Time series of air chemistry measurements at Georg-von-Neumayer station, Dronning Maud Land, Antarctica in the years 1982 to 1991

The first Air Chemistry Observatory at the German Antarctic station Georg von Neumayer (GvN) was operated for 10 years from 1982 to 1991. The focus of the established observational programme was on characterizing the physical properties and chemical composition of the aerosol, as well as on monitoring the changing trace gas composition of the background atmosphere, especially concerning greenhouse gases. The observatory was designed by the Institut für Umweltphysik, University of Heidelberg (UHEIIUP). The experiments were installed inside the bivouac lodge, mounted on a sledge and put upon a snow hill to prevent snow accumulation during blizzards. All experiments were under daily control and daily performance protocols were documented. A ventilated stainless steel inlet stack (total height about 3-4 m above the snow surface) with a 50% aerodynamic cut-off diameter around 7-10 µm at wind velocities between 4-10 m/s supplied all experiments with ambient air. Contamination free sampling was realized by several means: (i) The Air Chemistry Observatory was situated in a clean air area about 1500 m south of GvN. Due to the fact that northern wind directions are very rare, contamination from the base can be excluded for most of the time. (ii) The power supply (20 kW) is provided by a cable from the main station, thus no fuel-driven generator is operated in the very vicinity. (iii) Contamination-free sampling is controlled by the permanently recorded wind velocity, wind direction and by condensation particle concentration. Contamination was indicated if one of the following criteria were given: Wind direction within a 330°-30° sector, wind velocity <2.2 m/s or >17.5 m/s, or condensation particle concentrations >2500/cm**3 during summer, >800/cm**3 during spring/autumn and >400/cm**3 during winter. If one or a definable combination of these criteria were given, high volume aerosol sampling and part of the trace gas sampling were interrupted. Starting at 1982 through 1991-01-14 surface ozone was measured with an electrochemical concentration cell (ECC). Surface ozone mixing ratio are given in ppbv = parts per 10**9 by volume. The averaging time corresponds to the given time intervals in the data sheet. The accuracy of the values are better than ±1 ppbv and the detection limit is around 1.0 ppbv. Aerosols were sampled on two Whatman 541 cellulose filters in series and analyzed by ion chromatography at the UHEI-IUP. Generally, the sampling period was seven days but could be up to two weeks on occasion. The air flow was around 100 m**3/h and typically 10000-20000 m**3 of ambient air was forced through the filters for one sample. Concentration values are given in nanogram (ng) per 1 m**3 air at standard pressure and temperature (1013 mbar, 273.16 K). Uncertainties of the values were approximately ±10% to ±15% for the main components MSA, chloride, nitrate, sulfate and sodium, and between ±20% and ±30% for the minor species bromide, ammonium, potassium, magnesium and calcium.

(Table 1) Occurrence of selected planktonic foraminifers, other microfossils, and lithologic components at DSDP Hole 96-619

Site 619, located in the Pigmy Basin off the coast of Louisiana, penetrated the late Quaternary Ericson Zones X, Y, and Z. The penetrated section can be divided into four intervals. The lower interval (below 157 m sub-bottom) comprises 51 m of displaced sediments which probably originated from the Louisiana continental shelf. The upper three intervals (above 157 m) are dominated by pelagic/hemipelagic sedimentation associated with a closed basin. These are divided on the basis of planktonic foraminifers into Zones X, Y, and Z. These warm-cool water intervals are identified mainly by using the Globorotalia menardii complex (warm) and G. inflata (cool). The intervals correlate with published curves taken from piston core samples in the western Gulf of Mexico.

Bulk components and ice rafted debris of five sediment cores of the Sophia Basin, Arctic Ocean

Periods of enhanced terrigenous input to the ocean's basins of the North Atlantic have been reported for the last glacial period. We present a set of new sediment cores recovered from the Sophia Basin north of Svalbard which exhibit wide spread IRD layers reflecting enhanced terrigenous input throughout the last ~200 kyr. BP. Their consistent stratigraphic position, sedimentological character, high sedimentation rate and geochemical characteristic point to synchronously deposited layers which we name terrigenous input events (TIEs). Due to their higher densities, they generate excellent reflectors for sediment penetrating acoustic devices and prominent acoustic layers in the imagery of sedimentary structures. Therefore TIEs can be used for regional acoustic stratigraphy. Each of the events can be linked to major glacial activity on Svalbard. However, the Early Weichselian glaciation is not recorded as a TIE and, in agreement with other work, might not have occurred on Svalbard as a major glacial advance to the shelf break. Non-synchronous timing of western and northern sources on Svalbard points against sea-level induced iceberg discharge events.

