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.
Source: Not Available
Supplemental Information: Not Availble
Coverage: Not Available
Contributors:Edgerton, Harold E, Seibold, Eugen, Vollbrecht, Kurt, Werner, Friedrich
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.
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
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
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