Kelp forest community structure and demography in Kongsfjorden (Svalbard) across 25 years of Arctic warming.

The Arctic archipelago of Svalbard is a hotspot of global warming and many fjords experience a continuous increase in seawater temperature and glacial melt while sea-ice cover declines. In 1996/1998, 2012-2014, and 2021 macroalgal biomass and species diversity were quantified at the study site Hansneset, Kongsfjorden (W-Spitsbergen) in order to identify potential changes over time. In 2021, we repeated the earlier studies by stratified random sampling (1 × 1 m,  = 3) along a sublittoral depth transect (0, 2.

Phylogeography and molecular diversity of two highly abundant amphipod species in a rapidly changing Arctic Ocean.

Rapid warming in the Arctic is drastically impacting marine ecosystems, affecting species communities and food-web structure. Pelagic amphipods are a major component of the Arctic zooplankton community and represent a key link between secondary producers and marine vertebrates at higher trophic levels. Two co-existing species dominate in the region: the larger , considered a true polar species and the smaller , a sub-Arctic, boreal-Atlantic species.

Environmental DNA (eDNA) reveals potential for interoceanic fish invasions across the Panama Canal.

Interoceanic canals can facilitate biological invasions as they connect the world's oceans and remove dispersal barriers between bioregions. As a consequence, multiple opportunities for biotic exchange arise and the resulting establishment of migrant species often causes adverse ecological and economic impacts. The Panama Canal is a key region for biotic exchange as it connects the Pacific and Atlantic Oceans in Central America.

In vivo localization of iron starvation induced proteins under variable iron supplementation regimes in .

Unlabelled: The model pennate diatom is able to assimilate a range of iron sources. It therefore provides a platform to study different mechanisms of iron processing concomitantly in the same cell. In this study, we follow the localization of three iron starvation induced proteins (ISIPs) in vivo, driven by their native promoters and tagged by fluorophores in an engineered line of .

The Underwater Vision Profiler 6: an imaging sensor of particle size spectra and plankton, for autonomous and cabled platforms.

Autonomous and cabled platforms are revolutionizing our understanding of ocean systems by providing 4D monitoring of the water column, thus going beyond the reach of ship-based surveys and increasing the depth of remotely sensed observations. However, very few commercially available sensors for such platforms are capable of monitoring large particulate matter (100-2000 m) and plankton despite their important roles in the biological carbon pump and as trophic links from phytoplankton to fish. Here, we provide details of a new, commercially available scientific camera-based particle counter, specifically designed to be deployed on autonomous and cabled platforms: the Underwater Vision Profiler 6 (UVP6).

Annual transcriptome of a key zooplankton species, the copepod .

The copepod (Crustacea, Copepoda) is a key zooplanktonic species with a crucial position in the North Atlantic food web and significant contributor to ocean carbon flux. Like many other high latitude animals, it has evolved a programmed arrested development called diapause to cope with long periods of limited food supply, while growth and reproduction are timed to take advantage of seasonal peaks in primary production. However, anthropogenic warming is inducing changes in the expected timing of phytoplankton blooms, suggesting phenological mismatches with negative consequences for the N.

A Single-Year Cosmic Ray Event at 5410 BCE Registered in C of Tree Rings.

The annual C data in tree rings is an outstanding proxy for uncovering extreme solar energetic particle (SEP) events in the past. Signatures of extreme SEP events have been reported in 774/775 CE, 992/993 CE, and ∼660 BCE. Here, we report another rapid increase of C concentration in tree rings from California, Switzerland, and Finland around 5410 BCE.

Heat stress responses and population genetics of the kelp (Phaeophyceae) across latitudes reveal differentiation among North Atlantic populations.

To understand the thermal plasticity of a coastal foundation species across its latitudinal distribution, we assess physiological responses to high temperature stress in the kelp in combination with population genetic characteristics and relate heat resilience to genetic features and phylogeography. We hypothesize that populations from Arctic and cold-temperate locations are less heat resilient than populations from warm distributional edges. Using meristems of natural populations from six locations ranging between Kongsfjorden, Spitsbergen (79°N), and Quiberon, France (47°N), we performed a common-garden heat stress experiment applying 15°C to 23°C over eight days.

