Description: This data set contains the concentrations of chlorohyll a (chla) and the phytoplankton fuctional types from the CTD stations during PS 92, which were calculated from marker pigment ratios using the CHEMTAX program (Mackey et al, 1996).Pigment ratios were constrained as suggested by Higgins et al. (2011) based on microscopic examination of representative samples during the cruise, and the input matrix published by Fragoso et al. (2016) was applied. The resulting phytoplankotn group composition is represented in chl a concentrations. From the same bottles various trace gases were measured as carbon monoxide (CO) and the Volatile Organic Compounds (VOCs) as Dimethyl sulphide (DMS), methanethiol (MeSH) and isoprene.

Description: Understanding and responding to the rapidly occurring environmental changes in the Arctic over the past few decades require new approaches in science. This includes improved collaborations within the scientific community but also enhanced dialogue between scientists and societal stakeholders, especially with Arctic communities. As a contribution to the Third International Conference on Arctic Research Planning (ICARPIII), the Arctic in Rapid Transition (ART) network held an international workshop in France, in October 2014, in order to discuss high-priority requirements for future Arctic marine and coastal research from an early-career scientists (ECS) perspective. The discussion encompassed a variety of research fields, including topics of oceanographic conditions, sea-ice monitoring, marine biodiversity, land-ocean interactions, and geological reconstructions, as well as law and governance issues. Participants of the workshop strongly agreed on the need to enhance interdisciplinarity in order to collect comprehensive knowledge about the modern and past Arctic Ocean's geo-ecological dynamics. Such knowledge enables improved predictions of Arctic developments and provides the basis for elaborate decision-making on future actions under plausible environmental and climate scenarios in the high northern latitudes. Priority research sheets resulting from the workshop's discussions were distributed during the ICARPIII meetings in April 2015 in Japan, and are publicly available online.

Description: Recent observations of enhanced oceanic heat transfer into the Arctic concomitant with the rapid sea-ice decrease temptingly suggest a direct relationship between both features. However, except for marginal areas of the Arctic Ocean where warm and saline Atlantic Water (AW) reaches the surface, the majority of AW heat is presently isolated from the sea-ice cover by a cold and fresh halocline layer. No evidence has been found to suggest a weakening of the halocline across the central Arctic basins that would enhance the AW heat transfer to the surface. A more direct link between sea-ice reduction and AW inflow is, however, seen in the inflowing Barents Sea branch in both historical and observational time series. In this presentation the AW advection into the Arctic Ocean and its influence on sea-ice variability will be reviewed from a geological point of view. Records from the geologic past are of great value as the time span of modern observations and historical data is often too short to comprehend long-term trends and causes of AW variability, changes in the marginal ice zone, and the vertical structure of the Arctic water column. Paleoceanographic studies from the recent interglacial indirectly suggest that the strength of AW advection and its propagation into the Arctic interior is effective in melting sea ice in combination with other factors such as insolation, sea level, freshwater input, and upper water mass stratification. However, to date, very little paleoceanographic work in the Arctic has focused on how the strength and position of the halocline has changed during previous interglacial periods. More direct reconstructions of the Arctic’s vertical stratification in the geologic past are needed to provide a longer-term view on the stability of the halocline, and more generally, the role of Atlantic Water inflow on the stability of sea ice in the interior basins.

Description: The Arctic is currently undergoing rapid environmental and economic transformations. Recent and ongoing climate warming which is simplifying access to oil and gas resources, enabling trans-Arctic shipping and shifting the distribution of harvestable resources, has brought the Arctic Ocean to the top of national and international political agendas. Scientific knowledge of the present status of the Arctic Ocean and the process-based understanding needed to make predictions throughout the arctic region are thus urgently required. A step towards improving our capacity to predict future arctic change was undertaken with the Second International Conference on Arctic Research Planning (ICARP II) meetings in 2005 and 2006 which brought together scientists, policymakers, research managers, arctic residents and other stakeholders interested in the future of arctic climate change research. The Arctic in Rapid Transition (ART) Initiative developed out of an effort to synthesize the several resulting ICARP II science plans specific to the marine environment and has been a process driven by the early career scientists of the ICARP II Marine Roundtable. To this end, the ART Initiative is an integrative, international, multi-disciplinary, long-term pan-Arctic program to study changes and feedbacks among the physical characteristics and biogeochemical cycles of the Arctic Ocean and its' resulting capacity for biological productivity. The first ART workshop was held in Fairbanks, Alaska in November 2009 with 58 participants, the results of which will help to develop a science and implementation plan that integrates, updates and develops priorities for arctic marine science over the next decade. Our focus within the ART Initiative will be to bridge gaps in knowledge not only across disciplinary boundaries (e.g., geology, biology, physical oceanography, geochemistry and meteorology), but also across geographic boundaries (e.g., shelves, margins and the central Arctic Ocean) and temporal boundaries (e.g., paleo/geologic records, current process observations and future modeling studies). This interdisciplinary, international and integrated temporal approach of the ART Initiative will provide a means to better understand and predict change and ultimate responses in the Arctic Ocean system. More information about the ART Initiative can be found at www.aosb.org/art.html.