On the factors driving upper-ocean salinity variability at the western edge of the Eastern Pacific Fresh Pool

© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Farrar, J. T., & Plueddemann, A. J. On the factors driving upper-ocean salinity variability at the western edge of the Eastern Pacific Fresh Pool. Oceanography, 32(2), (2019):30-39, doi:10.5670/oceanog.2019.209.The tropical Eastern Pacific Fresh Pool (EPFP) has some of the highest precipitation rates and lowest sea surface salinities found in the open ocean. In addition, the sea surface salinity in the EPFP exhibits one of the strongest annual cycles in the world ocean. The region is strongly affected by the meridionally migrating Intertropical Convergence Zone and is also influenced by large-scale ocean currents and wind-driven Ekman currents. Recognizing the complexity of competing regional influences and the importance of sea surface salinity as an integrator of freshwater forcing, the Salinity Processes Upper-ocean Regional Study (SPURS) was undertaken to better understand how ocean processes and surface freshwater fluxes set surface salinity. Instrumentation on a surface mooring, deployed for 14 months near the western edge of the EPFP, allowed estimation of the surface fluxes of momentum, heat, and freshwater. Subsurface instrumentation on the mooring provided upper-ocean vertical structure and horizontal currents. These observations, along with horizontal gradients of surface salinity from the Soil Moisture Active Passive (SMAP) satellite instrument, were used to estimate the surface-layer salinity budget at the western edge of the EPFP. While the low salinity associated with the presence of the EPFP at the mooring site was sustained by heavy rainfall, it was found that seasonal variability in large-scale currents was important to controlling the transition between the “salty” and “fresh” seasons. Ekman advection was important to prolonging local high salinity as rainfall decreased. Although illuminating some key processes, the temporal variability of the surface-layer salinity budget also shows significant complexity, with processes such as surface freshwater fluxes and vertical mixing making notable contributions. The surface flux term and the terms involving mixing across the base of the surface layer oppose and nearly cancel each other throughout the deployment, such that the horizontal advection term effectively accounts for most of the variability in surface salinity at the site on monthly to seasonal timescales. Further investigation, taking advantage of additional observations during SPURS-2, will be needed to more thoroughly examine the relevant physical processes.We are grateful for helpful comments on the manuscript from guest editor Andrey Shcherbina and two anonymous reviewers. We thank the members of the WHOI Upper Ocean Processes Group (Ben Pietro, Emerson Hasbrouck, Raymond Graham, Nan Galbraith, Kelan Huang, Sebastien Bigorre, Ben Greenwood, Jason Smith, Geoff Allsup, and Bob Weller) for their contributions to preparation, deployment, and recovery of the SPURS-2 surface mooring. We thank the captains and crews of R/V Roger Revelle and R/V Thomas Thompson, and the chief scientists for the deployment and recovery cruises (Andy Jessup and Kyla Drushka). SMAP salinity data are produced by Remote Sensing Systems and sponsored by the NASA Ocean Salinity Science Team (data are available at http://www.remss.com). This work was supported by NASA grants NNX15AG20G and 80NSSC18K1494. The buoy and mooring data will soon be available from the NASA JPL PO.DAAC data center

Telescoping tube assembly

An extensible and retractable telescoping tube positions test devices that inspect large stationary objects. The tube has three dimensional adjustment capabilities and is vertically suspended from a frame. The tube sections are independently supported with each section comprising U-shaped housing secured to a thicker support plate. Guide mechanisms preferably mounted only to the thicker plates guide each tube section parallel to a reference axis with improved accuracy so that the position of the remote end of the telescoping tube is precisely known

Bottom boundary layer stress measurements with BASS tripods : data report STRESS 1988-89

Two Benthic Acoustic Stress Sensor (BASS) equipped tripods were deployed in the Sediment Transport Events on Shelves and Slopes (STRESS) experiment in November, 1988, and recovered in March, 1989, on the California Shelf. They measured velocity profiles in the bottom boundary layer over the lowest 5 meters. Transmissometers, thermistors, and a pressure sensor on each tripod provided suspended sediment concentration, stratification, and wave spectral information, as well.Funding was provided by the Office of Naval Research under Contract Nos. NOOOI4-89-J-1058 and NOOOI4-90-J-1046

In My View

I am pleased that in his review of my book, The Russian Presidency (Naval War College Review, Summer 2001, pp. 165–8), Sergei Khrushchev agreed with me (and we are among a very few in the scholarly community who have agreed on this issue) that presidentialism will serve Russia better than the parliamentary alternative. But elsewhere, Dr. Khrushchev disagrees with me, and I am writing not only to clarify to readers of the Review the nature of that disagreement but also to take issue with places where I believe he has mischaracterized the book

