Tim Jesper Suhrhoff


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Suhrhoff

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Tim Jesper

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0000-0002-7934-7159

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Publications 1 - 10 of 11
  • Tracing anthropogenic aerosol trace metal sources in the North Atlantic Ocean using Pb, Zn and Ni isotopes
    Item type: Journal Article
    Zhang, Xingchao; Lemaitre, Nolwenn; Rickli, Jörg Dominik; et al. (2024)
    Marine Chemistry
    Atmospheric deposition of trace metals of natural or anthropogenic origin is an important input of micronutrients to the surface ocean. However, understanding its direct impact on oceanic element cycles is challenging due to scarce data, coupled to diverse aerosol sources and variable solubilities. Here, we present a dataset that combines Ni, Zn and Pb isotopes for samples from the Moroccan and Senegalese coasts and in the high latitude North Atlantic Ocean. We combine the new with published data for other circum-North Atlantic sources to assess the processes that determine the isotope signatures in different types of aerosols. We then use open marine aerosol data to investigate the impact of these signatures in the open ocean. Isotope analyses were conducted on bulk aerosols (TSP), on their ultra-high-purity water leachates, and on rainwaters. Aerosols characterized by crustal elemental abundances have isotope compositions similar to Saharan mineral dust. Mixing with anthropogenic aerosols from Europe/North Africa results in lower ^206Pb/^207Pb and ^208Pb/^207Pb values for the Eastern North Atlantic region. Higher ^206Pb/^207Pb at a given ^208Pb/^207Pb, observed near the Canadian margin and occasionally at the Senegalese coast, points to anthropogenic inputs from North America. Based on trends in the aerosol data (e.g., δ^66Zn_JMC-Lyon versus ^206Pb/^207Pb, δ^60Ni_SRM986 versus Ni/V), we identify several anthropogenic sources of Zn and Ni. The δ^66Zn_JMC-Lyon of low-temperature pollution (e.g., non-exhaust traffic emission) appears to be around −0.1‰ to 0.2‰, while leachate δ^66Zn_JMC-Lyon as low as −0.21‰ indicates contributions from high-temperature combustion or smelting processes. Among aerosols with good correlations between Ni and V, δ^60Ni_SRM986 > 0.40‰ traces Ni contributions from oil combustion. Other Ni-enriched sources, possibly originating from laterite or sulfide, show relatively low δ60NiSRM986 (as low as −0.85‰) and low V/Ni. Generally, aerosol sources for Zn are consistent throughout the North Atlantic, while Ni can be highly heterogenous. Combining the new data with literature elemental data, ratios of soluble Zn/Pb in anthropogenic aerosols are 1–100 times surface ocean ratios, suggesting that the low δ^66Zn_JMC-Lyon observed in anthropogenic aerosol can be key in controlling the upper ocean Zn isotope composition. These aerosols have, however, much less significance for surface ocean Ni.
  • Grain size specific authigenic Nd isotope compositions in the Northwest Atlantic Ocean – Ubiquity of authigenic phases and impacts of boundary exchange processes
    Item type: Other Conference Item
    Rickli, Jörg; Tallon, Marie; Bamberg, Cédric; et al. (2023)
    Goldschmidt 2023 Abstract
  • Behavior of beryllium in the weathering environment and its delivery to the ocean
    Item type: Journal Article
    Suhrhoff, Tim Jesper; Rickli, Jörg; Crocket, Kirsty; et al. (2019)
    Geochimica et Cosmochimica Acta
  • Clay dissolution during early diagenesis? – Insights from neodymium isotopes
    Item type: Conference Poster
    Rickli, Jörg; Tallon, Marie; Bamberg, Cedric; et al. (2022)
  • Copper pollution exacerbates the effects of ocean acidification and warming on kelp microscopic early life stages
    Item type: Journal Article
    Leal, Pablo P.; Hurd, Catriona L.; Sander, Sylvia G.; et al. (2018)
    Scientific Reports
    Ocean warming (OW), ocean acidification (OA) and their interaction with local drivers, e.g., copper pollution, may negatively affect macroalgae and their microscopic life stages. We evaluated meiospore development of the kelps Macrocystis pyrifera and Undaria pinnatifida exposed to a factorial combination of current and 2100-predicted temperature (12 and 16 °C, respectively), pH (8.16 and 7.65, respectively), and two copper levels (no-added-copper and species-specific germination Cu-EC50). Meiospore germination for both species declined by 5–18% under OA and ambient temperature/OA conditions, irrespective of copper exposure. Germling growth rate declined by >40%·day−1, and gametophyte development was inhibited under Cu-EC50 exposure, compared to the no-added-copper treatment, irrespective of pH and temperature. Following the removal of copper and 9-day recovery under respective pH and temperature treatments, germling growth rates increased by 8–18%·day−1. The exception was U. pinnatifida under OW/OA, where growth rate remained at 10%·day−1 before and after copper exposure. Copper-binding ligand concentrations were higher in copper-exposed cultures of both species, suggesting that ligands may act as a defence mechanism of kelp early life stages against copper toxicity. Our study demonstrated that copper pollution is more important than global climate drivers in controlling meiospore development in kelps as it disrupts the completion of their life cycle.
  • Phytoprevention of Heavy Metal Contamination From Terrestrial Enhanced Weathering: Can Plants Save the Day?
    Item type: Journal Article
    Suhrhoff, Tim Jesper (2022)
    Frontiers in Climate
