Tracing Arctic precipitation changes in the North Atlantic Ocean

• Main Author: Klemm, Selina (author)
• Other Authors: Katsman, Caroline (mentor), Pietrzak, Julie (mentor), Luxemburg, Willem (mentor), Ypma, Steffie (mentor), Delft University of Technology (degree granting institution)
• Format: Master Thesis
• Language: English
• Published: 2018
• Subjects: Climate Change; Arctic precipitation change; AMOC; Langrangian approach; Arctic; Faroe Bank; Climate change; Denmark Strait; Fram Strait; Iceland; Labrador Sea; Nordic Seas; North Atlantic
• Online Access: http://resolver.tudelft.nl/uuid:919e174c-fdf9-479e-9485-1e953c623ec3

Climate models predict increased Arctic precipitation and subsequent Arctic freshening as a response to increased green house gas concentrations. Eulerian studies have shown that with increased Arctic precipitation AMOC (Atlantic Meridional Overturning Circulation) strength decreases. Decrease in AMOC strength comes with a decreased redistribution of heat from lower to higher latitudes which can have severe effects on our climate. Therefore, understanding the effects and mechanisms of Arctic precipitation change is a crucial building block for predicting and possibly preventing climate change. This study used a Lagrangian approach. The pathways of water at Fram Strait were investigated for present-day climate (control run) and two scenario runs with increased Arctic precipitation (+50% and +300% respectively). Importantly, it was found that Arctic water reaches the Labrador Sea through Denmark Strait for all three runs. Thus, the extra fresh water in the Arctic can possibly impact sinking and convection zones in the Labrador Sea. The total amount of Arctic water, passing Denmark Strait from Fram Strait, increases for the weak scenario and decreases for the strong scenario of this study. On the other side of Iceland, for the strong scenario of this study, Arctic water stops passing the Iceland-Faroe-Ridge through the Faroe Bank Channel. The amount of Arctic water going into and staying in the Nordic Seas remained almost unchanged with increased Arctic precipitation. The two routes passing from Fram Strait into the North Atlantic were analysed further with respect to depth changes and properties. On both routes particles were fresher compared to the control run when increasing Arctic precipitation. For the weak scenario particles were usually colder than the control run on both routes. For the strong scenario, particles were only colder at Fram Strait, but got warmer than the control run along the pathway.