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cti_cross_region_taxon This repository provides the data and codes used in the manuscript: Guillem Chust, Ernesto Villarino, Matthew McLean, Nova Mieszkowska, Lisandro Benedetti-Cecchi, Fabio Bulleri, Chiara Ravaglioli, Angel Borja, Iñigo Muxika, José A. Fernandes-Salvador, Leire Ibaibarriaga, Ainhize Uriarte, Marta Revilla, Fernando Villate, Arantza Iriarte, Ibon Uriarte, Soultana Zervoudaki, Jacob Carstensen, Paul J. Somerfield, Ana M. Queirós , Andrea J. McEvoy, Arnaud Auber, Manuel Hidalgo, Marta Coll, Joaquim Garrabou, Daniel Gómez-Gras, Cristina Linares, Francisco Ramírez, Núria Margarit, Mario Lepage, Chloé Dambrine, Jérémy Lobry, Myron A. Peck, Paula de la Barra, Anieke van Leeuwen, Gil Rilov, Erez Yeruham, Anik Brind'Amour, and Martin Lindegren. Cross-basin and cross-taxa patterns of marine community tropicalization and deborealization in warming European seas. Nature Communications Please check the github repo cti_cross_region_taxon for updates. Abstract Ocean warming and acidification, decreases in dissolved oxygen concentrations, and changes in primary production are causing an unprecedented global redistribution of marine life. The identification of underlying ecological processes underpinning marine species turnover, particularly the prevalence of tropicalization over deborealization, has been recently debated in the context of ocean warming. Here, we track changes in the mean thermal affinity of marine communities across European seas by calculating the Community Temperature Index for 65 biodiversity time series collected over four decades and containing 1,817 species from different communities (zooplankton, coastal benthos, pelagic and demersal invertebrates and fish). We show most communities and sites have clearly responded to ongoing ocean warming via abundance increases of warm-water species (tropicalization; 54%) and decreases of cold-water species (deborealization; 18%). Tropicalization dominated Atlantic sites compared to semi-enclosed basins such as the Mediterranean and Baltic Seas, probably due to physical barrier constraints to connectivity and species colonization. Semi-enclosed basins appeared to be particularly vulnerable to ocean warming, experiencing the fastest rates of warming and biodiversity loss through deborealization. Keywords: climate change, community temperature index, CTI, ocean connectivity. Acknowledgements This study has been supported by the European Union's Horizon 2020 research and innovation programme under grant agreement No 869300 (FutureMARES project) (G.C., E.V., J.F-S., M.P., M.Lin., C.D., D.G-G., G.R., L.B., C.R., M.C., F.R., G.R., P.B., M.P., M.Lep., J.L., A.B., N.M., J.G., F.B., L.B.C, A.Q., F.V., A.I., and I.U.), and by the Urban Klima 2050 -- LIFE 18 IPC 000001 project, which has been received funding from European Union's LIFE programme (G.C., E.V., L.I., A.B., A.U., and M.R.). Additional financial support was obtained from the Basque Government (PIBA2020-1-0028 & IT1723-22). We thank the NOAA Climate Prediction Center for providing Sea Temperature data through the NCEP Global Ocean Data Assimilation System (GODAS) www.cpc.ncep.noaa.gov/products/GODAS. We also thank Ocean Biodiversity Information System (OBIS) for providing global occurrences of the biological group studied here. Data from the Basque Country were obtained from the Basque Water Agency (URA) monitoring network, through a Convention with AZTI. M.C., J.G., D.G.-G. and F.R. acknowledge the 'Severo Ochoa Centre of Excellence' accreditation (CEX2019-000928-S). Authors M.H. and M.Lin. are grateful for the support from ICES Working Group on Comparative Ecosystem-based Analyses of Atlantic and Mediterranean marine systems (WGCOMEDA) for this research. This paper is contribution nº xxxx from AZTI, Marine Research, Basque Research and Technology Alliance (BRTA)

The effects of antifreeze proteins (AFPs) on the freezing temperatures of water is well studiedand known today. Studies of the affects of antifreeze proteins on glass transition and melting tem-peratures have been conducted on samples containing relatively high concentrations of glyceroland water. In this paper we conduct experiments with antifreeze proteins in water-dominatedglycerol water mixtures to determine how AFPs affect the glass transition and melting temper-atures of these samples. We present theory behind the various interactions that occur betweencomponents of the various mixtures studied and provide mathematical background and proofsto verify our methods. We discuss the hardware and software setups, experimental procedure,preparation of samples and analysis of the gathered data. The experimental results obtained fromthe raw data is presented as well as information on how the data was interpreted. Our analysisof a 23% glycerol water mixture with varying concentrations of teleost fish type III anti-freezeproteins suggest that there is a lowering effect to the glass transition temperature. Uncertainties,arbitrary choices and areas of future research are established for suggestions of the continuedresearch of these phenomena.i

