Quantifying the Effects of Wind Regimes and Temperature on Surface Melt over the Antarctic Peninsula (1982–2017) through Modeling, Remote Sensing and In-Situ Data

• Main Author: Datta, Rajashree
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: CUNY Academic Works 2018
• Subjects: Antarctic Peninsula; Larsen C ice shelf; climate model; foehn wind; surface melt; Atmospheric Sciences; Climate; Glaciology; Antarctic; Greenland; Kendall; The Antarctic; Antarc*; Ice Shelf; Ice Shelves
• Online Access: https://academicworks.cuny.edu/gc_etds/2928; https://academicworks.cuny.edu/context/gc_etds/article/3974/viewcontent/Thesis_RDatta_Sep18.pdf

Surface melting over the Antarctic Peninsula (AP) plays a crucial role for the stability of ice shelves and dynamics of grounded ice, hence modulating the mass balance in a region of the world which is particularly sensitive to increasing surface temperatures. Understanding the processes that drive melting using surface energy and mass balance models is fundamental to improving estimates of current and future surface melting and associated sea level rise through ice-shelf collapse. This is even more important in view of the specific challenges presented by how circulation patterns over the topographically-complex Antarctic Peninsula, especially foehn winds, impact surface melt. In this dissertation, I evaluate the regional climate model Modèle Atmosphérique Régionale (MAR) over the Antarctic Peninsula (AP) at a 10 km horizontal resolution. An initial run is assessed with both in situ data from AWS stations and melt occurrence estimates from passive and active microwave data. A subsequent run over the full 1982-2017 period is used to extract the primary patterns of surface melt variability and determine how interannual variability of these patterns impacts meltwater infiltration into the snowpack. MAR version 3.5.2 is used for a first run over the 2000-2014 period. This is the first time that this model, which has been validated extensively over Greenland, has been applied to the Antarctic Peninsula at a high resolution. Near-surface atmosphere model outputs are first compared to data retrieved from 10 automatic weather stations. We find that the atmosphere is adequately represented by MAR for the summer season, but note regionally-specific temperature biases which may impact surface melt. Using a non-parametric Mann-Kendall test, we find a slight summer and spring cooling trend in the northeast Antarctic Peninsula (including the Larsen C ice shelf) which confirms trends reported in previous literature. Trends in other regions of the AP or in the winter season are inconclusive. Model outputs uses outputs between ...