Search results for "Oceanic basin"
showing 6 items of 6 documents
Trans-equatorial migration routes, staging sites and wintering areas of a High-Arctic avian predator: the Long-tailed Skua (Stercorarius longicaudus).
2013
The Long-tailed Skua, a small (,300 g) Arctic-breeding predator and seabird, is a functionally very important component of the Arctic vertebrate communities in summer, but little is known about its migration and winter distribution. We used lightlevel geolocators to track the annual movements of eight adult birds breeding in north-east Greenland (n = 3) and Svalbard (n = 5). All birds wintered in the Southern Hemisphere (mean arrival-departure dates on wintering grounds: 24 October-21 March): five along the south-west coast of Africa (0–40uS, 0–15uE), in the productive Benguela upwelling, and three further south (30–40uS, 0–50uE), in an area extending into the south-west Indian Ocean. Diffe…
The Extratropical Transition of Tropical Cyclones. Part II: Interaction with the Midlatitude Flow, Downstream Impacts, and Implications for Predictab…
2019
Abstract The extratropical transition (ET) of tropical cyclones often has an important impact on the nature and predictability of the midlatitude flow. This review synthesizes the current understanding of the dynamical and physical processes that govern this impact and highlights the relationship of downstream development during ET to high-impact weather, with a focus on downstream regions. It updates a previous review from 2003 and identifies new and emerging challenges and future research needs. First, the mechanisms through which the transitioning cyclone impacts the midlatitude flow in its immediate vicinity are discussed. This “direct impact” manifests in the formation of a jet streak …
5. Introduction — palaeoclimate reconstructions and dating
2007
Publisher Summary This chapter describes four interglacials preceding the Holocene—that is, during the time from about 100 to 450 kyr. The first knowledge on this time has been extracted almost 40 years ago from marine deep sea cores with a sampling resolution of several thousand of years. Deep ocean sediments can be easily dated, because δ18O stratigraphy can be applied all over the ocean basins and tuned directly to the ice volume/sea-level master curve of SPECMAP, which is based on the beat of the orbital insolation cyclicities. This dynamic climate evolution of the past interglacial must have been of high importance also for the evolution of mankind. Neanderthal hominids lived and hunte…
Nile Basin Climates
2009
The climate of the Nile Basin is characterised by a strong latitudinal wetness gradient. Whereas the areas north of 18°N remain dry most of the year, to the south there is a gradual increase of monsoon precipitation amounts. Rainfall regimes can be divided into 9 types, among which summer peak regimes dominate. In the southern half of the basin, mesoscale circulation features and associated contrasts in local precipitation patterns develop as a result of a complex interplay involving topography, lakes and swamps. Precipitation changes and variability show up as 3 distinct modes of variability. Drying trends since the 1950s are found in central Sudan and to some extent the Ethiopian Highland…
Evolution of neodymium isotopic signature of seawater during the Late Cretaceous: implications for intermediate and deep circulation.
2016
20 pages; International audience; Neodymium isotopic compositions (εNd) have been largely used for the last fifty years as a tracer of past ocean circulation, and more intensively during the last decade to investigate ocean circulation during the Cretaceous period. Despite a growing set of data, circulation patterns still remain unclear during this period. In particular, the identification of the deep-water masses and their spatial extension within the different oceanic basins are poorly constrained. In this study we present new deep-water εNd data inferred from the Nd isotope composition of fish remains and Fe–Mn oxyhydroxide coatings on foraminifera tests, along with new εNd data of resid…
On the Mesozoic Ionian Basin
2001
SUMMARY New seismic reflection profiles of the Italian deep crust project CROP provide new insights on the structure of the Ionian sea. In spite of the Apennines and Hellenides Neogene subduction zones, two conjugate passive continental margins are preserved at the margins of the Ionian sea, along the Malta escarpment to the southwest and the Apulian escarpment to the northeast. The Ionian sea is likely to be a remnant of the Mesozoic Tethys Ocean, confined by these two conjugate passive continental margins. The transition from continental to oceanic crust appears sharper to the northeast than to the southwest. The basin between southeast Sicily and southwest Puglia was about 330 km wide an…