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This article considers the history of Fort Pitt (1780-1922), its military hospital (founded 1814) and, in particular, its Army Medical School (1860–63). The museum and library were the work of the hospital’s first directors: Dr David MacLoughlin and Sir James McGrigor, the latter the renowned reformer of military medical education. Central to the foundation of the medical school was Florence Nightingale who visited the site in 1856. The school opened in 1860 with five sets of students attending before it was transferred in 1863 to the Royal Victoria hospital, Netley, Hampshire. Fort Pitt was a “practical” medical school with students attending for 4-9 months of clinical experience. This included “instruction in tropical medicine” delivered by members of the Indian Medical Service. The foundation of a military medical school fulfilled an ambition dating back to at least 1796. Nightingale’s role (exerted through Sidney Herbert) was omitted from contemporary newspaper reports. Fort Pitt continued as a military hospital until 1922 when it was converted to a school. The medical school constitutes a landmark in British military medicine, a response to the failure of British medical care in the Crimean war (1853–1856) and a forgotten legacy of Florence Nightingale.

Marine plastic pollution, particularly microplastics, has been recognised as a global issue in the recent years, but research efforts in the Pacific are lagging. We carried out research on microplastics contamination of surface waters of the Vava'u archipelago, Tonga. Since microplastics smaller than the standard mesh size (333-335 μm) are readily reported in the literature on microplastics, we used a finer plankton net (100 μm) to determine the proportion of captured microplastics smaller than 300 μm. Isolated microplastics were counted and measured using stereomicroscope with polymer identification performed by FTIR spectroscopy. The analysis revealed high microplastics concentrations (329,299.7 ± 40,994.2 pcs km

The Campbell Plateau is a dominating bathymetric feature of New Zealand’s subantarctic region, strongly influencing the dynamics of both the Subtropical Front (STF) to the north and the Subantarcti...

The physical behaviour of estuaries controls the transport of substances from freshwater to the ocean. We conducted the first investigation of salinity distribution and its response to spring-neap ...

The Southern Ocean is the hub that interconnects the Pacific, Indian and Atlantic Oceans to allow the worldwide distribution of heat, salt, dissolved gases and nutrients. Such dispersal is dominated by the west-to-east, wind-driven, Antarctic Circumpolar Current (ACC) coupled with a north-south, buoyancy-forced meridional overturning circulation (SOMOC). Basically, relatively warm Circumpolar Deep Water (CDW) from the Northern Hemisphere ascends southward with its denser part reaching coastal Antarctica. There, cooling and addition of brine convert the CDW to dense Antarctic Bottom Water (AABW) that moves northward via far-reaching deep western boundary currents. Shallow CDW upwells further offshore under wind forcing and increased buoyancy caused by freshening and warming that transform CDW to lower density surface waters. These migrate north due to Ekman transport and subduct approaching the Subantarctic Front to form Subantarctic Mode and Antarctic Intermediate Waters that take up much of the anthropogenic heat and carbon dioxide. Thus, the MOC-ACC circulation ameliorates the impacts of modern climate change. However, the resultant warming ocean/climate affects ice stability, sea level rise, SOMOC buoyancy, production of AABW, stratification, and primary productivity. Increasing knowledge of these and other responses, plus a stronger multidisciplinary approach to understanding changes in the Southern Ocean, will enhance future projections.

Plastic pollution research on a global scale intensified considerably in the current decade ; however, research efforts in the South Pacific are still lagging. Here, we report on microplastic contamination of intertidal and subtidal sediments in the Vava'u archipelago, Tonga. While providing the first baseline data of its type in Tonga, the study also advances methods and adjusts them for low-budget research. The methods were based on density separation of microplastics from the sediment using CaCl2, a high-density salt which due to its high solubility, low cost and availability. Once separated, microplastics were quantified by microscopic analysis and polymers characterized via FTIR spectroscopy. Microplastics in intertidal and subtidal sediments were found in concentrations of 23.5 ± 1.9 and 15.0 ± 1.9 particles L−1 of sediment, respectively. The dominant type of microplastics in both intertidal (85 %) and subtidal sediments (62 %) were fibres.

The mean, interannual variability, decadal variability, and longer-term trends in the across-track geostrophic velocity of the poleward-flowing boundary current along the Fiordland coast (the Fiord...

Ocean temperature changes around New Zealand are estimated from satellite sea surface temperature (SST) products since 1981, two high resolution expendable bathythermograph transects (HRXBT...

