ALBERT

Description: Data archives with raw data of burrowing times and proportions of succesfully burrowed clams.

Description: In this study, we present new detailed biomarker-based sea ice records from two sediment cores recovered in the Chukchi Sea and the East Siberian Sea. These new biomarker data may provide new insights on processes controlling recent and past sea ice changes. The biomarker proxy records show (i) minimum sea ice extent during the Early Holocene, (ii) a prominent Mid-Holocene short-term high-amplitude variability in sea ice, primary production and Pacific-Water inflow, and (iii) significantly increased sea ice extent during the last ca. 4.5k cal a BP. This Late Holocene trend in sea ice change in the Chukchi and East Siberian Seas seems to be contemporaneous with similar changes in sea ice extent recorded from other Arctic marginal seas. The main factors controlling the millennial variability in sea ice (and surface-water productivity) are probably changes in surface water and heat flow from the Pacific into the Arctic Ocean as well as the long-term decrease in summer insolation. The short-term centennial variability observed in the high-resolution Middle Holocene record is probably related to solar forcing. Our new data on Holocene sea ice variability may contribute to synoptic reconstructions of regional to global Holocene climate change based on terrestrial and marine archives.

Description: About 50 Gt of carbon is fixed photosynthetically by surface ocean phytoplankton communities every year. Part of this organic matter is reprocessed within the plankton community to form aggregates which eventually sink and export carbon into the deep ocean. The fraction of organic matter leaving the surface ocean is partly dependent on aggregate sinking velocity which accelerates with increasing aggregate size and density, where the latter is controlled by ballast load and aggregate porosity. In May 2011, we moored nine 25 m deep mesocosms in a Norwegian fjord to assess on a daily basis how plankton community structure affects material properties and sinking velocities of aggregates (Ø 80–400 µm) collected in the mesocosms' sediment traps. We noted that sinking velocity was not necessarily accelerated by opal ballast during diatom blooms, which could be due to relatively high porosity of these rather fresh aggregates. Furthermore, estimated aggregate porosity (Pestimated) decreased as the picoautotroph (0.2–2 µm) fraction of the phytoplankton biomass increased. Thus, picoautotroph‐dominated communities may be indicative for food webs promoting a high degree of aggregate repackaging with potential for accelerated sinking. Blooms of the coccolithophore Emiliania huxleyi revealed that cell concentrations of ~1500 cells/mL accelerate sinking by about 35–40%, which we estimate (by one‐dimensional modeling) to elevate organic matter transfer efficiency through the mesopelagic from 14 to 24%. Our results indicate that sinking velocities are influenced by the complex interplay between the availability of ballast minerals and aggregate packaging; both of which are controlled by plankton community structure.

Description: This data contains XRF peak area data, elemental ratios and average values of sediment core ARA02B/16B-GC from the Arliss Plateau, off the East Siberian margin, western Arctic Ocean

Description: As part of the Norwegian research project "CarbonBridge - Bridging marine productivity regimes: How Atlantic advective inflow affects productivity, carbon cycling and export in a melting Arctic Ocean" (NRC #226415, RIS #6637), the concentration of inorganic nutrients and organic material (i.e. chlorophyll a, particulate organic matter), as well as primary and secondary production rates were determined from the upper 1000 m of the water column West and North of Spitsbergen. The flux of sinking organic material was also determined. In total three expeditions were conducted in 2014.

Description: At Site GS15-198-38, Greenland Sea, we analysed the surface sample (from a multicore) and eight Late Quaternary samples from a Calypso core. The age model for the Calypso core GS15-198-38CC is based on seven AMS 14C ages down to 345 cm, and a 5-cm resolution N. pachyderma sinistral isotope stratigraphy (1) below that level. We analysed the palynology, generated organic biomarker data (including IP25, sterols) and performed quantitative PCR (droplet digital PCR, ddPCR) of the sympagic dinoflagellate Polarella glacialis.

Description: The exponential growth of studies on the biological response to ocean acidification over the last few decades has generated a large amount of data. To facilitate data comparison, a data compilation hosted at the data publisher PANGAEA was initiated in 2008 and is updated on a regular basis (doi:10.1594/PANGAEA.149999). By January 2015, a total of 581 data sets (over 4 000 000 data points) from 539 papers had been archived. Here we present the developments of this data compilation five years since its first description by Nisumaa et al. (2010). Most of study sites from which data archived are still in the Northern Hemisphere and the number of archived data from studies from the Southern Hemisphere and polar oceans are still relatively low. Data from 60 studies that investigated the response of a mix of organisms or natural communities were all added after 2010, indicating a welcomed shift from the study of individual organisms to communities and ecosystems. The initial imbalance of considerably more data archived on calcification and primary production than on other processes has improved. There is also a clear tendency towards more data archived from multifactorial studies after 2010. For easier and more effective access to ocean acidification data, the ocean acidification community is strongly encouraged to contribute to the data archiving effort, and help develop standard vocabularies describing the variables and define best practices for archiving ocean acidification data.

Description: Carbonate separates from listvenite core BT1B, Oman Drilling Project, were analyzed for their stable oxygen and carbon isotope ratios and clumped isotope distribution to constrain the conditions of carbonate mineralization. This data set summarizes all individual measurement results of the reference materials used and of the unknown samples.