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Abstract Palmer Deep submarine canyon on the western Antarctic Peninsula hosts permanent penguin breeding rookeries and is characterized by elevated chlorophyll‐a compared to the surrounding continental shelf. Particle residence times within the canyon are shorter than phytoplankton doubling times, which points to the ecosystem's productivity being tied primarily to advection of externally generated biomass into the canyon. This view is supported by recent observational studies showing alignment of attractive flow structures with phytoplankton patches. While residence times are short, they vary in space and are longer than the timescale for submesoscale instabilities with strong vertical motions (an inertial period), allowing for biological sources to be regionally or episodically important. Here we use measurements of ocean surface velocities (from high‐frequency radars) and chlorophyll (from satellites) to calculate the Eulerian, Lagrangian, and horizontal advection terms of the surface chlorophyll budget. The Lagrangian term (including biological sources) is generally comparable in magnitude to advection, but the latter is more important on the canyon's western flank. We then compare joint distributions of relative vorticity and strain conditioned on a particle's net chlorophyll change. In general, parcels experiencing a net increase (decrease) in chlorophyll experience greater cyclonic (anticyclonic) vorticity. Although high‐vorticity features significantly influence parcel motion, trajectories generally align with an estimate of the balanced flow, which is often characterized by a cyclone over the central canyon and eastern flank. Without subsurface data we cannot confirm whether the Lagrangian change truly indicates biological accumulation but we offer some interpretations. 

Scenarios to stabilize global climate and meet international climate agreements require rapid reductions in human carbon dioxide (CO₂) emissions, often augmented by substantial carbon dioxide removal (CDR) from the atmosphere. While some ocean-based removal techniques show potential promise as part of a broader CDR and decarbonization portfolio, no marine approach is ready yet for deployment at scale because of gaps in both scientific and engineering knowledge. Marine CDR spans a wide range of biotic and abiotic methods, with both common and technique-specific limitations. Further targeted research is needed on CDR efficacy, permanence, and additionality as well as on robust validation methods—measurement, monitoring, reporting, and verification—that are essential to demonstrate the safe removal and long-term storage of CO₂. Engineering studies are needed on constraints including scalability, costs, resource inputs, energy demands, and technical readiness. Research on possible co-benefits, ocean acidification effects, environmental and social impacts, and governance is also required. 

AbstractPolar systems are experiencing major changes that has significant implications for ocean circulation and global biogeochemistry. While these changes are accelerating, access to polar systems is decreasing as ships and logistical capabilities are declining. Autonomous underwater buoyancy gliders have proven to be robust technologies that are capable of filling sampling gaps. Gliders have also provided a more sustained presence in polar seas than ships are able. Along the West Antarctic Peninsula, one of the most rapidly warming regions on this planet, gliders have proven to be a useful tool being used by the international community to link land research stations without requiring major research vessel ship support. The gliders are capable of adaptive sampling of subsurface features not visible from satellites, sustained sampling to characterize seasonal dynamics, and they increasingly play a central role in the management of natural resources. Future challenges to expand their utility include: (A) developing robust navigation under ice, which would allow gliders to provide a sustained bridge between the research stations when ship support is declining, and (B) expanding online resources to provide the international community open access to quality data in near real time. These advances will accelerate the use of gliders to fill critical sampling gaps for these remote ocean environments. 

Abstract. Phytoplankton form the base of marine food webs and playan important role in carbon cycling, making it important to quantify ratesof biomass accumulation and loss. As phytoplankton drift with oceancurrents, rates should be evaluated in a Lagrangian as opposed to an Eulerianframework. In this study, we quantify the Lagrangian (from Bio-Argo floatsand surface drifters with satellite ocean colour) and Eulerian (fromsatellite ocean colour and altimetry) statistics of mesoscale chlorophylland velocity by computing decorrelation time and length scales and relatethe frames by scaling the material derivative of chlorophyll. Because floatsprofile vertically and are not perfect Lagrangian observers, we quantify themean distance between float and surface geostrophic trajectories over thetime spanned by three consecutive profiles (quasi-planktonic index, QPI) toassess how their sampling is a function of their deviations from surfacemotion. Lagrangian and Eulerian statistics of chlorophyll are sensitive to thefiltering used to compute anomalies. Chlorophyll anomalies about a 31 dtime filter reveal an approximate equivalence of Lagrangian and Euleriantendencies, suggesting they are driven by ocean colour pixel-scale processesand sources or sinks. On the other hand, chlorophyll anomalies about aseasonal cycle have Eulerian scales similar to those of velocity, suggestingmesoscale stirring helps set distributions of biological properties, andratios of Lagrangian to Eulerian timescales depend on the magnitude ofvelocity fluctuations relative to an evolution speed of the chlorophyllfields in a manner similar to earlier theoretical results for velocityscales. The results suggest that stirring by eddies largely sets Lagrangiantime and length scales of chlorophyll anomalies at the mesoscale.