Ciencia. - Changes in westerly winds associated with melting glaciers

Madrid, 12 (Europe Press)

Mountain glaciers freeze and gain mass when the climate cools, and they melt and lose mass when the climate warms. However, it is unclear to what extent fluctuations in mountain glaciers reflect local, regional and even hemispheric climate changes, which has made it difficult for scientists to use glacial data to interpret past climate dynamics and predict the future.

A team of researchers from the University of Maine evaluated how atmospheric conditions are reflected in the massive fluctuations of mid-latitude glaciers on opposite sides of the Earth, and compared global temperature and wind changes with ice line heights. line heights”) in the New Zealand Southern Alps and in the European Alps observed over about four decades. Glacier extent depends on the height of the atmospheric snow line, below which the ice melts, which in turn is determined by atmospheric temperature.

The data showed that fluctuations in glacier ice lines reflect temperature changes over large regions of the atmosphere of the two studied mountain systems, even at hemispheric scales. In addition, the latitudes of westerly wind belts have been found to be important in regulating the ratio of cold versus warm air masses affecting melting and freezing of glaciers.

“This study really shows how intertwined the Earth’s climate system is. At first, small changes in the state of the climate system can create system-wide ripples with far-reaching consequences,” Alexandre Udet, lead author, said in a statement. From the study, which terminated the investigation. As a master’s student at the University of Maine. He is now pursuing his Ph.D. at the University of Nevada, Reno.

The results show that under global warming, shrinkage in the arctic of westerly wind belts could accelerate the warming and melting of glaciers in the mid-latitudes of both hemispheres.

“These findings highlight the sensitivity of Earth’s glaciers to large-scale atmospheric dynamics. They are incredibly sensitive physical thermometers that monitor atmospheric conditions from the sea surface to the top of the troposphere. Therefore, reconstructing past glacial changes from glacial topography can help.” This helps provide quantitative information about how large parts of the atmosphere behaved during previous episodes of abrupt climate change, and thus could provide clues about the climatic dynamics of a warming world, says Aaron Putnam, study co-author and associate professor in the University of Maine’s College of Earth and Climate Sciences.

The study was published in Geophysical Research Letters.