Satellites Reveal Arctic Rivers are Changing Faster than We Thought

New analysis integrating data from satellites, river gauges and hydrologic models reveals Arctic rivers are discharging much more water than previously thought.

Peer-Reviewed Publication


Figure 2

AMHERST, Mass. — A civil and environmental engineering researcher at the University of Massachusetts Amherst has, for the first time, assimilated satellite information into on-site river measurements and hydrologic models to calculate the past 35 years of river discharge in the entire pan-Arctic region. The research reveals, with unprecedented accuracy, that the acceleration of water pouring into the Arctic Ocean could be three times higher than previously thought.

The publicly available study, published recently in Nature Communications, is the result of three years of intensive work by research assistant professor Dongmei Feng, the first and corresponding author on the paper. The unprecedented research assimilates 9.18 million river discharge estimates made from 155,710 orbital satellite images into hydrologic model simulations of 486,493 Arctic river reaches from 1984-2018. The project and the paper are called RADR (Remotely-sensed Arctic Discharge Reanalysis) and was funded by NASA and National Science Foundation programs for early career researchers.

“We recreated the river discharge information all over the pan-Arctic region. Previous studies didn’t do this,” Feng says. “They only used some gauge data and only for certain rivers, not all of them, to calculate how much water is pouring into the Arctic Ocean.”

“This is a new, publicly available daily record of flow across the global North,” adds Colin Gleason, civil and environmental engineering professor and principal investigator on the study. “No one has ever tried to do it at this scale: teaching the models what the satellites saw daily in half a million rivers from millions of satellite observations. It’s a very sophisticated data assimilation, which is the process of merging models and data.”

River discharge integrates all hydrologic processes of upstream watersheds and defines a river’s carrying capacity. It is considered the single most important measurement needed to understand a river, yet the availability of this information is limited due to a lack of reliable, comprehensive, publicly available data, Feng says.

Physically gauging rivers – the “gold standard” for gaining discharge information – is expensive and labor intensive to install and maintain because gauges need to be physically recalibrated several times a year. Also, rough terrain around some rivers can make gauge installation very difficult. This makes it more practical for studies in this region to focus on larger rivers that empty into the Arctic Ocean, so many small rivers are not gauged at all. Also, some countries don’t make their gauge information publicly available. That leaves hydrologists and environmental scientists in the dark about a tremendous number of rivers, Feng says.

“This is one major contribution of our work, because we can provide river discharge information everywhere, especially for the Eurasia region,” says Feng. “Satellites are like a gauge in space. If we don’t have a gauge in place on the rivers, we can use the satellite to improve the data we have now.”

Traditional studies have had to rely on limited gauge information or on simulations based on a representative sample of rivers. Feng’s work focuses on all Arctic rivers that eventually drain into the Arctic Ocean, Bering Strait, and the Hudson, James and Ungava bays. It excludes the Greenland Ice Sheet.

One of RADR’s major findings is that the acceleration in pan-Arctic river discharge over the past 35 years is 1.2 to 3.3 times larger than previously estimated.

“This is the new reality that we’ve actually experienced, rather than a projection of what might happen. RADR looks into the past and shows that up to 17% more water than previously thought has already gone into the Arctic Ocean,” Gleason says of RADR’s findings.

The increase in water discharge was not homogenous, however.

“We found very significant regional differences,” Feng says. “Some places showed an increase, but others showed a decrease. We also found that North America and Eurasia show different patterns.”

“For example, Mongolia is actually getting drier, as are parts of the interior Mackenzie River,” Gleason says.

As more satellites launch, the data provided by RADR will only become more accurate. “We can improve even more significantly, because we have built up this method and with this framework, we can very easily assimilate more satellite data, and with more data we can for sure improve more,” Feng says. “This is an exciting and also promising direction.”

Feng is making the system open access in the hopes that those studying other aspects of the Arctic, such as climate change, will use it to obtain new calculations of factors like river sediment, rainfall, and carbon emissions.

“I’m really excited that not only did we do this, but that we’re making it public and just putting it out there and anyone can download it and use it,” Gleason says. “I’m hoping this becomes a standard global data set for anyone who studies the Arctic across any of the natural sciences.”