Near real time surface ocean velocity, Tyrrhenian Sea and Ligurian Sea in September 2016

The data set consists of maps of total velocity of the surface current in the North-Western Tyrrhenian Sea and Ligurian Sea averaged over a time interval of 1 hour around the cardinal hour. Surface ocean velocities estimated by HF Radar are representative of the upper 0.3-2.5 meters of the ocean. Total velocities are derived using least square fit that maps radial velocities measured from individual sites onto a cartesian grid. The final product is a map of the horizontal components of the ocean currents on a regular grid in the area of overlap of two or more radar stations.

Percentages of sand-sized material and biogenic components in sediment core GIK12392-1

The paleo-oceanography of the southeastern North Atlantic Ocean during the last 150,000 yr has been studied using biogenous and terrigenous components of hemipelagic sediments sampled close to the northwest African continental margin. Variations of oxygen isotope ratios in shells of benthic calcareous foraminifers in two cores allow the assignment of absolute ages to these cores (in the best case at 1000 yr increments). The uncorrected bulk sedimentation rates of the longest core range from 3.4 to 7.6 cm/ 1000 yr during Interglacial conditions, and from 6.5 to 9.9 cm/1000 yr during Glacial conditions; all other cores have given results of the same order of magnitude, but with generally increasing values towards the continental edge. The distribution of sediment components allow us to make inferences about paleo-oceanographic changes in this region. Frequencies of biogenic components from benthic organisms, oxygen isotope ratios measured in benthic calcareous foraminiferal shells, the total carbonate contents of the sediment and distributions of biogenic components from planktonic organisms often fluctuate in concert. However, all fluctuations which can be attributed to changes of the bottom water masses (North Atlantic Deep Water) seem to precede by several thousand years those which can be linked to changes of the surface water mass distributions or to changes of the climate over the neighboring land masses. Late Quaternary planktonic foraminiferal assemblages in the cores from the northwest African continental margin can be defined satisfactorily in the way that distributions of assemblages found in sediment surface samples from the northeast Atlantic Ocean have been explained. The distributions of assemblages in the northwest African cores can also be used to estimate past sea surface temperatures and salinities. The downcore record of these estimates reveals two warm periods during the last 150,000 yr, the lower one corresponding to the oxygen isotope stage 5 e (equivalent to the Eemian proper in Europe), the upper one to the younger half of the Holocene. Winter surface water temperatures during oxygen isotope stages 6, 4, 3, and 2 are remarkably constant in most cores, while summer sea surface temperatures during stage 3 reach values comparable to those of the warm periods during the Late Holocene and Eemian. Estimated winter sea surface temperatures range from > 16 °C to < 11°C, the summer sea surface temperatures from > 22 °C to < 15 °C during the last 150,000 yr. Estimates of the winter sea surface salinities fluctuate between 36.6? and 35.5?, the higher values being restricted to the warm periods since the penultimate Glacial. Estimates for sea surface temperatures and salinities for two cores from the center of today's coastal upwelling region show less pronounced fluctuations than the record of the open ocean cores in the case of the station 12379 off Cape Barbas, more pronounced in the case of station 12328 off Cape Blanc. Seasonal differences between winter and summer sea surface temperatures derived from the estimated temperatures are today more pronounced in the boundary region of the ocean to the continent than further away from the continent. The differences are generally higher during warm climatic periods of the last 150,000 yr than during cooler ones. The abundance of terrigenous grains in the coarse fractions generally decreases with increasing distance from the continental edge, and also from south to north. The dominant portion of the terrigenous detritus is carried out into the ocean during the relatively cool climatic periods (stage 6, 4, later part of stage 3, stage 2 and oldest part of stage 1). The enhanced precision of dating combined with the stratigraphic resolution of these high deposition rate cores make it clear that the peaks of the terrigenous input off this part of the northwest African continental margin occur simultaneously with times of rapid sea level fluctuations resulting from large volume changes of the large Glacial ice sheets.

