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  • 1
    Publication Date: 2023-11-10
    Description: Abstract
    Description: This data publication is supplementary to a study on the climatic controls on leaf wax hydrogen isotopes, by Gaviria-Lugo et al. (2023). The dataset contains hydrogen isotope ratios from leaf wax n-alkanes (δ2Hwax) taken from soils, river sediments and marine surface sediments along a climatic gradient from hyperarid to humid in Chile. In addition, for each sampling site the hydrogen isotope ratios from precipitation (δ2Hpre) from the grids produced by the Online Isotopes in Precipitation Calculator (OIPC) (Bowen and Revenaugh, 2003). Furthermore, for each sampling site we report mean annual data of precipitation, actual evapotranspiration, relative humidity, and soil moisture, all derived from TerraClimate (Abatzoglou et al., 2018). Also provide data of mean annual temperature and the annual average of maximum daily temperature derived from WorldClim (Fick and Hijmans, 2017). As a final climatic parameter, we also derived data of aridity index from the Consultative Group of the International Agricultural Research Consortium for Spatial Information (CGIARCSI) (Trabucco and Zomer, 2022). In addition to climatic variables, for each site we include land cover fractions of trees, shrubs, grasses, crops, and barren land. These land cover fractions were obtained from Collection 2 of the Copernicus Global Land Cover layers (Buchhorn et al., 2020) via Google Earth Engine. For further comparison here we provide δ2Hwax compiled from 26 publications (see references) that reported both the n-C29 and n-C31 n-alkanes homologues from soils and lake sediments. For each sampling site of the global compilation, we provide δ2Hpre and the same climatic and land cover parameters as for the Chilean data (i.e., precipitation, actual evapotranspiration, relative humidity, soil moisture, aridity index, temperature, fraction of trees, fraction of grasses, etc.), using the same sources. The data is provided here as one single .xlsx file containing 9 data sheets, but also as 9 individual .csv files, to be accessed using the file format of preference. Additionally, 5 supplementary figures that accompany the publication Gaviria-Lugo et al. (2023) are provided in one single .pdf file. The samples taken for this study were assigned International Geo Sample Numbers (IGSNs), which are included in the provided tables S4, S5 and S6.
    Keywords: Leaf-wax ; n-alkanes ; compound specific isotopes ; aridity ; evapotranspiration ; apparent fractionation ; hyperaridity ; Chile ; non-linear ; river sediment ; soils ; marine surface sediments ; chemical 〉 biochemical substance 〉 lipid ; chemical 〉 organic substance 〉 hydrocarbon 〉 alkane ; climate 〉 climate type 〉 desert climate ; EARTH SCIENCE 〉 ATMOSPHERE 〉 ATMOSPHERIC WATER VAPOR 〉 EVAPOTRANSPIRATION ; EARTH SCIENCE 〉 CLIMATE INDICATORS 〉 PALEOCLIMATE INDICATORS 〉 BIOLOGICAL RECORDS 〉 BIOMARKER ; EARTH SCIENCE 〉 CLIMATE INDICATORS 〉 PALEOCLIMATE INDICATORS 〉 PALEOCLIMATE RECONSTRUCTIONS 〉 DROUGHT/PRECIPITATION RECONSTRUCTION ; EARTH SCIENCE 〉 LAND SURFACE 〉 LAND USE/LAND COVER 〉 LAND COVER ; EARTH SCIENCE 〉 LAND SURFACE 〉 SOILS 〉 SOIL MOISTURE/WATER CONTENT ; EARTH SCIENCE 〉 PALEOCLIMATE 〉 LAND RECORDS 〉 ISOTOPES ; EARTH SCIENCE 〉 PALEOCLIMATE 〉 LAND RECORDS 〉 SEDIMENTS
    Type: Dataset , Dataset
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  • 2
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    PANGAEA
    In:  Supplement to: Baumgart, Anne; Jennerjahn, Tim C; Mohtadi, Mahyar; Hebbeln, Dierk (2010): Distribution and burial of organic carbon in sediments from the Indian Ocean upwelling region off Java and Sumatra, Indonesia. Deep Sea Research Part I: Oceanographic Research Papers, 57(3), 458-467, https://doi.org/10.1016/j.dsr.2009.12.002
    Publication Date: 2023-03-03