“This is a really huge amount of information we can use for a lot of applications, like water resource management, hydropower, or other infrastructure impacted by rivers,” Feng says. “We can also improve the global river discharge simulation’s accuracy significantly.”

But the work has implications far beyond the Arctic, she adds.

“Because we show satellites can help us improve the accuracy of [measurements of] river discharge, we can use it to improve the data for river discharge all over the world,” she says.

The RADR framework “is a vector-based product, so it looks like a river network, and it’s going to be publicly available flow in literally half a million rivers, as narrow as three meters,” Gleason says.

Now that RADR has shown that previous predictions of river discharge are inaccurate, models using the new findings will have to be created.

“Now that we know this about the past, how does that change our future predictions? That’s where we’re going next,” Gleason says. “Climate change, ecology, pollution and sediment — those are the big things that will dramatically change.”

The paper, “Recent Changes to Arctic River Discharge,” can be found at doi 10.1038/s41467-021-27228-1


Nature Communications


doi 10.1038/s41467-021-27228-1 


Not applicable


Recent changes to Arctic river discharge



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Steve Case
November 29, 2021 10:07 pm

If the Climate Change headline says, 
 “Worse than previously thought” 
Historical data has been re-written.

Reply to  Steve Case
November 30, 2021 2:57 am

It’s all getting a bit silly. If there was more precipitation, more water in the river, even a village idiot will know that river flows will speed-up.
What they need to show there was more rain and snow falls, since when and how much.

Reply to  Vuk
November 30, 2021 6:42 am

More precipitation does not automatically lead to more water in the river and higher river flows. It can also lead to more snowpack. Conversely, more river flow can come from melting snowpack.

Reply to  Vuk
November 30, 2021 12:45 pm

It takes a lot of energy to increase the amount of rain/snow fall. If energy is being spent evaporating water, it is no longer available to warm air.

Strong negative feedback.

Thomas Gasloli
November 29, 2021 10:10 pm

“Its a very sophisticated data assimilation merging models and data.”

Isn’t that what is known as data fudging?

Zig Zag Wanderer
Reply to  Thomas Gasloli
November 30, 2021 12:14 am

No, not at all. It’s Climate Scientology, doncha know!

Alan the Brit
Reply to  Thomas Gasloli
November 30, 2021 1:49 am

I’ve said it before, but a Sophist was a paid public speaker paid to stand on street corners & spout whatever he was paid to spout, & my trusty yet rather tatty Pocket Oxford Dictionary states that the word “sophisticated” means corrupt & adulterated!!! So fudging is correct!!!

Alastair gray
November 29, 2021 10:17 pm

Isnt this just what rivers do fast or slow and every drop of rain that falls either evaporates or finds its way into a river or an aquifer. Not much elsefor a raindrop to do . It is in its job description

Alastair gray
Reply to  Alastair gray
November 29, 2021 10:20 pm

Of course melting permafrost contributes too. Nasty stuff permafrost. Glad i dont have it in my garden

Zig Zag Wanderer
Reply to  Alastair gray
November 30, 2021 12:15 am

Technically, it’s job description is to drop, as rain. The evaporation bit is inevitable, though.

Clyde Spencer
Reply to  Alastair gray
November 30, 2021 7:00 am

Not much elsefor a raindrop to do .

It can be incorporated into vegetation or delayed in its journey by finding its way into a lake.

Reply to  Clyde Spencer
November 30, 2021 4:03 pm

Rain can add to biomass that gets locked away particularly when buried under snow for millennia.

November 29, 2021 10:20 pm

The Eco-Loons must have a large computing machine somewhere pumping out these repetitive catastrophe studies and also adjusting the historical data to match the output.

Zig Zag Wanderer
Reply to  nicholas tesdorf
November 30, 2021 12:16 am

Damn! You’ve rumbled the Climate Scientology MO!

Roald J. Larsen(@roaldjlarsen)
November 29, 2021 10:22 pm

Changes in river discharge only document changing weather patterns, it’s not evidence that plant food controls the sun, no matter how many times they write “could”! (“.. of water pouring into the Arctic Ocean could be three times higher than previously thought ..” – And no, it’s not caused by humans!) 

Reply to  Roald J. Larsen
November 30, 2021 12:48 pm

Once again we are being presented with 1/2 of the AMO cycle worth of data.

November 29, 2021 10:23 pm

All because of man-made CO2, of course.

