International Satellite to Track Impacts of Small Ocean Currents

est in January at a Thales Alenia Space facility in Cannes, France, where the satellite is being assembled. SWOT will measure elevations of Earth’s ocean and surface water, giving researchers information with an unprecedented level of detail. Credits: CNES/Thales Alenia Space

SWOT’s solar panels unfold as part of a test in January at a Thales Alenia Space facility in Cannes, France, where the satellite is being assembled. SWOT will measure elevations of Earth’s ocean and surface water, giving researchers information with an unprecedented level of detail. Credits: CNES/Thales Alenia Space

The Surface Water and Ocean Topography mission will explore how the ocean absorbs atmospheric heat and carbon, moderating global temperatures and climate change.

Though climate change is driving sea level rise over time, researchers also believe that differences in surface height from place to place in the ocean can affect Earth’s climate. These highs and lows are associated with currents and eddies, swirling rivers in the ocean, that influence how it absorbs atmospheric heat and carbon.

Enter the Surface Water and Ocean Topography (SWOT) mission, a joint effort of NASA and French space agency Centre National d’Études Spatiales (CNES), with contributions from the Canadian Space Agency (CSA) and the United Kingdom Space Agency. Launching in November 2022, SWOT will collect data on ocean heights to study currents and eddies up to five times smaller than have been previously detectable. It will also gather detailed information on freshwater lakes and rivers.

currents in moderating climate change, as well as the elevations of bodies of fresh water. The mission is jointly led by NASA and CNES, with contributions from the UKSA and CSA. Credits: NASA/JPL-Caltech/CNES/Thales Alenia Space

The SWOT mission will collect information on sea level height, which will help scientists study the role of currents in moderating climate change, as well as the elevations of bodies of fresh water. The mission is jointly led by NASA and CNES, with contributions from the UKSA and CSA. Credits: NASA/JPL-Caltech/CNES/Thales Alenia Space

Observing the ocean at relatively small scales will help scientists assess its role in moderating climate change. The planet’s largest storehouse of atmospheric heat and carbon, the ocean has absorbed more than 90% of the heat trapped by human-caused greenhouse gas emissions.

Much of the continued uptake of that heat – and the excess carbon dioxide and methane that produced it – is thought to occur around currents and eddies less than 60 miles (100 kilometers) across. These flows are small relative to currents such as the Gulf Stream and the California Current, but researchers estimate that in the aggregate they transfer up to half the heat and carbon from surface waters to the ocean’s depths.

Better understanding this phenomenon may be key to determining whether there’s a ceiling to the ocean’s ability to absorb heat and carbon from human activities.

“What is the turning point at which the ocean starts releasing huge amounts of heat back into the atmosphere and accelerating global warming, rather than limiting it?” said Nadya Vinogradova Shiffer, SWOT’s program scientist at NASA Headquarters in Washington. “SWOT can help answer one of the most critical climate questions of our time.”

Thinking Small

Existing satellites can’t detect smaller-scale currents and eddies, limiting research into how those features interact with each other and with larger-scale flows.

“That’s a place where we will learn a lot from having better observations of the small scales,” said J. Thomas Farrar, a SWOT oceanography science lead with Woods Hole Oceanographic Institution in Falmouth, Massachusetts.

In addition to helping researchers study the climate impacts of small currents, SWOT’s ability to “see” smaller areas of Earth’s surface will allow it to collect more precise data along coastlines, where rising ocean levels and the flow of currents can have immediate impacts on land ecosystems and human activity.

Higher seas, for example, can cause storm surges to penetrate farther inland. Also, currents intensified by sea level rise may increase saltwater intrusion into deltas, estuaries, and wetlands, as well as groundwater supplies.

“In the open ocean, the whole phenomenon of drawing down heat and carbon will affect humanity for years to come,” said Lee-Lueng Fu, the SWOT project scientist at NASA’s Jet Propulsion Laboratory in Southern California. “But in coastal waters, the effects of currents and sea height are felt over days and weeks. They affect human lives directly.”

