Variability in the lower circumpolar deep water and the Lazarev Sea

• Main Authors: Donnelly, Matthew, Leach, Harry, Strass, Volker
• Format: Text
• Language: English
• Subjects: Greenwich; Lazarev; Lazarev Sea; Southern Ocean; Weddell
• Online Access: http://livrepository.liverpool.ac.uk/16813/; http://livrepository.liverpool.ac.uk/16813/1/DonnellyMatt_Mar2014_200364961.pdf

Furthering our understanding of the Southern Ocean as a critical component of the global climate system and its variability in both space and time is the focus of many investigations. This thesis aims to add to that effort by addressing two important questions. The first chapter will set the role of the Southern Ocean into greater context, clarifying the framework and background for its examination. The second chapter will examine a simple 1-dimensional model of the modification of the Lower Circumpolar Deep Water as it moves southwards across the ACC and into the Weddell Gyre. This leads into the third chapter which will address the first question of how variable are the characteristics of the Lower Circumpolar Deep Water? The variability of the salinity maximum associated with the Lower Circumpolar Deep Water is examined in order to address its spatial variability – from entry via the South Atlantic, through its circumpolar transit, ending with a terminal repository in the Weddell Gyre – by making use of freely available hydrographic data. It also examines temporal variability where repeat data allows, and provides new estimates of deep ocean mixing rates. The fourth chapter will seek to address the second question of how variable was the volume transport during the Lazarev Sea Krill Study (LaKriS) cruises? The LaKriS cruises provide a rare set of semi-repeat grids of hydrographic measurements near the Greenwich Meridian. This provides the opportunity to attempt to assess seasonal and inter-annual variability by making use of an inverse modelling technique. The fifth and final chapter will set the knowledge gained from addressing these two questions against the wider knowledge of the Southern Ocean system and consider the implications for future oceanic sampling and research.