Biogenic particle and biomarker flux from a mooring time-series at AWI HAUSGARTEN

Since 2000 long-term measurements of vertical particle flux have been performed with moored sediment traps at the long-term observatory HAUSGARTEN in the eastern Fram Strait (79°N/4°E). The study area, which is seasonally covered with ice, is located in the confluence zone of the northward flowing warm saline Atlantic water with cold, low salinity water masses of Arctic origin. Current projections suggest that this area is particularly vulnerable to global warming. Total matter fluxes and components thereof (carbonate, particulate organic carbon and nitrogen, biogenic silica, biomarkers) revealed a bimodal seasonal pattern showing elevated sedimentation rates during May/June and August/September. Annual total matter flux (dry weight, DW) at ~ 300 m depth varied between 13 and 32 g/m**2/a during 2000 and 2005. Of this total flux 6-13 % was due to CaCO3, 4-21 % to refractory particulate organic carbon (POC), and 3-8 % to biogenic particulate silica (bPSi). The annual flux of all biogenic components together was almost constant during the period studied (8.5-8.8 g/m**2/a), although this varied from 27 to 67 % of the total annual flux. The fraction was lowest in a year characterized by the longest duration of ice coverage (91 and 70 days for the calendar year and summer season, May-September, respectively). Biomarker analyses revealed that organic matter originating from marine sources was present in excess of terrigenious material in the sedimented matter throughout most of the study period. Fluxes of recognizable phyto- and protozooplankton cells amounted up to 60x106 m**2/d. Diatoms and coccolithophorids were the most abundant organisms. Diatoms, mainly pennate species, dominated during the first years of the investigation. A shift in the composition occurred during the last year when numbers of diatoms declined considerably, leading to a dominance of coccolithoporids. This was also reflected in a decrease in the sedimentation of bPSi. The sedimentation of biogenic matter, however, did not differ from the amount observed during the previous years. Among the larger organisms, pteropods at times contributed significantly to both the total matter and CaCO3, fluxes.

Near real time surface ocean velocity in the Bay of Biscay - Basque Country from Mai to September 2016

The data set consists of maps of total velocity of the surface current in the Southeastern Bay of Biscay averaged over a time interval of 1 hour around the cardinal hour. Surface ocean velocities estimated by this HF Radar(4.65 MHz) are representative of the upper 2-3 meters of the ocean. The main objective of near real time processing is to produce the best product from available data at the time of processing. Total velocities are derived using least square fit that maps radial velocities measured from individual sites onto a cartesian grid. The final product is a map of the horizontal components of the ocean currents on a regular grid in the area of overlap of two or more radar stations.

(Table 2) Seasonal flux data and percentages of major bulk components of total flux at the mesotrophic sediment trap site CB from 1988 - 2012

A more than two-decadal sediment trap record from the Eastern Boundary Upwelling Ecosystem (EBUE) off Cape Blanc, Mauritania, is analysed with respect to deep ocean mass fluxes, flux components and their variability on seasonal to decadal timescales. The total mass flux revealed interannual fluctuations which were superimposed by fluctuations on decadal timescales. High winter fluxes of biogenic silica (BSi), used as a measure of marine production (mostly by diatoms) largely correspond to a positive North Atlantic Oscillation (NAO) index (December-March). However, this relationship is weak. The highest positive BSi anomaly was in winter 2004-2005 when the NAO was in a neutral state. More episodic BSi sedimentation events occurred in several summer seasons between 2001 and 2005, when the previous winter NAO was neutral or even negative. We suggest that distinct dust outbreaks and deposition in the surface ocean in winter and occasionally in summer/autumn enhanced particle sedimentation and carbon export on short timescales via the ballasting effect. Episodic perturbations of the marine carbon cycle by dust outbreaks (e.g. in 2005) might have weakened the relationships between fluxes and large-scale climatic oscillations. As phytoplankton biomass is high throughout the year, any dry (in winter) or wet (in summer) deposition of fine-grained dust particles is assumed to enhance the efficiency of the biological pump by incorporating dust into dense and fast settling organic-rich aggregates. A good correspondence between BSi and dust fluxes was observed for the dusty year 2005, following a period of rather dry conditions in the Sahara/Sahel region. Large changes of all bulk fluxes occurred during the strongest El Niño-Southern Oscillation (ENSO) in 1997-1999 where low fluxes were obtained for almost 1 year during the warm El Niño and high fluxes in the following cold La Niña phase. For decadal timescales, Bakun (1990) suggested an intensification of coastal upwelling due to increased winds (''Bakun upwelling intensification hypothesis''; Cropper et al., 2014) and global climate change. We did not observe an increase of any flux component off Cape Blanc during the past 2 and a half decades which might support this. Furthermore, fluxes of mineral dust did not show any positive or negative trends over time which might suggest enhanced desertification or ''Saharan greening'' during the last few decades.