Buoyant plastics enter estuaries largely from urban streams and an unknown fraction is retained before further transport to the open ocean. Plastic drifters were launched in a well-mixed estuary to simulate the movement of surface buoyant plastics. Two experiments were conducted, one during spring tides and one during neap tides, both with similar river flows and winds. Stronger tidal currents during spring tides resulted in larger dispersion and further downstream transport of the drifters. Half of the drifters were grounded within two tidal cycles. During the neap experiment, even more of the drifters (87%) were retained in the estuary. The grounding of such a high proportion of drifters suggests that much of the plastic pollution in estuaries of this type remains close to the riverine source. These findings imply that local clean-up programs removing grounded litter can reduce over half of the plastic pollution input to these estuaries.

Approximately 25% of Antarctic Bottom Water has its origin as dense water exiting the western Ross Sea, but little is known about what controls the release of dense water plumes from the Drygalski Trough. We deployed two moorings on the slope to investigate the water properties of the bottom water exiting the region at Cape Adare. Salinity of the bottom water has increased in 2018 from the previous measurements in 2008–2010, consistent with the observed salinity increase in the Ross Sea. We find High Salinity Shelf Water from the Drygalski Trough contributes to two pulses of dense water at Cape Adare. The timing and magnitude of the pulses is largely explained by an inverse relationship with the tidal velocity in the Ross Sea. We suggest that the diurnal and low frequency tides in the western Ross Sea may control the magnitude and timing of the dense water outflow.

Several fast, narrow boundary currents flow along the eastern margin of New Zealand forming part of the western boundary current system of the South Pacific. In this study, using over 20 years of satellite altimeter observations and in situ data, we investigate the mean and variability of the current transports at seasonal, interannual and decadal time scales. We relate the means and fluctuations of the currents to the Southern Oscillation Index and to potential drivers of the circulation, including local and basin-scale winds. We also investigate the barotropic and baroclinic responses of the currents to basin-scale wind forcing using Rossby wave models. We find the currents are highly variable and there are no discernible trends in the transports since 1993. There is little coherence between transports along the boundary, suggesting a range of mechanisms drive the variability of the currents individually rather than the system as a whole. There is little correspondence between transports in any of the boundary currents and the El Nino/Southern Oscillation. We also find that the transports are not well described by the arrival of linear Rossby waves. At decadal time scales, only transports in the Subantarctic Front show a close correspondence with the variability of the wind stress curl averaged over the South Pacific. Seasonality is significant in two of the currents, likely driven by seasonality in local winds. In contrast with the larger East Australian Current, which forms part of the same South Pacific western boundary current system, we see collectively little evidence of a link between trends and variability in the New Zealand boundary currents and large-scale or local wind forcing.

Accelerated warming of western boundary currents due to the strengthening of subtropical gyres has had cascading effects on coastal ecosystems and is widely expected to result in further tropicalization of temperate regions. Predicting how species and ecosystems will respond requires a better understanding of the variability in ocean warming in complex boundary current regions. Using three ≥50 year temperature records we demonstrate high variability in the magnitude and seasonality of warming in the Southwest Pacific boundary current region. The greatest rate of warming was evident off eastern Tasmania (0.20 °C decade−1), followed by southern New Zealand (0.10 °C decade−1), while there was no evidence of annual warming in northeastern New Zealand. This regional variability in coastal warming was also evident in the satellite record and is consistent with expected changes in regional-scale circulation resulting from increased wind stress curl in the South Pacific subtropical gyre. Warming trends over the satellite era (1982–2016) were considerably greater than the longer-term trends, highlighting the importance of long-term temperature records in understanding climate change in coastal regions. Our findings demonstrate the spatial and temporal complexity of warming patterns in boundary current regions and challenge widespread expectations of tropicalization in temperate regions under future climate change.

The variability of Subtropical Mode Water (STMW) in the Southwest Pacific is investigated using a 28-year-long time series (1986 to 2014) of high-resolution expendable bathythermograph data north of New Zealand (PX06) and a shorter time series, the Roemmich-Gilson monthly Argo optimal interpolation for the 2004-2014 period. The variability in STMW inventories is compared to the variability in air-sea heat fluxes, mixed layer depths and transport of the East Auckland Current (EAUC) to assess both the atmospheric and oceanic roles influencing the formation and decay of STMW. The STMW north of New Zealand has a short lifespan with little persistence of the water mass from one year to the next one. Deeper mixed layers and negative anomalies in surface heat fluxes are correlated with increased formation of STMW. The heat content of the STMW layer is anticorrelated with inventories, particularly during the El Nino years. This suggests that large volumes of STMW are coincident with cooler conditions in the prior winter and less oceanic heat storage. There is significant seasonal and interannual variability in STMW inventories, however there are no trends in STMW properties, including its core layer temperature over the last decade. The variability of the winter EAUC transport is highly correlated with the STMW inventories and thermocline depth in the following spring, suggesting ocean dynamics deepen the thermocline and precondition for deeper mixed layers.