    Enhanced weathering is a promising approach to remove carbon dioxide from the atmosphere. However, it may also pose environmental risks through the release of heavy metals, in particular nickel and chromium. In this perspective article I explore the potential role of plants in modulating these heavy metal fluxes. Agricultural basaltic soils may be valuable study sites in this context. However, the effect of biomass harvesting on the accumulation of heavy metals is currently not well studied. Mostly caused by different parent rock concentrations, there is a large variability of heavy metal concentrations in basaltic and ultramafic soils. Hence, to minimize environmental risks of enhanced weathering, basalts with low heavy metal concentrations should be favored. Existing phytoremediation strategies may be used to “phytoprevent” the accumulation of nickel and chromium released from enhanced weathering in soils. As a result, elevated nickel and chromium concentrations in rocks must not preclude enhanced weathering in all settings. In particular, hyperaccumulating plants could be used as part of a crop rotation to periodically remove heavy metals from soils. Enhanced weathering could also be employed on fields or forests of (non-hyper) accumulating plants that have a high primary production of biomass. Both approaches may have additional synergies with phytomining or bioenergy carbon capture and storage, increasing the total amount of carbon dioxide drawdown and at the same time preventing heavy metal accumulation in soils.
  • Dominance of benthic fluxes in the oceanic beryllium budget and implications for paleo-denudation records
    Item type: Journal Article
    Deng, Kai; Rickli, Jörg; Suhrhoff, Tim Jesper; et al. (2023)
    Science Advances
    The ratio of atmosphere-derived 10Be to continent-derived 9Be in marine sediments has been used to probe the long-term relationship between continental denudation and climate. However, its application is complicated by uncertainty in 9Be transfer through the land-ocean interface. The riverine dissolved load alone is insufficient to close the marine 9Be budget, largely due to substantial removal of riverine 9Be to continental margin sediments. We focus on the ultimate fate of this latter Be. We present sediment pore-water Be profiles from diverse continental margin environments to quantify the diagenetic Be release to the ocean. Our results suggest that pore-water Be cycling is mainly controlled by particulate supply and Mn-Fe cycling, leading to higher benthic fluxes on shelves. Benthic fluxes may help close the 9Be budget and are at least comparable to, or higher (~2-fold) than, the riverine dissolved input. These observations demand a revised model framework, which considers the potentially dominant benthic source, to robustly interpret marine Be isotopic records.
  • Extracting paleo-weathering signals from authigenic phases in lake sediments: A case-study of Lake Baikal
    Item type: Journal Article
    Suhrhoff, Tim Jesper; Rickli, Jörg; Christl, Marcus; et al. (2024)
    Chemical Geology
    Authigenic phases in lake sediments hold the potential to record changes in the isotope compositions of past lake water, potentially yielding valuable information on secular changes in continental weathering patterns and rates, including over past glacial cycles. Here, different leaching approaches are investigated with the aim of extracting Sr, Nd, Pb, and Be hosted in authigenic Fe-Mn (oxy)hydroxide sediment phases for precise isotope measurements. Elemental Al/Mn, Ca/Mn, and P/Mn ratios obtained via a mild reductive leach agree well with the composition of marine authigenic Fe-Mn phases. For core top sediments, leached Sr isotope compositions obtained with this leach agree well with the composition of lake water. The Be and Nd isotope compositions of core top leachates are consistent with the spatial variability observed in the water column. Due to high concentrations in Fe-Mn phases, leachate compositions are dominated by authigenic Be, Sr, Nd, and Pb, even in cases when as much as 40% of leached phases (by mass) are non-authigenic. These lines of evidence suggest that the mild reductive leach successfully extracts the modern lake isotope composition from modern sediments in terms of the isotope systems investigated. We further show that the leaching method is also reliable for older sediments (<340 ka): leached paleo-Sr isotope compositions are consistent between the current and previous interglacial periods, as well as for glacial periods. This suggests that reconstructed water isotope compositions are not affected by early diagenetic processes, instead reflecting environmental factors around the lake that determine the composition of weathering fluxes. Although more difficult to assess for Be, Nd, and Pb due to the heterogeneity of modern lake water, the data we present indicate the overall robustness of the leaching approach. These promising results open up lakes as archives for paleo-weathering reconstructions. Given that marine reconstructions face some important limitations (e.g., integration of basin-wide changes in weathering processes, long residence times for Sr, etc.Fe), lake records provide an avenue to improve our understanding of changes in regional weathering processes over glacial-interglacial timescales. The mild reductive leach used here may also be useful for meteoric Be studies in marine shelf settings, to prevent leaching of terrestrial sedimentary Fe-Mn oxy(hydroxide) phases.
  • Diet shapes cold-water corals bacterial communities
    Item type: Journal Article
    Galand, Pierre E.; Remize, Marine; Meistertzheim, Anne-Leila; et al. (2020)
    Environmental Microbiology
Publications 1 - 10 of 11