Satellite image of the Great Lakes captured on February 24, 2024, by the Visible Infrared Imaging Radiometer Suite sensing unit aboard the Suomi NPP satellite.The results of a warm winter in the upper Midwest are apparent in the absence of lake ice.Ice coverage on the Great Lakes normally reaches its yearly peak in late February or early March. But at that time in 2024, the lakes were notably without ice. Owing to warmer winter season weather condition and above-average surface water temperatures, ice cover stood at historic lows.Since satellite-based measurements began in 1973, ice protection at its maximum winter degree exceeds, typically, 40 percent. In late February 2024, it stood at only about one-tenth of the average optimum. The VIIRS (Visible Infrared Imaging Radiometer Suite) sensor aboard the Suomi NPP satellite got this image of the lakes on February 24, 2024. Historic Trends and Recent ObservationsThe extent to which the lakes freeze is highly variable. In 2014, for instance, protection went beyond 80 percent. Given that 1973, nevertheless, levels have actually been trending down. Yearly maximum ice protection has actually reduced by approximately 5 percent per decade, according to NOAAs Great Lakes Environmental Research Laboratory (GLERL). Warmer winter conditions in the Great Lakes region are contributing to more frequent low-ice years.2023-2024 Winter Season AnalysisThe chart above shows ice coverage for the 2023– 2024 winter (red) relative to the previous 50 winter seasons. The warm start to the existing ice season is reflected in this line. Ordinarily, the first cold air masses of the season relocation over the upper Midwest in December and start to cool the lake water. This “priming” did not take place in December of 2023, leading to the most affordable January ice cover on record in 2024. When an arctic chill stuck around over much of the U.S. in mid-January, ice cover grew to its most likely season maximum of about 16 percent before dissipating when warmer temperatures returned.Climatic Influences on Ice CoverAir temperature levels are highly correlated with ice cover, said Jia Wang, an ice climatologist at GLERL, and 4 patterns of climate variability impact temperature level over the Great Lakes. This year, 3 of the four patterns put in a strong influence, stated Wang. “El Niño, the Atlantic Multidecadal Oscillation, and the Pacific Decadal Oscillation all at once imposed warming to the Great Lakes.”Environmental and Ecological ImpactsAn lack of ice can make shorelines and facilities more prone to damage from strong wind and waves. It can also leave some fish species without security from predators during generating season. In addition, an absence of ice cover may influence water levels by enabling more evaporation to occur. NOAA reported no significant effect on water level as of late February; lake and air temperatures are comparable, keeping evaporation rates low.Outlook for the Remaining SeasonThe Great Lakes ice season runs through March, and it is still possible for blasts of arctic air to reach the area and stimulate durations of ice formation, according to NOAA professionals. Those cold air events are more likely to be short-lived, and a major shift in weather condition patterns would be required for this seasons ice to break from its below-average pattern, they said.NASA Earth Observatory images by Michala Garrison and Lauren Dauphin, utilizing VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Suomi National Polar-orbiting Partnership, and lake ice data from NOAA– Great Lakes Environmental Research Laboratory.
Owing to warmer winter season weather condition and above-average surface area water temperatures, ice cover stood at historical lows.Since satellite-based measurements started in 1973, ice coverage at its maximum winter season extent surpasses, on average, 40 percent. When an arctic chill lingered over much of the U.S. in mid-January, ice cover grew to its likely season optimum of about 16 percent before dissipating when warmer temperature levels returned.Climatic Influences on Ice CoverAir temperature levels are highly associated with ice cover, stated Jia Wang, an ice climatologist at GLERL, and 4 patterns of environment irregularity influence temperature level over the Great Lakes. NOAA reported no considerable effect on water level as of late February; lake and air temperature levels are similar, keeping evaporation rates low.Outlook for the Remaining SeasonThe Great Lakes ice season runs through March, and it is still possible for blasts of arctic air to reach the region and spur periods of ice development, according to NOAA professionals. Those cold air occasions are more most likely to be temporary, and a significant shift in weather condition patterns would be needed for this seasons ice to break from its below-average trend, they said.NASA Earth Observatory images by Michala Garrison and Lauren Dauphin, using VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, and the Suomi National Polar-orbiting Partnership, and lake ice information from NOAA– Great Lakes Environmental Research Laboratory.