This paper investigates the mechanisms causing interannual variability of upper ocean heat content and sea surface temperature (SST) in the southwest Pacific. Using the ECCOv4 ocean reanalysis it is shown that air–sea heat flux and ocean heat transport convergence due to ocean dynamics both contribute to the variability of upper ocean temperatures around New Zealand. The ocean dynamics responsible for the ocean heat transport convergence are investigated. It is shown that SSTs are significantly correlated with the arrival of barotropic Rossby waves estimated from the South Pacific wind stress over the latitudes of New Zealand. Both Argo observations and the ECCOv4 reanalysis show deep isotherms fluctuate coherently around the country. The authors suggest that the depth of the thermocline around New Zealand adjusts to changes in the South Pacific winds, modifies the vertical advection of heat into the upper ocean, and contributes to the interannual variability of SST in the region.

BACKGROUND AND OBJECTIVES: The American Academy of Pediatrics 2014 bronchiolitis guidelines recommend against the routine use of continuous pulse oximetry (CPO) because it has been implicated in prolonging the length of stay (LOS). At our institution, infants admitted with bronchiolitis were monitored by using CPO during the entire hospital stay and intermittent desaturations METHODS: The quality improvement project was implemented on the inpatient units of 2 community hospitals during the 2016 and 2017 bronchiolitis seasons. In cycle 1 (January 2016 to April 2016), the bronchiolitis pathway from the associated quaternary children’s hospital was used to (1) limit the use of CPO to patients with severe bronchiolitis and those at high risk for apnea or severe disease, (2) discontinue CPO as patients improved and stabilized, and (3) standardize discharge criteria. In cycle 2 (November 2016 to April 2017), the clinical pathway was adopted. The main outcome measure was LOS, measured from the time of the admission order to the time of the discharge order. Process measures included compliance with the interventions. RESULTS: The project included 373 patients, 180 preintervention and 193 postintervention. The average LOS decreased by 20 hours, from 53 hours at baseline to 33 hours in cycle 2. No adverse events were noted, and there was no significant change in the number of emergency department revisits and readmissions within 7 days. CONCLUSIONS: In our study, LOS was successfully reduced in bronchiolitis patients by using a clinical pathway that limited CPO to patients with severe bronchiolitis and those at risk for severe disease or apnea.

New Zealand’s subantarctic region is a dynamic oceanographic zone with the Subtropical Front (STF) to the north and the Subantarctic Front (SAF) to the south. Both the fronts and their associated currents are strongly influenced by topography: the South Island of New Zealand and the Chatham Rise for the STF, and Macquarie Ridge and Campbell Plateau for the SAF. Here for the first time we present a consistent picture across the subantarctic region of the relationships between front positions, bathymetry and water mass structure using eight high resolution oceanographic sections that span the region. Our results show that the northwest side of Campbell Plateau is comparatively warm due to a southward extension of the STF over the plateau. The SAF is steered south and east by Macquarie Ridge and Campbell Plateau, with waters originating in the SAF also found north of the plateau in the Bounty Trough. Subantarctic Mode Water (SAMW) formation is confirmed to exist south of the plateau on the northern side of the SAF in winter, while on Campbell Plateau a deep reservoir persists into the following autumn. Antarctic Intermediate Water (AAIW) is observed in the deeper regions around the edges of the plateau, but not on the plateau, confirming that the waters on the plateau are effectively isolated from AAIW and deeper water masses that typify the open Southern Ocean waters.

Fish are an important food source for South Pacific (SP) island countries, yet there is little information on contamination of commercial marine fish species by plastic. The aim of our study was to perform a broad-scale assessment of plastic ingestion by fish common in the diet of SP inhabitants. We examined 932 specimens from 34 commercial fish species across four SP locations, and some of the prey they ingested, for the presence of marine plastics. Plastic was found in 33 species, with an average ingestion rate (IR) of 24.3 ± 1.4% and plastic load of 2.4 ± 0.2 particles per fish. Rapa Nui fish exhibited the greatest IR (50.0%), significantly greater than in other three locations. Rapa Nui is located within the SP subtropical gyre, where the concentration of marine plastics is high and food is limited. Plastic was also found in prey, which confirms the trophic transfer of microplastics.

