Description: The Lofoten Basin is the most eddy rich region in the Norwegian Sea. In this paper, the characteristics of these eddies are investigated from a comprehensive database of nearly two decades of satellite altimeter data (1995-2013) together with Argo profiling floats and surface drifter data. An automated method identified 1695/1666 individual anticyclonic/cyclonic eddies in the Lofoten Basin from more than 10,000 altimeter-based eddy observations. The eddies are found to be predominantly generated and residing locally. The spatial distributions of lifetime, occurrence, generation sites, size, intensity, and drift of the eddies are studied in detail. The anticyclonic eddies in the Lofoten Basin are the most long-lived eddies (〉60 days), especially in the western part of the basin. We reveal two hotspots of eddy occurrence on either side of the Lofoten Basin. Furthermore, we infer a cyclonic drift of eddies in the western Lofoten Basin. Barotropic energy conversion rates reveals energy transfer from the slope current to the eddies during winter. An automated colocation of surface drifters trapped inside the altimeter-based eddies are used to corroborate the orbital speed of the anticyclonic and cyclonic eddies. Moreover, the vertical structure of the altimeter-based eddies is examined using colocated Argo profiling float profiles. Combination of altimetry, Argo floats, and surface drifter data is therefore considered to be a promising observation-based approach for further studies of the role of eddies in transport of heat and biomass from the slope current to the Lofoten Basin.

Description: This data set provides climatological distributions of d13C of dissolved inorganic carbon for the global oceans. This includes present and reconstructed preindustrial d13C, and the decline over the industrialized period; the full oceanic 13C Suess effect. These distributions were constructed as described in: Eide, Marie; Olsen, Are; Ninnemann, Ulysses S; Eldevik, Tor (in press): A global estimate of the full oceanic 13C Suess Effect since the Preindustrial. Global Biogeochemical Cycles, 31(3), 492-514, doi:10.1002/2016GB005472 and Eide, Marie; Olsen, Are; Ninnemann, Ulysses S; Johannessen, Truls (in press): A global ocean climatology of preindustrial and modern ocean d13C. Global Biogeochemical Cycles, 31(3), 515-534, doi:10.1002/2016GB005473 These articles should be cited whenever the data are used. The data are provided as two files; one for the global oceans for 200 m and deeper levels, this includes present and preindustrial d13C and the 13C Suess effect; and one that cover the entire water column but only includes the 13C Suess effect estimates as d13C distributions have not been constructed for the upper 200 m. See Eide et al. (2017a) and Eide et al. (2017b) for details. The Suess effect estimates from 200 m and downwards are the same in the two data files. The climatology is based on data that were mostly collected during the 1990s, and the present d13C and 13C Suess effect distributions should be considered to represent that time period. The preindustrial distribution is based on the modern observations, corrected for the full 13C Suess effect since the industrial revolution. The data are provided on a 1 degree x 1 degree grid at the following depth levels: For the present and preindustrial d13C and the 13C Suess effect: 10 to 33 (200 m to 5500 m) For the 13C Suess effect including the upper 200 m: 1 to 33 (0 to 5500 m)

Description: The Nordic Seas overflows are an important part of the Atlantic thermohaline circulation. While there is growing evidence that the overflow of dense water changed on orbital time scales during the Holocene, less is known about the variability on shorter time scales beyond the instrumental record. Here we reconstruct the relative changes in flow strength of Iceland-Scotland Overflow Water (ISOW), the eastern branch of the overflows, on multidecadal-millennial time scales. The reconstruction is based on mean sortable silt (SS) from a sediment core on the Gardar Drift (60°19′N, 23°58′W, 2081 m). Our SS record reveals that the main variance in ISOW vigor occurred on millennial time scales (1-2 kyr) with particularly prominent fluctuations after 8 kyr. Superimposed on the millennial variability, there were multidecadal-centennial flow speed fluctuations during the early Holocene (10-9 kyr) and one prominent minimum at 0.9 kyr. We find a broad agreement between reconstructed ISOW and regional North Atlantic climate, where a strong (weak) ISOW is generally associated with warm (cold) climate. We further identify the possible contribution of anomalous heat and freshwater forcing, respectively, related to reconstructed overflow variability. We infer that ocean poleward heat transport can explain the relationship between regional climate and ISOW during the middle to late Holocene, whereas freshwater input provides a possible explanation for the reduced overflow during early Holocene (8-10 kyr).