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To determine spatiotemporal variability of methane (CH4) ebullition and its drivers, we measured CH4 ebullition rates, sedimentation rates and characteristics of the sedimented material, sediment chemical and physical characteristics and environmental parameters at Lake Windsborn in 2017 and 2018. Measurements of CH4 ebullition were conducted bi-weekly from May to October 2017 and April to November 2018. Sedimentation rates were measured in 2018 in four-week intervals. Characteristics of the sedimented material were measured in 2017 and 2018. Sediment characteristics were measured in November 2017, spring 2018 and August 2019. Meterological parameters (temperature and air pressure) were constantly measured from a floating platform in the lake center.

The Sesame dataset contains mesozooplankton data collected during April 2008 in the Marmara Sea (between 40°15' - 34°00N latitude and 19°00 - 23°10'E longitude). Sampling was always performed in day hours (07:00-18:00 local time). Samples were taken at 6 stations in the Marmara Sea. Mesozooplankton samples were collected by using a WP-2 closing net with 200 µm mesh size. Sample was immediately fixed and preserved in a formaldehyde-seawater solution (4% final concentration) to be successively analyzed in the laboratory for species composition, abundance and total biomass. The algal organisms materials were then seperated from the mesozooplankton subsample at the dissecting microscope in the laboratory because of the contamination of the net samples with large-sized algae and mucilaginous organic matters. Afterwards, each samples were filtered on GF/C (pre combusted and weighed) for biomass measurements for dry weight. The dataset includes samples analyzed for mesozooplankton species composition, abundance and total mesozooplankton biomass.Sampling volume was estimated by multiplying the mouth area with the wire length. Sampling biomass was measured by weighing filters and then determined according to sampling volume.1/2 sample or an aliquot was analyzed under the binocular microscope. Copepod species were identified and enumerated; the other mesozooplankters were identified and enumerated at higher taxonomic level (commonly named as mesozooplankton groups). Taxonomic identification was done at the METU-Institute of Marine Sciences by Tuba Terbıyık using the relevant taxonomic literatures.

This data set includes noble gas measurements and modeled recharge temperatures from 32 separate groundwater studies, each analyzed using the same consistent framework and set of noble gas temperature models (CE, PR, and OD models). Along with noble gas data and modeled temperatures are site information (coordinates, recharge elevation), groundwater age data, modern recharge temperatures, other model outputs (excess air, fractionation), and uncertainties for all variables of interest. These data were used to estimate LGM-Late Holocene temperature differences from each site and, together, for the large-scale low-latitude, low-elevation land surface. Please cite the dataset with the data citation and the paper citation Seltzer et al., 2021.

We simulated an experimental summer storm in large-volume (~1200 m3, ~16m depth) enclosures in Lake Stechlin by mixing deeper water masses from the meta- and hypolimnion into the mixed layer (epilimnion). The mixing included the disturbance of a deep chlorophyll maximum (DCM) which was present at the same time of the experiment in Lake Stechlin and situated in the metalimnion of each enclosure during filling. Water physical variables and water chemistry was monitored for 42 days after the experimental disturbance event. Mixing disrupted the thermal stratification, increasing concentrations of dissolved nutrients and CO2 and changing light conditions in the epilimnion. Mixing, thus, stimulated phytoplankton growth, resulting in higher particulate matter concentrations of carbon, nitrogen and phosphorous. Further Principal Investigators:CaCO3: Gessner, MarkParticulate Inorganic Carbon: Gessner, MarkTotal Phosphorus: Gessner, MarkSoluble Reactive Phosphorus: Gessner, MarkTotal Nitrogen: Gessner, MarkNitrate: Gessner, MarkNitite: Gessner, MarkAmmonium: Gessner, MarkTotal Dissolved Nitrogen: Gessner, MarkDissolved Silicate: Gessner, MarkDissolved Organic Carbon: Gessner, MarkSodium: Casper, PeterPotassium: Casper, PeterMagnesium: Casper, PeterCalcium: Casper, PeterChloride: Casper, PeterSulfate: Casper, PeterBarometric pressure from LakeESP buoy: Gessner, MarkFurther Project information:Core Facility grant; Award: GE 1775/2-1