We present a record of melt events obtained from the East Greenland Ice Core Project (EastGRIP) ice core in central northeastern Greenland, covering the largest part of the Holocene. The data were acquired visually using an optical dark-field line scanner. We detect and describe melt layers and lenses, seen as bubble-free layers and lenses, throughout the ice above the bubble–clathrate transition. This transition is located at 1150 m depth in the EastGRIP ice core, corresponding to an age of 9720 years b2k. We define the brittle zone in the EastGRIP ice core as that from 650 to 950 m depth, where we count on average more than three core breaks per meter. We analyze melt layer thicknesses, correct for ice thinning, and account for missing layers due to core breaks. Our record of melt events shows a large, distinct peak around 1014 years b2k (986 CE) and a broad peak around 7000 years b2k, corresponding to the Holocene Climatic Optimum. In total, we can identify approximately 831 mm of melt (corrected for thinning) over the past 10 000 years. We find that the melt event from 986 CE is most likely a large rain event similar to that from 2012 CE, and that these two events are unprecedented throughout the Holocene. We also compare the most recent 2500 years to a tree ring composite and find an overlap between melt events and tree ring anomalies indicating warm summers. Considering the ice dynamics of the EastGRIP site resulting from the flow of the Northeast Greenland Ice Stream (NEGIS), we find that summer temperatures must have been at least 3 ± 0.6 ∘C warmer during the Early Holocene compared to today.

This study presents simulations of Greenland surface melt for the Eemian interglacial period (∼130 000 to 115 000 years ago) derived from regional climate simulations with a coupled surface energy balance model. Surface melt is of high relevance due to its potential effect on ice core observations, e.g., lowering the preserved total air content (TAC) used to infer past surface elevation. An investigation of surface melt is particularly interesting for warm periods with high surface melt, such as the Eemian interglacial period. Furthermore, Eemian ice is the deepest and most compressed ice preserved on Greenland, resulting in our inability to identify melt layers visually. Therefore, simulating Eemian melt rates and associated melt layers is beneficial to improve the reconstruction of past surface elevation. Estimated TAC, based on simulated melt during the Eemian, could explain the lower TAC observations. The simulations show Eemian surface melt at all deep Greenland ice core locations and an average of up to ∼30 melt days per year at Dye-3, corresponding to more than 600 mm water equivalent (w.e.) of annual melt. For higher ice sheet locations, between 60 and 150 mmw.e.yr-1 on average are simulated. At the summit of Greenland, this yields a refreezing ratio of more than 25 % of the annual accumulation. As a consequence, high melt rates during warm periods should be considered when interpreting Greenland TAC fluctuations as surface elevation changes. In addition to estimating the influence of melt on past TAC in ice cores, the simulated surface melt could potentially be used to identify coring locations where Greenland ice is best preserved.

As part of the Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP), several climate modeling centers performed a coordinated pre-study experiment with interactive stratospheric aerosol models simulating the volcanic aerosol cloud from an eruption resembling the 1815 Mt. Tambora eruption (VolMIP-Tambora ISA ensemble). The pre-study provided the ancillary ability to assess intermodel diversity in the radiative forcing for a large stratospheric-injecting equatorial eruption when the volcanic aerosol cloud is simulated interactively. An initial analysis of the VolMIP-Tambora ISA ensemble showed large disparities between models in the stratospheric global mean aerosol optical depth (AOD). In this study, we now show that stratospheric global mean AOD differences among the participating models are primarily due to differences in aerosol size, which we track here by effective radius. We identify specific physical and chemical processes that are missing in some models and/or parameterized differently between models, which are together causing the differences in effective radius. In particular, our analysis indicates that interactively tracking hydroxyl radical (OH) chemistry following a large volcanic injection of sulfur dioxide (SO2) is an important factor in allowing for the timescale for sulfate formation to be properly simulated. In addition, depending on the timescale of sulfate formation, there can be a large difference in effective radius and subsequently AOD that results from whether the SO2 is injected in a single model grid cell near the location of the volcanic eruption, or whether it is injected as a longitudinally averaged band around the Earth.