Dissolved aluminium in the ocean conveyor of theWest Atlantic Ocean: Effects of the biological cycle, scavenging, sediment resuspension and hydrography

The concentrations of dissolved aluminium (dissolved Al) were studied along the West Atlantic GEOTRACESGA02 transect from 64°N to 50°S. Concentrations ranged from~0.5 nmol kg-1 in the high latitude surface watersto ~48 nmol kg-1 in surfacewaters around 25°N. Elevated surfacewater concentrations due to atmospheric dustloading have little influence on the deep water distribution. However, just belowthe thermocline, both Northernand Southern Hemisphere Subtropical Mode Waters are elevated in Al, most likely related to atmospheric dustdeposition in the respective source regions.In the deep ocean, high concentrations of up to 35 nmol kg-1 were observed in North Atlantic DeepWater as aresult of Al input via sediment resuspension. Comparatively lowdeepwater concentrationswere associatedwithwater masses of Antarctic origin. During water mass advection, Al loss by scavenging overrules input viaremineralisation and sediment resuspension at the basin wide scale. Nevertheless, sediment resuspension ismore important than previously realised for the deep ocean Al distribution and even more intensive samplingis needed in bottom waters to constrain the spatial heterogeneity in the global deep ocean.This thus far longest (17,500 km) full depth ocean section shows that the distribution of Al can be explained by itsinput sources and the combination of association with particles and release from those particles at depth, thelattermost likelywhen the particles remineralise. The association of Alwith particles can be due to incorporationof Al into biogenic silica or scavenging of Al onto biogenic particles. The interaction between Al and biogenicparticles can lead to the coupled cycling of Al and silicate that is observed in some ocean regions. However, inother regions this coupling is not observed due to (i) advective processes bringing in older water masses thatare depleted in Al, (ii) unfavourable scavenging conditions in the water column, (iii) low surface concentrationsof Al or (iv) additional Al sources, notably sediment resuspension

Propagation pathways of classical Labrador Sea water from its source region to 26°N

More than two decades of hydrography on the Abaco line east of the Bahamas at 26 degrees N reveals decadal variability in the salinity of classical Labrador Sea Water (cLSW), despite the long distance from its source region in the North Atlantic Ocean. Hydrographic time series from the Labrador Sea and from the Abaco line show a pronounced step-like decrease in salinity between 1985 and 1995 in the Labrador Sea and between 1995 and 2010 at the Abaco line, suggesting a time lag between the two locations of approximately 9 years. The amplitude of the anomaly at the Abaco line is 50% of the amplitude in the Labrador Sea. A similar time lag and reduction of amplitude is found in the high-resolution OFES model, in which salinity anomalies can be observed propagating through the Deep Western Boundary Current as well as through a broad interior pathway. On its way south to the Abaco line, the cLSW becomes 8 standard deviations saltier due to isopycnal mixing with Mediterranean Outflow Water (MOW). Climatological data in the North Atlantic suggests that the mixing ratio of MOW to cLSW at the Abaco line is 1:4 and that no variability in MOW is required to explain the observed variability at the Abaco line. The data studied here suggest that decadal cLSW anomalies stay relatively coherent while getting advected, despite the important role of interior pathways

Transport of Nordic Seas Overflow Water Into and Within the Irminger Sea: An Eddy-Resolving Simulation and Observations

Results from a climatologically forced, eddy-resolving (1/12 degrees) Atlantic simulation using the Hybrid Coordinate Ocean Model help clarify some presently unresolved connections between volume transports of Nordic Seas overflow water at key locations in the northernmost North Atlantic Ocean. The model results demonstrate that, in addition to the known westward flow through the Charlie Gibbs Fracture Zone (CGFZ), some Iceland Scotland overflow water (ISOW) flows westward through gaps in the Reykjanes Ridge north of the CGFZ into the Irminger Sea, and some flows southward along the eastern flank of the Mid-Atlantic Ridge into the West European Basin. These results provide insights into the well-known inconsistency between observed westward transport of ISOW through the CGFZ (2.4 Sv) and the transports upstream at Southeast of Iceland section (3.2 Sv) and downstream in the western Irminger Sea (4.5 Sv). Although the portion of the simulated ISOW that flows through CGFZ is about 500 m deeper than observed, the model results also show two ISOW pathways of this flow into the Irminger Sea, one northward along the western flank of the Reykjanes Ridge and the other westward before turning north-eastward on the western side of the Irminger Basin. Comparisons with the long-term moored instrument database in the Irminger Sea show that the model-based mean circulation is in reasonable agreement with observed volume transports of overflow water and that it gives approximately correct temperature and salinity characteristics

