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Water/ice velocity data and instrument status from a Nortek Aquadopp Profiler 2MHz acoustic doppler current profiler (ADCP) attached to a remotely operated vehicle (ROV) during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition between November 2019 and September 2020. The Aquadopp System Integrator Manual by Nortek AS can be found here: https://sensor.awi.de/rest/sensors/onlineResources/getOnlineResourcesFile/1764/system-integrator-manual_Mar2016.pdf

This bibliography unites different data types collected by a remotely operated vehicle (ROV) underneath drifting sea ice during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition of the research vessel Polarstern (AWI, 2017) between November 2019 and September 2020 (Nicolaus et al., 2022). The observation class M500 ROV was manufactured by Ocean Modules AB (Åtvidaberg, Sweden) and is owned by the Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung (Bremerhaven, Germany). It was equipped with an extended multidisciplinary sensor payload. To investigate the under-ice light field and bio-optical properties, the ROV was equipped with hyperspectral radiometers, transmissometers and a triplet fluorometer. Oceanographic properties were recorded with a standard CTD package including sensors for dissolved oxygen, nitrate and pH. Single beam and multibeam sonar allowed for a three-dimensional mapping of the ice underside, while an acoustic current profiler measured relative water currents. In addition to different video and still cameras for visual documentation of the under-ice environment, the ROV was equipped with a hyperspectral imager. For sampling of the under-ice ecosystem, a suction sampling system and an under-ice plankton as well as a gypsum net were attached to the ROV. Data were collected for all seasons and for various sea-ice and surface conditions. All data are provided at their original temporal resolution and have a common GPS synchronized timestamp. All times are given in UTC. Horizontal position of the ROV was determined using a long baseline acoustic positioning system and is provided in a floe-fixed, relative coordinate system (X, Y) with the origin (X=0 m, Y=0 m) at the ROV access hole in the MOSAiC central observatory (CO). Operations were conducted in a 300 m radius around the hole. A one function manipulator in combination with the ROV's six degrees of freedom enabled deployment and recovery of equipment (e.g. sediment traps) underneath the ice cover. Details about the respective deployment conditions can be found in the respective cruise reports of MOSAiC. A technical description of the ROV can be found in Katlein et al. (2017). MATLAB codes used for processing the data are published on ZENODO (Anhaus et al., 2023). The data will be described in a respective ROV data paper. When reusing the data, please refer to this data paper (Anhaus et al., in prep.) and the actual datasets listed below (Datasets listed in this bibliography). Please carefully read the comment section below and contact the author(s) before using the data.

Raw data acquired by GPS1 position sensors on board research aircraft Polar 6 during the campaign P6_237_BACSAM_2022 were processed to receive a validated master track which can be used as reference of further expedition data. Novatel FlexPak6 GPS receiver was used as navigation sensors during the campaign. Data were downloaded from DAVIS SHIP data base (https://dship.awi.de) with a resolution of 1 sec. Processed data are provided as a master track with 1 sec resolution and a generalized track with a reduced set of the most significant positions of the master track. A detailed report on processing is also available for each flight.