In 2009, the federal government committed over $3 billion nationwide to help states and districts turn around their worst-performing schools. The U.S. Department of Education intended for the School Improvement Grants (SIGs) to spur dramatic change.This report looks at the results of a field study of the first-year implementation of those grants in Washington State, which received $50 million in SIG funding over three years. Researchers hoped to see what school-level changes were underway, how they compared to the intent of the grants, and the early role that districts played in SIG implementation.The report provides findings from the state, district, and school level. Researchers found that, with some exceptions, districts and schools in Washington State are approaching the turnaround work in ways only marginally different from past school improvement efforts. Despite the hard work of administrators, principals, and especially teachers, the majority of schools studied show little evidence of the type of ...

A Mean Dynamic Topography (MDT) is required to estimate mean transport in the ocean, to combine with altimetry to derive instantaneous geostrophic surface velocities, and to estimate transport from shipboard hydrography. A number of MDTs are now available globally but differ most markedly in boundary currents and the Antarctic Circumpolar Current. We evaluate several MDTs in two boundary currents off New Zealand (in the subtropical western boundary current system east of the country and in the Subantarctic Front to the south) using satellite, hydrographic, and Argo observations near two altimeter tracks. Argo float trajectories are combined with estimates of shear to produce new MDTs along both altimeter tracks: sufficiently high numbers of Argo floats travel in both boundary currents to allow a useful estimate of the mean flow at 1000 m depth and conservation of potential vorticity is used to account for more realistic flow paths. In finding a MDT, we show the uncertainties in the estimates of velocity differences between 1000 m and the surface from density climatologies, while often not estimated, need to be considered. The MDT computed from the Argo trajectories is generally consistent with the CLS09 MDT in both boundary currents and, in some locations, distinctly different from the MDT using a “level of no motion” assumption. The comparison suggests velocities from Argo trajectories can be usefully combined with other observations to improve estimates of flows and MDT in boundary currents.

We present the first proxy record of sea-ice area (SIA) in the Ross Sea, Antarctica, from a 130 year coastal ice-core record. High-resolution deuterium excess data show prevailing stable SIA from the 1880s until the 1950s, a 2–5% reduction from the mid-1950s to the early-1990s, and a 5% increase after 1993. Additional support for this reconstruction is derived from ice-core methanesulphonic acid concentrations and whaling records. While SIA has continued to decline around much of the West Antarctic coastline since the 1950s, concurrent with increasing air and ocean temperatures, the underlying trend is masked in the Ross Sea by a switch to positive SIA anomalies since the early-1990s. This increase is associated with a strengthening of southerly winds and the enhanced northward advection of sea ice.

The Tasman Front is a narrow band of eastward flowing subtropical water crossing the Tasman Sea from Australia to North Cape, New Zealand. It is the link between the two subtropical western boundary currents of the South Pacific, the East Australian Current (EAC) off eastern Australia, and the East Auckland Current (EAUC) off northeastern New Zealand. Here we report the first direct measurements of flow in the Tasman Front from a moored array deployed across gaps in the submarine ridges south of Norfolk Island and hydrographic and ADCP measurements during the deployment and recovery voyages. The mean flow through the array over July 2003 to August 2004 was found to be eastward only in the upper 800 m with a transport of ∼6 Sv. Below 800 m a weak westward mean flow (∼1.5 Sv) was measured, associated with Antarctic Intermediate Water (AAIW). Using sea surface height to account for additional transport south of the moored array results in a total mean eastward transport between Norfolk Island and North Cape, New Zealand of ∼8 Sv, varying between −4 and 18 Sv. The measurements show that the Tasman Front is much shallower than either the EAC or EAUC, both of which extend below 2000 m depth, has less transport than either the EAC or EAUC and has instances of flow reversal. Thus, the Tasman Front is a weaker connection between the EAC and EAUC than the paradigm of a contiguous South Pacific western boundary current system would suggest.

