While global warming is accelerating, an unknown phenomenon threatens the stability of antarctic ice: atmospheric rivers. These hot air and water vapor currents, invisible but powerful, could double in frequency by 2100 and accelerate the cast iron of the cap.
When hot air rivers transform the pack ice into a battlefield
First, atmospheric rivers form a ribbon tightened with clouds that stretches over several thousand kilometers. They carry huge amounts ofhumidity From the tropics to the poles. Thus, they act as a treadmill air loaded with water.
Then, when they arrived in Antarctica, these rivers poured their load in the form of rain or from snowdepending on the local temperature. In a warmer climate, the rain dominates. This liquid water saturated and softened the frozen surface.
Furthermore, themild air Provides a Thermal shock With cold ice. This brutal contrast accelerates the fusion on the surface. As a result, snow melts faster and loses its ability to protect the ice floe.
In addition, liquid water infiltrates the upper layer of snow. She attacks the ice from below. From then on, fractures are formed, weakening the structure.
Finally, these fractures widen and mobilize sides of ice of several square kilometers. These stand out and flow, releasing large volumes of fresh water in the ocean.
Why a warmer climate fuels these murderous air flows
First, the capacity of the air to retain water vapor increases from 7 % by degree of warming. Thus, a warmer ocean releases morehumiditynourishing atmospheric rivers.
Second, the study is based on a climate model high resolution. It shows that the number of major river events above the western peninsula of Antarctica could go from two to four per decade.
In addition, simulations provide for an increase in 30 % of heat flow transported by these rivers. Therefore, each episode becomes both more intense and longer.
Consequently, the extreme cast iron periods, already observed in southern summer, will become more frequent. This exposes the cap to increased and regular thermal stress.
Moreover, the researchers point out that the meteorological variability is reinforced. The rivers create a more climate volatilewith brutal temperature and humidity fluctuations.
How these atmospheric assaults threaten the rise of the oceans
On the one hand, thesnow effect Coming from solid precipitation can add ice mass. However, snow remains less dense than ice. It therefore delays the melting in a very limited manner.
On the other hand, thecast iron effect linked to lukewarm rain causes accelerated erosion. Each soft air storm generates channels And weakens floating platforms.
In addition, the collapse of these platforms exposes the terrestrial glacier to the sea. This rupture then promotes a fast influx ice in the ocean.
Consequently, the sea level accelerates. The new study considers that integrating these rivers, the increase forecasts could increase to 10 to 20 cm by 2100.
In reality, these figures matter for more than 200 millions people living in low areas. Coastal infrastructure and current alert systems are based on less severe scenarios.
It is important to no longer neglect these rivers of burning air in our forecasts
Ultimately, Atmospheric rivers impose themselves as a hitherto underestimated parameter. Ignore these extreme flows compromises the reliability of the projections of the cast iron in Antarctica.
Thus, scientists must develop Multi-physical simulations which coupled atmosphere, ocean and ice cream. Decision -makers must, for their part, integrate these results into the strategies of prevention and ofadaptation.
In short, Antarctica remains the barometer of our climate. Recognizing and modeling these invisible rivers is now crucial to preserving planetary balance and protecting coastal populations.
