Credit: Lusha TronstadAccording to recent research led by scientists from the University of Wyoming, the period for which Yellowstone Lake stays ice-covered each year has actually stayed consistent over the previous century, even amidst increasing local temperatures.That is an unforeseen finding, as many lakes around the world are experiencing shorter periods of ice cover, the researchers note in a new paper released in the journal Environmental Research Letters. “The changeless ice phenology of Yellowstone Lake stands in plain contrast to comparable lakes in the Northern Hemisphere.” Other scientists involved in the study are from Utah State University, Colorado State University, and Colorado Mesa University.Geographic and Environmental ContextSituated at 7,733 feet above sea level in the heart of Yellowstone National Park, Yellowstone Lake is North Americas biggest high-elevation lake, approximately 20 miles long and 14 miles wide with a surface location of 132 square miles. They also compared Yellowstone Lakes data with seven comparable lakes in northern Europe.The absence of long-lasting modification in the period of Yellowstone Lakes ice cover was unexpected due to the fact that the Yellowstone region has seen a warming environment, the scientists say.
Yellowstone Lake, North Americas largest high-elevation lake, freezes over totally in late December or early January and usually thaws in late May or early June. The period of ice cover has not altered in the last century, in spite of warming temperature levels in the region. Credit: Lusha TronstadAccording to current research study led by researchers from the University of Wyoming, the duration for which Yellowstone Lake remains ice-covered each year has remained constant over the past century, even amidst rising local temperatures.That is an unexpected finding, as many lakes around the globe are experiencing much shorter durations of ice cover, the scientists note in a new paper published in the journal Environmental Research Letters.” We reveal that contrary to expectation, the ice phenology of Yellowstone Lake has been uniquely resistant to climate modification,” wrote the researchers, led by Lusha Tronstad, lead invertebrate zoologist with UWs Wyoming Natural Diversity Database and Department of Zoology and Physiology, and Isabella Oleksy, a previous UW postdoctoral researcher now on the University of Colorado-Boulder professors. “The imperishable ice phenology of Yellowstone Lake stands in stark contrast to similar lakes in the Northern Hemisphere.” Other scientists included in the research study are from Utah State University, Colorado State University, and Colorado Mesa University.Geographic and Environmental ContextSituated at 7,733 feet above sea level in the heart of Yellowstone National Park, Yellowstone Lake is North Americas biggest high-elevation lake, approximately 20 miles long and 14 miles wide with a surface area of 132 square miles. It freezes over totally in late December or early January and generally defrosts in late May or early June.Records for the lakes ice-off date have actually been tape-recorded each year by Lake Village Ranger Station staff since 1927, and the ice-on date has been recorded since 1931. In addition to studying those records, the scientists examined climate information for the very same duration, 1927-2022, including air temperature levels and precipitation. They also compared Yellowstone Lakes information with seven similar lakes in northern Europe.The absence of long-lasting modification in the duration of Yellowstone Lakes ice cover was unanticipated because the Yellowstone region has actually seen a warming climate, the researchers say. Given that 1950, annual temperature levels have increased by 1.8 degrees Fahrenheit throughout the higher Yellowstone ecosystem. The changes are especially noticable at the high elevation of Yellowstone Lake, where air temperatures increased by about 2.5 degrees Fahrenheit between 1980-2018.” Using local weather data, we discovered some proof for increased fall, summer season, and spring temperatures, primarily in the last 3 decades,” the scientists composed about air temperatures at Yellowstone Lake. “Given the essential role of air temperature levels in driving ice development and separation, it is noteworthy that we did not discover evidence for matching shifts in ice phenology.” The Role of Snow in Ice PhenologyWhy the obvious discrepancy?While it is possible that fall minimum temperature levels– which are very important in predicting ice development– are not increasing as quickly as overall temperature patterns in the region, a most likely explanation is that increased snowfall at Yellowstone Lake has actually functioned as a buffer versus warmer weather condition, the scientists say.Snow cover, especially in spring, can postpone ice separation. Cumulative spring snow, which was strongly associated with postponed ice-off dates, has almost folded the last century at Yellowstone Lake, the research study revealed. In general, rainfall has increased in spring and fall there.That differs from the Upper Green River Basin to the south, where snowfall has actually declined or been reasonably steady at high elevations.” Shifts in local precipitation, particularly increases in fall and spring snow, appear to be buffering (Yellowstone Lake) ice phenology versus warming temperature levels,” the scientists wrote.But, the scientists are uncertain how long this phenomenon will last, noting projections of continued warming and moving rainfall programs in the high Rocky Mountains.” Our outcomes, coupled with recent analyses of climate forecasts, suggest a tipping point might be coming when ice phenology quickly changes for Yellowstone Lake,” they wrote. “This tipping point will mostly come from the ongoing shift from snow- to rain-dominated rainfall regimes in the fall and spring.” … Increased spring rains has actually not yet triggered a detectable long-term trend towards earlier ice split, potentially since of the neutralizing impacts of increased spring snow. As temperatures warm even more, and fall and spring snowfall decreases, ice phenology might rapidly alter on Yellowstone Lake.” If that occurs, “there might be extensive effects for nutrient cycling, lake efficiency, fisheries, and entertainment,” the researchers concluded.Reference: “Despite a century of warming, increased snowfall has actually buffered the ice phenology of North Americas largest high-elevation lake versus climate change” by Lusha Tronstad, Isabella Oleksy, Justin P. F. Pomeranz, Daniel Preston, Gordon Gianniny, Katrina Cook, Ana Holley, Phil Farnes, Todd Koel and Scott Hotaling, 8 April 2024, Environmental Research Letters.DOI: 10.1088/ 1748-9326/ ad3bd1.