Abstracted/indexed

The upper mixed layer, shallower than the depth of the euphotic zone, is one of the preconditions for enhanced primary production in the ocean. In the Baltic Sea, the general understanding is that the upper mixed layer is much deeper in winter. In this study, we demonstrate that wintertime shallow stratification and an elevated phytoplankton biomass proxy, chlorophyll, are common in the Gulf of Finland. Stratification is invoked by the westward flow of riverine water forced by an easterly wind.

Our investigations give detailed insight on the seasonally changing current system at intermediate depth in the Arabian Sea that is influenced by the monsoon. The changing currents influence the oxygen transport in the interior ocean and thus allow us to draw conclusions on the maintenance and seasonal variability of the upper part of the oxygen minimum zone in the Arabian Sea.

During the mid-1970s and quite recently in 2017, a large open-water area appeared in the Antarctic sea-ice pack, the so-called Maud Rise polynya. From several model studies, the reoccurrence time of this polynya seems arbitrary. In this study, we address the reoccurrence time of the polynya using a high-resolution climate model. We find a preferred multidecadal return time in polynya formation. The return time of the polynya is associated with a large-scale ocean mode in the Southern Ocean.