The creation, movement, and consumption of distinct biomolecules by marine organisms has far reaching implications regarding ecosystem material and energy flow and how we manage the marine environment. Lipids are ubiquitous, energy rich biomolecules that are essential for all life and are used for cell membrane structure, energy storage and serve as useful indicators for ecosystem and food web dynamics. In this dissertation, the flow of specific lipid biomolecules through multiple marine environments is measured, explored, and clarified to better understand biogeochemical cycles, marine food webs and ecosystem connectivity. In the first chapter of my dissertation, I measure, quantify, and close the loop of the open ocean microbial hydrocarbon cycle, with implications for priming effects of the ocean microbiome to oil spills. It is estimated that seeps, spills, and other oil pollution introduce ~ 1.3 million tons (1.3 Tg) of hydrocarbons into the ocean each year. Additionally, it is known that globally abundant marine cyanobacteria Prochlorococcus and Synechococcus which account for ~25% of ocean net primary production also produce hydrocarbons from fatty acids. But little is known about the size, turnover and fate of these cyanobacterial hydrocarbons and the implications for the ocean’s microbiome response to future oil spills. From a research expedition in the North Atlantic, I report that cyanobacteria in an oligotrophic gyre mainly produce n-pentadecane which correlates tightly with fluorescence and Prochlorococcus abundance in oligotrophic waters. Using chemical and isotopic tracing I find that pentadecane production and diel dynamics mainly occurs in the lower euphotic zone at the deep chlorophyll maximum. I estimate the global flux of cyanobacteria-produced pentadecane exceeds total oil input in the ocean by 100 to 500-fold, with cyanobacteria producing ~ 130-650 million tons of pentadecane per year. Analysis of sinking particles at the base of the euphotic zone show that nearly all pentadecane (< 0.001 % remaining) is consumed within the euphotic zone, suggesting near complete consumption of these hydrocarbons by hydrocarbon degrading microbes. These findings characterize a wide-spread microbial hydrocarbon cycle that selectively primes the ocean’s microbiome with long-chain alkanes. In the second chapter of my dissertation, I conduct a large-scale feeding experiment on a symbiotic reef-building coral (Stylophora pistillata) in the Red Sea to clarify fatty acid and isotopic biomarker patterns of coral heterotrophy for use in the field. Coral heterotrophy is an often-overlooked facet of coral nutrition that provides essential nutrients that help corals resist and recover from thermally induced bleaching that is degrading reef ecosystems around the world due to rising global ocean temperatures. Yet, methods for measuring coral mixotrophy, the balance between organic matter contributions to the coral host from autotrophic photo endosymbionts and heterotrophy on particles and plankton have typically been too coarse to elucidate source contributions. Through my experiment I show that fatty acids and isotopic biomarkers reliably separate experimental and reef nutritional source groups (heterotrophic or autotrophic). I show that heterotrophic fatty acid biomarkers are reliably recorded into coral host and symbiont tissues, with a divergent metabolic pattern of autotrophic biomarkers as feeding increases due to positive feedback of heterotrophy on the in hospite photo symbiont population. Additionally, I show that nitrogen and essential fatty acids are preferentially recorded into coral tissue while most heterotrophic carbon is respired or exuded as mucous; this shows that the use of bulk carbon isotopes as a feeding proxy for the last ~ 40 years is largely underestimating the contribution of heterotrophy to the trophic ecology of reef building corals. Overall, this finding underscores a connectivity between oceanic phyto- and zooplankton and reef-building coral. In the third chapter of my dissertation, I explore the mixotrophic differences of divergent bleaching responses of Acropora hyacinthus colonies on the forereef of Mo’orea during the 2019 mass bleaching event. During this bleaching event, all colonies of A. hyacinthus on the deep forereef (14 m) bleached and recovered, while colonies on the shallow forereef (5 m) near the reef crest resisted bleaching entirely, despite the same temperature stress. Using fatty acid and isotopic biomarkers I show through several lines of evidence that bleaching resistant colonies near the reef crest were likely consuming more particulate organic matter than deep forereef colonies. This conclusion is supported by isotopic feeding proxies, less isotopic niche overlap of the host and symbiont of resistant colonies, and larger proportions of putative POM fatty acid biomarkers in the host of resistant colonies relative to recovered colonies. This interpretation is in line with observations that benthic communities on the reef crest are a net sink of oceanic POM and that increased reliance on heterotrophy is associated with bleaching resistance. These data show the vital importance of reef environment, coral heterotrophy, and planktonic subsidies in structuring bleaching response of corals in a warming ocean and ultimately show that the reef crest may serve as a potent zone for reseeding coral populations after marine heat waves.

The data sets under this data collection include detailed snow pit studies of snow temperature, density, specific surface area (SSA), stratigraphy (snow grain type & size and hand hardness), and salinity as well as high-resolution snow penetrometer measurement profiles. The data were collected during the ALERT2018 campaign (Multidisciplinary Arctic Program (MAP) - Last Ice) off Alert, Nunavut, Canada in the Lincoln Sea in May 2018. For more detailed information, please refer to the individual data sets.

