The shape of change: an EOF approach to identifying sources of transient thickness change in an ice shelf

• Published in: Annals of Glaciology
• Main Authors: Adam J. Campbell, Christina L. Hulbe, Choon-Ki Lee
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press 2017
• Subjects: glaciological model experiments; ice shelves; laser altimetry; Meteorology. Climatology; QC851-999; Ross Ice Shelf; Byrd; Byrd Glacier; Annals of Glaciology; Ice Shelf; Ice Shelves
• Online Access: https://doi.org/10.1017/aog.2017.16; https://doaj.org/article/c0e9e2cf491042a1923b9bfe5f127b60

Ross Ice Shelf (RIS) is known to experience transient thickness change due to changes in the flow of its tributary ice streams and glaciers and this may complicate identification of external, climate-forced signals in contemporary observations of ice shelf thinning and thickening. Flux changes at the lateral boundaries produce both instantaneous and longer timescale adjustments in the coupled velocity and thickness fields. Here, we adapt a statistical approach to output from a numerical model of ice shelf flow to identify characteristic patterns (spatial response surfaces) associated with stepped and cyclic perturbations to boundary fluxes. Once known, characteristic patterns identified in observational data may be attributed to specific sources. An example involving discharge of Byrd Glacier into RIS is described. We find that spatial response surfaces for thickness and velocity generated in individual flow model experiments appear to be independent of flux perturbation shape and magnitude. Additionally, recent acceleration of Byrd Glacier is apparent in ICESat-detected change in RIS thickness.