(Table 1) Biomass of plankton in the Sea of Japan at Station VITYAZ6674

Vertical distribution of zooplankton biomass from the surface to bottom layers (3400 m) is examined. Material was collected layer by layer by a BR 113/140 net at 41°59' N and 133°37' E on July 2 and 3, 1970. Quantity of plankton below 1000 m was found to be much less than at corresponding depths in the adjacent regions of the ocean. This impoverishment is due to absence of oceanic bathypelagic animals in deep layers of the Sea of Japan. Absence of specialized predators (plankton-feeders) deep in the Sea of Japan results in underconsumption of interzonal animals that sink to great depths. Upon dying they should reach the floor in larger quantities than in the ocean.

Solar radiation over and under sea ice during the POLARSTERN cruise ARK-XXVI/3 (TransArc) in summer 2011

Arctic sea ice has declined and become thinner and younger (more seasonal) during the last decade. One consequence of this is that the surface energy budget of the Arctic Ocean is changing. While the role of surface albedo has been studied intensively, it is still widely unknown how much light penetrates through sea ice into the upper ocean, affecting sea-ice mass balance, ecosystems, and geochemical processes. Here we present the first large-scale under-ice light measurements, operating spectral radiometers on a remotely operated vehicle (ROV) under Arctic sea ice in summer. This data set is used to produce an Arctic-wide map of light distribution under summer sea ice. Our results show that transmittance through first-year ice (FYI, 0.11) was almost three times larger than through multi-year ice (MYI, 0.04), and that this is mostly caused by the larger melt-pond coverage of FYI (42 vs. 23%). Also energy absorption was 50% larger in FYI than in MYI. Thus, a continuation of the observed sea-ice changes will increase the amount of light penetrating into the Arctic Ocean, enhancing sea-ice melt and affecting sea-ice and upper-ocean ecosystems.

Age determination of sediment core HZM, lake Holzmar (Tables 1, 2)

AMS radiocarbon ages have been determined on terrestrial macrofossils selected from the annually laminated sediments of lake Holzmaar (Germany). The radiocarbon chronology of this lake covers the last 12.6 ka. Comparison of the radiocarbon dated varve chronology with tree ring data shows that an additional 878 years have to be added to the varve chronology. The corrected 14C varve chronology of Holzmaar reaches back to ca. 13.8 ka cal. BP and compares favourably with the results from Soppensee (Switzerland) (Hajdas et al., 1993, doi:10.1007/BF00209748). The corrected ages for the onset and the end of the Younger Dryas biozone are 11,940 cal. BP and 11,490 cal. BP, respectively. The ash layer of the Laacher See volcanic eruption is dated at 12,201 ± 224 cal. BP and the Ulmener Tephra layer is dated at 10,904 cal. BP.

Particle size of Saharan dust in the Atlantic Ocean, from October 2012 to November 2013

Mineral dust has a large impact on regional and global climate, depending on its particle size. Especially in the Atlantic Ocean downwind of the Sahara, the largest dust source on earth, the effects can be substantial but are poorly understood. This study focuses on seasonal and spatial variations in particle size of Saharan dust deposition across the Atlantic Ocean, using an array of submarine sediment traps moored along a transect at 12° N. We show that the particle size decreases downwind with increased distance from the Saharan source, due to higher gravitational settling velocities of coarse particles in the atmosphere. Modal grain sizes vary between 4 and 33 µm throughout the different seasons and at five locations along the transect. This is much coarser than previously suggested and incorporated into climate models. In addition, seasonal changes are prominent, with coarser dust in summer, and finer dust in winter and spring. Such seasonal changes are caused by transport at higher altitudes and at greater wind velocities during summer than in winter. Also the latitudinal migration of the dust cloud, associated with the Intertropical Convergence Zone, causes seasonal differences in deposition as the summer dust cloud is located more to the north, and more directly above the sampled transect. Furthermore, increased precipitation and more frequent dust storms in summer coincide with coarser dust deposition. Our findings contribute to understanding Saharan dust transport and deposition relevant for the interpretation of sedimentary records for climate reconstructions, as well as for global and regional models for improved prediction of future climate.

(Table 1) Sample descriptions and results: Carbon, lipid, and kerogen analyses, at DSDP Leg 64 Holes

Pleistocene sediments in the Guaymas Basin, Gulf of California, have been intruded by sills and their organic matter thus subjected to thermal stress. Sediment samples from DSDP/IPOD Sites 477, 478, and 481, and samples of thermally unaltered materials from Sites 474 and 479 were analyzed to characterize the lipids and kerogens and to evaluate the effects of the intrusive thermal stresses. The lipids of the thermally unaltered samples are derived from microbial and terrestrial higher-plant detritus. The samples from the sill proximities contain the distillates, and those adjacent to the sills contain essentially no lipids. The pyrograms of the kerogens from the unaltered samples reflect their predominantly autochthonous microbial origin. When compared with the unaltered samples, the pyrograms of the altered kerogen samples reflect the thermal effects by a reduction in the complexity of the products. Kerogens adjacent to the sills produced little or no pyrolysis products. The effects of intrusions into unconsolidated, wet sediments resulted in in situ pyrolysis of the organic matter, as confirmed by these data.

