128 research outputs found

    Late Holocene sea level variability and Atlantic Meridional Overturning Circulation

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    Pre-twentieth century sea level (SL) variability remains poorly understood due to limits of tide gauge records, low temporal resolution of tidal marsh records, and regional anomalies caused by dynamic ocean processes, notably multidecadal changes in Atlantic Meridional Overturning Circulation (AMOC). We examined SL and AMOC variability along the eastern United States over the last 2000 years, using a SL curve constructed from proxy sea surface temperature (SST) records from Chesapeake Bay, and twentieth century SL-sea surface temperature (SST) relations derived from tide gauges and instrumental SST. The SL curve shows multidecadal-scale variability (20–30 years) during the Medieval Climate Anomaly (MCA) and Little Ice Age (LIA), as well as the twentieth century. During these SL oscillations, short-term rates ranged from 2 to 4 mm yr−1, roughly similar to those of the last few decades. These oscillations likely represent internal modes of climate variability related to AMOC variability and originating at high latitudes, although the exact mechanisms remain unclear. Results imply that dynamic ocean changes, in addition to thermosteric, glacio-eustatic, or glacio-isostatic processes are an inherent part of SL variability in coastal regions, even during millennial-scale climate oscillations such as the MCA and LIA and should be factored into efforts that use tide gauges and tidal marsh sediments to understand global sea level rise

    Empowering employees with chronic diseases: process evaluation of an intervention aimed at job retention

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    Purpose Employees with a chronic disease may experience work-related problems that contribute to the risk of job loss. We developed a group-based intervention programme aimed at clarifying problems, making these a subject of discussion at work, and realizing solutions. This process evaluation investigates the intervention's feasibility and the satisfaction of 64 participants in eight groups. Methods Data were collected through process evaluation forms and self-report questionnaires. Results The recruitment of participants was time-consuming. Highly educated women working in the service sector were overrepresented. The programme was administered as planned, although components were sometimes only discussed briefly, due to lack of time. Satisfaction with the overall programme among participants was high; it was perceived as effective and there were only three dropouts. In particular, the focus on feelings and thoughts about having a chronic disease was highly valued, as were the exchange of experiences and role-playing directed at more assertive communication. Conclusions A vocational rehabilitation programme aimed at job retention is feasible and is perceived to be effective. Such a programme should address psychosocial aspects of working with a chronic disease beside practical problems. The recruitment of participants is time-consuming. Cooperation with outpatient clinics is necessary in order to reach all groups of employees with a chronic disease that might benefit from job retention programmes. Trial registration: ISRCTN77240155

    Relative sea-level rise and climate change over the last 1500 years

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    ABSTRACT We constructed a detailed relative sea-level rise curve for the last 1500 years using a novel approach, i.e. charting the rate of relative sea-level rise using microfaunal and geochemical data from a coastal salt marsh sequence (Clinton, CT, USA). The composition of benthic foraminifera1 assemblages and the iron abundance in peats were used to describe shifts in marsh environment through time uantitatively. The resulting sea-level rise Curve, with age control from 4C dating and the onset of anthropogenic metal pollution, shows strong increases in the rate of relative sea-level rise during modem global warming (since the late nineteenth century), but not during the Little Climate Optimum (AD 1000-1300). There was virtually no rise in sea-level during the Little Ice Age (AD 1400-1700). Most of the relative sea-level rise over the last 1200 years in Clinton appears to have occurred during two warm episodes that jointly lasted less than 600 years. Changes from slow to fast rates of relative sea-level rise apparently occurred over periods of only a few decades. We suggest that changes in ocean circulation could contribute to the sudden increases in the rate of relative sea-level rise along the northeastern USA seaboard. Relative sea-level rise in that area is currently faster than the worldwide average, which may result partially from an ocean surface effect caused by hydrodynamics. Our data show no unequivocal correlation between warm periods (on a decaal to centennial time-scale) and accelerated sea-level rise. One period of acderated sea-level rise may have occurred between about AD 1200 and 1450, which was the transition for the Little Climate Optimum to the Little Ice Age, i.e. a period of cooling (at least in northwestern Europe). Local changes in tidal range might also have contributed to this apparent increase in the rate of relative sea-level, however. The second period of accelerated sea-level rise occurred during the period of modem global warming that started at the end of the last century