Art Slartibartfast
November 29, 2021 10:33 pm

How is Mongolia part of the Arctic? Oh, and models, reliable as ever…

Izaak Walton
Reply to  Art Slartibartfast
November 29, 2021 11:07 pm

No. But rivers in Mongolia flow into the Arctic and such rivers where the object of the study as it states: “Feng’s work focuses on all Arctic rivers that eventually drain into the Arctic Ocean”

Alexy Scherbakoff
Reply to  Izaak Walton
November 30, 2021 12:57 am

So do the rivers in Australia.

November 29, 2021 10:36 pm

A comical read

Last edited 1 month ago by Spectr
David Sulik
November 29, 2021 10:51 pm

Quite large error bars for making such an assertive definitive guestimate as factual.

Rich Davis
Reply to  David Sulik
November 30, 2021 3:43 am

Wow, imagine that! Up to a whole FOUR PERCENT more than settled science previously had known for sure certainly was settled science. We are supposed to assume that this is unprecedented and catastrophic I guess.

More typical YouReekAlot! nonsense.

Clyde Spencer
Reply to  Rich Davis
November 30, 2021 7:39 am

What is the range of uncertainty on the four percent?

I looked at the actual published article, and as is all too common with research into climatology-related phenomena, there is a dearth of uncertainties associated with stated nominal values. Early on there is a range given (e.g. 3-17%), but it is probably a reflection of the range of previous estimates, and does not address uncertainties in their actual remote sensing-derived values. The closest they come to the rigor expected in other disciplines is a color illustration (Fig. 2) that is an ambiguous mixture of percentage changes (+/-4%) shown as a color, with an enumerated nominal value and associated uncertainty. (e.g. 414 +/-40) It appears that the uncertainties are about 10% of the nominal values. It is unclear just what they are trying to show when their nominal values have an uncertainty typically more than twice the claimed percentage changes.

Reply to  Clyde Spencer
November 30, 2021 10:13 am

If the satellite photogrammetry can be correlated to actual data there may be some predictive value, but there would need to be more than estimation of river flow merely based upon enlarged flow basins without correlations.

Matthew Sykes
November 29, 2021 11:11 pm

“[xxx]  times higher than previously thought.” Instant loss of credibility.

This isnt science, this is spin. Clearly.

You think Newton wrote in Principia ‘the acceleration due to gravity is three times higher than previously thought’?

Zig Zag Wanderer
November 30, 2021 12:12 am

The unprecedented research assimilates 9.18 million river discharge estimates made from 155,710 orbital satellite images into hydrologic model simulations of 486,493 Arctic river reaches from 1984-2018.

So, once again, it’s models all the way down, is it? Models based on estimated inputs too!

Climate Scientology in action!

November 30, 2021 12:25 am

Faster than “we thought” or estimated (e.g. proxies), but neither unprecedented nor evidence of “[anthropogenic] climate change”.

Last edited 1 month ago by n.n
Tom Abbott
Reply to  n.n
November 30, 2021 5:48 am

Yes, I was wondering what they meant by “faster than we thought”. It wasn’t explained.

This seemed like a pretty straighforward study. They didn’t seem to be promoting it as an answer to human-caused climate change, or as revealing anything new about the human-caused climate change narrative.

Compiling flow information on half a million rivers is impressive, I would say.

One question: Can a three-meter-wide flow be considered a river? We call them creeks around here.

Last edited 1 month ago by Tom Abbott
Clyde Spencer
Reply to  Tom Abbott
November 30, 2021 7:42 am

They filtered out all watercourses narrower than 90 m.

November 30, 2021 12:31 am

Climate change ALARMISM increasing a thousand times faster than we thought.

