year of drought with water reservoirs at critically low levels. The governor has proposed state-mandated water-use cutbacks to combat the dry spell.

The mission is designed to take about three years. Scientists are looking forward to the data provided by SMAP and expressed relief that it's working properly. The complex system that deploys instruments includes an arm the unfurls like a lasso.

"It's fabulous, just the fact that everything has deployed and turned on and worked as we thought it would," said project scientist Dr. Eni  G. Njoku. "Now we're seeing the first data, and it looks very good. I think it's unprecedented that an instrument works this well and is so well calibrated."

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