The confluence of subtropical and subantarctic boundary currents east of New Zealand creates strong fronts. The fronts have clear signatures in sea surface height (SSH) and sea surface temperature (SST) which make the confluence a good region to investigate the variability of the boundary currents of the South Pacific. Analysis of the 20 year time series of the SSH is used to investigate the location and strength of fronts, measured as the gradient in SSH (∇SSH), and the eddy kinetic energy (EKE) and their relationship to local and large-scale wind forcing. The intensity of the ∇SSH and the EKE have increased at a rate of 0.02 cm km−1 and 32 cm2 s−2 decade−1, respectively. There is a significant correlation (r = 0.7, p

Paleoceanographic archives derived from 17 marine sediment cores reconstruct the response of the Southwest Pacific Ocean to the peak interglacial, Marine Isotope Stage (MIS) 5e (ca. 125 ka). Paleo-Sea Surface Temperature (SST) estimates were obtained from the Random Forest model—an ensemble decision tree tool—applied to core-top planktonic foraminiferal faunas calibrated to modern SSTs. The reconstructed geographic pattern of the SST anomaly (maximum SST between 120 and 132 ka minus mean modern SST) seems to indicate how MIS 5e conditions were generally warmer in the Southwest Pacific, especially in the western Tasman Sea where a strengthened East Australian Current (EAC) likely extended subtropical influence to ca. 45°S off Tasmania. In contrast, the eastern Tasman Sea may have had a modest cooling except around 45°S. The observed pattern resembles that developing under the present warming trend in the region. An increase in wind stress curl over the modern South Pacific is hypothesized to have spun-up the South Pacific Subtropical Gyre, with concurrent increase in subtropical flow in the western boundary currents that include the EAC. However, warmer temperatures along the Subtropical Front and Campbell Plateau to the south suggest that the relative influence of the boundary inflows to eastern New Zealand may have differed in MIS 5e, and these currents may have followed different paths compared to today.

[1] The increased use of ambient seismic noise for seismic imaging requires better understanding of the ambient seismic noise wavefield and its source locations and mechanisms. Although the source regions and mechanisms of Rayleigh waves have been studied extensively, characterization of Love wave source processes are sparse or absent. We present here the first systematic comparison of ambient seismic noise source directions within the primary (~10–20 s period) and secondary (~5–10 s period) microseism bands for both Rayleigh and Love waves in the Southern Hemisphere using vertical- and horizontal-component ambient seismic noise recordings from a dense temporary network of 68 broadband seismometers in New Zealand. Our analysis indicates that Rayleigh and Love waves within the primary microseism band appear to be mostly generated in different areas, whereas in the secondary microseism band they arrive from similar backazimuths. Furthermore, the source areas of surface waves within the secondary microseism band correlate well with modeled deep-water and near-coastal source regions.

The concept of a southward-flowing West Auckland Current off the west coast of Northland has become an accepted feature of the ocean circulation around New Zealand. Knowledge of this flow is based on sparse data collected in the 1950s. Here we quantify the flows in the area for the first time using a current meter array deployed for a year (2003–2004) across the shelf and slope offshore of Hokianga Harbour and three hydrographic surveys along a transect coincident with the current meter array. Flows are found to be weak, and dominated by the variability. There is a southeastward drift in the mean flow offshore of the 1000-m isobath, with a northwestward mean found inshore of this. The offshore flows appear to result from large-scale sea surface height gradients, while the inshore flows respond to wind forcing in a complex manner.

Stirring in the Tasman Sea is examined using surface geostrophic currents derived from satellite altimeter measurements. Calculations of the distribution of finite-time Lyapunov exponents (FTLEs) indicate that the stirring in this region is not uniform and stretching rates over 15 days vary from less than 0.02 day−1 to over 0.3 day−1. These variations occur at both small (∼10 km) and large (∼1000 km) scales and in both cases are linked to dynamical features of the flow. The small-scale variations are related to the characteristics of coherent vortex structures, and there are low FTLEs inside vortices and filaments of high FTLEs in strain-dominated regions surrounding these vortices. Regional variations in the stirring are closely related to variations in mesoscale activity and eddy kinetic energy (EKE). High values of mean FTLE occur in regions of high EKE (highest mean values of around 0.2 day−1 occur in the East Australia Current separation region) whereas small values occur in regions with low EKE (mean values around 0.03 day−1 in the east Tasman Sea). There is a compact relationship between the mean FTLEs and EKE, raising the possibility of using the easily calculated EKE to estimate the stirring. This possibility is even more intriguing because the FTLE distributions can be approximated, for the time scales considered here, by Weibull distributions with shape parameter equal to 1.6, which can be defined from the mean value alone.

Ocean temperature changes between 1991 and 2005 in the eastern Tasman Sea were analysed. This area was chosen because of a combination of data availability, low mesoscale variability and because of its importance in determining the climate of the downwind New Zealand landmass. A large warming extending to the full depth of the water column (c. 800 m) was found to have occurred between 1996 and 2002. This warming was seen in measurements by expendable bathythermographs and also in satellite sea surface temperature and sea surface height products, and has a clear impact on New Zealand's terrestrial temperature. The nature of the warming is discussed, together with likely forcing mechanisms. No local forcing mechanisms are consistent with the observed warming, leading to the conclusion that the signal seen in the Tasman Sea is part of a larger South Pacific‐wide phenomenon.

