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• 1. [Article] The Impact of a Large-Scale Climate Event on Antarctic Ecosystem Processes

  Extreme climate and weather events, such as a drought, hurricanes, or ice storms, can strongly imprint ecosystem processing and may alter ecosystem structure. Ecosystems in extreme environments are particularly ...

  Citation × Citation Citation Abstract Copy Title: The Impact of a Large-Scale Climate Event on Antarctic Ecosystem Processes Author: Fountain, Andrew G., Saba, Grace, Adams, Byron, Doran, Peter, Fraser, William, Gooseff, Michael N., Obryk, Maciej K., Priscu, John Charles, Stammerjohn, Sharon, Virginia, Ross A. Year: 2016 Extreme climate and weather events, such as a drought, hurricanes, or ice storms, can strongly imprint ecosystem processing and may alter ecosystem structure. Ecosystems in extreme environments are particularly vulnerable because of their adaptation to severe limitations in energy, water, or nutrients. The vulnerability can be expressed as a relatively long-lasting ecosystem response to a small or brief change in environmental conditions. Such an event occurred in Antarctica and affected two vastly different ecosystems: a marine-dominated coastal system and a terrestrial polar desert. Both sites experienced winds that warmed air temperatures above the 0°C threshold, resulting in extensive snow and ice melt and triggering a series of cascading effects through the ecosystems that are continuing to play out more than a decade later. This highlights the sensitivity of Antarctic ecosystems to warming events, which should occur more frequently in the future with global climate warming. Title: The Impact of a Large-Scale Climate Event on Antarctic Ecosystem Processes Author: Fountain, Andrew G., Saba, Grace, Adams, Byron, Doran, Peter, Fraser, William, Gooseff, Michael N., Obryk, Maciej K., Priscu, John Charles, Stammerjohn, Sharon, Virginia, Ross A. Year: 2016 Extreme climate and weather events, such as a drought, hurricanes, or ice storms, can strongly imprint ecosystem processing and may alter ecosystem structure. Ecosystems in extreme environments are particularly vulnerable because of their adaptation to severe limitations in energy, water, or nutrients. The vulnerability can be expressed as a relatively long-lasting ecosystem response to a small or brief change in environmental conditions. Such an event occurred in Antarctica and affected two vastly different ecosystems: a marine-dominated coastal system and a terrestrial polar desert. Both sites experienced winds that warmed air temperatures above the 0°C threshold, resulting in extensive snow and ice melt and triggering a series of cascading effects through the ecosystems that are continuing to play out more than a decade later. This highlights the sensitivity of Antarctic ecosystems to warming events, which should occur more frequently in the future with global climate warming. Close

• 2. [Article] The Influence of Föhn Winds on Glacial Lake Washburn and Palaeotemperatures in the McMurdo Dry Valleys, Antarctica, During the Last Glacial Maximum

  Large glacial lakes, including Glacial Lake Washburn, were present in the McMurdo Dry Valleys, Antarctica, during the Last Glacial Maximum (LGM) despite a colder and drier climate. To address the mechanism ...

  Citation × Citation Citation Abstract Copy Title: The Influence of Föhn Winds on Glacial Lake Washburn and Palaeotemperatures in the McMurdo Dry Valleys, Antarctica, During the Last Glacial Maximum Author: Obryk, Maciej, Doran, Peter, Waddington, Ed, McKay, Chris Year: 2017 Large glacial lakes, including Glacial Lake Washburn, were present in the McMurdo Dry Valleys, Antarctica, during the Last Glacial Maximum (LGM) despite a colder and drier climate. To address the mechanism capable of generating enough meltwater to sustain these large lakes, a conceptual model was developed based on the warming potential of infrequent contemporary föhn winds. The model suggests that föhn winds were capable of generating enough meltwater to sustain large glacial lakes during the LGM by increasing degree days above freezing (DDAF) and prolonging the melt season. A present-day relationship between infrequent summer föhn winds and DDAF was established. It is assumed that the Taylor Dome ice core record represents large-scale palaeoclimatic variations for the McMurdo Dry Valleys region. This analysis suggests that because of the warming influence of the more frequent föhn winds, summer DDAF in the McMurdo Dry Valleys during the LGM were equivalent to present-day values, but this enhanced summer signal is not preserved in the annually averaged ice core temperature record. © Antarctic Science Ltd 2017 Title: The Influence of Föhn Winds on Glacial Lake Washburn and Palaeotemperatures in the McMurdo Dry Valleys, Antarctica, During the Last Glacial Maximum Author: Obryk, Maciej, Doran, Peter, Waddington, Ed, McKay, Chris Year: 2017 Large glacial lakes, including Glacial Lake Washburn, were present in the McMurdo Dry Valleys, Antarctica, during the Last Glacial Maximum (LGM) despite a colder and drier climate. To address the mechanism capable of generating enough meltwater to sustain these large lakes, a conceptual model was developed based on the warming potential of infrequent contemporary föhn winds. The model suggests that föhn winds were capable of generating enough meltwater to sustain large glacial lakes during the LGM by increasing degree days above freezing (DDAF) and prolonging the melt season. A present-day relationship between infrequent summer föhn winds and DDAF was established. It is assumed that the Taylor Dome ice core record represents large-scale palaeoclimatic variations for the McMurdo Dry Valleys region. This analysis suggests that because of the warming influence of the more frequent föhn winds, summer DDAF in the McMurdo Dry Valleys during the LGM were equivalent to present-day values, but this enhanced summer signal is not preserved in the annually averaged ice core temperature record. © Antarctic Science Ltd 2017 Close