    Detection of volcanic ash clouds from Nimbus 7/total ozone mapping spectrometer

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    Measured radiances from the Version 7 reprocessing of the Nimbus 7/total ozone mapping spectrometer (TOMS) 340- and 380-nm channels are used to detect absorbing particulates injected into the atmosphere after the El Chichon eruption on April 4, 1982. It is shown that while the single-channel reflectivity determined from the 380-nm channel is able to detect clouds and haze composed of nonabsorbing aerosols, the spectral contrast between the 340- and 380-nm channels is sensitive to absorbing particulates such as volcanic ash, desert dust, or smoke from biomass burning. In this paper the spectral contrast between these two channels is used to detect the volcanic ash injection into the atmosphere and to track its evolution for several days. The movement of the ash clouds is shown to be consistent with the motions expected from the National Centers for Environmental Prediction (NCEP)-derived balanced wind fields in the troposphere and lower stratosphere. The movement of the volcanic SO2 cloud detected from TOMS data was also in agreement with the NCEP wind at higher altitudes of up to 100–10 mbar. The vertical wind shear in the neighborhood of the eruption site resulted in a clear separation of the ash and SO2 clouds. The location and movement of the ash cloud are consistent with information obtained by the advanced very high resolution radiometer (AVHRR) instrument on board the NOAA 7 satellite and to ground reports of ash fall

    Effects of work ability and health promoting interventions for women with musculoskeletal symptoms: A 9-month prospective study

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    <p>Abstract</p> <p>Background</p> <p>Women working in the public human service sector in 'overstrained' situations run the risk of musculoskeletal symptoms and long-term sick leave. In order to maintain the level of health and work ability and strengthen the potential resources for health, it is important that employees gain greater control over decisions and actions affecting their health – a process associated with the concept of self-efficacy. The aim of this study was to describe the effects of a self-efficacy intervention and an ergonomic education intervention for women with musculoskeletal symptoms, employed in the public sector.</p> <p>Methods</p> <p>The design of the study was a 9-month prospective study describing the effects of two interventions, a comprehensive self-efficacy intervention (<it>n </it>= 21) and an ergonomic education intervention (<it>n </it>= 21). Data were obtained by a self-report questionnaire on health- and work ability-related factors at baseline, and at ten weeks and nine months follow-up. Within-group differences over time were analysed.</p> <p>Results</p> <p>Over the time period studied there were small magnitudes of improvements within each group. Within the self-efficacy intervention group positive effects in perceived work ability were shown. The ergonomic education group showed increased positive beliefs about future work ability and a more frequent use of pain coping strategies.</p> <p>Conclusion</p> <p>Both interventions showed positive effects on women with musculoskeletal symptoms, but in different ways. Future research in this area should tailor interventions to participants' motivation and readiness to change.</p

    An objective method for the production of isopach maps and implications for the estimation of tephra deposit volumes and their uncertainties

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    Characterization of explosive volcanic eruptive processes from interpretation of deposits is a key for assessing volcanic hazard and risk, particularly for infrequent large explosive eruptions and those whose deposits are transient in the geological record. While eruption size—determined by measurement and interpretation of tephra fall deposits—is of particular importance, uncertainties for such measurements and volume estimates are rarely presented. Here, tephra volume estimates are derived from isopach maps produced by modeling raw thickness data as cubic B-spline curves under tension. Isopachs are objectively determined in relation to original data and enable limitations in volume estimates from published maps to be investigated. The eruption volumes derived using spline isopachs differ from selected published estimates by 15–40 %, reflecting uncertainties in the volume estimation process. The formalized analysis enables identification of sources of uncertainty; eruptive volume uncertainties (>30 %) are much greater than thickness measurement uncertainties (~10 %). The number of measurements is a key factor in volume estimate uncertainty, regardless of method utilized for isopach production. Deposits processed using the cubic B-spline method are well described by 60 measurements distributed across each deposit; however, this figure is deposit and distribution dependent, increasing for geometrically complex deposits, such as those exhibiting bilobate dispersion. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00445-015-0942-y) contains supplementary material, which is available to authorized users
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