The McMurdo Dry Valleys (MDVs) are the largest unglaciated region in Antarctica and are populated with permanently ice-covered lakes. These ice covers define the available habitat within the water column, providing a shield from atmospheric exchange and wind mixing events, and greatly reducing the amount of available photosynthetically active radiation. As climate change accelerates warming in the MDVs, it is critical to understand how the ice covers will be impacted since they are foundational to the aquatic habitat of this extreme ecosystem. Long-term data collection by the McMurdo Dry Valleys Long-Term Ecological Research program shows that the lake ice covers go through decadal thinning and thickening trends, ranging between 2.5 to 6.5 meters thick. These fluctuations are often thought to be driven by air temperature and changes in albedo due to aeolian sediment deposition. Although the drivers have long been identified, the actual mechanics behind these shifts in thickness are not well understood. Here, we use a combination of Landsat imagery, historical data, and high frequency in situ climate measurements to quantify the drivers regulating ice thickness in this extreme environment. Understanding how the permanent ice covers of MDV lakes function is critical in predicting how and under what conditions the lakes might change in the future as a result of climate change.

Authors:

Charles Dougherty, University of Wisconsin-Madison  (cedougherty@wisc.edu)

Hilary Dugan, University of Wisconsin-Madison  (hdugan@wisc.edu)

Mark Salvatore, Northern Arizona State University  (Mark.Salvatore@nau.edu)

Peter Doran, Louisiana State University  (pdoran@lsu.edu)