A Statistical Model for Risk Stratification on the Basis of Left Ventricular Ejection Fraction and Heart-Rate Turbulence

The MPIP data set was used to obtain a model for mortality risk stratification of acute myocardial infarction patients. The predictors heart rate turbulence (HRT) and left-ventricular ejection fraction (LVEF) were employed. HRT was a categorical variable of three levels; LVEF was continuous and its influence on the relative risk was explained by the natural logarithm function (found using fractional polynomials). Cox - PH model with HRT and lnLVEF was constructed and used for risk stratification. The model can be used to divide the patients into two or more groups according to mortality risk. It also describes the relationship between risk and predictors by a (continuous) function, which allows the calculation of individual mortality risk

Data report : stress measurements in the bottom boundary layer with BASS tripods STRESS II 1990-91

Two Benthic Acoustic Strss Sensor (BASS) equipped tripods were deployed in the Sediment TRansport Events on Shelves and Slopes (STRESS) experiment on the Californa Shelf acquiring data from January to March 1991. They measured velocity profiles in the bottom boundary layer over the lowest 5 meters. Trasmissometers, thermistors, and a pressure sensor on each tripod provided suspended sediment concentration, stratification, and wave spectral information, as well.Funding was provided by the Office of Naval Research under Grant Nos. N00014-89-J-1058 and N00014-90-J-1046

Optimal taxation without state-contingent debt

To recover a version of Barro's (1979) `random walk' tax smoothing outcome, we modify Lucas and Stokey's (1983) economy to permit only risk--free debt. This imparts near unit root like behavior to government debt, independently of the government expenditure process, a realistic outcome in the spirit of Barro's. We show how the risk--free--debt--only economy confronts the Ramsey planner with additional constraints on equilibrium allocations that take the form of a sequence of measurability conditions. We solve the Ramsey problem by formulating it in terms of a Lagrangian, and applying a Parameterized Expectations Algorithm to the associated first--order conditions. The first--order conditions and numerical impulse response functions partially affirm Barro's random walk outcome. Though the behaviors of tax rates, government surpluses, and government debts differ, allocations are very close for computed Ramsey policies across incomplete and complete markets economies.Optimal taxation, incomplete markets, recursive contracts, tax smoothing, parameterized expectations

Phase i study of \u27dose-dense\u27 pemetrexed plus carboplatin/radiotherapy for locally advanced non-small cell lung carcinoma.

BACKGROUND: This phase I study investigates the feasibility of carboplatin plus dose-dense (q2-week) pemetrexed given concurrently with radiotherapy (XRT) for locally advanced and oligometastatic non-small cell lung cancer (NSCLC). METHODS: Eligible patients had Stage III or IV (oligometastatic) NSCLC. Patients received XRT to 63 Gy in standard fractionation. Patients received concurrent carboplatin (AUC = 6) during weeks 1 and 5 of XRT, and pemetrexed during weeks 1, 3, 5, and 7 of XRT. The starting dose level (level 1) of pemetrexed was 300 mg/m2. Following the finding of dose limiting toxicity (DLT) in dose level 1, an amended dose level (level 1A) continued pemetrexed at 300 mg/m2, but with involved field radiation instead of extended nodal irradiation. Consolidation consisted of carboplatin (AUC = 6) and pemetrexed (500 mg/m2) q3 weeks × 2 -3 cycles. RESULTS: Eighteen patients were enrolled. Fourteen patients are evaluable for toxicity analysis. Of the initial 6 patients treated on dose level 1, two experienced DLTs (one grade 4 sepsis, one prolonged grade 3 esophagitis). There was one DLT (grade 5 pneumonitis) in the 8 patients treated on dose level 1A. In 16 patients evaluable for response (4 with oligometastatic stage IV disease and 12 with stage III disease), the median follow-up time is 17.8 months. Thirteen of 16 patients had in field local regional response. The actuarial median survival time was 28.6 months in all patients and 34.7 months (estimated) in stage III patients. CONCLUSIONS: Concurrent carboplatin with dose-dense (q2week) pemetrexed at 300 mg/m2 with involved field XRT is feasible and encouraging in patients with locally advanced and oligometastatic NSCLC

Spin transfer switching of spin valve nanopillars using nanosecond pulsed currents

Spin valve nanopillars are reversed via the mechanism of spin momentum transfer using current pulses applied perpendicular to the film plane of the device. The applied pulses were varied in amplitude from 1.8 mA to 7.8 mA, and varied in duration within the range of 100 ps to 200 ns. The probability of device reversal is measured as a function of the pulse duration for each pulse amplitude. The reciprocal pulse duration required for 95% reversal probability is linearly related to the pulse current amplitude for currents exceeding 1.9 mA. For this device, 1.9 mA marks the crossover between dynamic reversal at larger currents and reversal by thermal activation for smaller currents