    Description: Sediments were sampled and oxygen profiles of the water column were determined in the Indian Ocean off west and south Indonesia in order to obtain information on the production, transformation, and accumulation of organic matter (OM). The stable carbon isotope composition (d13Corg) in combination with C/N ratios depicts the almost exclusively marine origin of sedimentary organic matter in the entire study area. Maximum concentrations of organic carbon (Corg) and nitrogen (N) of 3.0% and 0.31%, respectively, were observed in the northern Mentawai Basin and in the Savu and Lombok basins. Minimum d15N values of 3.7 per mil were measured in the northern Mentawai Basin, whereas they varied around 5.4 per mil at stations outside this region. Minimum bottom water oxygen concentrations of 1.1 mL L**1, corresponding to an oxygen saturation of 16.1%, indicate reduced ventilation of bottom water in the northern Mentawai Basin. This low bottom water oxygen reduces organic matter decomposition, which is demonstrated by the almost unaltered isotopic composition of nitrogen during early diagenesis. Maximum Corg accumulation rates (CARs) were measured in the Lombok (10.4 g C m**-2 yr**-1) and northern Mentawai basins (5.2 g C m**-2 yr**-1). Upwelling-induced high productivity is responsible for the high CAR off East Java, Lombok, and Savu Basins, while a better OM preservation caused by reduced ventilation contributes to the high CAR observed in the northern Mentawai Basin. The interplay between primary production, remineralisation, and organic carbon burial determines the regional heterogeneity. CAR in the Indian Ocean upwelling region off Indonesia is lower than in the Peru and Chile upwellings, but in the same order of magnitude as in the Arabian Sea, the Benguela, and Gulf of California upwellings, and corresponds to 0.1-7.1% of the global ocean carbon burial. This demonstrates the relevance of the Indian Ocean margin off Indonesia for the global OM burial.
    Keywords: Center for Marine Environmental Sciences; GeoB10008-4; GeoB10010-1; GeoB10014-1; GeoB10015-1; GeoB10016-2; GeoB10022-6; GeoB10024-3; GeoB10025-3; GeoB10026-2; GeoB10027-3; GeoB10028-4; GeoB10029-3; GeoB10031-3; GeoB10033-5; GeoB10034-3; GeoB10036-3; GeoB10037-2; GeoB10038-3; GeoB10039-3; GeoB10040-3; GeoB10041-3; GeoB10042-2; GeoB10043-2; GeoB10044-3; GeoB10047-1; GeoB10049-5; GeoB10050-1; GeoB10058-1; GeoB10059-1; GeoB10061-4; GeoB10063-5; GeoB10064-5; GeoB10065-9; GeoB10066-6; GeoB10067-5; GeoB10068-2; GeoB10069-4; GeoB10070-6; MARUM; MUC; MultiCorer; PABESIA; SO184/1; SO184/2; Sonne
    Type: Dataset
    Format: application/zip, 2 datasets
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  • 3
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    PANGAEA
    In:  Supplement to: Hessler, Ines; Young, Martin; Holzwarth, Ulrike; Mohtadi, Mahyar; Lückge, Andreas; Behling, Hermann (2013): Imprint of eastern Indian Ocean surface oceanography on modern organic-walled dinoflagellate cyst assemblages. Marine Micropaleontology, 101, 89-105, https://doi.org/10.1016/j.marmicro.2013.02.005
    Publication Date: 2023-03-03
    Description: Assemblages of organic-walled dinoflagellate cysts (dinocysts) from 116 marine surface samples have been analysed to assess the relationship between the spatial distribution of dinocysts and modern local environmental conditions [e.g. sea surface temperature (SST), sea surface salinity (SSS), productivity] in the eastern Indian Ocean. Results from the percentage analysis and statistical methods such as multivariate ordination analysis and end-member modelling, indicate the existence of three distinct environmental and oceanographic regions in the study area. Region 1 is located in western and eastern Indonesia and controlled by high SSTs and a low nutrient content of the surface waters. The Indonesian Throughflow (ITF) region (Region 2) is dominated by heterotrophic dinocyst species reflecting the region's high productivity. Region 3 is encompassing the area offshore north-west and west Australia which is characterised by the water masses of the Leeuwin Current, a saline and nutrient depleted southward current featuring energetic eddies.
