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The presence of warm Atlantic water on the Greenland continental shelf has been connected to the accelerated melting of the Greenland Ice Sheet, particularly in the southwest and southeast shelf regions. Results from two high‐resolution coupled ocean‐sea ice simulations that utilized either the 1/10° Parallel Ocean Program (POP) or the 1/12° HYbrid Coordinate Ocean Model (HYCOM) are used to understand the flux of heat on and off the southern Greenland shelf. The analysis reveals that the region of greatest heat flux onto the shelf is southeast Greenland. On the southwestern shelf, heat is mainly exported from the shelf to the interior basins. We identify differences in the shelf break current structure and on‐shelf heat content between the two simulations. Just south of the Denmark Strait, there is a seasonally persistent pattern of multi‐day variability in the cross‐shelf heat flux in both simulations. In the POP simulation, this high‐frequency signal results in net on‐shore heat flux. In the HYCOM simulation, the signal is weaker and results in net off‐shelf heat flux. This variability is consistent with Denmark Strait Overflow eddies traveling along the shelf break. Plain Language Summary: Melting of the Greenland Ice Sheet has been accelerating in recent decades because of rising ocean and air temperatures. Warm ocean water in the deep basin from the subtropical North Atlantic is separated from the ice sheet margin (glacier termini in the Greenland fjords) by the shallower continental shelf region. In this study we compare two simulations of the ocean and sea ice that represent the currents and eddying motions around Greenland realistically. We identify how and where heat is moved on and off the southern Greenland shelf and consider the results to be robust when they are common to both simulations. Warm water mainly moves onto the southeast shelf and off the southwest shelf; the currents on the shelf transport the warm water around the southern tip of Greenland. Near the Denmark Strait we identify oscillations in the warm water crossing onto the shelf that are associated with the presence of Denmark Strait Overflow eddies. On average, these eddies move heat onto the shelf in one model and off the shelf in the other. Understanding how warm water reaches the shelf allows us to better understand how the ocean contributes to the melting of the Greenland Ice Sheet. Key Points: Cross‐shelf heat flux is strongest over the southeast continental shelf in both POP and HYCOM ocean modelsDenmark Strait Overflow eddies traveling along the shelf break drive multi‐day oscillations of on‐shelf heat fluxOn‐shelf heat fluxes along the wide sector of the southeast Greenland shelf are associated with the mean flow in HYCOM and eddies in POP [ABSTRACT FROM AUTHOR]

Baroclinic seamount-trapped waves are thought to influence their surrounding ecosystem; however, trapped waves are not well-studied in near-equatorial settings, where stratification is strong and Burger numbers (...) are large. Motivated by observations, we use daily output (2005-2009) from the global Parallel Ocean Program Model (POP) to examine topographically trapped baroclinic waves around the Seychelles Plateau (S > 400) in the tropical Indian Ocean. These trapped waves are associated with velocity and temperature oscillations at periods of 15-16 days, similar to the dominant period of some equatorial Yanai waves. Energy flux maps using POP output suggest that quasi-biweekly equatorial Yanai waves excite trapped waves on the western and south-western flanks of the Seychelles Plateau, near the surface. The anticyclonic energy flux associated with the trapped wave extends vertically throughout the water column and around most of the plateau circumference, diminishing on the eastern flank of the plateau. This work highlights the role that equatorial planetary waves and trapped waves play in facilitating energy redistribution, dissipation, and mixing in the tropical ocean. [ABSTRACT FROM AUTHOR]

Significant wave height (SWH) stems from a combination of locally generated "wind-sea" and remotely generated "swell" waves. In the Northern and Southern Hemispheres, wave heights typically undergo a sinusoidal annual cycle, with larger SWH in winter in response to seasonal changes in high-latitude storm patterns that generate equatorward propagating swell. However, some locations deviate from this hemispheric-scale seasonal pattern in SWH. For example, in the California coastal region, local wind events occur in boreal spring and summer, leading to a wind speed (WSP) annual cycle with a distinct maximum in boreal spring and a corresponding local response in SWH. Here ocean regions with a WSP annual cycle reaching a maximum in late spring, summer, or early fall are designated as seasonal wind anomaly regions (SWARs). Intra-annual variability of surface gravity waves is analyzed globally using two decades of satellite-derived SWH and WSP data. The phasing of the WSP annual cycle is used as a metric to identify SWARs. Global maps of probability of swell based on wave age confirm that during the spring and summer months, locally forced waves are statistically more likely in SWARs than in surrounding regions. The magnitude of the deviation in the SWH annual cycle is determined by the exposure to swell and characteristics of the wave field within the region. Local winds have a more identifiable impact on Northern Hemisphere SWARs than on Southern Hemisphere SWARs due to the larger seasonality of Northern Hemisphere winds. [ABSTRACT FROM AUTHOR]

