EGU2020-245
https://doi.org/10.5194/egusphere-egu2020-245
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Pathways of ocean heat towards Pine Island and Thwaites grounding lines

Yoshihiro Nakayama1,2, Georgy Manucharyan3, Hong Zhang2, Pierre Dutrieux4, Hector S. Torres2, Patrice Klein2,5, Helene Seroussi2, Michael Schodlok2, Eric Rignot2,6, and Dimitris Menemenlis2
Yoshihiro Nakayama et al.
  • 1Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan (yoshihiro.nakayama@lowtem.hokudai.ac.jp)
  • 2Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA, USA
  • 3University of Washington, Seattle, WA, USA
  • 4Lamont-Doherty Earth Observatory, Columbia University, NY, USA
  • 5Laboratoire de Physique des Océans, IFREMER‐CNRS‐IRD‐UBO, Plouzané, France
  • 6Earth System Science, University of California Irvine, CA, USA

In the Amundsen Sea, modified Circumpolar Deep Water (mCDW) intrudes into ice shelf cavities, causing high ice shelf melting near the ice sheet grounding lines, accelerating ice flow, and controlling the pace of future Antarctic contributions to global sea level. The pathways of mCDW towards grounding lines are crucial as they directly control the heat reaching the ice. A realistic representation of mCDW circulation, however, remains challenging due to the sparsity of in-situ observations and the difficulty of ocean models to reproduce the available observations. In this study, we use an unprecedentedly high-resolution (200 m horizontal and 10 m vertical grid spacing) ocean model that resolves shelf-sea and sub-ice-shelf environments inqualitative agreement with existing observations during austral summer conditions. We demonstrate that the waters reaching the Pine Island and Thwaites grounding lines follow specific, topographically-constrained routes, all passing through a relatively small area located around 104ºW and 74.3ºS. The temporal and spatial variabilities of ice shelf melt rates are dominantly controlled by the sub-ice shelf ocean current. Our findings highlight the importance of accurate and high-resolution ocean bathymetry and subglacial topography for determining mCDW pathways and ice shelf melt rates. 


We also briefly introduce our various existing model outputs focusing on the Amundsen Sea and demonstrate how to access these model outputs, plot some basic variables, and create animations. We hope that these model output can be utilized for many different aspects of oceanographic researches including observational planning, data analysis for physical, biological and chemical oceanography, and boundary conditions for ocean and ice sheet models. 

 

How to cite: Nakayama, Y., Manucharyan, G., Zhang, H., Dutrieux, P., S. Torres, H., Klein, P., Seroussi, H., Schodlok, M., Rignot, E., and Menemenlis, D.: Pathways of ocean heat towards Pine Island and Thwaites grounding lines, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-245, https://doi.org/10.5194/egusphere-egu2020-245, 2019

Displays

Display file