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Glacial fjords often contain ice mélange, a frozen conglomeration of icebergs, brash ice, and sea ice, that have been postulated to influence both glacier dynamics and fjord circulation through coupled mechanical and thermodynamic processes. Ice mélange meltwater can alter stratification of the water column by releasing cool, fresh water across a range of depths in the upper layer of the fjord. This meltwater input can subsequently modify the depth at which the subglacial discharge plume reaches neutral buoyancy and therefore the underlying buoyancy-driven fjord circulation and heat exchange with warm ocean shelf waters. Despite a spate of recent modelling studies exploring these proposed feedbacks, we lack in situ observations quantifying changes to the water column induced by ice mélange meltwater. Here we use a novel dataset collected before and after the melt, breakup, and down-fjord transport of an ephemeral ice mélange in front of Kangilliup Sermia (Rink Isbræ) to directly investigate the extent to which ice mélange meltwater can modify glacier-adjacent water properties. We find that even a short-lived ice mélange (4 days) can cause substantial cooling (0.18 °C) and freshening (0.25 g kg-1) of the water column that leads to stratification change down to the depth of the outflowing discharge plume. We compare our observations to an adjacent fjord, Kangerlussuup Sermia, where ice mélange seldom forms in the summertime, and show that the presence or absence of ice mélange melt creates fundamental differences in their upper layer hydrography. These observations provide critical constraints for recent modelling studies that have suggested ice mélange meltwater needs to be included in ocean circulation models for glaciers with deep grounding lines and high ice fluxes, which are precisely the glaciers exhibiting the largest magnitude terminus retreats at present. [ABSTRACT FROM AUTHOR]

Frontal ablation has caused 32 %–66 % of Greenland Ice Sheet mass loss since 1972, and despite its importance in driving terminus change, ocean thermal forcing remains crudely incorporated into large-scale ice sheet models. In Greenland, local fjord-scale processes modify the magnitude of thermal forcing at the ice–ocean boundary but are too small scale to be resolved in current global climate models. For example, simulations used in the Ice Sheet Intercomparison Project for CMIP6 (ISMIP6) to predict future ice sheet change rely on the extrapolation of regional ocean water properties into fjords to drive terminus ablation. However, the accuracy of this approach has not previously been tested due to the scarcity of observations in Greenland fjords, as well as the inability of fjord-scale models to realistically incorporate icebergs. By employing the recently developed IceBerg package within the Massachusetts Institute of Technology general circulation model (MITgcm), we here evaluate the ability of ocean thermal forcing parameterizations to predict thermal forcing at tidewater glacier termini. This is accomplished through sensitivity experiments using a set of idealized Greenland fjords, each forced with equivalent ocean boundary conditions but with varying tidal amplitudes, subglacial discharge, iceberg coverage, and bathymetry. Our results indicate that the bathymetric obstruction of external water is the primary control on near-glacier thermal forcing, followed by iceberg submarine melting. Despite identical ocean boundary conditions, we find that the simulated fjord processes can modify grounding line thermal forcing by as much as 3 °C , the magnitude of which is largely controlled by the relative depth of bathymetric sills to the Polar Water–Atlantic Water thermocline. However, using a common adjustment for fjord bathymetry we can still predict grounding line thermal forcing within 0.2 °C in our simulations. Finally, we introduce new parameterizations that additionally account for iceberg-driven cooling that can accurately predict interior fjord thermal forcing profiles both in iceberg-laden simulations and in observations from Kangiata Sullua (Ilulissat Icefjord). [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate and compare the concentration of water-soluble bioactive compounds in tomato products (polyphenols profile, water-soluble vitamins and nucleophilic substances) with the concentration of the same bioactive molecules existing in a water-soluble patented tomato extract, water-soluble tomato extract (WSTC), commercially available as FruitFlow®. This patented tomato extract has been recognised by EFSA (European Food Safety Authority) in a specific Health Claim declaration as having an "Antiplatelet health effect". More than 100 commercial tomato samples, coming from 18 different processing tomato companies worldwide, were analysed and compared with the FruitFlow® supplement. According to the multivariate statistical analyses applied to the data matrix, it is possible to conclude that the commercial tomato products measured (pastes, purees, others) show a significantly higher concentration of water-soluble bioactive molecules (nucleosides/nucleotides and polyphenols) responsible for an anti-platelet aggregation effect than the FruitFlow® dietary supplement. [ABSTRACT FROM AUTHOR]

Frontal ablation at tidewater glaciers, which comprises iceberg calving, submarine and subaerial melting, is a key boundary condition for numerical ice sheet models but remains difficult to measure directly in-situ. Many previous studies have quantified frontal ablation over varying spatio-temporal scales, however most use ice discharge as an approximation for frontal ablation, thereby neglecting the influence of terminus location change. Frontal ablation estimates that do account for terminus location change are spatio-temporally limited by the availability of observational data. Here, we present a processing chain to quantify frontal ablation using open-source observational data. We apply the processing chain to 49 tidewater glaciers in Greenland with reliable near-terminus bathymetry data in the BedMachine V4 dataset. Nearterminus volume change over the time period 1987 - 2020 is determined using a previously published dataset of terminus positions (TermPicks), ice thicknesses from ArcticDEM and AeroDEM, adjusted for surface elevation change over time, and bathymetry data from BedMachine v4. Assuming a vertical terminus geometry and uniform ice density, we estimate frontal ablation as the difference between mass flux towards the terminus (Mankoff et al., 2020) and mass change between consecutive observation. The frontal ablation dataset offers exciting opportunities for developing new insights into ice dynamics, including helping to improve numerical model hindcasting and projections. Lastly, we provide a processing chain that may serve as a community standard for determining frontal ablation from observational data for any tidewater glacier. [ABSTRACT FROM AUTHOR]