So how will measuring ocean height lead to better knowledge of currents and eddies?

Researchers use height differences between points – known as the slope – to calculate the motion of currents. The math accounts for the force of Earth’s gravity, which pulls water from high to low, and the planet’s rotation, which, in the Northern Hemisphere, bends the flow clockwise around high points and counterclockwise around low points. The effect is the opposite in the south.

The height of the ocean is associated with currents and eddies on the ocean’s surface, which are shown in this visualization based on the period from June 2005 to June 2007. SWOT will be able to observe currents and eddies smaller than those illustrated, down to 12 miles (20 kilometers) across. Credits: NASA/SVS Download video

Systems of currents hundreds of miles wide flow around broad expanses of the ocean. Along the way, smaller currents and eddies spin off and interact with one another. When they come together, they drive water from the surface downward to colder depths, taking along heat and carbon from the atmosphere. When those smaller currents and eddies flow apart, water from those colder depths rises to the surface, ready to absorb heat and carbon again.

This vertical movement of heat and carbon also occurs at eddies themselves. In the Northern Hemisphere, clockwise eddies generate downward flows, while counterclockwise eddies create upward flows. The reverse occurs in the Southern Hemisphere.

Filling in the Gaps

By measuring ocean heights down to 0.16-inch (0.4-centimeter) increments, as well as their slopes, SWOT’s two Ka-band Radar Interferometer (KaRIn) antennas will help researchers discern currents and eddies as small as 12 miles (20 kilometers) across.

SWOT will also employ a nadir altimeter, an older technology that can identify currents and eddies down to about 60 miles (100 kilometers) wide. Where the nadir altimeter will point straight down and take data in one dimension, the KaRIn antennas will tilt. This will enable the KaRIn antennas to scan the surface in two dimensions and, working in tandem, collect data with greater precision than the nadir altimeter alone.

“Currently, to get a two-dimensional view from a one-dimensional line, we take all of our one-dimensional lines and estimate what’s happening between them,” said Rosemary Morrow, a SWOT oceanography science lead at Laboratoire d’Études en Géophysique et Océanographie Spatiales in Toulouse, France. “SWOT will directly observe what’s in the gaps.”

More About the Mission

SWOT is being jointly developed by NASA and CNES, with contributions from the CSA and the UK Space Agency. JPL, which is managed for NASA by Caltech in Pasadena, California, leads the U.S. component of the project. For the flight system payload, NASA is providing the KaRIn instrument, a GPS science receiver, a laser retroreflector, a two-beam microwave radiometer, and NASA instrument operations. CNES is providing the Doppler Orbitography and Radioposition Integrated by Satellite (DORIS) system, nadir altimeter, the KaRIn RF subsystem (with support from the UK Space Agency), the platform, and ground control segment. CSA is providing the KaRIn high-power transmitter assembly. NASA is providing the launch vehicle and associated launch services.

To learn more about the mission, visit:

https://swot.jpl.nasa.gov/

4 4 votes
Article Rating
22 Comments
Oldest
Newest Most Voted
Inline Feedbacks
View all comments
Steve Case
May 11, 2022 10:08 pm

The Surface Water and Ocean Topography mission will explore how the ocean absorbs atmospheric heat and carbon, 
_______________________________________________________________

Carbon? Are they ever going to stop the nonsense?

Brad-DXT
Reply to  Steve Case
May 11, 2022 10:38 pm

I think that every grant seeker has to provide a link to “climate change” to have a reasonable chance of gaining funding, even if it is to study ocean currents.
I imagine that there are a number of practical reasons to study and understand ocean currents that go beyond the eye-washing cover of “climate change”.

Redge
May 11, 2022 10:14 pm

Is it worse than we thought yet?