Many analysts have argued that the most harmful forms of drug use are disproportionately concentrated in poor communities of color, and that this pattern—combined with law enforcement's tendency to focus on outdoor drug activity—explains racial disparity in drug arrests. Others contend that comparatively high black and Latino drug arrest rates result from racial bias or racist intent on the part of the architects or lieutenants of the drug war. This article offers an alternative explanation of racial disparity in drug arrests in Seattle, Washington. Specifically, we argue that the racialization of imagery surrounding drugs in general and crack cocaine in particular had long-lasting institutional and cultural effects that continue to shape police perceptions and practices, and that these effects explain much of the disparity that characterizes drug possession in Seattle.

Ocean surface circulation can be estimated by automated tracking of thermal infrared features in pairs of sequential satellite imagery. A 7-yr time series of velocity, extracted from thermal imagery of the East Australian Current using the maximum cross-correlation (MCC) technique, provides enough measurements for a more statistical evaluation of the method than has previously been possible. Excluding 1 yr with extensive cloud cover, the method produces about 8000 velocity estimates per month with some seasonal variation. Method precision is estimated to be between 0.08 and 0.2 m s21 rms, the lower value with more restrictive compositing. Mean flow, time-dependent flow, and eddy kinetic energy from the time series are compared with values derived from a dynamic height climatology, altimeter analyses, and drifter datasets in the region. The observations reproduce similar features in the flow. The differences between the observations are discussed in relation to noise in the methods and differences in the types of velocities they measure.

Mapping the mesoscale surface velocity stream function by combining estimates of surface height from satellite altimetry and surface currents from sequential infrared (sea-surface temperature) imagery using optimal interpolation is described. Surface currents are computed from infrared images by the method of maximum cross-correlations (MCC) and are combined with altimeter sea-level anomaly data from the TOPEX/Poseidon and ERS satellites. The analysis method was applied to 6 years of data from the East Australian Current region. The covariance of velocity and sea-level data is consistent with the statistical assumptions of homogeneous, isotropic turbulence, with typical length scales of order 220 km and time scales of 10 days in this region. Augmenting the analysis of altimeter data with MCC velocity observations improves the resolution of the surface currents, especially near the Australian coast, and demonstrates that the two data sources provide consistent and complementary observations of the surface mesoscale circulation. The volume of MCC data is comparable to that from a satellite altimeter, but with a more variable distribution of spatial and temporal resolution. In concert with altimetry, satellite radiometer velocimetry represents a technique useful for retrospective analysis of currents from high-resolution satellite radiometer data-sets.

The Southwest Pacific Ocean Circulation and Climate Experiment (SPICE) is an international research program under the auspices of CLIVAR. The key objectives are to understand the Southwest Pacific Ocean circulation and the South Pacific Convergence Zone (SPCZ) dynamics, as well as their influence on regional and basin‐scale climate patterns. South Pacific thermocline waters are transported in the westward flowing South Equatorial Current (SEC) toward Australia and Papua‐New Guinea. On its way, the SEC encounters the numerous islands and straits of the Southwest Pacific and forms boundary currents and jets that eventually redistribute water to the equator and high latitudes. The transit in the Coral, Solomon, and Tasman Seas is of great importance to the climate system because changes in either the temperature or the amount of water arriving at the equator have the capability to modulate the El Niño‐Southern Oscillation, while the southward transports influence the climate and biodiversity in the Tasman Sea. After 7 years of substantial in situ oceanic observational and modeling efforts, our understanding of the region has much improved. We have a refined description of the SPCZ behavior, boundary currents, pathways, and water mass transformation, including the previously undocumented Solomon Sea. The transports are large and vary substantially in a counter‐intuitive way, with asymmetries and gating effects that depend on time scales. This paper provides a review of recent advancements and discusses our current knowledge gaps and important emerging research directions. Por pares

