Breaking the Arctic ice

 

Thermal AVHRR image with land masked in black. Can see the lead coming off of Barrow Alaska very bright. The arrows are sea ice drift vectors.

Cascade over mossy rocks near Sol Duc Falls, Olympic National Park, WA.

When you hear about fractures in sea ice, you might visualize the enormous fissures that rupture ice shelves, which release massive icebergs to the sea. This is what happened back in July 2017 when a Delaware-sized iceberg broke off from the Larsen C ice shelf in Antarctica. However, there are other types of fractures occurring in sea ice that may be impacted by atmospheric conditions. Our guest this week, CEOAS Masters student Ben Lewis investigates how interactions between the atmosphere and sea ice in the Beaufort Sea (north of Alaska in the Canadian Archipelago) impact the formation of fractures. His research involves mapping atmospheric features, such as wind and pressure, at the point in time when the fractures occurred and provides insight into the effect of the atmosphere on the formation and propagation of fractures. Utilizing satellite imagery compiled by the Geographical Information Network of Alaska from 1993 to 2013, Ben has conducted a qualitative analysis to determine the location and time when these ice fractures occurred and what type of physical characteristics they possess.

Southern Alps from the summit of Avalanche Peak, New Zealand.

While fractures appear small on the satellite image, the smallest fractures that Ben can observe by are actually 250 meters wide. Fractures can span hundreds of kilometers, and the propagate very quickly; Ben cites one example of a fracture near Barrow, Alaska that grew to 500 kilometers within 6 hours!

Fractures are potentially deadly for people and animals hunting in the Arctic. As weather flux in the fragile Arctic ecosystem has become more erratic with climate change, it has been difficult for people to predict when it was safe to hunt on the ice based on patterns observed in prior seasons. Additionally, it has been problematic to track weather in the Arctic because of its harsh conditions and sparse population. A well-catalogued record of weather is not available for all locations. Modeling atmospheric conditions, such as pressure and wind, based on what has been captured by satelliteimagery, will facilitate better prediction of future fracture events.

Sunset over Sandfly Beach, New Zealand.

While pursuing an undergraduate degree in physics at the University of Arkansas, Ben was able to study abroad James Cook University in Australia, where he gravitated towards environmental physics, while taking advantage of incredible opportunities for nature photography. He also did a semester abroad in New Zealand, where he studied geophysical fluid dynamics and partial differential equations. Ben came to OSU as a post-baccalaureate student in climate science, and while at OSU, he became acquainted with his future PI, Jennifer Hutchings,  and his interest in Arctic research grew. He cites learning about snowball earth, glaciology, and the cryosphere, as providing the basis for his desire to pursue Arctic climate research. Eventually, Ben would like to pursue a PhD, but in the immediate future, he plans to keep his options open for teaching and research opportunities.

 

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