For the determination of prokaryotic cell numbers, 1 cm³ sediment was fixed with sterile filtered formalin/seawater at a final concentration of 2% and stored at 4°C until further analyses in the home laboratory. Samples were filtered on 0.2 µm polycarbonate filters, stained with acridine orange (Meyer-Reil, 1983, doi:10.1007/bf00395813), and counted using an epifluorescence microscope (Axiophot II Imaging, Zeiss, Jena, Germany). For each sample, 30 random grids from two replicate filters were counted and averaged.

The described studies were carried out in the eastern part of the sea during the end of the summer seasonal succession from September 1 to October 12, 1997. Concentration of chlorophyll a in the surface layer varied from 0.09 to 1.24 mg/m**3; it tended to increase in the southern regions (<74°N). Primary production in the water column (P_p) varied from 24 to 214 mg C/m**2/day and was on average 91 mg C/m**2/day. The low level of P_p seems to result from combination of physical and chemical environmental factors unfavorable for photosynthesis (e.g. deficiency of nutrients and low values of insolation and temperature) and intensive grazing of phytoplankton by zooplankton. The lower boundary of the photosynthetic layer in open waters was located at depth 60-75 m; irradiance there was 0.1-0.5% of incident irradiance. In deep-water regions (>200 m) the subsurface maximum of chlorophyll occurred in the layer at 20-40 m; usually this maximum resulted in formation of additional maxima of primary production. Supplement to: Vedernikov, Vladimir I; Gagarin, Vladimir I (1998): Primary production and chlorophyll in the Barents Sea in September-October, 1997. Translated from Okeanologiya, 1998, 38(5), 710-718, Oceanology, 38(5), 642-649

Mouth diameter of the net was 113 cm, mesh size 200 µm. Sample aliquots were immediately immediately utilized for biomass measurements. Volumes of filtered seawater were estimated by multiplying the area of the net mouth by heights of sampled layers from winch readings. Total mesozooplankton biomass was measured as dry weight on a fresh aliquot of an original sample. The samples were filtered through pre-weighed GF/C filters, briefly rinsed with distilled water to remove salt, dried in an oven at 60 °C for some hours onboard and preserved frozen. Later in the lab, the samples were dried again in the oven for 24 hours and then weighted on a microbalance.

The discrete biogeochemical measurements from RV Polarstern PS114 and RV Maria S. Merian MSM77 sampled for dissolved organic matter, heterotrophic bacteria and gel particles. The parameters include chlorophyll, DOC/TDN/TDP/DOP, dissolved hydrolysable amino acids, dissolved combined carbohydrates, heterotrophic bacterial abundance and production, gel particles like TEP and CSP. The samples were aquired within 0-100 m of the Greenland Sea between 78°N to 80°N and 2°W to 14°E. The data was collected daily on board PS114 from 16th July 2018-23rd July 2018 and on board MSM77 from 16th September 2018-4th October 2018. The water collection occured using a CTD and laboratory methods varied by parameter. Chlorophyll was extracted using acetone, DOC/TDN was analysed using High-Temperature Catalytic Oxidation (TOC-VCSH), TDP/DOP was analysed colorimetrically using Acidic Molybdate Solution, dissolved hydrolysable amino acids were analysed using High Performal Liquid Chromatography (HPLC) Ortho-phthaldialdehyde Derivatization, dissolved combined carbohydrates were analysed using High Performance Anion Exchange Chromatography (HPAEC) coupled with Pulsed Amperometric Detection (PAD), cell abundance was analysed using flow cytometery, bacterial production was analysed using radioactively labelled 3H-Leucine and apllication of the microcentrifuge method, gel particles were analysed microscopically followed by image analysis. The purpose of data collection was to understand seasonal cycling of organic mater and heterotrophic bacteria dynamics within microbial loop.