Imagine what it would mean if scientists could literally measure the amount of moisture in the top 2 inches (5 cm) of soil worldwide not from the ground, but from space; if they could provide early warning systems of anticipated droughts long before they would happen; or if they could better forecast weather patterns and trends with enhanced accuracy.
This will come to pass near the end of January when NASA launches an orbiting observatory in a polar orbit around the Earth that will, believe it or not, measure the amount of water in the top layer of soil everywhere on the planet’s surface.
The satellite called SMAP, which stands for Soil Moisture Active and Passive, will help to measure and understand how freshwater cycles over the Earth’s land surfaces in the form of soil moisture. The mission will produce the most accurate, highest-resolution global maps ever obtained from space of the moisture present in the top layer of Earth’s soils. It also will detect and map whether the ground is frozen or thawed. This data will be used to enhance scientists’ understanding of the processes that link Earth’s water, energy and carbon cycles.
“With data from SMAP, scientists and decision makers around the world will be better equipped to understand how Earth works as a system and how soil moisture impacts a myriad of human activities, from floods and drought to weather and crop yield forecasts,” said
Christine Bonniksen, SMAP program executive with the Science Mission Directorate’s Earth Science Division at NASA Headquarters in Washington. “SMAP’s global soil moisture measurements will provide a new capability to improve our understanding of Earth’s climate.”
SMAP is designed to measure soil moisture over a three-year period, every 2-3 days. This permits changes, around the world, to be observed over time scales ranging from major storms to repeated measurements of changes over the seasons.
NASA reports that soil moisture information is key to understanding the flows of water and heat energy between the surface and atmosphere that impact weather and climate. NASA also suggests we know little about soil moisture variability at either regional or global scales. Frequent and reliable soil moisture measurements from SMAP will help improve the predictive capability of weather and climate models.
The amount of water available to evaporate from the land surfaces can be used by meteorologists to improve their forecasts of local and regional weather over spans of days to weeks. Forecasting the weather requires continuously observing the state of the atmosphere and including the level of moisture of the soil and water sources on the ground.
A detailed description can be found in the SMAP Hand-book (PDF, 4.09 MB).
How important is it to better understand the consequences of weather? Consider this— nearly 90% of the emergencies declared by the U.S. Federal Emergency Management Agency and approximately 70% of air traffic delays are caused by weather at a cost of billions of dollars per year. The 2012 drought in the Midwest alone led to harvest failures costing an estimated $30 billion.
Source NASA, from Jim Novak from Turfgrass Producers International