    Keywords: Center for Marine Environmental Sciences; MARUM
    Type: Dataset
    Format: application/zip, 5 datasets
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  • 4
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    PANGAEA
    In:  Supplement to: Martínez Fontaine, Consuelo; De Pol-Holz, Ricardo; Michel, Elisabeth; Siani, Giuseppe; Reyes-Macaya, Dharma; Martínez Méndez, Gema; DeVries, Tim; Stott, Lowell D; Southon, John; Mohtadi, Mahyar; Hebbeln, Dierk (2019): Ventilation of the deep ocean carbon reservoir during the last deglaciation: results from the southeast pacific. Paleoceanography and Paleoclimatology, 34(12), 2080-2097, https://doi.org/10.1029/2019PA003613
    Publication Date: 2023-03-03
    Description: Supplementary material for Martínez Fontaine et al., 2019 (Table S1), including the radiocarbon ages in benthonic and planktonic foraminifera in six cores in the Chilean margin, beetween ~31°S and ~36°S (Table S3). The age models for the cores are detailed in Martínez Fontaine et al., 2019 and were produced using the information on planktonic δ13C (Table S2). Also included are the Δ14C resulting from the age models.
    Keywords: Center for Marine Environmental Sciences; Deglaciation; MARUM; radiocarbon; Southeast Pacific
    Type: Dataset
    Format: application/zip, 2 datasets
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  • 5
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    PANGAEA
    In:  Supplement to: Martínez Méndez, Gema; Hebbeln, Dierk; Mohtadi, Mahyar; Lamy, Frank; De Pol-Holz, Ricardo; Reyes-Macaya, Dharma; Freudenthal, Tim (2013): Changes in the advection of Antarctic Intermediate Water to the northern Chilean coast during the last 970 kyr. Paleoceanography, 28, 1-12, https://doi.org/10.1002/palo.20047
    Publication Date: 2023-03-03
    Description: The Antarctic Intermediate Water (AAIW) is a key player in global-scale oceanic overturning processes and an important conduit for heat, fresh water, and carbon transport. The AAIW past variability is poorly understood mainly due to the lack of sedimentary archives at intermediate water depths. We present records of benthic stable isotopes from sediments retrieved with the seafloor drill rig MARUM-MeBo at 956 m water depth off northern Chile (GeoB15016, 27°29.48'S, 71°07.58'W) that extend back to 970 ka. The sediments at this site are presently deposited at the boundary between AAIW and Pacific Deep Water (PDW). For previous peak interglacials, our results reveal similar benthic d13C values at site GeoB15016 and of a newly generated stack of benthic d13C from various deep Pacific cores representing the "average PDW." This suggests, unlike today, the absence of AAIW at the site and the presence of nearly pure PDW. In contrast, more positive d13C values at site GeoB15016 compared to the stack imply a considerable AAIW contribution during cold phases of interglacials and especially during glacials. Besides, we used three short sediment cores to reconstruct benthic d13C values from the AAIW core during the last glacial and found a d13C signature similar to today's. Assuming that this was the case also for the past 970 kyr, we demonstrate that sea level changes and latitudinal migrations of the AAIW formation site can only account for about 50% of the full range of past d13C increases at site GeoB15016 during cold periods. Other processes that could explain the remaining of the positive d13C anomalies are increases in glacial AAIW production and/or deeper convection of the AAIW with respect to preceding interglacials.