Siblings versus parents and friends:Longitudinal linkages to adolescent externalizing problems

Background: It is well documented that friends’ externalizing problems and negative parent–child interactions predict externalizing problems in adolescence, but relatively little is known about the role of siblings. This four-wave, multi-informant study investigated linkages of siblings’ externalizing problems and sibling–adolescent negative interactions on adolescents’ externalizing problems, while examining and controlling for similar linkages with friends and parents. Methods: Questionnaire data on externalizing problems and negative interactions were annually collected from 497 Dutch adolescents (M = 13.03 years, SD = 0.52, at baseline), as well as their siblings, mothers, fathers, and friends. Results: Cross-lagged panel analyses revealed modest unique longitudinal paths from sibling externalizing problems to adolescent externalizing problems, for male and female adolescents, and for same-sex and mixed-sex sibling dyads, but only from older to younger siblings. Moreover, these paths were above and beyond significant paths from mother–adolescent negative interaction and friend externalizing problems to adolescent externalizing problems, 1 year later. No cross-lagged paths existed between sibling–adolescent negative interaction and adolescent externalizing problems. Conclusions: Taken together, it appears that especially older sibling externalizing problems may be a unique social risk factor for adolescent externalizing problems, equal in strength to significant parents’ and friends’ risk factors

Family and personality project data guide [Data set and Data Guide]

Contains fulltext : 134792.pdf (publisher's version ) (Open Access)36 p

Project "gelaagde Noordzee 81/82": CTD-waarnemingen 1982

Ia het kader van het onderzoeksproject "gelaagde Noordzee 81/82" werden in 1982 drie tochten gemaakt met het onderzoekingsvaartuig "Tyro". Gedurende deze reizen werden metingen uitgevoerd door medewerkers van het NIOZ (Texel), het KNMI (de Bilt) en door medewerkers en studenten van het IMOU (Utrecht). De tocht Tyro I/82 vond plaats in de opbouwfase van de thermische gelaagdheid in mei, de tocht Tyro II/81 in de periode van maximale gelaagdheid in Augustus en de tocht Tyro III/82 in de periode dat de gelaagdheid werd afgebroken, eind september-begin oktober. In dit verslag worden de resultaten van de CTD-waarnemingen gedurende de drie tochten geanalyseerd. In de toegevoegde appendices A, B en C wordt een overzicht gegeven van alle individuele CTD-registraties. In Appendix D is het verslag opgenomen m.b.t. de uitgevoerde calibratie van de CTD waarnemingen. -]-gelaagde Noordzee 81/8

Project "gelaagde Noordzee 81/82": Meteorologische waarnemingen 1982

In het kader van het onderzoek naar de thermische stratificatie in de Noordzee werden in 1982 met het m.s. Tyro drie onderzoekstochten uitgevoerd op de Noordzee, in mei, augustus en eind september tot begin oktober. Deze tochten concentreerden zich rond het "centrale punt" op 54°30' N, 4°30' O. De gedurende deze reis ingenomen posities zijn beschreven door van Aken (1983). Gedurende deze reizen werden standaard meteorologische waarnemingen uitgevoerd ("SHIP") terwijl tevens uurlijks de kortgolvige straling werd gemeten. In dit verslag worden deze waarnemingen grafisch weergegeven en tevens het hieruit berekende energiebudget van het zeeoppervlak en de windschuifspanning. Tevens wordt per tocht een aantal markante zaken i.v.m. de synoptische situaties besproken.gelaagde Noordzee 81/8