PICANTE - Processes, Impacts, and Changes of ANTarctic Extreme weather
Lead Research Organisation:
University of Sheffield
Department Name: Geography
Abstract
Extreme weather events, from heatwaves to flooding, are becoming stronger and more frequent in a visible manifestation of climate change. In Antarctica, extreme weather depletes the ice sheet through enhanced melting, which can raise global sea level, or strengthens the ice sheet through enhanced snowfall, which can lower global sea level.
Antarctic extreme weather events (AEWE) are poorly understood and complex phenomena driven by factors across a range of scales. At the regional scale, they are driven by high and low-pressure systems, such as those seen on weather maps, and by atmospheric rivers - currents of air thousands of kilometres long - which bring warm and moist air from lower latitudes. In turn, these weather systems are driven by larger-scale patterns of climate variability, such as the El Niño/Southern Oscillation and the strength of the westerly winds encircling the Antarctic, which may themselves be affected by human-induced climate change.
The PICANTE project aims to transform our understanding of the characteristics and drivers of AEWE, to disentangle the roles of natural climate variability and human influence, and to use this knowledge to predict the impact of future AEWEs on Antarctic climate and ice shelves. Ice shelves are particularly vulnerable to AEWE because they melt from both the bottom up (from warm ocean water) and the top down (from warm air). Thinner ice shelves are less stable and prone to collapse; this is important because ice shelves dam the flow of Antarctica's grounded ice into the ocean. Losing the ice shelves causes the ice sheet to slide into the sea faster, causing global sea level to rise.
To achieve our aim, we have identified five objectives fit to the scope of the call.
1) To compile a comprehensive dataset of AEWEs, their weather system drivers, and their local climate impacts using observations from Antarctica's weather station network, interpolated data from a wider network of observations (climate reanalysis) and simulations from climate models.
2) To use these data and state-of-the-art artificial intelligence techniques, to investigate the relative contribution of the chain of drivers of AEWE across different scales. We will then use high resolution climate simulations, novel satellite observations and simulations of the ice sheet surface to connect these to local impacts on ice shelf stability.
3) To understand the potential future distribution of AEWE and their impacts, we will use simulations of future climate under a range of possible scenarios together with new simulations of the ice sheet surface and ocean to investigate how changes to AEWE will affect future ice shelf stability.
4) This will naturally lead to identifying model improvements needed to improve projections of AEWEs and their impacts, specifically in terms of local climate, ice surface and ocean models.
5) Finally, we leave space to discover unprecedented extremes. Since the observed extremes from (1) can only represent a sample; more extreme events may be possible in the current climate, with potentially unprecedented impacts.
The Intergovernmental Panel on Climate Change projects that Antarctica will warm by up to 5oC by the end of the century, and that extreme weather events will become stronger and more frequent. Understanding the causes and impacts of AEWE is therefore now critical if we are to understand the implications of these changes for the fate of the Antarctic ice sheet and global sea level rise.
Antarctic extreme weather events (AEWE) are poorly understood and complex phenomena driven by factors across a range of scales. At the regional scale, they are driven by high and low-pressure systems, such as those seen on weather maps, and by atmospheric rivers - currents of air thousands of kilometres long - which bring warm and moist air from lower latitudes. In turn, these weather systems are driven by larger-scale patterns of climate variability, such as the El Niño/Southern Oscillation and the strength of the westerly winds encircling the Antarctic, which may themselves be affected by human-induced climate change.
The PICANTE project aims to transform our understanding of the characteristics and drivers of AEWE, to disentangle the roles of natural climate variability and human influence, and to use this knowledge to predict the impact of future AEWEs on Antarctic climate and ice shelves. Ice shelves are particularly vulnerable to AEWE because they melt from both the bottom up (from warm ocean water) and the top down (from warm air). Thinner ice shelves are less stable and prone to collapse; this is important because ice shelves dam the flow of Antarctica's grounded ice into the ocean. Losing the ice shelves causes the ice sheet to slide into the sea faster, causing global sea level to rise.
To achieve our aim, we have identified five objectives fit to the scope of the call.
1) To compile a comprehensive dataset of AEWEs, their weather system drivers, and their local climate impacts using observations from Antarctica's weather station network, interpolated data from a wider network of observations (climate reanalysis) and simulations from climate models.
2) To use these data and state-of-the-art artificial intelligence techniques, to investigate the relative contribution of the chain of drivers of AEWE across different scales. We will then use high resolution climate simulations, novel satellite observations and simulations of the ice sheet surface to connect these to local impacts on ice shelf stability.
3) To understand the potential future distribution of AEWE and their impacts, we will use simulations of future climate under a range of possible scenarios together with new simulations of the ice sheet surface and ocean to investigate how changes to AEWE will affect future ice shelf stability.
4) This will naturally lead to identifying model improvements needed to improve projections of AEWEs and their impacts, specifically in terms of local climate, ice surface and ocean models.
5) Finally, we leave space to discover unprecedented extremes. Since the observed extremes from (1) can only represent a sample; more extreme events may be possible in the current climate, with potentially unprecedented impacts.
The Intergovernmental Panel on Climate Change projects that Antarctica will warm by up to 5oC by the end of the century, and that extreme weather events will become stronger and more frequent. Understanding the causes and impacts of AEWE is therefore now critical if we are to understand the implications of these changes for the fate of the Antarctic ice sheet and global sea level rise.