Raw data acquired by GPS1 position sensors on board research aircraft Polar 6 during the campaign P6_235_IceBird_2022 were processed to receive a validated master track which can be used as reference of further expedition data. Novatel FlexPak6 GPS receiver was used as navigation sensors during the campaign. Data were downloaded from DAVIS SHIP data base (https://dship.awi.de) with a resolution of 1 sec. Processed data are provided as a master track with 1 sec resolution and a generalized track with a reduced set of the most significant positions of the master track. A detailed report on processing is also available for each flight.

Patterned ground of the polygonal tundra yields sensitive indicators of environmental and climate change. Polygon ponds, mires and cryosoils are typical components of Arctic Siberian wetlands underlain by permafrost. Field studies of recent environmental dynamics were carried out within the frame of the joint German-Russian DFG-RFBR project Polygons in tundra wetlands: state and dynamics under climate variability in Polar Regions (POLYGON) field studies were carried out in the Kolyma Delta in 2012 around the small fishing settlement Pokhodsk in summer 2012 and 2013. Using a multidisciplinary approach, several stages of polygonal systems were studied as modern tundra habitats . The floral and faunal associations of the polygonal tundra landscape were described. Ecological, hydrological, meteorological, limnological and cryological features were analyzed in order to evaluate modern environmental conditions and their essential controlling parameters. A monitoring program was carried out to measure changes of air, water and ground temperatures as well as water conductivity, water level and soil moisture and to collect water, diatom, zooplankton, and zoobenthos, samples. These data sets contain environmental field data, logger data, various ecological data, and analyses of sediments and water.

The data set consists of high resolution airborne measurements that were obtained mainly over Svalbard and near the sea ice edge north of Svalbard on three days in March 2013 during the campaign "SpringTime Atmospheric Boundary Layer Experiment (STABLE). STABLE was led by the Alfred Wegener Institue (AWI) and by the Finnish Meteorological Institute (FMI). The measurements were performed using the POLAR 5 research aircraft, where all research flights of 5-6 hours duration started and ended at Longyearbyen airport. During STABLE, observations focused on the vertical structure of the lower troposphere as well as boundary layer modifications, e.g. during marine cold-air outbreaks and by convection over leads in sea ice. The data set presented here predominantly consists of measurements that were obtained over the Wijdefjorden, which is a North-South oriented fjord with a length of more than 100km in the northern part of Spitsbergen. The measurements were carried out to study the boundary layer structure in the fjord as well as for analyses of the role of the topography on the atmospheric conditions. In its southern part, the fjord was covered by land-fast sea ice until about 72.5km north of the fjord's head. In its northern part, there was open water. On all three days, the corresponding flight patterns mainly consisted of vertical aircraft profiles between 30m and 1000-1500m height during saw-tooth patterns and of low- and high-level horizontal flight legs from the marginal ice zone towards the fjord and vice versa. Each file consists of measurements from one flight leg, where in each file name we include start and end time (in UTC) and the following abbreviations: • h: low-level horizontal flight leg (below 1000m flight altitude) • H: high-level horizontal flight leg (above 1000m flight altitude) • t: ascent or descent with an altitude difference 1500m (or ascent/descent at high altitudes) The airborne measurements were obtained by instruments installed in and at a turbulence nose-boom. The following variables are included in the data set (see Table 1): air pressure (static & dynamic) and wind obtained from a Rosemount 858 five-hole probe as well as temperature (Pt100 resistance thermometer), all with 100 Hz sampling rate, relative humidity (Vaisala HUMICAP in a Rosemount housing, 1Hz), radar altimeter (1Hz), and surface temperature (KT-19 radiation thermometer, 10Hz). Global Position System (GPS) and Inertial Navigation System (INS) were used to derive the aircraft's height, velocity, and position, and also for the calculation of the three wind components. Besides the GPS-based height, we provide also the more reliable pressure-based altitude. All variables are provided with 100Hz in each file. Air pressure and air temperature data were corrected as described in detail by Michaelis et al. (2022). Relative humidity data were corrected for adiabatic heating, which occurs due to compression of the air entering the Vaisala HUMICAP sensor situated in the Rosemount housing (see Smit et al., 2013). More detailed description on the measurements including the instruments' accuracies and the quality-processing of the measurements is provided by Suomi et al. (2023), for which this data set is a supplement, as well as by Michaelis et al. (2021, 2022) and Tetzlaff et al. (2014, 2015). In the latter four publications, data from the STABLE campaign is used as well but mainly from flight days other than in this data set. The corresponding data are available at Lüpkes et al. (2021a, b). Master tracks for all STABLE research flights can be found at Steinhage (2015). Finally, Hartmann et al. (2018) provide more details on the quality of such airborne measurements in general including instrument calibrations and the determination of related measurement accuracies. Note that for the wind measurements the full accuracy is only achieved and the estimates on uncertainty are only valid for straight level flight sections (Hartmann et al., 2018).

