Understanding polar atmosphere-ocean-sea ice momentum transfer using remote sensing and modeling techniques
Over the last half a century, the Arctic sea ice extent and volume have been decreasing as a result of the amplified warming taking place in the Arctic. Similarly, the Antarctic summertime sea ice extent maximum has been the lowest in the satellite record for the last three years. As sea ice at both...
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| Other Authors: | , |
| Format: | Doctoral or Postdoctoral Thesis |
| Language: | English |
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Universität Bremen
2024
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| Online Access: | https://media.suub.uni-bremen.de/handle/elib/8054 https://doi.org/10.26092/elib/3088 https://nbn-resolving.org/urn:nbn:de:gbv:46-elib80544 |
| Summary: | Over the last half a century, the Arctic sea ice extent and volume have been decreasing as a result of the amplified warming taking place in the Arctic. Similarly, the Antarctic summertime sea ice extent maximum has been the lowest in the satellite record for the last three years. As sea ice at both poles is changing in a warming climate, it is necessary to better understand the fundamental processes that determine sea ice properties such as extent, thickness, volume and drift. These processes, namely dynamic and thermodynamic ones, are triggered by the surrounding atmosphere and ocean. The overarching goal of this dissertation is to study dynamic processes while also considering thermodynamic aspects. Chapter 3 delves into the abovementioned dynamic and thermodynamic processes at mesoscale in the study of polynya events and thin sea ice anomalies above Maud Rise in the Antarctic. Chapter 4 looks at parameters that quantify dynamics, specifically at drag coefficients (Cd) that determine the momentum transfer between the atmosphere and sea ice, on a pan-Arctic scale. Finally, Chapter 5 implements the derived estimates of drag from observations into a coupled regional atmosphere-ocean-sea ice model in order to investigate the impact of variable drag on sea ice properties Arctic-wide. The Weddell Sea Polynya (occurring in 1974-1976 and 2016-2017) is an excellent case study in the impact of mesoscale as well as synoptic scale processes on sea ice. My analysis of the events corroborates past studies that identify the Weddell Sea polynya as one that is driven by dynamic as well as thermodynamic processes. In addition, using satellite-borne microwave imaging radiometers, large thin sea ice anomalies have been identified in polynya-free years (2010-2020). Given the reported links between the polynya and different dynamic and thermodynamic ocean and atmosphere processes, our results suggest that when an insufficient amount of these processes are active, a thin sea ice anomaly may emerge instead. The neutral sea ... |
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