Sea ice characteristics and volume flux in the western Ross Sea through high-resolution satellite imagery and altimetry

• Main Author: Farooq, Usama
• Format: Other/Unknown Material
• Language: English
• Published: University of Canterbury 2021
• Subjects: Antarctic; Asar; McMurdo Sound; Ross Ice Shelf; Ross Sea; Southern Ocean; Terra Nova Bay; The Antarctic; Antarc*; Antarctica; Ice Shelf; Sea ice
• Online Access: https://hdl.handle.net/10092/102487; https://doi.org/10.26021/11598

Sea ice and the related processes in formation, transformation, and melt, play a significant role in the global climate, considerably influencing Earth’s energy budget and global ocean circulation. Sea ice motion in combination with thickness determines the transportation of fresh ice to the areas of sea ice decay. The sea ice area has been regularly monitored using satellite remote sensing but the volume is still uncertain. This is especially true for the Southern Ocean. The reason behind this is that the thickness of sea ice is not extensively explored. The observation of Antarctic sea ice mass balance therefore needs further investigation. To understand changes in sea ice mass balance it is essential to observe sea ice thickness and dynamics. Due to the inaccessibility and extreme weather of Antarctica, the field measurements of sea ice kinematics and thickness are spatially and temporally sparse. This study aims to improve the knowledge of sea ice mass balance by advancing the understanding of sea ice dynamics and thickness by using satellite remote sensing. In the Antarctic, Ross Sea ice extent has been increasing over the past 40 years of satellite records but the trend substantially declined from 2014 and again started to increase in 2017. The western Ross Sea region, including three main polynya areas in McMurdo Sound, Terra Nova Bay, and in front of the Ross Ice Shelf, has experienced a significant increase in sea ice extent, and is the area under investigation. The sea ice morphology in this region ranges from simple land-fast sea ice to complex pack ice. To pursue this, sea ice drift is assessed in the first part of this study using sequential high- resolution (150 m) Advanced Synthetic Aperture Radar (ASAR) images from the Envisat satellite from 2002 to 2012. The output motion vectors were validated with manually drawn vectors. The low correlations and high directional differences are found between high- resolution velocity vectors and NSIDC low-resolution sea ice motion product. The high- resolution ...