The climate elements uncovered in a recent study provide insights into Greenland’s climate and could aid in forecasting the future of its ice sheet.
In recent years, Greenland has experienced warming at a rate quicker than the global average. A new study has pinpointed several key elements, including clear-sky downwelling longwave radiation (the heat from the atmosphere directed to the surface), moisture advection, high-pressure anomalies, and surface albedo feedback, as significant factors driving this heightened warming. These elements are playing a crucial role in the rapid melting of Greenland’s ice sheet. The results of this research are essential for predicting the future behavior of the ice sheet and its potential implications for global sea levels.
Global warming, largely a result of human activities, has caused average global temperatures to rise. Yet, Greenland’s temperature increase has outpaced this global trend, resulting in faster melting of its ice sheet. This increased warming in the Arctic, termed Arctic Amplification, has the potential to significantly elevate sea levels, threatening coastal regions and ecosystems around the world. Thus, comprehending the factors behind this phenomenon is vital for forecasting future climate impacts.
Prior studies have linked Arctic Amplification to local climate feedback mechanisms, heat released from the Arctic Ocean, and energy transport from the south. The melting of sea ice during summer months further boosts warming trends through surface albedo feedback, where a decrease in ice cover leads to less sunlight being reflected back into space. Moreover, the Greenland blocking index—a climate metric that measures the intensity of high-pressure blocking patterns over Greenland—has been connected to temperature shifts in the area. However, earlier investigations have mainly focused on overall warming trends, often neglecting the precise causes of unusual year-to-year temperature fluctuations and depending primarily on energy balance models.
To fill these knowledge gaps, a research team from Korea, headed by Professor Kyung-Ja Ha of the Department of Climate System at Pusan National University, alongside Manuel Tobias Blau from the same institution and Dr. Eui-Seok Chung from the Division of Atmospheric Sciences at Korea Polar Research Institute, examined the unusual warming patterns in Greenland from 1979 to 2021. “In this study, we concentrated on the year-to-year variations in the surface energy budget to clarify Greenland’s extreme temperature,” explains Prof. Ha. Their research was published in the journal Communications Earth & Environment on July 28, 2024.
The researchers utilized a surface energy budget framework that distinguishes the impacts of radiative and non-radiative sources to scrutinize temperature anomaly occurrences across Greenland. Their analysis found that the increase in clear-sky downwelling longwave radiation—the atmospheric heat delivered to the surface on clear days—and the subsequent surface albedo feedback were the primary factors in the warming of Greenland’s surface.
Additionally, the researchers explored the reasons behind the rise in clear-sky radiation and discovered that an increase in atmospheric temperature was the main catalyst. In warm years, elevated surface temperatures, combined with warming in the troposphere, facilitated turbulent heat exchange between the atmosphere and the surface. This interaction also improved moisture transport from the southern regions to Greenland and aided in forming a high-pressure system resembling a blocking anticyclone, which maintained warm conditions. These dynamics resulted in significant ice melting, creating a feedback loop that intensified the warming effects. Moreover, various natural climate variability patterns, especially those connected to the blocking index, can either strengthen or weaken these warming trends, resulting in extreme temperature occurrences.
“Our findings indicate that natural variability plays a significant role in explaining the atmospheric anomalies that lead to extreme summers in Greenland,” states Prof. Ha. Emphasizing the study’s significance, she adds, “Given climate change considerations, the extreme summer temperatures in Greenland will likely accelerate ice sheet melting, resulting in rapid sea level rise.”
By providing clarity on the factors driving extreme summer temperatures in Greenland, this study delivers essential insights that could assist in predicting the future of the Greenland ice sheet and developing strategies to mitigate further deterioration.
