LA CAñADA FLINTRIDGE >> Although many Angelenos have commented about how a rainstorm would offer some respite to our drought-plagued Southland, few realized soil moisture could help NASA scientists better predict weather and climate, droughts, and even where floods might occur.
Eni Njoku, a Jet Propulsion Laboratory scientist, said experts don’t have sufficient global data on soil moisture, which evaporates, continues through the water cycle to form clouds and rain. Apart from satellite data, the only way to measure soil moisture is to insert sensors into the ground at specific areas, but scientists can’t realistically cover the planet on foot, he said.
That’s where NASA’s Soil Moisture Active Passive instrument comes in. SMAP, built and soon-to-be operated by NASA’s JPL, is scheduled to launch Jan. 29 from Vandenberg Air Force Base in Lompoc.
“SMAP is the first of its kind,” said Njoku, senior research scientist with the SMAP mission. “There have been other satellites that have provided some soil information in the past but never with the accuracy and spatial resolution that SMAP will.”
SMAP, NASA’s fifth Earth science mission since January, will orbit the Earth at an altitude of 526 miles. It will carry radar, radiometer and antenna tools expected to output data at a spatial resolution of about 1.9 miles. It will cover Earth’s land surface every two to three days.
Randy Koster of NASA’s Goddard Space Flight Center in Greenbelt, Md., said SMAP will be an exciting development.
“It will provide global measurements of near-surface soil moisture at a resolution unmatched by any other system.”
Its closest competition was a European Space Agency’s satellite, which was launched five years ago and provided data at a spatial resolution of about 25 miles, Njoku said.
It’s crucial for policy makers to have a scientific understanding of how the change in future water resources may affect water supply and food supply, according to the SMAP website.
The orbiter may help farmers improve plant growth and agricultural productivity because improved growing season forecasts will help growers strategize next season’s crop. And for those in sub-Saharan Africa and South Asia, where hunger could be a real problem, SMAP data will help with early famine warning systems.
Soil moisture is also a key variable when it comes to natural disasters such as floods and landslides. High-resolution observations could help scientists warn people who will be affected by these catastrophes earlier.
Additionally, improved weather forecasts will upgrade predictions for heat stress and virus-spreading rates. In short, SMAP will allow policy makers to plan farther ahead into the future.
Njoku said it’s too early to say when the raw data could be used to improve forecasts of things such as weather, climate, droughts and floods. But NASA’s new satellite should significantly improve weather predictions, which currently become less reliable beyond three to five days, he said.
