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.

Fragm. lat. I 99 - Liber dialogorum (L.II c.1 - 2 Vita s.Benedicti; PL 66,126 - 132)

Trägerband: 15/474; Vorbesitzer: Dominikanerkloster Frankfurt am Main

Corporate political activity in less developed countries:The Volta River Project in Ghana, 1958-66

The article expands existing categorisations of political and economic governance by including literature on less developed countries (LDCs). In four consecutive negotiations between the US multinational Kaisers and the US and Ghana governments in the early 1960s, it is argued that the company reached levels of influence that are at odds with existing explanations. In order to understand corporate political activities in LDCs, analysis needs to go beyond static factors (political risk) and include dynamic factors such as diplomatic relations and 'arenas of power', and consider the role of the investor's home country relative to the host economy.

Medical School Donor Recognition Reception Photo 66

http://digitalcommons.fiu.edu/com_images/1071/thumbnail.jpg

Global compilation of benthic data sets I

Approaches to quantify the organic carbon accumulation on a global scale generally do not consider the small-scale variability of sedimentary and oceanographic boundary conditions along continental margins. In this study, we present a new approach to regionalize the total organic carbon (TOC) content in surface sediments (<5 cm sediment depth). It is based on a compilation of more than 5500 single measurements from various sources. Global TOC distribution was determined by the application of a combined qualitative and quantitative-geostatistical method. Overall, 33 benthic TOC-based provinces were defined and used to process the global distribution pattern of the TOC content in surface sediments in a 1°x1° grid resolution. Regional dependencies of data points within each single province are expressed by modeled semi-variograms. Measured and estimated TOC values show good correlation, emphasizing the reasonable applicability of the method. The accumulation of organic carbon in marine surface sediments is a key parameter in the control of mineralization processes and the material exchange between the sediment and the ocean water. Our approach will help to improve global budgets of nutrient and carbon cycles.

Fragm. lat. VI 66 - Breviarium (De lancea et clavis)

Trägerbände: Inc. qu. 979; Inc. oct. 271 Bd. 1; Vorbesitzer: Dominikanerkloster Frankfurt am Main

Annotated record of the detailed examination of Mn deposits from the R/V Rig Seismic Cruise 11 (BMR 66) in 1986 over the Great Australian Bight Basin area

Late Cretaceous and younger sediments dredged from the upper continental slope and canyon walls in the Great Australian Bight Basin between 126° and 136°E broadly confirm the stratigraphy which had been established previously from scattered exploration wells. Late Cretaceous to Early Eocene marine and marginal marine terrigenous sediments are overlain by Middle Eocene and younger pelagic carbonate (fine limestone and calcareous ooze). The samples provide the first evidence of truly marine Maastrichtian sedimentation, with abundant calcareous nannoplankton, on the southern margin of the continent. Other samples of interest include Precambrian sheared granodiorite on the upper slope south of Eyre Terrace, Paleocene phosphatic sediment in 'Eucla' Canyon at 128° 30'E, and terrigenous Early Miocene mudstone at 133° 20' and 134° 50'E. The mudstone is of note as an exception to the uniform pelagic carbonate wackestone and ooze which characterise Middle Eocene and younger sedimentation at all other sites. Fragments of alkali basalt lava of unknown age were recovered in 'Eucla' Canyon. Cores are mostly pelagic calcareous ooze, but those from submarine canyons include terrigenous turbidites.

La construcción de un Departamento Científico en un proceso intensivo de modernización académica : El caso de la física en Cs. Exactas (UBA), 1955-66

Fil: Buschini, José Daniel. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Modernización académica y politización cultural. El caso de la Univ. de B.Aires, 1955-66 : Líneas de interpretación histórica

Fil: Prego, Carlos Alberto. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

La construcción de un Departamento Científico en un proceso intensivo de modernización académica : El caso de la física en Cs. Exactas (UBA), 1955-66

Fil: Buschini, José Daniel. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Modernización académica y politización cultural. El caso de la Univ. de B.Aires, 1955-66 : Líneas de interpretación histórica

Fil: Prego, Carlos Alberto. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

La construcción de un Departamento Científico en un proceso intensivo de modernización académica : El caso de la física en Cs. Exactas (UBA), 1955-66

Fil: Buschini, José Daniel. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Modernización académica y politización cultural. El caso de la Univ. de B.Aires, 1955-66 : Líneas de interpretación histórica

Fil: Prego, Carlos Alberto. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.