“Antarctica’s ice is melting three times faster than we thoughtThe rate of Antarctic ice melt has tripled in the past five years, with more than 200 billion tonnes of ice flooding into oceans annually, according to new research” oh my, so funny the

Underwater glacial melting up to 100 times faster than …// › climate-change › news › glacial-melting-climate-breakdown-sea-level-rise-study-a9021266.html
Underwater glacial melting is happening up to 100 times faster than previously thought,

Last edited 1 month ago by richard
November 30, 2021 12:40 am

They wanted gauge measurements on the Greenland discharge.
There is one, Watson river.
And no, it has not increased the last 5 Years on contrary.
2010 was a top at 11 cubic kilometers.
Latest was less than 4 cubic kilometers disharge.
You will find it here:

Ron Long
November 30, 2021 1:40 am

Not sure what to make of this purported “study”. Maybe the increase in modelled discharge shows the earlier estimates were not accurate? Or, it is correct, but doesn’t mean anything on a global scale as sea level rise does not show this acceleration. Maybe Arctic is less cold and Antarctica is more cold? The only obvious answer is to send them more research money so they and Braden can save the planet.

Paul Homewood(@notalotofpeopleknowthat)
November 30, 2021 1:43 am

There is nothing new in this.

During the Arctic warming in th early 20thC, the same happened, as milder winters meant more rainfall/snow in Siberia

As the rivers there mainly flow north, this led to a build up of freshwater in the Arctic Ocean, which had the effect of countering the inflow of warm, salty water from the Atlantic. This of course directly led to the sea ice years in the 1970s and 80s, when sea ice expanded rapidly and temperatures fell.

We will see the same thing happen in a few years time

Ben Vorlich
November 30, 2021 2:22 am

Models, estimates, become more accurate, improve the accuracy, becoming drier, regional differences

What all this means is they don’t know what it was like in the past, they don’t know for sure what it’s like now, and have no idea at all what it’s going to be like in the future.

Reply to  Ben Vorlich
November 30, 2021 4:19 am

That about sums it up, Ben.

But hey, they do know it’s unprecedented. I think we’re supposed to be impressed by that.

Smart Rock
November 30, 2021 3:11 am

In the paper, their fig. 1b shows an acceleration in total river discharge of 0.22% per year, or 7.92% increase over the 36-year period. Not particularly alarming.

The “1.2 to 3.3 times greater” would appear to reflect using estimates from 486,493 rivers instead of the 1,300 rivers with actual gauges in previous estimates. Therefore entirely misleading about the “worse than we thought” spin that the news article puts on it. Surprise surprise!!

The skeptic in me wonders how much of the (modelled, not measured) increase can be attributed to increasing resolution of satellite imagery since the 1980s.

Last edited 1 month ago by Smart Rock
Reply to  Smart Rock
November 30, 2021 10:03 am

I want to know what the garage data said. If the gauge data told a different story, there’s a good chance the difference came from the model.

Joseph Zorzin
November 30, 2021 3:24 am

Keep in mind, the author is at U. Mass., Amherst. A state with a net zero by ’50 law. The state that sued the EPA to declare carbon a pollutant. A state in which the Dems make up something like 90% of the state legislature. By the way, last night here in north central MA, it got down to 18F. I suppose I should be happy it wasn’t another half degree higher, to avoid floods, droughts, hurricanes, forest fires.

Last edited 1 month ago by Joseph Zorzin
November 30, 2021 3:50 am

It seems to me that everyone is being a bit unfair. I can’t find any reference to “Climate Change” or CAGW and so far as I can see this investigation has found out something that wasn’t generally known before.
Is that not a good thing?

Reply to  Oldseadog
November 30, 2021 4:50 am

“Climate change, ecology, pollution and sediment — those are the big things that will dramatically change.” Climate change is #1.

Reply to  BallBounces
November 30, 2021 6:25 am

Well, the climate is changing, it always has. This paper doesn’t claim that humans are responsible which for me is a refreshing change.

Reply to  Oldseadog
November 30, 2021 4:59 am

It’s the rhetoric being used in the writeup, Oldseadog.

My thought was that it was good that someone was using better satellite imagery that covered more of the rivers than in times past. But the data from the past are so rough and sparse that it really doesn’t allow any room to discuss how the discharge has changed.

Going forward, after a few years of using this new method, then it would be fine to discuss any changes noted from the initial effort.

It’s like checking your weight with a really crappy bathroom scale over the years that is accurate to maybe +/-5kg. Then you toss that scale and get a new one that is accurate to +/-1kg. You’ve been tracking your weight, but you really can’t say if you’ve gained or lost weight just based on the new weights from the better scale. And you can’t go back and refine the records of your old measures based on the new scale.

IMO, this article deserves a good bit of ridicule for discussing the change in discharge. IMO, the study should have stopped at “We were missing all of this, but now we’re able to get improved estimates since we can capture what was missed.”