Ocean circulation shapes marine phytoplankton communities by setting environmental conditions and dispersing organisms. In addition, processes acting on the water column (e.g., heat fluxes and mixing) affect the community structure by modulating environmental variables that determine in situ growth and loss rates. Understanding the scales over which phytoplankton communities vary in time and space is key to elucidate the relative contributions of local processes and ocean circulation on phytoplankton distributions. Using a global ocean ecosystem model, we quantify temporal and spatial correlation scales for phytoplankton phenotypes with diverse functional traits and cell sizes. Through this analysis, we address these questions: (1) Over what timescales do perturbations in phytoplankton populations persist? and (2) over what distances are variations in phytoplankton populations synchronous? We find that correlation timescales are short in regions of strong currents, such as the Gulf Stream and Antarctic Circumpolar Current. Conversely, in the subtropical gyres, phytoplankton population anomalies persist for relatively long periods. Spatial correlation length scales are elongated near ocean fronts and narrow boundary currents, reflecting flow paths and frontal patterns. In contrast, we find nearly isotropic spatial correlation fields where current speeds are small, or where mixing acts roughly equally in all directions. Phytoplankton timescales and length scales also vary coherently with phytoplankton body size. In addition to aiding understanding of phytoplankton population dynamics, our results provide global insights to guide the design of biological ocean observing networks and to better interpret data collected at long‐term monitoring stations. Plain Language Summary: Using a global model of the marine planktonic ecosystem, we quantify the temporal and spatial correlation scales of diverse types of phytoplankton. The timescales reflect the persistence of anomalies in time and the stability of the planktonic system. The spatial scales measure over what distances variations in phytoplankton populations are synchronous. We find that timescales and length scales vary with cell size and that global patterns of correlation are shaped by ocean currents. These results provide valuable insights for the design of ocean observing systems with a unique ecological perspective. We also discuss how regional differences in phytoplankton community correlation scales are relevant for interpreting data collected at long‐term monitoring stations. Key Points: Correlation timescales in phytoplankton communities are longer in the subtropical gyres and shorter in regions of strong circulationSpatial correlations in phytoplankton communities are strongly anisotropic along frontal zones and boundary currentsOcean currents shape global patterns of temporal and spatial correlation scales in phytoplankton communities [ABSTRACT FROM AUTHOR]

The Solomon Sea is a marginal sea in the western Pacific warm pool that contains the South Pacific low latitude western boundary currents. These low latitude western boundary currents chiefly exit the Solomon Sea through three channels (Vitiaz Strait, St. George's Channel, and Solomon Strait) and serve as the primary source water for the Equatorial Undercurrent. Simulations have shown that transport partitioning between the straits determines the water mass structure of the Equatorial Undercurrent, but the relative contributions of transport through each strait have not been observed before. As part of the Southwest Pacific Ocean Circulation and Climate Experiment, an array of moorings was deployed simultaneously in the three outflow channels of the Solomon Sea from July 2012 until March 2014 to resolve transport and water properties in each strait. Above deep isopycnals (σ0 ≤ 27.5), Vitiaz and Solomon Straits account for 54.2% and 36.2% of the mean transport, respectively, with the remaining 9.6% exiting through St. George's Channel. The strongest subinertial transport variability is observed in Solomon Strait and dominates total Solomon Sea transport variability, and a significant fraction of this variability is at intraseasonal time scales. Finally, a previously unobserved deep current at 1,500‐m depth is found to enter the Solomon Sea through Solomon Strait, with a deployment‐mean transport of 4.6 Sv (Sv ≡106 m3/s). Key Points: Vitiaz and Solomon Straits are the primary pathways from the Solomon Sea to the Equatorial PacificVitiaz Strait transport is steady in time, and Solomon Strait dominates total transport variabilityA previously unobserved deep current is found entering the Solomon Sea through Solomon Strait [ABSTRACT FROM AUTHOR]