TY - JOUR A1 - Bertilsson, Stefan A1 - Burgin, Amy A1 - Carey, Cayelan C. A1 - Fey, Samuel B. A1 - Grossart, Hans-Peter A1 - Grubisic, Lorena M. A1 - Jones, Ian D. A1 - Kirillin, Georgiy A1 - Lennon, Jay T. A1 - Shade, Ashley A1 - Smyth, Robyn L. T1 - The under-ice microbiome of seasonally frozen lakes JF - Limnology and oceanography N2 - Compared to the well-studied open water of the "growing" season, under-ice conditions in lakes are characterized by low and rather constant temperature, slow water movements, limited light availability, and reduced exchange with the surrounding landscape. These conditions interact with ice-cover duration to shape microbial processes in temperate lakes and ultimately influence the phenology of community and ecosystem processes. We review the current knowledge on microorganisms in seasonally frozen lakes. Specifically, we highlight how under-ice conditions alter lake physics and the ways that this can affect the distribution and metabolism of auto-and heterotrophic microorganisms. We identify functional traits that we hypothesize are important for understanding under-ice dynamics and discuss how these traits influence species interactions. As ice coverage duration has already been seen to reduce as air temperatures have warmed, the dynamics of the under-ice microbiome are important for understanding and predicting the dynamics and functioning of seasonally frozen lakes in the near future. Y1 - 2013 U6 - https://doi.org/10.4319/lo.2013.58.6.1998 SN - 0024-3590 SN - 1939-5590 VL - 58 IS - 6 SP - 1998 EP - 2012 PB - Wiley CY - Waco ER - TY - JOUR A1 - Kroh, Daniel A1 - Eller, Fabian A1 - Schötz, Konstantin A1 - Wedler, Stefan A1 - Perdigón-Toro, Lorena A1 - Freychet, Guillaume A1 - Wei, Qingya A1 - Dörr, Maximilian A1 - Jones, David A1 - Zou, Yingping A1 - Herzig, Eva M. A1 - Neher, Dieter A1 - Köhler, Anna T1 - Identifying the signatures of intermolecular interactions in blends of PM6 with Y6 and N4 using absorption spectroscopy JF - Advanced functional materials N2 - In organic solar cells, the resulting device efficiency depends strongly on the local morphology and intermolecular interactions of the blend film. Optical spectroscopy was used to identify the spectral signatures of interacting chromophores in blend films of the donor polymer PM6 with two state-of-the-art nonfullerene acceptors, Y6 and N4, which differ merely in the branching point of the side chain. From temperature-dependent absorption and luminescence spectroscopy in solution, it is inferred that both acceptor materials form two types of aggregates that differ in their interaction energy. Y6 forms an aggregate with a predominant J-type character in solution, while for N4 molecules the interaction is predominantly in a H-like manner in solution and freshly spin-cast film, yet the molecules reorient with respect to each other with time or thermal annealing to adopt a more J-type interaction. The different aggregation behavior of the acceptor materials is also reflected in the blend films and accounts for the different solar cell efficiencies reported with the two blends. KW - charge-transfer states KW - Frank-Condon analysis KW - morphology KW - organic solar cells Y1 - 2022 U6 - https://doi.org/10.1002/adfm.202205711 SN - 1616-301X SN - 1616-3028 VL - 32 IS - 44 PB - Wiley-VCH CY - Weinheim ER - TY - GEN A1 - Arboleda-Zapata, Mauricio A1 - Angelopoulos, Michael A1 - Overduin, Pier Paul A1 - Grosse, Guido A1 - Jones, Benjamin M. A1 - Tronicke, Jens T1 - Exploring the capabilities of electrical resistivity tomography to study subsea permafrost T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Sea level rise and coastal erosion have inundated large areas of Arctic permafrost. Submergence by warm and saline waters increases the rate of inundated permafrost thaw compared to sub-aerial thawing on land. Studying the contact between the unfrozen and frozen sediments below the seabed, also known as the ice-bearing permafrost table (IBPT), provides valuable information to understand the evolution of sub-aquatic permafrost, which is key to improving and understanding coastal erosion prediction models and potential greenhouse gas emissions. In this study, we use data from 2D electrical resistivity tomography (ERT) collected in the nearshore coastal zone of two Arctic regions that differ in their environmental conditions (e.g., seawater depth and resistivity) to image and study the subsea permafrost. The inversion of 2D ERT data sets is commonly performed using deterministic approaches that favor smoothed solutions, which are typically interpreted using a user-specified resistivity threshold to identify the IBPT position. In contrast, to target the IBPT position directly during inversion, we use a layer-based model parameterization and a global optimization approach to invert our ERT data. This approach results in ensembles of layered 2D model solutions, which we use to identify the IBPT and estimate the resistivity of the unfrozen and frozen sediments, including estimates of uncertainties. Additionally, we globally invert 1D synthetic resistivity data and perform sensitivity analyses to study, in a simpler way, the correlations and influences of our model parameters. The set of methods provided in this study may help to further exploit ERT data collected in such permafrost environments as well as for the design of future field experiments. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1285 Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-571234 SN - 1866-8372 IS - 1285 SP - 4423 EP - 4445 ER - TY - JOUR A1 - Arboleda-Zapata, Mauricio A1 - Angelopoulos, Michael A1 - Overduin, Pier Paul A1 - Grosse, Guido A1 - Jones, Benjamin M. A1 - Tronicke, Jens T1 - Exploring the capabilities of electrical resistivity tomography to study subsea permafrost JF - The Cryosphere N2 - Sea level rise and coastal erosion have inundated large areas of Arctic permafrost. Submergence by warm and saline waters increases the rate of inundated permafrost thaw compared to sub-aerial thawing on land. Studying the contact between the unfrozen and frozen sediments below the seabed, also known as the ice-bearing permafrost table (IBPT), provides valuable information to understand the evolution of sub-aquatic permafrost, which is key to improving and understanding coastal erosion prediction models and potential greenhouse gas emissions. In this study, we use data from 2D electrical resistivity tomography (ERT) collected in the nearshore coastal zone of two Arctic regions that differ in their environmental conditions (e.g., seawater depth and resistivity) to image and study the subsea permafrost. The inversion of 2D ERT data sets is commonly performed using deterministic approaches that favor smoothed solutions, which are typically interpreted using a user-specified resistivity threshold to identify the IBPT position. In contrast, to target the IBPT position directly during inversion, we use a layer-based model parameterization and a global optimization approach to invert our ERT data. This approach results in ensembles of layered 2D model solutions, which we use to identify the IBPT and estimate the resistivity of the unfrozen and frozen sediments, including estimates of uncertainties. Additionally, we globally invert 1D synthetic resistivity data and perform sensitivity analyses to study, in a simpler way, the correlations and influences of our model parameters. The set of methods provided in this study may help to further exploit ERT data collected in such permafrost environments as well as for the design of future field experiments. Y1 - 2022 U6 - https://doi.org/10.5194/tc-16-4423-2022 SN - 1994-0424 VL - 16 SP - 4423 EP - 4445 PB - Copernicus CY - Katlenburg-Lindau ER -