Arctic warming increases the degradation of permafrost soils but little is known about floodplain soils and other permafrost soils in the permafrost region. This dataset present soil properties from twelve analyzed cores located in the northeastern Siberian Lena River Delta within the continuous permafrost zone in northern Yakutia, Russia that were sampled in 2018. The cores represent intact yedoma, yedoma thaw slumps, and floodplain profiles. The soil coring and sampling was carried out in August 2018 for a total of 30 soil cores, 35 soil profiles, and 341 sediment samples. First, vegetation and other characteristics of the plots were described. Then, the active layer soils were excavated, described, and sampled with a fixed volume cylinder (250 cm³). Then the permafrost layers were sampled with a modified, snow, ice, and permafrost (SIPRE) auger to a depth of 1 m (core diameter of 7.62 cm) and visually described in their characteristics. Each core was divided into subsamples with 5-10 cm length according to its facies horizons, transported frozen to Alfred Wegener Institute in Potsdam, and stored at -20 °C until analysis. A subset of these sediment samples (n=105 from 12 cores) were later analyzed in the laboratory for physical and chemical properties; this data is presented here. The analysis from these samples includes: water content, dry bulk density, gravimetric ice content, pH, conductivity, total organic carbon content, total inorganic carbon content, total carbon content, total nitrogen content, carbon density, TOC storage, and TN storage. Selected samples were further analyzed for radiocarbon, grain size analysis, and potential CH4 and CO2 production using aerobic and anaerobic soil incubations for 356-days at 20 °C.

Understanding what factors shape the magnitude of divergence under rapid evolution is critical. Phenotypic divergence, specifically, can be influenced by selective forces such as the environment (climate, geographic distance) as well as non-selective forces (genetic composition of the founding population). Threespine sticklebacks provide a unique opportunity to study the magnitude of divergence under rapid evolution. Marine sticklebacks independently colonized freshwater habitats at the end of the last ice age (~12,000 years ago) generating multiple replicate pairs that represent a natural experiment. However, studies rely on untested assumptions that marine sticklebacks are not phenotypically varied and are unchanged from their ancestors. Here, we test how differential environmental conditions impact the estimated magnitude of phenotypic divergence and parallelism of independent freshwater stickleback populations. We find that marine variation is comparable to freshwater variation. Importantly, the inferred magnitude of phenotypic divergence of each freshwater population is dependent on marine sampling location. The geographic distance and environmental similarity between the marine and freshwater pairs explain a significant degree of variance. When estimating the degree of parallelism among freshwater pairs, marine reference also affects the inferred magnitude. The observed pattern suggests the choice of reference population and its geographic distance are important aspects to consider when estimating freshwater divergence and parallelism. Results also implicate a signature of local adaptation and/or isolation by distance. We provide recommendations for choosing ecologically relevant marine references in future studies on this important evolutionary model system.