These 2 NASA satellites are 'smart water meters' that can track groundwater in Northern California

NASA's GRACE satellite observing mission aims to track the motion of all of Earth's surface and groundwater, giving a more complete picture of water supply.

NASA's GRACE satellite observing mission aims to track the motion of all of Earth's surface and groundwater, giving a more complete picture of water supply.

BENEATH OUR FEET. REPORTER: FOR THE PAST TWO DECADES, SCIENTISTS WITH NASA HAVE BEEN USING A PAIR OF SATELLITES WITH HIGHLY SENSITIVE INSTRUMENTS TO LOOK FOR CHANGES IN SURFACE AND GROUNDWATER ALL OVER THE PLANET. NAMED GRACE, WHICH STANDS FOR GRAVITY RECOVERY AND CLIMATE EXPERIMENT, THIS ONGOING MISSION ALLOWS SCIENTISTS TO GET A CLEAR PICTURE OF WHAT’S HAPPENING WITH THE WATER DEEP BENEATH OUR FEET. WATER THAT THE CENTRAL VALLEY USES TO SUPPORT WATER NEEDS AND THE STATE’S AG INDUSTRY. DR. FELIX LANDERER IS A PROJECT SCIENTIST WITH THE GRACE MISSION. >> WE TEND TO REFER TO THESE SATELLITES AS KIND OF SMART WATER METERS BECAUSE THEY TELL US ABOUT WATER DISTRIBUTION ON THE SURFACE OF THE EARTH BUT CRUCIALLY ALSO FAR UNDERNEATH WHERE WE OTHERWISE HAVE NO WAY OF DETECTING MASS CHANGES, CERTAINLY NOT FROM SPACE. REPORTER: THE WAY THESE TWO SATELLITES WORK IS PRETTY COOL. ONE FOLLOWS THE OTHER’S ORBIT PATH ABOUT 100 MILES BEHIND. EARTH’S GRAVITY FORCES TINY CHANGES IN THAT DISTANCE. WE’RE TALKING A FRACTION OF A HUMAN HAIR. AND THE SATELLITES ARE SENSITIVE ENOUGH TO DETECT THAT. THOSE TINY CHANGES CAN RESULT FROM SOMETHING LIKE A DEEP SNOWPACK IN THE SIERRA OR MISSING GROUNDWATER IN THE VALLEY. AND THAT’S HOW THE GRACE MISSION TRACKS CHANGES IN WATER STORAGE. LANDERER SAYS THAT DATA GATHERED LAST YEAR SHOWS THAT CENTRAL VALLEY AQUIFERS LIKELY REACHED A NEW RECORD LOW IN NOVEMBER. A REMINDER THAT DESPITE IMPROVED SURFACE WATER STORAGE, WE STILL HAVE A LONG WAY TO GO TO RECOVER FROM DECADES OF OVERPUMPING. >> WHAT WE SEE AT THE SURFACE, EVEN THOUGH NOW EVERYTHING IS LUSH AND GREEN AND LOOKS QUITE GOOD, DEEP UNDERNEATH IN THE AQUIFER REGIONS, WE STILL HAVE A VERY BIG WATER DEFICIT THAT WILL TAKE MANY YEARS OF THIS KIND OF PRECIPITATION TO REPLENISH . REPORTER: EXCESS WATER FROM JANUARY’S STORMS PUT A BIG FOCUS ON INTENTIONALLY RECHARGING GROUNDWATER BY DIRECTING FLOOD WATER INTO FARM FIELDS AND WILDLAND AREAS. LANDERER SAYS HE IS HOPEFUL THAT AS THOSE MANAGED AQUIFER RECHARGE PROJECTS EXPAND, THE GRACE MISSION CAN HELP TRA

These 2 NASA satellites are 'smart water meters' that can track groundwater in Northern California

NASA's GRACE satellite observing mission aims to track the motion of all of Earth's surface and groundwater, giving a more complete picture of water supply.

