Chris Polashenski

chris

Adjunct Associate Professor of Engineering, Dartmouth College

Research Geophysicist, US Army Cold Regions Research and Engineering Laboratory CRREL

Chris Polashenski grew up in eastern Pennsylvania, and studied at Dartmouth College, where he began to study snow and ice.  He received a BA in Environmental Engineering, and a PhD in Materials Engineering, also at Dartmouth.

His research interests are in sea ice geophysics; the interaction of sunlight with ice and snow; the Arctic system and climate change

He is the author of ~70 publications (as of 11/2023) on sea-ice properties and processes, snow deposition and redistribution, and the albedo of sea ice and ice sheets. His research interests involve both remote sensing and detailed in situ field study of cryospheric processes.,Dr. Polashenski is a member of the American Geophysical Union, the International Glaciological Society, and the Association of Polar Early Career Scientists.

Interviews

2012

Chris Polashenski, a researcher specializing in the structure of sea ice, was found a couple of miles out on the sea ice, deeply engaged in his work. He studies how the physical characteristics of sea ice influence its melting patterns. Polashenski explains the significance of sea ice in the Earth’s climate system, highlighting its role as a reflective surface. The ice, being predominantly white, reflects most of the sunlight hitting it back into space, helping to keep the planet cooler. He contrasts this with the dark open water, which absorbs sunlight and heats up. This absorption of heat by the ocean exacerbates the melting of the remaining sea ice, leading to more exposure of the ocean surface. This feedback loop accelerates climate change by reducing the amount of energy reflected back into space. Polashenski’s research underscores the critical role of sea ice in regulating the Earth’s temperature and the profound implications of its melting due to climate change.

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2023

Chris Polashenski shares his journey into Arctic research, which began with a childhood love for snow and led to his involvement in the Arctic studies program at Dartmouth College. Influenced by Ross Virginia, he initially worked as a technician in Barrow (now Utqiaġvik) for a field program related to the Arctic tundra. His interest in the Arctic was further nurtured by mentors like Matthew Sturm and Don Perovich, leading to a long-term career in the field. Polashenski holds a complex professional role, dividing his time between Vermont and Fairbanks to stay close to his research area. He is involved with Dartmouth for graduate student supervision and teaching, while also conducting field work in the Arctic every winter and spring. Despite his academic focus, Polashenski emphasizes the deep personal connections he has formed within the Arctic community, mentioning close relationships with various Arctic researchers and residents. His story underscores the interconnectedness of personal passion, academic research, and community ties in the pursuit of Arctic studies.

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Chris Polashenski, an expert on sea ice, discusses the complexities of understanding and measuring the Arctic’s changing ice landscape. His focus is on the structure and melting patterns of sea ice, particularly the contrast between the reflective white ice and dark open water, which significantly impacts the planet’s energy balance. Polashenski explains that the loss of sea ice exposes more ocean, absorbing additional sunlight, which in turn melts more ice – a cycle that accelerates climate change. He is involved in a campaign to better understand snow accumulation on sea ice, expanding the Ice Mass Balance Buoy program to include numerous measurements of snow depth. This research is crucial for understanding the reflective and insulating properties of snow on sea ice and for accurately measuring ice thickness, which is essential for climate modeling. Polashenski’s work involves ground-truthing satellite data to improve remote sensing techniques for snow and ice. His journey into Arctic research began with a simple love for snow and has evolved into tackling some of the most pressing environmental challenges in the Arctic.

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Chris Polashenski, expressing pessimism about global efforts to address climate change, shares his personal and professional experiences related to climate mitigation. Despite his efforts in public talks and educating people about the urgency of climate action, he has been disappointed by the limited response. Shifting his focus, Polashenski is actively engaged in climate mitigation activities, particularly on his wife’s farm in Vermont. They have committed to eliminating fossil fuel emissions from the farm within ten years, a project started in 2018. So far, they have significantly reduced emissions by implementing various initiatives like solar panels, heat pumps, and hybrid vehicles. Polashenski finds this approach of leading by example both achievable and impactful. However, he acknowledges the challenges in motivating broader societal change, highlighting the need for a deeper understanding of human behavior and motivation to drive effective climate action. His advice to those uncertain about their future is to consistently choose paths that are fun and involve good people, a principle that has guided his own career.

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Chris Polashenski, a scientist focusing on Arctic sea ice, discusses his work in the context of climate change. His career primarily revolves around improving future climate predictions by targeting weak areas in existing models. He collaborates with the National Center for Atmospheric Research to identify aspects of the models that need refinement. Polashenski’s work has significantly focused on melt ponds—pools that form on sea ice, darken it, and accelerate melting by absorbing more sunlight. His efforts have involved observational campaigns to understand the evolution of melt ponds, initially in Barrow and later expanded across the Arctic using remote sensing technologies. Polashenski has also shifted his focus to other areas like snow on sea ice and its insulating properties, as well as the mechanical properties of ice, distinguishing between the resistance to fracturing in first-year ice and multi-year ice. These research initiatives are geared toward enhancing the accuracy of climate models, thereby helping in better predicting and understanding the rapid environmental changes occurring in the Arctic.

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Chris Polashenski, a physicist with observational experience in Arctic biology, discusses the ecological impacts of diminishing sea ice on Arctic wildlife and primary production. He notes a significant increase in phytoplankton growth beneath the ice, attributed to greater sunlight penetration through thinner ice and melt ponds. This change is leading to larger phytoplankton blooms and shifts in species composition, potentially impacting the entire Arctic food chain. Polashenski also observes a marked decrease in encounters with polar bears and Arctic foxes, suggesting a decline in their populations. He links these changes to the substantial reduction in sea ice over the past 15 years, which has altered the natural habitat of ice-dependent species, affecting their hunting and survival patterns. Polashenski’s insights underscore the profound and rapid ecological transformations occurring in the Arctic due to climate change.

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Chris Polashenski discusses the Mosaic expedition, an extensive Arctic research campaign that he was set to join but was unable due to the pandemic. Instead, he supported his graduate students who continued the work in his absence. Polashenski highlights the logistical challenges and the success of the expedition in gathering a comprehensive data set across an entire year. He points out a significant finding: the expedition’s ship drifted from one side of the Arctic to the other in less than a year, a journey that previously took three years, illustrating the rapid changes in Arctic sea ice. The ice’s increased thinness and dynamism were so pronounced that traditional measurement methods, like ice mass balance stakes, were rendered ineffective—none survived the entire year. This drastic change in ice behavior not only underscores the accelerated pace of Arctic transformation but also challenges scientists to develop new methods for studying and understanding these rapid environmental shifts.

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Chris Polashenski, in his discussion, reflects on the dramatic changes he has observed in the Arctic over his career. Starting in 2005 in Kaktovik, he recalls seeing multi-year sea ice blocks several meters thick. In contrast, in recent years, he hasn’t seen any such ice formations, with the ice often not even grounding offshore. Polashenski notes the significant reduction in stable ice platforms, making operations like ice camps increasingly challenging and risky. He compares his experiences to those in the 1970s when ice camps like T3 could be occupied for decades, highlighting the drastic shift in ice stability and thickness. Polashenski also discusses his participation in Navy ice camps, noting their adaptation to the changing conditions by shortening camp durations and using more mobile and quick-setup structures. The changing ice dynamics have led to a shift from a permanent settlement approach to a more expeditionary one, with a growing focus on risk management due to the unpredictable and dynamic nature of the ice. This transformation, he observes, is a stark indicator of the rapid environmental changes occurring in the Arctic.

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