Jim Gorman
Reply to  H.R.
November 30, 2021 10:06 am

This is good analogy of what is happening with temperatures. You can’t take a temperature recorded in 1910 with integer figures, subtract a baseline with 1/100th resolution and end up with a measurement of 1/100th resolution.

Tom Abbott
Reply to  Oldseadog
November 30, 2021 6:01 am

I agree with you, Oldseadog.

Clyde Spencer
Reply to  Oldseadog
November 30, 2021 7:48 am

They claim to have “found out something that wasn’t generally known before.” However, there are no error bars on any of their results. Therefore, there is no way to judge how reliable their claims are! Have they really found out anything? How do we know?

Reply to  Oldseadog
November 30, 2021 5:30 pm

read Paul Homewood’s post several replies upthread. Seems it is known

Tom Halla
November 30, 2021 4:54 am

If I read this correctly, they had really bad flow estimates pre-satellite, and now the actual measurements show something different than estimates based on based on those really bad estimates.
This is cause for immediate panic.

Tom Abbott
Reply to  Tom Halla
November 30, 2021 6:03 am

I don’t think they are even saying it is a cause for panic. It was just an unknown that they think they know better now, after the study.

Andrew Wilkins
Reply to  Tom Abbott
November 30, 2021 1:35 pm

So they’ll be chucking out all the old results and starting from scratch, I take it.

Dave Fair
Reply to  Tom Halla
November 30, 2021 2:11 pm

I assume CliSciFi will have to trash all their previous studies and conclusions that were based on the previous estimates.

November 30, 2021 7:08 am

So where did all that water go? No acceleration of SLR!

Reply to  Rah
November 30, 2021 10:35 am

Rain, hail and snow falls on the land .Its called precipitation and most of it eventually runs off into the rivers ,
Why did these fake scientists not have rain /snow gauges across the northern lands flowing into the Arctic ? They might have saved them selves a lot of time and trouble .

Andy Pattull
November 30, 2021 10:35 am

Models involved so skepticism is appropriate, but that doesn’t mean they are wrong. It should not be too hard to take their outputs and test them against rivers that are measure dried directly. Ideally this is a blinded assessment where true predictions are made before the data is available and then validation of the models tested against reality. IF they are presenting the output of models as fact then they are overstepping.

Dave Fair
November 30, 2021 2:08 pm

Way cool: They have used satellites to measure river flows (how accurately, we don’t know) over the latest 35-year upswing period of the 70-year temperature cycle. What about the previous 35-year period of cooling? Without understanding at least the 70-year cycle and its causes, we don’t understand climate change. Throw in the millennial cycles over the Holocene for an even better understanding.

I hope this satellite and river model data prove to be useful to track satellite-era river flows and future changes, not to predict future catastrophic climate change. I assume the river models use observed changes and that the model output accurately tracks historical flows.

November 30, 2021 2:39 pm

It’s Amherst, so the red flag warnings are up all over.

November 30, 2021 4:10 pm

New analysis integrating data from satellites, river gauges and hydrologic models reveals Arctic rivers are discharging much more water than previously thought.

My estimate for net evaporation from oceans to precipitation over land is 60Gt in the 12months to end June 2020.

This is quite a lot higher than the GRDC estimates:

This report indicates that GRDC are not getting all significant flows. Also it is expected that northern rivers would be increasing flows as the precession cycle moves perihelion ever later than the boreal summer solstice.

Al Gicasi
December 1, 2021 1:08 am

The increase in water discharge…’ This really is a fatuous statement. They do not know if there is a time-based increase in discharge; merely a difference between a previous estimate to this, a bit more of a granular estimate. Give me more money!

Coach Springer
December 1, 2021 6:42 am

“Higher than previously thought.” Even more meaningless than “in recorded history.”

Tim McDonald
December 1, 2021 11:02 am

So the information we had is either very accurate (only 20% low) or totally inaccurate (around 80% low) by their set of assumptions, based on satellite pictures with no data at all on what the flow rate is at the particular moment the picture was taken? Sorry, this does not look like more data to me at all, but more conjecture based on whatever result they wanted to find. This is NOT what I think of when I think of science, and certainly not what I think of when I think of data sets.

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