Changes in Circulation and Particle Scavenging in the Amerasian Basin of the Arctic Ocean over the Last Three Decades Inferred from the Water Column Distribution of Geochemical Tracers.

Since the 1980-1990s, international research efforts have augmented our knowledge of the physical and chemical properties of the Arctic Ocean water masses, and recent studies have documented changes. Understanding the processes responsible for these changes is necessary to be able to forecast the local and global consequences of these property evolutions on climate. The present work investigates the distributions of geochemical tracers of particle fluxes and circulation in the Amerasian Basin and their temporal evolution over the last three decades (from stations visited between 1983 and 2015).

Increased Arctic influence on the midlatitude flow during Scandinavian Blocking episodes.

Recent studies have suggested that Arctic teleconnections affect the weather of the midlatitudes on time-scales relevant for medium-range weather forecasting. In this study, we use several numerical experimentation approaches with a state-of-the-art global operational numerical weather prediction system to investigate this idea further. Focusing on boreal winter, we investigate whether the influence of the Arctic on midlatitude weather, and the impact of the current Arctic observing system on the skill of medium-range weather forecasts in the midlatitudes is more pronounced in certain flow regimes.

Metabolism and foraging strategies of mid-latitude mesozooplankton during cyanobacterial blooms as revealed by fatty acids, amino acids, and their stable carbon isotopes.

Increasing sea surface temperatures (SST) and blooms of lipid-poor, filamentous cyanobacteria can change mesozooplankton metabolism and foraging strategies in marine systems. Lipid shortage and imbalanced diet may challenge the build-up of energy pools of lipids and proteins, and access to essential fatty acids (FAs) and amino acids (AAs) by copepods. The impact of cyanobacterial blooms on individual energy pools was assessed for key species temperate and boreal spp.

Aerial surveys for Antarctic minke whales () reveal sea ice dependent distribution patterns.

This study investigates the distribution of Antarctic minke whales (AMW) in relation to sea ice concentration and variations therein. Information on AMW densities in the sea ice-covered parts of the Southern Ocean is required to contextualize abundance estimates obtained from circumpolar shipboard surveys in open waters, suggesting a 30% decline in AMW abundance. Conventional line-transect shipboard surveys for density estimation are impossible in ice-covered regions, therefore we used icebreaker-supported helicopter surveys to obtain information on AMW densities along gradients of 0%-100% of ice concentration.

Multimodel Evidence for an Atmospheric Circulation Response to Arctic Sea Ice Loss in the CMIP5 Future Projections.

Previous single-model experiments have found that Arctic sea ice loss can influence the atmospheric circulation. To evaluate this process in a multimodel ensemble, a novel methodology is here presented and applied to infer the influence of Arctic sea ice loss in the CMIP5 future projections. Sea ice influence is estimated by comparing the circulation response in the RCP8.

BedMachine v3: Complete Bed Topography and Ocean Bathymetry Mapping of Greenland From Multibeam Echo Sounding Combined With Mass Conservation.

Greenland's bed topography is a primary control on ice flow, grounding line migration, calving dynamics, and subglacial drainage. Moreover, fjord bathymetry regulates the penetration of warm Atlantic water (AW) that rapidly melts and undercuts Greenland's marine-terminating glaciers. Here we present a new compilation of Greenland bed topography that assimilates seafloor bathymetry and ice thickness data through a mass conservation approach.

Ice residual properties in mixed-phase clouds at the high-alpine Jungfraujoch site.

Ice residual (IR) and total aerosol properties were measured in mixed-phase clouds (MPCs) at the high-alpine Jungfraujoch research station. Black carbon (BC) content and coating thickness of BC-containing particles were determined using single-particle soot photometers. The ice activated fraction (IAF), derived from a comparison of IR and total aerosol particle size distributions, showed an enrichment of large particles in the IR, with an increase in the IAF from values on the order of 10 to 10 for 100 nm (diameter) particles to 0.

Mid-2000s North Atlantic shift: Heat budget and circulation changes.

Prior to the 2000s, the North Atlantic was the basin showing the greatest warming. However, since the mid-2000s during the so-called global warming hiatus, large amounts of heat were transferred in this basin from upper to deeper levels while the dominance in terms of atmospheric heat capture moved into the Indo-Pacific. Here we show that a large transformation of modal waters in the eastern North Atlantic (ENA) played a crucial role in such contrasting behavior.