Measurements of velocity, density, and pressure gradient in the lower Hudson River estuary were used to quantify the dominant terms in the momentum equation and to characterize their variations at tidal and spring‐ neap timescales. The vertical momentum flux (assumed to be due mainly to turbulent shear stress) was estimated indirectly, based on the residual from the acceleration and pressure gradient terms. The indirect estimates of stress compared favorably to bottom stress estimates using a quadratic drag law, supporting the hypothesis that the tidal momentum equation involves a local balance between tidal acceleration, pressure gradient, and stress divergence. Estimates of eddy viscosity indicated that there was significant tidal asymmetry, with flood tide values exceeding ebb values by a factor of 2. As a consequence of the asymmetry, the vertical structure of the tidally averaged stress bore no resemblance to the tidally averaged shear. In spite of the asymmetry of vertical mixing, the tidally averaged, estuarine circulation was found to depend simply on the intensity of bottom turbulence, which could be parameterized by a Rayleigh drag formulation based on the tidal velocity magnitude and the tidally averaged near-bottom flow. This seemingly paradoxical result indicates that the estuarine circulation can be modeled without detailed knowledge of the effective eddy viscosity, only requiring an estimate of the bottom drag coefficient, the tidal forcing conditions, and the baroclinic pressure gradient. A notable characteristic of this solution is an inverse dependence of the estuarine circulation on the amplitude of the tides.

A set of moored, bottom-mounted and shipboard measurements, obtained in a straight section of the lower Hudson estuary during late summer and early fall of 1995, determine velocity, density, and along-channel pressure gradient throughout the 15-m water column, as well as providing direct eddy-correlation estimates of Reynolds stress and indirect inertial-range estimates of dissipation within 3 m of the bottom. The analysis focuses on testing 1) a simplified turbulent kinetic energy equation, in which production balances dissipation; 2) the Prandtl–Karman law of the wall, which is a relationship between bottom stress and near-bottom velocity gradient; and 3) a simplified depth-integrated along-channel momentum balance involving local acceleration, pressure gradient, and bottom stress. Estimates of production and dissipation agree well throughout the entire record. The relationship between bottom stress and velocity gradient is consistent with the law of the wall within approximately 1 m of the sea...

A new Mathematica study, conducted with the Center on Reinventing Public Education, highlights approaches five successful charter school management organizations (CMOs) use to help improve student achievement. This report expands on a previous report showing that CMOs with the greatest positive impact on student achievement were most likely to establish consistent schoolwide behavior expectations for students, as well as use an intense approach to monitoring and coaching teachers. The latest report offers guidance for schools and districts looking to replicate these promising practices.

A new analysis from the National Study of Charter Management (CMO) Effectiveness provides the first systematic evidence available on the effects of CMOs on the critical long-term outcomes of high school graduation and college entry. The study shows that some—but not all—CMOs substantially boost students' chances of graduating from high school and enrolling in postsecondary education. The study also shows that each CMO's impact on test scores is typically consistent across schools, suggesting that CMOs are having some success in promoting uniformity (whether in a positive or negative direction). Further, some CMOs have implemented policies, programs, and procedures that enable them to outperform other CMOs.

Interim report on charter school outcomes, such as test scores and measures of charter school benefit.

Measurements of the natural background levels of 50- and 60-Hz radio noise by ELF/VLF (extremely low frequency/very low frequency) radiometers located at various sites around the world are reported. The measurements are made on the magnetic fields of the noise using loop antennas, and they cover the first three harmonics of the power line frequencies (frequencies in the range 50-180 Hz). Due to the likelihood of contamination from local electrical power systems, or even from nonlocal systems, the measurements at each power line frequency were made at adjacent frequencies and the desired noise amplitudes obtained by interpolation. It is shown that the magnetic spectral densities of the natural noise typically lie in the range 20-600 fT/ square root Hz or, taking the 50/60-Hz frequencies specifically, in the range 150-600 fT/ square root Hz. These ranges should be typical for most locations on the Earth's surface and for most seasons. >

Spectral measurements of solar ultraviolet (UV) radiation taken at McMurdo Station, Antarctica are used to determine biologically effective UV dose, ozone column content, and effective cloud optical depth. The seasonal variation in these parameters from September 15, 1988 through April 15, 1989 is presented and discussed. Although no days from September 15 through October experienced UV dose exceeding that occurring at summer solstice, the temporal variation in the level of UV radiation is markedly asymmetric with respect to summer solstice. A general enhancement by about 20% in biologically effective UV dose in October, 1988 compared to March, 1989 is clearly evident. The main cause of this asymmetry appears to be the coincident deficiency in ozone abundance appears to be the coincident deficiency in ozone abundance by about 8% in spring compared to fall. The percent increase in UV dose per percent decrease in ozone abundance is about 2.5 in agreement with theoretical predictions. The total ozone amount is generally depleted (to about 250 DU) during October 1988, but there are large day-to-day fluctuations. Presumably these fluctuations are caused primarily by the motion of the polar vortex. After summer solstice UV radiation levels and ozone amounts exhibit much less pronounced day-to-daymore » fluctuations. No spring/fall asymmetry in cloudiness, as it affects the surface ultraviolet radiation budget, is discernible from the measurements if the surface albedo is assumed to vary symmetrically around solstice.« less

