Unveiling 12,000 Years of European History: The Mont Blanc Ice Core Record

A team of researchers from the Desert Research Institute’s (DRI) Ice Core Lab has made a groundbreaking discovery by analyzing a 40-meter long ice core from the French Alps. This study, published in the June issue of PNAS Nexus, reveals an intact record of atmospheric aerosols and climate dating back at least 12,000 years.

The ice core, collected from Mont Blanc’s Dôme du Goûter, provides a unique insight into Europe’s local climate during different time periods. By using radiocarbon dating techniques, the research team established that the glacier offers an accurate record of past atmospheric aerosols and climate transitions.

Aerosols play a significant role in regional climate through their interactions with clouds and solar radiation. The insights offered by this ice core record can help inform accurate climate modeling for both the past and future.

One of the most striking aspects of this study is that it reveals a temperature difference of about 3 degrees Celsius between the last Ice Age and the current Holocene Epoch. Using pollen records embedded in the ice, reconstructions of summer temperatures during the last Ice Age were about 2 degrees Celsius cooler throughout western Europe, and about 3.5 degrees Celsius cooler in the Alps.

The phosphorous record also tells researchers the story of vegetation changes in the region over the last 12,000 years. Phosphorous concentrations in the ice were low during the last Ice Age, increased dramatically during the early to mid-Holocene, and then decreased steadily into the late Holocene.

Records of sea salt also helped researchers examine changes in historical wind patterns. The ice core revealed higher rates of sea salt deposition during the last Ice Age that may have resulted from stronger westerly winds offshore of western Europe.

The most dramatic story told by this study is the change in dust aerosols during the climatic shift. Dust serves as an important driver of climate by both absorbing and scattering incoming solar radiation and outgoing planetary radiation, and impacts cloud formation and precipitation by acting as cloud condensation nuclei.

During the last Ice Age, dust was found to be about 8-fold higher compared to the Holocene. This contradicts the mere doubling of dust aerosols between warm and cold climate stages in Europe simulated by prior climate models.

This study is only the beginning of the Mont Blanc ice record’s story, as researchers plan to continue analyzing it for indicators of human history. The first step in uncovering every ice core’s record is to use isotopes and radiocarbon dating to establish how old each layer of ice is. Now, with that information, scientists can take an even deeper look at what it can tell us about past human civilizations and their impact on the environment.

The Mont Blanc ice record has the potential to reveal more stories entombed in its layers, and researchers are eager to continue exploring this ancient history for a better understanding of our planet’s climate variability and human history.

The United States is no stranger to bone-chilling winter cold, despite a warming climate. A recent study has shed light on why this phenomenon persists, pointing to two specific patterns in the polar vortex – a swirling mass of cold air high in the stratosphere. These variations can steer extreme cold to different regions of the country, often contradicting broader warming trends.

Researchers from an international team, including Prof. Chaim Garfinkel (Hebrew University), Dr. Laurie Agel and Prof. Mathew Barlow (University of Massachusetts), Prof. Judah Cohen (MIT and Atmospheric and Environmental Research AER), Karl Pfeiffer (Atmospheric and Environmental Research Hampton), and Prof. Jennifer Francis (Woodwell Climate Research Center), have published their findings in Science Advances.

The study reveals that since 2015, the Northwest US has experienced more of these cold outbreaks due to a shift in stratospheric behavior tied to broader climate cycles. In contrast, other regions may experience milder winters. Understanding this relationship can improve long-range forecasting, allowing cities, power grids, and agriculture to better prepare for winter extremes – even as the climate warms overall.

“It’s not just about warming everywhere all the time,” explained the researchers. “Climate change also means more complex and sometimes counterintuitive shifts in where extreme weather shows up.”

The work was funded by a US NSF-BSF grant by Chaim Garfinkel of HUJI and Judah Cohen of AER&MIT, highlighting the importance of international collaboration in addressing global climate challenges.

Scientists from the Hereon Institute of Coastal Ocean Dynamics have made a groundbreaking discovery by capturing high-resolution images of the ocean surface using a specially developed laser measurement system. Led by Dr. Marc Buckley, the team has successfully mapped the interactions between wind and waves on the open ocean, shedding new light on the complex mechanisms that control energy exchange between the atmosphere and the ocean.

Using Particle Image Velocimetry (PIV), an established technique in fluid dynamics, the researchers were able to visualize both the air and water sides of the ocean surface. The laser beam passed through both media, illuminating tiny droplets suspended in the air above the water. This allowed the team to capture precise information about flow structure and wind speeds.

The breakthrough findings reveal two distinct wind-wave coupling mechanisms that occur simultaneously but operate differently. Short waves, approximately one meter in length, move slower than the wind, creating a pressure difference that transfers energy to the wave. Long waves, up to 100 meters in length, move faster than the wind and generate different airflow patterns through their motion.

These discoveries have significant implications for advancing atmospheric and oceanic models. The interactions between wind and waves are a central component of the Earth’s climate and weather systems, controlling the exchange of energy, heat, and greenhouse gases between the atmosphere and the ocean.

The research team plans to further develop the system to capture movements below the water surface with greater precision. This cutting-edge research aims to preserve a world worth living in by generating knowledge and researching new technologies for greater resilience and sustainability – for the benefit of the climate, the coast, and people.