Correction to “Decadal analysis of hydrography and in situ nutrient budgets in the western and eastern North Atlantic subtropical gyre”

Author Posting. © American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 113 (2008): C03005, doi:10.1029/2008JC004762

Long-Term Changes of Particle Flux in the Canary Basin Between 1991 and 2009 and Comparison to Sediment Trap Records Off Mauritania

Eastern Boundary Upwelling Ecosystems (EBUEs) are associated with high biological productivity, high fish catch and they highly contribute to marine carbon sequestration. Whether coastal upwelling has intensified or weakened under climate change in the past decades is controversially discussed and different approaches (e.g., time-series of chlorophyll, wind, sea surface temperature, modeling experiments) have been considered. We present a record of almost two decades of particle fluxes (1991–2009) from ca. 600 to 3100 m water depth in the Canary Basin at site ESTOC (European Station for Time series in the Ocean Canary Islands; ca. 29°N, 15°30.W, ca. 3600 m water depth), located in the offshore transition zone of the northern Canary Current-EBUE. We compare these flux records with those measured at a mesotrophic sediment trap site further south off Cape Blanc (Mauritania, ca. 21°N). The deep ocean fluxes at ESTOC in ca. 3 km recorded the evolution of the coastal Cape Ghir filament (30–32°N, 10–12°W) due to lateral advection of particles, whereas the upper water column sediment traps in ca. 1 km reflected the oligotrophic conditions in the overlying waters of ESTOC. We observed an increased emphasis in spring-time fluxes since 2005, associated with a change in particle composition, while satellite chlorophyll biomass did not show this pattern. Due to its northern location in the CC-EBUEs, spring biogenic fluxes at ESTOC provide a better relationship to the forcing of the North Atlantic Oscillation than those recorded further south off Cape Blanc. Off Cape Blanc, deep fluxes showed the best overlap with the deep ESTOC fluxes during the spring season before 2005. On the long-term, both chlorophyll and particle fluxes showed an increasing trend at ESTOC which was not observed further south at the mesotrophic Cape Blanc site. This might indicate that, depending on their location along the NW African margin, coastal upwelling systems react differently to global change

Decadal analysis of hydrography and in situ nutrient budgets in the western and eastern North Atlantic subtropical gyre

Author Posting. © American Geophysical Union, 2007. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 112 (2007): C07025, doi:10.1029/2006JC003788.The current debate about the mechanisms and magnitude of new nutrient input to the euphotic zone in subtropical gyres calls for studies which consider large and mesoscale perspectives by combining in situ time series and remote observations. We carried out a first of its kind comparative analysis of hydrography and sea level anomaly (SLA) at the oligotrophic time series stations BATS (Bermuda Atlantic Time Series Study) and ESTOC (European Station for Time Series, Canary Islands) using concomitant 10-yr in situ and satellite altimetry data. The stations are located at about the same latitude in the western and eastern boundaries of the subtropical North Atlantic gyre, respectively, and provide the opportunity to study differences that may exist between both regions. Observed SLA was 0.25 m at BATS, compared with 0.12 m at ESTOC, a consequence of the higher eddy kinetic energy in the western compared with the eastern subtropical gyre. We quantified a detailed in situ nutrient budget for both time series stations; ESTOC received about 75% of the nutrients available for new production at BATS (in average 0.28 mol N m−2 yr−1 compared with 0.38 mol N m−2 yr−1, respectively), but the difference was not significant. However, significant differences in input mechanisms existed between both stations; eddy pumping constituted the main new nutrient source BATS, whereas wintertime convection was the main nutrient supply mechanism at ESTOC. In addition, the nutricline was significantly shallower at ESTOC compared with BATS, partly compensating for shallower mixed-layer depths and SLA variability at the western station. We found considerable interannual variability in both eddy pumping and wintertime convection which may be related to NAO-induced changes in the pattern of the subtropical gyre.This work was supported by a NASA-EOS grant to Susanne Neuer

Regional differences in modelled net production and shallow remineralization in the North Atlantic subtropical gyre