[1] Ocean eddy variability dominates many important processes in the ocean at a range of length and timescales. We describe the eddy statistics in the Tasman Sea–New Zealand region using drifter data from the Global Drifter Program (GDP) to derive Lagrangian statistics and TOPEX/Poseidon (T/P) satellite data to derive Eulerian statistics. The ratio η of the Lagrangian to Eulerian timescales is also a measure of length scales in the ocean; when η is high, Lagrangian length scales are short compared with Eulerian length scales and vice versa. We compute η both in the time domain from temporal autocorrelations of drifter and satellite data, and in the frequency domain from drifter and satellite velocity spectra. The zonal component of this ratio appears to be constant in the Tasman Sea, whereas the meridional component shows a latitudinal dependence. We argue that if η is known, all Eulerian and Lagrangian timescales can be determined from relatively easy measurements of the Eulerian timescale and eddy kinetic velocity.

[1] Large fluctuations in sea surface height (SSH) occurred in the southwest Pacific between New Zealand and Fiji in the late 1990s. A model of SSH including steric heating and wind-driven Rossby waves explains more than 40% of the observed SSH variance in the region over the 12 years of satellite measurements. The modelled SSH also agrees with dynamic height calculated from subsurface temperatures measured along an expendable bathythermograph (XBT) line between New Zealand and Fiji. The model simulations show a large high in SSH was created by anomalous downward Ekman pumping during 1998 when the seasonal change to upwelling failed to occur. The 50-year wind record shows other downwelling events have occurred in the region predominantly during El Nino conditions.

[1] The spatial and temporal variability of the East Australian Current (EAC) is investigated using 6 years (1993–1998) of surface geostrophic stream function from an optimal interpolation of altimeter sea surface heights and velocities derived from tracking thermal features in satellite imagery. Variability appears as a series of cyclones and anticyclones propagating southwestward and westward with periods between 90 and 180 days. The behavior of the variability changes over the 6 years. Energy in the mesoscale frequencies moves slowly south and diminishes with more westward propagation in the region where the current separates from the coast. We find no evidence for a consistent forcing of the EAC by mesoscale signals propagating westward from the South Pacific basin. We suggest that the observations are consistent with variability originating between 32°S and 35°S through intrinsic instabilities of the current.

[1] The transport of salt along the channel of an estuary determines the length of the saline intrusion and provides bounds on the transfer of other substances. Observations of salt transport have been hampered by a lack of long time series measurements and complexities of the sampling situation (e.g., local topography and simultaneous variations of tides, freshwater, and winds). Here we estimate salt transport at a relatively uniform section of the Hudson Estuary over a 70-day period during drought conditions. The salt balance of the estuary is also assessed by comparing salt transport at the section with surveys of total salt content in the estuary. Most salt enters the estuary in monthly pulses of estuarine salt transport (i.e., spatial variations of tidally-averaged velocity and salinity) during apogean neap tides when vertical stratification is greatest. Oscillatory salt transport (i.e., the covariance of tidally-varying velocity and salinity) is a more minor player in the salt balance and shows a surprising lack of spring-neap variation. Integrated salt transport at the section is consistent with estimates of total salt content of the estuary; however, the mismatch in magnitude of the variations indicates that the salinity intrusion is not in equilibrium within the spring-neap cycle. In contrast, the salt balance adjusts rapidly to an increase in freshwater flow at the end of the deployment. A scaling argument is derived to illustrate the adjustment of the salinity intrusion to the tides and freshwater flow. The results suggest that time dependence is an intrinsic part of the estuarine salt balance.

The horizontal stirring properties of the flow in a region of the East-Australian Current are calculated. A surface velocity field derived from remotely sensed data, using the Maximum Cross Correlation method, is integrated to derive the distribution of the finite-time Lyapunov exponents. For the region studied (between latitudes 36 S and 41 S and longitudes 150 E and 156 E) the mean Lyapunov exponent during 1997 is estimated to be 4 x 10^{-7} s^{-1}. This is in close agreement with the few other measurements of stirring rates in the surface ocean which are available. Recent theoretical results on the multifractal spectra of advected reactive tracers are applied to an analysis of a sea-surface temperature image of the study region. The spatial pattern seen in the image compares well with the pattern seen in an advected tracer with a first-order response to changes in surface forcing. The response timescale is estimated to be 20 days., Comment: 11 pages and 8 figures. Minor changes to original version