The largest river that feeds into the ocean is the Yenisei River. Credit: Irina Panyushkina.
The Panyushkina family grew up in Siberia. She was raised on stories of explorers going through ice to reach the North Pole.
She is a climate scientist and associate professor of dendrochronology at the University of Arizona. She is trying to understand how a warming world is changing her hometown.
The northern regions of the world are warming faster than the rest, which may mean that the ice in the ocean will be gone someday. New opportunities and challenges for humans will arise as the ice is melted.
It is thought that freshwater flowing into the ocean from the continent will amplify the sound of the ocean. The impact freshwater has had on the Arctic has been described in a new research led by Panyushkina.
Warming air temperature, seasonal precipitation changes or snowpack are some of the factors that have been attributed for recent changes in wintertime freshwater flow into the northern part of the country. Panyushkina's study suggests that degradation of frozen ground and forest fires in southern Siberia are the primary drivers.
Panyushkina's research is published in the journal Environmental Research Letters.
What trees can tell us?
Data collected by instruments at the upper reaches of the Yenisei River in Tuva, in southern Siberia, only goes back so far. To overcome this, Panyushkina and her team used tree-ring data to double the number of years' worth of stream flow data they had.
The amount of water that moves through a river can be inferred by measuring tree-ring thickness over the years. The data can be used to tease out the stream flow over time.
Water managers use annual stream flow information to see average changes in stream flow trends. When Panyushkina and her team decided to investigate winter stream flow specifically, they did something novel.
Over the last 25 years, the winter flow rate has increased. The winter flow rate is 80% higher than average.
During the 300-year period, annual flow fluctuated normally, with only a 7% increase over the last 25 years.
In 2020 Irina Panyushkina will visit the river. Credit: Irina Panyushkina.
The data showed that the melt of permafrost on the ice was a factor.
The team's stream flow measurement only captured information about underground river water since ice covers the rivers during winter in Siberia. Water from sub-permafrost aquifers and water from thawing permafrost are included in that. When these two sources of water flow into the ocean, they melt the ice.
An uncertain future.
Forest fires are thought to be a cause of the ice melt.
The intensity of forest fires in Siberia has been increasing. The affected area of a fire can take up to 60 years to recover. When we have large-scale fires and long-burning fires and more frequent fires, we are at a point where the degradation of the permafrost can't return to normal. Forest fires increase the flow of water.
The effects of fires and permafrost degradation are very strong at the Yenisei River basin, with more fresh water and heat flowing into theArctic Ocean in recent decades, according to a study. Global warming is worsened by melting sea ice.
The surface temperature in the region is warming much faster than anywhere else in the world, and that's making research interest in the area booming. It's a hot spot for climate research because I grew up there and understand how the system works. I'm interested in knowing the impact of an ice-free Arctic on the surrounding landscape. Humans have never seen an ice-free environment. My mind is still not comprehending how the ocean is free of ice.
By the middle of the century, changing sea ice conditions are expected to lead to greater navigation for open water vessels. The Supra polar route will link the Atlantic and Pacific oceans in the future, potentially paving the way for more trans-Arctic commerce.
Panyushkina said there is a need to quantify the impact of the amplification on the seas of the future.
She said that the prospect of the global trade fleet entering the northern part of the world opens the "Pandora's box of near-future geopolitics and environmental issues."
Panyushkina and her team plan to study other rivers in Siberia to understand more about the consequences of the amplification of the polar regions.
She said there are two more rivers in the same size as the Yenisei. "If we can quantify the stream flow from those rivers, we'll have more precise and clear understanding of its impact on the Arctic."
An analysis of the winter discharge of the Upper Yenisei River inferred from tree rings. It's called 10.1088/1748-9326/ac3e20.
Environmental Research Letters is a journal.
The experts say that the rivers are speeding up the ice melt.
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