© The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Biogeosciences 9 (2012): 2831-2846, doi:10.5194/bg-9-2831-2012.We used 5-yr concomitant data of tracer distribution from the BATS (Bermuda Time-series Study) and ESTOC (European Station for Time-Series in the Ocean, Canary Islands) sites to build a 1-D tracer model conservation including horizontal advection, and then compute net production and shallow remineralization rates for both sites. Our main goal was to verify if differences in these rates are consistent with the lower export rates of particulate organic carbon observed at ESTOC. Net production rates computed below the mixed layer to 110 m from April to December for oxygen, dissolved inorganic carbon and nitrate at BATS (1.34±0.79 mol O2 m−2, −1.73±0.52 mol C m−2 and −125±36 mmol N m−2) were slightly higher for oxygen and carbon compared to ESTOC (1.03±0.62 mol O2 m−2, −1.42±0.30 mol C m−2 and −213±56 mmol N m−2), although the differences were not statistically significant. Shallow remineralization rates between 110 and 250 m computed at ESTOC (−3.9±1.0 mol O2 m−2, 1.53±0.43 mol C m−2 and 38±155 mmol N m−2) were statistically higher for oxygen compared to BATS (−1.81±0.37 mol O2 m−2, 1.52±0.30 mol C m−2 and 147±43 mmol N m−2). The lateral advective flux divergence of tracers, which was more significant at ESTOC, was responsible for the differences in estimated oxygen remineralization rates between both stations. According to these results, the differences in net production and shallow remineralization cannot fully explain the differences in the flux of sinking organic matter observed between both stations, suggesting an additional consumption of non-sinking organic matter at ESTOC.B. Mourino was supported by the Ramon y Cajal program from the Spanish Minister of Science and Technology. Funding for this study was provided by the Xunta de Galicia under the research project VARITROP (09MDS001312PR, PI B. Mourino) and by the Ministerio de Ciencia e Innovation MOMAC project (CTM2008-05914/MAR)

Fachinformation und EDV-Arbeitstechniken für Historiker: Einführung und Arbeitsbuch

'Der Sammelband versucht, die Erfahrungen einzufangen, die von den Herausgebern in den vergangenen Jahren an der Humboldt-Universität zu Berlin in der studentischen EDV-Ausbildung und beim Aufbau vernetzter Informationsdienste für Historiker gemacht wurden. Es handelt sich weder um einen der üblichen Sammelbände noch um eine einfache Softwareeinführung, sondern um ein praktisches Arbeitsbuch für Studierende und Nachwuchswissenschaftler zu Fragen des EDV-Einsatzes in den Geschichtswissenschaften. Dabei stehen das 'Internet' bzw. der Einsatz der sogenannten 'Neuen Medien' im Mittelpunkt. Im ersten Kapitel wird zunächst das Verhältnis der EDV zu den Geisteswissenschaften geklärt. Dies schließt eine Einführung in die Geschichte der EDV und die Betrachtung der EDV-Einsatzfelder in den Geschichtswissenschaften zu den Themen Bibliotheken im Internet, Wissenschaftlicher Alltag und Lehre sowie spezielle historische Fachinformationsangebote ein. Im zweiten Kapitel wird näher auf die Grundlagen der Datenverarbeitung eingegangen. Dabei liegt neben dem PC- und Netzbasiswissen das Hauptaugenmerk auf dem Internet und seinen Diensten. Darauf aufbauend werden im dritten Kapitel ausgewählte Applikationen aus den Bereichen Textverarbeitung, Beschreibungs- und Skriptsprachen, Tabellenkalkulation, Datenanalyse & Datenbanksysteme sowie Grafik, Präsentation und Multimedia an historischen Beispielen in ihrem Funktionsumfang vorgestellt. Im abschließenden vierten Kapitel wird der EDV-Einsatz in den Geschichtswissenschaften an ausgewählten Projekten in Forschung und Lehre exemplarisch beschrieben.' (Autorenreferat

Phytoplankton clone library matches collected from the R/V Atlantic Explorer and R/V Oceanus cruises along the Bermuda Atlantic Time Series Station (BATS) from 2008-2010 (Plankton particle flux project)

Dataset: Phytoflux_BATS - Clone Library 2008-1010This dataset includes links to GenBank accession of 18S rRNA gene clone library sequences with the closest sequence matches from the NCBI database. The samples are from the upper water column as well as from shallow drifting traps during regular BATS cruises from December 2008-April 2010. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/564859NSF Division of Ocean Sciences (NSF OCE) OCE-075259

Prokaryote and eukaryote abundance in phytodetrital aggregates (PA), fecal aggregates (FA), and the ambient seawater from samples collected during R/V Atlantic Explorer cruises AE1718 and AE1809 in 2017 and 2018 at BATS in Bermuda

Dataset: Prokaryotic and eukaryotic abundance in BATS microbial communitiesAbundances of prokaryotic classes and eukaryotic orders and species found in phytodetrital aggregates (PA), fecal aggregates (FA), and the ambient seawater in the fall and spring seasons, as well as of species in DNA extraction negative controls. Abundance values are prior to (raw) and following rarefaction. These data were published in Neuer et al. (2021). For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/855296NSF Division of Ocean Sciences (NSF OCE) OCE-165852