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  • Abstract: A winter (DJFM) North Atlantic Oscillation index (NAOi) has been reconstructed over the peridod 1781-1996 by calibrating the winter frequencies of Lamb weather types to the winter PC-based NAOi of Hurrell (1995, doi:10.1126/science.269.5224.676). The data file contains 4 columns: year of JFM, NAOi, uncertainty (1 std), number of unclassified days over this winter. The NAOi has no unit since regressed to a normalised index. Note that this index has not been renormalised (to an average value of zero and standard deviation of 1). The number of unclassified days directly affects the reliability and consistency of the NAOi. For instance, Delaygue et al. (2018) require less than 24 unclassified days per winter to consider the NAOi. Category: geoscientificInformation Source: Not Available Supplemental Information: Not Availble Coverage: Not Available
    Data Types:
    • Tabular Data
    • Dataset
  • Interval frequency
    Data Types:
    • Tabular Data
    • Dataset
  • Abstract: Transport studies that employ column experiments in closed-flow mode complement classical approaches by providing new characteristic features observed in the breakthrough behavior and an equilibrium between liquid and solid phase. Specific to the closed-flow mode is the recirculation of the column effluent to the inflow via a mixing vessel. Depending on the ratio of volume of the water-filled pore space to the volume of the mixing vessel, a damped oscillating solute concentration emerges in effluent and mixing vessel. Oscillation frequency, extent of damping and amplitude are thereby governed by the transport properties of the porous medium. These characteristics allow for the analysis of transport processes in soils in a similar fashion as known for classical open-flow column experiments. However, the experimental design considers feedbacks of liquid solid interactions by connecting the effluent solution with the inflow. In this way, solute and porous medium can equilibrate with respect to all physicochemical parameters, thereby permitting a convenient consideration of mass balances. With this paper, the features emerging in the breakthrough of column experiments run in closed-flow mode and methods of evaluation are illustrated under experimental boundary conditions forcing the appearance of these oscillations. Additionally, the effect of flow velocity and mixing vessel volume on the breakthrough is investigated. We demonstrate that the water content of the porous medium and the pumping rate can be determined from a conservative tracer breakthrough curve. In this way, external preconditioning of the soil material, e.g., drying, can be avoided. This renders the closed-flow column approach especially interesting for the study of porous media with diverse mineral content and bacterial community that react strongly on changes in the water content. Furthermore, the basis for the modeling of closed-flow experiments is given by the derivation of constitutive equations and numerical implementation, validated by the presented experiments. Category: geoscientificInformation Source: Supplement to: Ritschel, Thomas; Totsche, Kai Uwe (2016): Closed-flow column experiments - insights into solute transport provided by a damped oscillating breakthrough behavior. Water Resources Research, 52(3), 2206-2221, https://doi.org/10.1002/2015WR018317 Supplemental Information: Not Availble Coverage: Not Available
    Data Types:
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  • Abstract: A detailed survey of the Mittelgrund in Eckernförde Bay shows slope breaks at 10-12 m and 15-16 m water depth. They are thought to be mainly the result of marine abrasion. Utilizing records from the Edgerton mud-penetrator, a map of holocene sediment thickness has been drawn. From the pattern of bottom echos 4 types of stratification can be recognized. An interpretation of them is attempted, as they are supposed to serve as models for other transgression contacts. Category: geoscientificInformation Source: Supplement to: Edgerton, Harold E; Seibold, Eugen; Vollbrecht, Kurt; Werner, Friedrich (1966): Morphologische Untersuchungen am Mittelgrund (Eckernförder Bucht, westliche Ostsee). Meyniana, 16, 37-50, https://doi.org/10.2312/meyniana.1966.16.37 Supplemental Information: Wind reportings were only considered if they exceeded the threshhold of 50 cm/s oscillation speed at a given depth. Coverage: EVENT LABEL: * LATITUDE: 54.514010 * LONGITUDE: 10.070660 * DATE/TIME START: 1960-01-01T00:00:00 * DATE/TIME END: 1963-12-31T00:00:00 * ELEVATION START: -7.5 m * ELEVATION END: -15.0 m * LOCATION: Eckernfoerder Bay, Western Baltic Sea
    Data Types:
    • Tabular Data
    • Dataset
  • Abstract: The Lamb weather type series is a subjective catalogue of daily atmospheric patterns and flow directions over the British Isles, covering the period 1861–1996. Based on synoptic maps, meteorologists have empirically classified surface pressure patterns over this area, which is a key area for the progression of Atlantic storm tracks towards Europe. We apply this classification to a set of daily pressure series from a few stations from western Europe, in order to reconstruct and to extend this daily weather type series back to 1781. We describe a statistical framework which provides, for each day, the weather types consistent enough with the observed pressure pattern, and their respective probability. Since the low frequency variability of synoptic conditions is directly related to the North Atlantic Oscillation (NAO), we derive from the weather type series an NAO index for winter. An interesting feature is a larger multidecadal variability during the nineteenth century than during the twentieth century. Category: geoscientificInformation Source: Supplement to: Delaygue, Gilles; Brönnimann, Stefan; Jones, Philip D; Blanchet, Juliette; Schwander, Mikhaël (2019): Reconstruction of Lamb weather type series back to the eighteenth century. Climate Dynamics, 52(9-10), 6131-6148, https://doi.org/10.1007/s00382-018-4506-7 Supplemental Information: Not Availble Coverage: Not Available
