The molecular geography of dissolved organic matter in the Atlantic and Southern Ocean

• Main Author: Seibt, Maren
• Format: Thesis
• Language: unknown
• Published: 2017
• Subjects: Science and mathematics; Southern Ocean
• Online Access: http://oops.uni-oldenburg.de/3451/; http://oops.uni-oldenburg.de/3451/1/seimol17.pdf

Dissolved organic matter (DOM) is a key component in the carbon cycle and therefore relevant in the global climate system. In this thesis, DOM samples from the Atlantic and Southern Ocean were analyzed via ultrahigh-resolution Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). In the first study, two indices are established to assess the impact of bioproduction and photodegradation on the molecular composition of DOM from the Atlantic and Southern Ocean. In the second study, the molecular fingerprints from the Atlantic and Southern Ocean are compared to an arithmetically constructed two-source mixing model. It is shown that the molecular geography can be explained as the result of mixing two specific endmembers, i.e. the molecular signatures of freshly produced and long-term stable DOM. In the third study, the distribution of dissolved organic nitrogen (DON) in the Atlantic and Southern Ocean and the reasons behind the observed distribution are explored.