Geoff Sherrington
May 11, 2022 10:35 pm

There is inexcusable, unscientific use of the word “carbon”. There is a false assertion that the oceans are the world,S largest storehouse of carbon. Is ‘coal” now a cancelled word?
Speculation is absent from the press release. Water density can be affected by temperature and suspended life forms and local surges and waves and salinity, with local variations of any and all of these causing changes in surface height, so that speculative assumptions have to be made about the variables that are not measured by the satellite.
The words quoted above have sweeping assertions about heat, water expansion and quantitative relations between them. Show some valid, confirmed, mathematical equations that indicate how many mm ocean surface height changes per degree C of temperature change. Good luck with that search.
Coastal ocean level changes have already been measured quite accurately all over the world. I cannot see how the cost of a new satellite to measure again is economically justified. Nor is there an explanation why ocean level change over the past couple of thousand years has been quite constant, with no change detectable since before and after CO2 allegations of warmer seas from CO2 causing rises,
The whole press release quoted justifies a short, sharp description of “woke wank”. It fails to demonstrate proper, hard, empirical science. Geoff S

Pete Yates
May 12, 2022 12:13 am

“Launching in November 2022, SWOT will collect data on ocean heights … up to five times smaller than have been previously detectable.” .. I think this seems to cast doubt on the accuracy of the satellite-measured Sea Level Rise of about 3.5mm/yr. Do you agree?

ATheoK
Reply to  Pete Yates
May 12, 2022 6:52 pm

Sea level heights are allegedly measured by satellites with large measurement error bars.

Their proclaimed accuracy is another one of NASA/NOAA’s inept averaging falsehoods. That repeated bad measurements can be averaged into accuracy.

Tim Gorman
Reply to  ATheoK
May 13, 2022 7:50 am

Wow! You nailed it! NASA/NOAA and the rest of the CAGW advocates actually ignore true uncertainty and its propagation into a final result and, instead, try to substitute the standard deviation of sample means instead. The issue is that the standard deviation of the sample means can be small but the average of those sample means can be WAY OFF from a true value. It’s the blind leading the blind!

It’s like a rifle grouping all its shots on a target at the very edge of the paper when the aimed point (the bullseye) is in the middle of the paper. Small deviation in the grouping doesn’t mean the shots are accurate!

Steve Richards
May 12, 2022 3:51 am

Looking at the linked site, it appears to be on a 21 day repeat orbit.
Not sure how a measurement taken today can be compared with one 21 days later, if you were looking for small currents.
Large ocean waves and swell make a mockery of this.

David Dibbell
Reply to  Steve Richards
May 12, 2022 4:22 am

“Large ocean waves and swell make a mockery of this.” Tides, too.

And to your point about the orbit, here is a quote from the website, for those just skimming these comments: “Phase E (Operations & Sustainment), nominally lasting three years, will have a 21-day repeat orbit to balance global coverage and frequent sampling. This non-sun-synchronous orbit was chosen to minimize tidal aliasing and ensure coverage of major water bodies on land. SWOT’s 120-km-wide (~75-mi-wide) swath will result in overlapping measurements over most of the globe with an average revisit time of 11 days.”

Tidal aliasing? It seems obvious to me that the ocean tides will completely obscure whatever sub-centimeter measurement increments are being claimed.

miket
May 12, 2022 4:04 am

Scientists saying carbon when they mean CO2 is unforgivable, when they know most people won’t understand that they mean CO2.

Also the dye is cast before they even start as, more than once, they talk of assisting moderation of climate change.

ATheoK
Reply to  miket
May 12, 2022 6:58 pm

You are correct, but with a little misunderstanding.

Carbon dioxide concentrations in lakes, rivers and oceans are quickly utilized and converted into carbonates.

Reading the above writeup, I doubt the alleged scientists understand carbon dioxide, photosynthesis or the myriad forms that utilize carbon dioxide in constructing their shells, skeletons and exoskeletons.

DHR
May 12, 2022 4:46 am

To measure ocean heigth to within an accuracy of 0.4 cm don’t they need to know the altitude of the satellite better than that? If so, how is this done?

Alexy Scherbakoff
Reply to  DHR
May 12, 2022 5:00 am

Magic.

Reply to  DHR
May 12, 2022 12:44 pm

DHR:
And if SWOT is the new & improved version [+/-0.4cm] for satellite sea level measurement
just how do they expect us to believe they have been measuring sea level to tenths of
a millimeter?!
Alexy’s “Magic” indeed!

