Satellites reveal Arctic rivers are changing faster than we thought

Regional differences in river discharge patterns are shown in temporal trends. Areas in blue show increases in discharge, while those in red show decreases. The chart shows that there has been a decrease in streamflow over the past 35 years. Only rivers with statistically significant trends are mapped. Credit was given to Dongmei Feng and her co-conspirators.

A civil and environmental engineering researcher at the University of Massachusetts Amherst has been using satellite data to calculate the past 35 years of river discharge in the entire pan-Arctic region. The research shows that the speed of water pouring into the ocean could be three times higher than previously thought.

Three years of intensive work by a research assistant professor led to the publication of a study in Nature Communications. 9.18 million river discharge estimates were made from 155,710 satellite images and were used to create a model of the river. The project and paper were funded by NASA and the National Science Foundation.

The river discharge information was recreated all over the region. "Previous studies didn't do this." They only used some gauge data to calculate how much water is flowing into the ocean.

Colin Gleason, civil and environmental engineering professor and principal investigator on the study, says that the daily record of flow across the global North is now publicly available. No one has ever tried to teach the models what the satellites saw in half a million rivers from millions of satellite observations. The process of merging models and data is very sophisticated.

The discharge of a river defines a river's carrying capacity. It is considered the 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.

The "gold standard" for gaining discharge information is physically gauging rivers, which is expensive and labor-intensive to install and maintain. It can be difficult to install a gauge around rough terrain. It's 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. Some countries don't make their gauge information public. That leaves hydrologists and environmental scientists in the dark about a lot of rivers.

"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 used to gauge space. If we don't have a gauge on the rivers, we can use the satellite to get better data.

Traditional studies used limited gauge information or simulations based on a sample of rivers. The Hudson, James and Ungava bays are the focus of Feng's work. The ice sheet is excluded.

The acceleration in the discharge of the pan-Arctic river over the past 35 years is larger than previously thought.

This is the new reality that we've actually experienced, rather than a projection of what might happen. RADR looked into the past and found that up to 17% more water had already gone into the ocean.

The increase in water discharge was not random.

Satellite data is attributed to discharge differences. The areas where the satellites were more accurate are depicted in blue and red. No change is indicated by white. There are four pullout boxes at the bottom. Satellite adjustment has added water in some areas and removed water in others. Credit was given to Dongmei Feng and her co-conspirators.

There were significant regional differences found. Some places showed an increase while others showed a decrease. North America and Eurasia have different patterns.

"For example, parts of the interior of the Mackenzie River are getting more dry than before."

The data provided by RADR will only get better as more satellites are launched. "We can improve even more significantly, because we have built up this method and with this framework, we can very easily integrate more satellite data, and with more data we can for sure improve more." This direction is promising and exciting.

The system is being made open access in hopes that those studying other aspects of the Arctic, such as climate change, will use it to get new calculations.

"I'm really excited that we did this, and that we're making it public, and that anyone can download it, and use it, and that's what I'm most excited about," he says. I hope this becomes a standard global data set for anyone who studies the polar regions.

"This is a huge amount of information we can use for a lot of applications, like water resource management, hydropower, or other infrastructure impacted by rivers." The global river discharge simulation can be improved.

She says the work has implications beyond the north.

She says that satellites can help improve the accuracy of river discharge data all over the world.

The framework looks like a river network, and it's going to be publicly available in half a million rivers, as narrow as three meters.

Now that the previous predictions of river discharge have been shown to be incorrect, models will have to be created.

How does knowing the past change our predictions? "That's where we're going next." Climate change, ecology, pollution and sediment are the things that will change the most.

The recent changes to the discharge of the river is more information. There is a DOI titled " 10.1038/s41467-021-27228-1".

Nature Communications is a journal.

Satellites show thearctic rivers are changing faster than we thought.

The document is copyrighted. Any fair dealing for the purpose of private study or research cannot be reproduced without written permission. The content is not intended to be used for anything other than information purposes.