Northern California's surface water is relatively easy to track. Mainly because we can see it: accumulating in the snowpack and flowing into reservoirs, rivers and other bodies of freshwater. By comparison, keeping tabs on groundwater is much harder because it exists deep beneath our feet in various aquifers and well systems. Yet tracking that groundwater is crucial to anticipating the water supply for the state in the short term but especially in the long term. During dry years, groundwater can account for up to 60% of the state's drinking water availability. Following years of drought and decades of over-pumping, that groundwater is severely depleted. Just last year, scientists with NASA's Jet Propulsion Laboratory discovered that California's groundwater likely reached a new low.Felix Landerer is one of the NASA scientists who analyzed that data as part of the ongoing GRACE Follow-On satellite mission, which launched in 2018. "What we saw in the data up to November is this long-term decline and in fact, we think our first preliminary analysis shows us that November in 2022 was a new record low for water storage," Landerer said.The GRACE-FO mission, short for Gravity Recovery and Climate Experiment Follow-On, comprises two twin satellites orbiting Earth one behind the other. Those satellites are spaced approximately 100 miles apart but differences in surface and groundwater concentrations on Earth below can alter that distance ever so slightly."The distance only varies by a fraction of the thickness of a human hair," Landerer said.And the twin satellites are sensitive enough to detect those minuscule changes.According to Landerer, areas of Earth with more surface or groundwater "feel heavier" to the satellites. Said another way, added water increases the force of gravity on the satellites, which changes the distance between the two."So California is literally quite a bit heavier in the wintertime," Landerer. Of course, that's assuming the mountains are covered in snow. This unique ability to "see" California's groundwater and watch it shift throughout the planet can provide important insights into water supply forecasting. Currently, hydrology models do not take the movement of groundwater into account. "So what we're doing here is really tracking this mass redistribution over time and we're trying to make an impact with our data and inform water managers so that our decision making as it relates to water is based on data and on facts," Landerer said.It takes approximately a month for new data to come in from the satellites, so information from January's storms is likely being processed now. While even that substantial rain will likely have only a small impact on the Central Valley's groundwater supply, Landerer said he is looking forward to hopefully being able to use GRACE-FO data to track an increase in groundwater for the Golden State. GRACE-FO is also tasked with analyzing phenomena including glacial melt and sea level rise resulting from human-caused climate change. The two satellites currently in orbit are part of the second round of NASA's GRACE-FO mission, which launched in 2018. The original GRACE mission launched back in 2002. Scientists are making plans to continue this observing project through at least the end of this decade.

Northern California's surface water is relatively easy to track. Mainly because we can see it: accumulating in the snowpack and flowing into reservoirs, rivers and other bodies of freshwater.

By comparison, keeping tabs on groundwater is much harder because it exists deep beneath our feet in various aquifers and well systems.

Yet tracking that groundwater is crucial to anticipating the water supply for the state in the short term but especially in the long term. During dry years, groundwater can account for up to 60% of the state's drinking water availability.

Following years of drought and decades of over-pumping, that groundwater is severely depleted. Just last year, scientists with NASA's Jet Propulsion Laboratory discovered that California's groundwater likely reached a new low.

Felix Landerer is one of the NASA scientists who analyzed that data as part of the ongoing GRACE Follow-On satellite mission, which launched in 2018.

"What we saw in the data up to November is this long-term decline and in fact, we think our first preliminary analysis shows us that November in 2022 was a new record low for water storage," Landerer said.

The GRACE-FO mission, short for Gravity Recovery and Climate Experiment Follow-On, comprises two twin satellites orbiting Earth one behind the other. Those satellites are spaced approximately 100 miles apart but differences in surface and groundwater concentrations on Earth below can alter that distance ever so slightly.

"The distance only varies by a fraction of the thickness of a human hair," Landerer said.

And the twin satellites are sensitive enough to detect those minuscule changes.

According to Landerer, areas of Earth with more surface or groundwater "feel heavier" to the satellites. Said another way, added water increases the force of gravity on the satellites, which changes the distance between the two.

"So California is literally quite a bit heavier in the wintertime," Landerer.

Of course, that's assuming the mountains are covered in snow.

This unique ability to "see" California's groundwater and watch it shift throughout the planet can provide important insights into water supply forecasting. Currently, hydrology models do not take the movement of groundwater into account.

"So what we're doing here is really tracking this mass redistribution over time and we're trying to make an impact with our data and inform water managers so that our decision making as it relates to water is based on data and on facts," Landerer said.

It takes approximately a month for new data to come in from the satellites, so information from January's storms is likely being processed now. While even that substantial rain will likely have only a small impact on the Central Valley's groundwater supply, Landerer said he is looking forward to hopefully being able to use GRACE-FO data to track an increase in groundwater for the Golden State.

GRACE-FO is also tasked with analyzing phenomena including glacial melt and sea level rise resulting from human-caused climate change.

The two satellites currently in orbit are part of the second round of NASA's GRACE-FO mission, which launched in 2018. The original GRACE mission launched back in 2002. Scientists are making plans to continue this observing project through at least the end of this decade.

These 2 NASA satellites are 'smart water meters' that can track groundwater in Northern California

NASA's GRACE satellite observing mission aims to track the motion of all of Earth's surface and groundwater, giving a more complete picture of water supply.

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