Ketones in hydrothermal petroleums and sediments from Guaymas Basin

The polar compound (NSO) fractions of seabed petroleums and sediment extracts from the Guaymas Basin hydrothermal system have been analyzed by gas chromatography and gas chromatography-mass spectrometry. The oils were collected from the interiors and exteriors of high temperature hydrothermal vents and represent hydrothermal pyrolysates that have migrated to the seafloor by hydrothermal fluid circulation. The downcore samples are representative of both thermally unaltered and thermally altered sediments. The survey has revealed the presence of oxygenated compounds correlated with samples exhibiting a high degree of thermal maturity. Several homologous series of related ketone isomers are enriched in the interiors of the hydrothermal vent samples or in hydrothermally-altered sequences of the downcore sediments (DSDP Holes 477 and 481A). The n-alkanones range in carbon number from C11 to C33 with a Cmax from 14 to 23, distributions that are similar to those of the n-alkanes. The alkan-2-ones are usually in highest concentrations, with lower amounts of 3-, 4-, 5-, 6-, 7- (and higher) alkanones, and they exhibit no carbon number preference (there is an odd carbon number preference of alkanones observed for downcore samples). The alkanones are enriched in the interiors of the hydrothermal vent spires or in downcore hydrothermally-altered sediments, indicating an origin at depth or in the hydrothermal fluids and not from an external biogenic deposition. Minor amounts of C13 and C18 isoprenoid ketones are also present. Simulation of the natural hydrothermal alternation process by laboratory hydrous pyrolysis techniques provided information regarding the mode of alkanone formation. Hydrous pyrolysis of n-C32H66 at 350°C for 72 h with water only or water with inorganic additives has been studied using a stainless steel reaction vessel. In each experiment oxygenated hydrocarbons, including alkanones, were formed from the n-alkane. The product distributions indicate a reaction pathway consisting of n-alkanes and a-olefins as primary cracking products with internal olefins and alkanones as secondary reaction products. Hydrous pyrolyses of Messel shale spiked with molecular probes have been performed under similar time and temperature constraints to produce alkanone distributions like those found in the hydrothermal vent petroleums.

Seasonal variations in surface metabolite composition of Fucus vesiculosus and Fucus serratus sampled at outer Kiel Fjord (August 2012 - July 2013)

The chemical composition of surface associated metabolites of two Fucus species (Fucus vesiculosus and Fucus serratus) was analysed by means of gas chromatography-mass spectrometry (GC-MS) to describe temporal patterns in chemical surface composition. Method: The two perennial brown macroalgae F. vesiculosus and F. serratus were sampled monthly at Bülk, outer Kiel Fjord, Germany (54°27'21 N / 10°11'57 E) over an entire year (August 2012 - July 2013). Per month and species six non-fertile Fucus individuals were collected from mixed stands at a depth of 0.5 m under mid water level. For surface extraction approx. 50 g of the upper 5-10 cm apical thalli tips were cut off per species. The surface extraction of Fucus was performed according to the protocol of de Nys and co-workers (1998) with minor modifications (see Rickert et al. 2015). GC/EI-MS measurements were performed with a Waters GCT premier (Waters, Manchester, UK) coupled to an Agilent 6890N GC equipped with a DB-5 ms 30 m column (0.25 mm internal diameter, 0.25 mM film thickness, Agilent, USA). The inlet temperature was maintained at 250°C and samples were injected in split 10 mode. He carrier gas flow was adjusted to 1 ml min-1. Alkanes were used for referencing of retention times. For further details (GC-MS sample preparation and analysis) see the related publication (Rickert et al. submitted to PLOS ONE).

Occurrence of Inoceramus in the South Atlantic and oxygen isotopic paleotemperatures in DSDP Hole 75-530A

Inoceramus occurs in every DSDP hole that penetrated Cretaceous sediments in the South Atlantic Ocean, and specimen occurrence has been mapped in detail for each core. Oxygen and carbon isotope measurements were completed on 18 Inoceramus specimens from Hole 530A. Textural evidence of diagenesis is accompanied by depletion in 18O. Paleotemperature results were obtained from 11 well-preserved specimens. Bottom water temperatures in the Angola Basin decreased from 23°C during the Coniacian to 13°C near the end of the Campanian.