    Keywords: Center for Marine Environmental Sciences; MARUM
    Type: Dataset
    Format: application/zip, 11 datasets
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  • 6
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    PANGAEA
    In:  Supplement to: Kuhnert, Henning; Kuhlmann, Holger; Mohtadi, Mahyar; Meggers, Helge; Baumann, Karl-Heinz; Pätzold, Jürgen (2014): Holocene tropical western Indian Ocean sea surface temperatures in covariation with climatic changes in the Indonesian region. Paleoceanography, https://doi.org/10.1002/2013PA002555
    Publication Date: 2023-03-03
    Description: The sea surface temperature (SST) of the tropical Indian Ocean is a major component of global climate teleconnections. While the Holocene SST history is documented for regions affected by the Indian and Arabian monsoons, data from the near-equatorial western Indian Ocean are sparse. Reconstructing past zonal and meridional SST gradients requires additional information on past temperatures from the western boundary current region. We present a unique record of Holocene SST and thermocline depth variations in the tropical western Indian Ocean as documented in foraminiferal Mg/Ca ratios and d18O from a sediment core off northern Tanzania. For Mg/Ca and thermocline d18O, most variance is concentrated in the centennial to bicentennial periodicity band. On the millennial time scale, an early to mid-Holocene (~7.8-5.6 ka) warm phase is followed by a temperature drop by up to 2°C, leading to a mid-Holocene cool interval (5.6-4.2 ka). The shift is accompanied by an initial reduction in the difference between surface and thermocline foraminiferal d18O, consistent with the thickening of the mixed layer and suggestions of a strengthened Walker circulation. However, we cannot confirm the expected enhanced zonal SST gradient, as the cooling of similar magnitude had previously been found in SSTs from the upwelling region off Sumatra and in Flores air temperatures. The SST pattern probably reflects the tropical Indian Ocean expression of a large-scale climate anomaly rather than a positive Indian Ocean Dipole-like mean state.
    Keywords: Center for Marine Environmental Sciences; MARUM
    Type: Dataset
    Format: application/zip, 2 datasets
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  • 7
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    In:  Supplement to: Mohtadi, Mahyar; Prange, Matthias; Oppo, Delia W; De Pol-Holz, Ricardo; Merkel, Ute; Zhang, Xiao; Steinke, Stephan; Lückge, Andreas (2014): North Atlantic forcing of tropical Indian Ocean climate. Nature, 509(7498), 76-80, https://doi.org/10.1038/nature13196
    Publication Date: 2023-03-03
    Description: The response of the tropical climate in the Indian Ocean realm to abrupt climate change events in the North Atlantic Ocean is contentious. Repositioning of the intertropical convergence zone is thought to have been responsible for changes in tropical hydroclimate during North Atlantic cold spells1, 2, 3, 4, 5, but the dearth of high-resolution records outside the monsoon realm in the Indian Ocean precludes a full understanding of this remote relationship and its underlying mechanisms. Here we show that slowdowns of the Atlantic meridional overturning circulation during Heinrich stadials and the Younger Dryas stadial affected the tropical Indian Ocean hydroclimate through changes to the Hadley circulation including a southward shift in the rising branch (the intertropical convergence zone) and an overall weakening over the southern Indian Ocean. Our results are based on new, high-resolution sea surface temperature and seawater oxygen isotope records of well-dated sedimentary archives from the tropical eastern Indian Ocean for the past 45,000 years, combined with climate model simulations of Atlantic circulation slowdown under Marine Isotope Stages 2 and 3 boundary conditions. Similar conditions in the east and west of the basin rule out a zonal dipole structure as the dominant forcing of the tropical Indian Ocean hydroclimate of millennial-scale events. Results from our simulations and proxy data suggest dry conditions in the northern Indian Ocean realm and wet and warm conditions in the southern realm during North Atlantic cold spells.
    Keywords: Center for Marine Environmental Sciences; MARUM
    Type: Dataset
    Format: application/zip, 4 datasets
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  • 8
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    PANGAEA
    In:  Supplement to: Steinke, Stephan; Prange, Matthias; Feist, Christin; Groeneveld, Jeroen; Mohtadi, Mahyar (2014): Upwelling variability off southern Indonesia over the past two millennia. Geophysical Research Letters, 41(21), 7684-7693, https://doi.org/10.1002/2014GL061450
    Publication Date: 2023-03-03
    Description: Modern variability in upwelling off southern Indonesia is strongly controlled by the Australian-Indonesian monsoon and the El Niño-Southern Oscillation, but multi-decadal to centennial-scale variations are less clear. We present high-resolution records of upper water column temperature, thermal gradient and relative abundances of mixed layer- and thermocline-dwelling planktonic foraminiferal species off southern Indonesia for the past two millennia that we use as proxies for upwelling variability. We find that upwelling was generally strong during the Little Ice Age (LIA) and weak during the Medieval Warm Period (MWP) and the Roman Warm Period (RWP). Upwelling is significantly anti-correlated to East Asian summer monsoonal rainfall and the zonal equatorial Pacific temperature gradient. We suggest that changes in the background state of the tropical Pacific may have substantially contributed to the centennial-scale upwelling trends observed in our records. Our results implicate the prevalence of an El Niño-like mean state during the LIA and a La Niña-like mean state during the MWP and the RWP.