Paul Stevens
May 12, 2022 5:19 am

researchers estimate that in the aggregate they transfer up to half the heat and carbon from surface waters to the ocean’s depths.”

How accurate have their projections of future climate been when they didn’t understand the “transfer of up to half the heat and carbon from surface waters to the ocean’s depth” previously?

And will this mean that soon the science will finally be settled?

Tim Gorman
Reply to  Paul Stevens
May 12, 2022 2:25 pm

If you are transferring heat from the ocean surface to the ocean depths, shouldn’t the surface be warmer than the depths? How then can the ocean cool? Wouldn’t that mean less heat transferred to the ocean depths?

Neil Jordan
Reply to  Tim Gorman
May 12, 2022 6:30 pm

Using a term I noted on WUWT some years ago, moving heat against a thermal gradient is done by immaculate convection.

May 12, 2022 5:43 am

It’s funny how when they announce any new climate scientific project, the first thing they announce is what they’re going to find.

Last edited 1 month ago by Phil Salmon
Yooper
May 12, 2022 6:03 am

Check the Blue Blob section of : https://electroverse.net/cold-spring-keeping-n-d-mosquitoes-at-bay-corn-yield-gone-blue-blob-halted-melting-sulina-canal-restricted/
I wonder if SWOT can measure this? If it can then it might be worth it.

Insufficiently Sensitive
May 12, 2022 7:35 am

Higher seas, for example, can cause storm surges to penetrate farther inland. Also, currents intensified by sea level rise may increase saltwater intrusion into deltas, estuaries, and wetlands, as well as groundwater supplies.

Looks like someone’s mixing micro and macro measurements here, most likely a journalist. Just how much higher is the center of a microcurrent, just 60 miles wide, than the average sea level around it? Do these microcurrents invade shorelines and flood the neighbors? How much of a slope can the sides of these little devils achieve against gravity, and what holds them up?

H. D. Hoese
May 12, 2022 8:40 am

I really would like to know more about small details, but this seems like a big earth for one satellite, but may be interesting if it is accurate enough and we, apparently they won’t or can’t, detect the differences between cause and effect. “The SWOT mission will collect information on sea level height, which will help scientists study the role of currents in moderating climate change, as well as the elevations of bodies of fresh water.”

They may not understand much with their simplistic description, one example–“This vertical movement of heat and carbon also occurs at eddies themselves.” I think that they mean ‘in.’ “Currently, to get a two-dimensional view from a one-dimensional line, we take all of our one-dimensional lines and estimate what’s happening between them,…” At least they are getting a little closer to understanding that the ocean is 3-dimensional.

ATheoK
May 12, 2022 6:48 pm

Though climate change is driving sea level rise over time, researchers also believe that differences in surface height from place to place in the ocean can affect Earth’s climate.”

Weather is more likely to affect sea level surface height, than the reverse.

The math accounts for the force of Earth’s gravity, which pulls water from high to low, and the planet’s rotation, which, in the Northern Hemisphere, bends the flow clockwise around high points and counterclockwise around low points.”

A very gross assumption.

Next up, these researchers will claim all weather fronts flow clockwise/counter-clockwise because of high and low ocean points, when the reality if that the low high points are caused by the current itself.

“By measuring ocean heights down to 0.16-inch (0.4-centimeter) increments, as well as their slopes, SWOT’s two Ka-band Radar Interferometer (KaRIn) antennas will help researchers discern currents and eddies as small as 12 miles (20 kilometers) across.”

I expect their actual accuracy will be limited by the same issues affecting the tide satellites. orbital and sensing wavelengths will still be limiting factors.

Nor are 12 mile diameter currents very small.

“The planet’s largest storehouse of atmospheric heat and carbon”

No!
Earth’s largest storehouse of carbon are the abundant carbonate deposits worldwide, not the oceans.

The whole write up appears to be high school level of topic understanding, confirmation bias and gross assumptions.

%d bloggers like this: