Department of Climate and Space Sciences and Engineering in the College of Engineering at the University of Michigan

CLaSP Seminar Series - Dr. Hannah Zanowski

Date: October 25, 2018
Time: 3:30 pm - 5:00 am
Location: CSRB Auditorium, room 2246

Our guest for this week's CLaSP Seminar Series will be Dr. Hannah Zanowski of the University of Washington. Please join us!

Title: "Circumpolar Deep Water variability on the West Antarctic continental shelf in high-resolution coupled climate models"

Abstract: Observational studies have shown that West Antarctic ice shelf basal melt is strongly related to warm Circumpolar Deep Water (CDW) impinging on the continental shelf in this region. This critical discovery has led to a number of high-resolution regional modelling studies aimed at identifying the underlying mechanisms that lead to CDW intrusions on the West Antarctic continental shelf and their subsequent circulation in ice shelf cavities. These studies typically show that CDW intrusions are linked to a variety of processes, including eddy-mediated cross-shelf exchange and the local wind stress curl at the continental shelf break. However, many of these models do not include a coupled atmosphere, potentially missing relevant ice-ocean-atmosphere interactions that impact CDW variability in the West Antarctic.

Here we characterize West Antarctic CDW variability in two coupled climate models with 0.1˚ oceans and identify the mechanisms that control this variability on interannual timescales. In both models, we find that there are individual periods where the local winds at the shelf break lead to warming on the continental shelf, but the overall correlation between shelf break wind stress and on-shelf temperatures is low. This is largely due to oceanic mean state biases, particularly the vertical temperature structure on the shelf and the southern extent of the Antarctic Circumpolar Current (ACC). Despite these biases, we find that the models’ shelf temperatures are more strongly correlated with off-shelf CDW variability in the West Antarctic sector, a mechanism that has only recently been explored in the literature. Depending on the region, this mechanism can account for up to 30% of model on-shelf temperature variability and has a broad spatial pattern consistent with the large-scale ocean circulation.

Upcoming Events

January 24th
3:30 pm - 5:00 pm
CLaSP Seminar Series - Prof. David Southwood
January 31st
3:30 pm - 5:00 pm
CLaSP Seminar Series - Prof. Anantha Aiyyer
February 7th
3:30 pm - 5:00 pm
CLaSP Seminar Series - Prof. Dustin Schroeder
February 14th
3:30 pm - 5:00 pm
CLaSP Seminar Series - Prof. James Kasting
More Events