    Keywords: Center for Marine Environmental Sciences; MARUM
    Type: Dataset
    Format: application/zip, 4 datasets
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  • 9
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    In:  Supplement to: Gibbons, Fern T; Oppo, Delia W; Mohtadi, Mahyar; Rosenthal, Yair; Cheng, Jun; Liu, Zhengyu; Linsley, Braddock K (2014): Deglacial d18O and hydrologic variability in the tropical Pacific and Indian Oceans. Earth and Planetary Science Letters, 387, 240-251, https://doi.org/10.1016/j.epsl.2013.11.032
    Publication Date: 2023-03-03
    Description: Evidence from geologic archives suggests that there were large changes in the tropical hydrologic cycle associated with the two prominent northern hemisphere deglacial cooling events, Heinrich Stadial 1 (HS1; ~19 to 15 kyr BP; kyr BP = 1000 yr before present) and the Younger Dryas (~12.9 to 11.7 kyr BP). These hydrologic shifts have been alternatively attributed to high and low latitude origin. Here, we present a new record of hydrologic variability based on planktic foraminifera-derived d18O of seawater (d18Osw) estimates from a sediment core from the tropical Eastern Indian Ocean, and using 12 additional d18Osw records, construct a single record of the dominant mode of tropical Eastern Equatorial Pacific and Indo-Pacific Warm Pool (IPWP) hydrologic variability. We show that deglacial hydrologic shifts parallel variations in the reconstructed interhemispheric temperature gradient, suggesting a strong response to variations in the Atlantic Meridional Overturning Circulation and the attendant heat redistribution. A transient model simulation of the last deglaciation suggests that hydrologic changes, including a southward shift in the Intertropical Convergence Zone (ITCZ) which likely occurred during these northern hemisphere cold events, coupled with oceanic advection and mixing, resulted in increased salinity in the Indonesian region of the IPWP and the eastern tropical Pacific, which is recorded by the d18Osw proxy. Based on our observations and modeling results we suggest the interhemispheric temperature gradient directly controls the tropical hydrologic cycle on these time scales, which in turn mediates poleward atmospheric heat transport.
    Keywords: Center for Marine Environmental Sciences; IMAGES; International Marine Global Change Study; MARUM
    Type: Dataset
    Format: application/zip, 4 datasets
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  • 10
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    In:  Supplement to: Kwiatkowski, Cornelia; Prange, Matthias; Varma, Vidya; Steinke, Stephan; Hebbeln, Dierk; Mohtadi, Mahyar (2015): Holocene variations of thermocline conditions in the eastern tropical Indian Ocean. Quaternary Science Reviews, 114, 33-42, https://doi.org/10.1016/j.quascirev.2015.01.028
    Publication Date: 2023-03-03
    Description: Climate phenomena like the monsoon system, El Niño Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) are interconnected via various feedback mechanisms and control the climate of the Indian Ocean and its surrounding continents on various timescales. The eastern tropical Indian Ocean is a key area for the interplay of these phenomena and for reconstructing their past changes and forcing mechanisms. Here we present records of upper ocean thermal gradient, thermocline temperatures (TT) and relative abundances of planktic foraminifera in core SO 189-39KL taken off western Sumatra (0°47.400' S, 99°54.510' E) for the last 8 ka that we use as proxies for changes in upper ocean structure. The records suggest a deeper thermocline between 8 ka and ca 3 ka compared to the late Holocene. We find a shoaling of the thermocline after 3 ka, most likely indicating an increased occurrence of upwelling during the late Holocene compared to the mid-Holocene which might represent changes in the IOD-like mean state of the Indian Ocean with a more negative IOD-like mean state during the mid-Holocene and a more positive IOD-like mean state during the past 3 ka. This interpretation is supported by a transient Holocene climate model simulation in which an IOD-like mode is identified that involves an insolation-forced long-term trend of increasing anomalous surface easterlies over the equatorial eastern Indian Ocean.
    Keywords: Center for Marine Environmental Sciences; MARUM
    Type: Dataset
    Format: application/zip, 2 datasets
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