    Data Types:
    • Other
    • Collection
  • Abstract: The R codes provide Bayesian model fitting procedures for AAR-^14^C datasets. These codes are updated versions of the analytical scripts published by Allen et al. (2013). Based on the ages derived from the models fitted, it is possible then to account for the time-averaging (temporal resolution of the fossil record). The time-averaging estimates are based on empirical posterior distributions, accounting for dating uncertainty, as in Ritter et al. (2017). In addition, the R codes implements the figures produced both the cited dissertation and its derived manuscripts, like the best models fitted, age-frequency distribuitions (Histograms), its relations with sea-level oscilation in the Southern Brazilian shelf etc. Category: geoscientificInformation Source: Not Available Supplemental Information: Not Availble Coverage: Not Available
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  • Abstract: We examined coarse fraction contents of pelagic carbonates deposited between 2000-and 3700-m water depth in the tropical Indian Ocean using Ocean Drilling Program (ODP) sites 722 (Owen Ridge, Arabian Sea) and 758 (Ninetyeast Ridge, eastern equatorial Indian Ocean), and four giant piston cores collected by the French R/V Marion Dufresne during the SEYMAMA expedition. Over the last 1500 kyr, coarse fraction records display high-amplitude oscillations with an irregular wavelength on the order of ~500 kyr. These oscillations can be correlated throughout the entire equatorial Indian Ocean, from the Seychelles area eastward to the Ninetyeast Ridge, and into the Arabian Sea. Changes in grain size mainly result from changes in carbonate dissolution as evidenced by the positive relationship between coarse fraction content and a foraminiferal preservation index based on test fragmentation. The well-known 'mid-Bruhes dissolution cycle' represents the last part of this irregular long-term dissolution oscillation. The origin of this long-term oscillation is still poorly understood. Our observations suggest that it is not a true cycle (it has an irregular wavelength) and we propose that it may result from long-term changes in Ca++ flux to the ocean. Sites 722 and 758 d18O records provide a high-resolution stratigraphy that allows a detailed intersite comparison of the two coarse fraction records over the last 1500 kyr. Site 722 (2030 m) lies above the present and late Pleistocene lysocline. The lysocline shoaled to the position of site 758 (2925 m) only during the interglacial intervals that occurred between about 300 and 500 ka (Peterson and Prell, 1985a). Despite these supralysoclinal positions of the two sites, short-term changes in coarse fraction contents are correctable from one site to another and probably result from regional (or global) dissolution pulses. By stacking the normalized coarse fraction records from sites 722 and 758, we constructed a Composite Coarse Fraction Index (CCFI) curve in which most of the local signals cancelled out. The last 800 kyr of this curve appear to compare extremely well with the Composite Dissolution Index curve from core V34-53 (Ninetyeast Ridge), which unambiguously records past variations of carbonate dissolution in the equatorial Indian Ocean (Peterson and Prell, 1985a). In the late Pleistocene the CCFI variations are mainly associated with glacial-interglacial changes. They show strong 100 and 41 kyr periodicities but no clear precession-related periodicities. As proposed earlier by Peterson and Prell (1985a), the lack of precession frequencies may suggest that the regional carbonate dissolution signal is driven by changes in deepwater circulation. We cannot totally reject the possibility, however, that low temporal resolution and/or bioturbation degrade somehow the precessional signal at ODP sites 722 and 758. In contrast, spectral density of dissolution cycles in the giant (53 m long) piston core MD900963 (Maldives area) displays clear maxima centered on the precession frequencies (23 and 19 kyr**-1) as well as on the kyr**-1 frequency but shows little power at the 100- ky**-1 frequency. These high-frequency changes most probably result from changes in surface productivity associated with monsoon variability. Dissolution at this site may be ultimately controlled by the oxidation of organic matter which appears to be incorporated into the sediments in greater quantity during periods of weak SW monsoon and/or increased dry NE Category: geoscientificInformation Source: Supplement to: Bassinot, Franck C; Beaufort, Luc; Vincent, Edith; Labeyrie, Laurent D; Rostek, Frauke; Müller, Peter J; Quidelleur, Xavier; Lancelot, Yves (1994): Coarse fraction fluctuations in pelagic carbonate sediments from the tropical Indian Ocean: A 1500-kyr record of carbonate dissolution. Paleoceanography, 9(4), 579-600, https://doi.org/10.1029/94PA00860 Supplemental Information: Not Availble Coverage: EVENT LABEL: (GS900963) * LATITUDE: 5.040000 * LONGITUDE: 73.530000 * DATE/TIME: 1990-09-12T00:00:00 * ELEVATION: -2446.0 m * Recovery: 53.6 m * CAMPAIGN: MD65 * BASIS: Marion Dufresne (1972) * METHOD/DEVICE: Piston corer
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  • strength/frequency... Oscillation
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    • Collection
    • Tabular Data
    • Text
  • frequency... frequency.... Oscillation
    Data Types:
    • Collection
    • Tabular Data
    • Text
  • frequency... Oscillation
    Data Types:
    • Collection
    • Tabular Data
    • Text
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