45 research outputs found
Effects of peatland management on aquatic carbon concentrations and fluxes
Direct land-to-atmosphere carbon exchange has been the primary focus in previous studies of peatland disturbance and subsequent restoration. However, loss of carbon via the fluvial pathway is a significant term in peatland carbon budgets and requires consideration to assess the overall impact of restoration measures. This study aimed to determine the effect of peatland land management regime on aquatic carbon concentrations and fluxes in an area within the UK's largest tract of blanket bog, the Flow Country of northern Scotland. Three sub-catchments were selected to represent peatland land management types: non-drained, drained, and restoration (achieved through drain blocking and tree removal). Water samples were collected on a fortnightly basis from September 2008 to August 2010 at six sampling sites, one located upstream and one downstream within each sub-catchment. Concentrations of dissolved organic carbon (DOC) were significantly lower for the upstream non-drained sub-catchment compared to the drained sub-catchments, and there was considerable variation in the speciation of aquatic carbon (DOC, particulate organic carbon (POC), CO2, and CH4) across the monitoring sites, with dissolved gas concentrations inversely correlated with catchment area and thereby contributing considerably more to total aquatic carbon in the smaller headwater catchments. Significantly higher POC concentrations were observed in the restored sub-catchment most affected by tree removal. Aquatic carbon fluxes were highest from the drained catchments and lowest from the non-drained catchments at 23.5 and 7.9 g C m−2 yr−1, respectively, with variability between the upstream and downstream sites within each catchment being very low. It is clear from both the aquatic carbon concentration and flux data that drainage has had a profound impact on the hydrological and biogeochemical functioning of the peatland. In the restoration catchment, carbon export varied considerably, from 21.1 g C m−2 yr−1 at the upper site to 10.0 g C m−2 yr−1 at the lower site, largely due to differences in runoff generation. As a result of this hydrological variability, it is difficult to make definitive conclusions about the impact of restoration on carbon fluxes, and further monitoring is needed to corroborate the longer-term effects
Spatially Resolved Neutral Wind Response Times During High Geomagnetic Activity Above Svalbard
It has previously been shown that in the high-latitude thermosphere, sudden changes in plasma velocity (such as those due to changes in interplanetary magnetic field) are not immediately propagated into the neutral gas via the ion-drag force. This is due to the neutral particles (O, O 2, and N 2) constituting the bulk mass of the thermospheric altitude range and thus holding on to residual inertia from a previous level of geomagnetic forcing. This means that consistent forcing (or dragging) from the ionospheric plasma is required, over a period of time, long enough for the neutrals to reach an equilibrium with regard to ion drag. Furthermore, mesoscale variations in the plasma convection morphology, solar pressure gradients, and other forces indicate that the thermosphere-ionosphere coupling mechanism will also vary in strength across small spatial scales. Using data from the Super Dual Auroral Radar Network and a Scanning Doppler Imager, a geomagnetically active event was identified, which showed plasma flows clearly imparting momentum to the neutrals. A cross-correlation analysis determined that the average time for the neutral winds to accelerate fully into the direction of ion drag was 75Â min, but crucially, this time varied by up to 30Â min (between 67 and 97Â min) within a 1,000-km field of view at an altitude of around 250 km. It is clear from this that the mesoscale structure of both the plasma and neutrals has a significant effect on ion-neutral coupling strength and thus energy transfer in the thermosphere
Probing Star Formation at Low Metallicity: The Radio Emission of Super Star Clusters in SBS0335-052
We present high-resolution radio continuum observations of the nascent
starburst in the metal-poor galaxy SBS 0335-052. These radio data were taken
with the Very Large Array and include observations at 0.7cm, 1.3cm, 2cm, 3.6cm,
and 6cm. These observations enable us to probe the thermal radio nebulae
associated with the extremely young star-forming regions in this galaxy. Two
discrete and luminous star-forming regions are detected in the south of the
galaxy that appear to be associated with massive star clusters previously
identified at optical wavelengths. However, the remaining optically-identified
massive star clusters are not clearly associated with radio emission (either
thermal or non-thermal) down to the sensitivity limits of these radio data. The
spectral energy distributions of the two radio-detected clusters are consistent
with being purely thermal, and the entire region has an inferred ionizing flux
of ~1.2 x 10^ 53 s^-1, which is equivalent to ~12,000 "typical" O-type stars
(type O7.5 V). The observations presented here have resolved out a significant
contribution from diffuse non-thermal emission detected previously, implying a
previous episode of significant star formation. The current star formation rate
(SFR) for this southern region alone is ~1.3 M_sun yr^-1, or ~ 23M_sun yr^-1
kpc^-2. This SFR derived from thermal radio emission also suggests that
previous optical recombination line studies are not detecting a significant
fraction of the current star formation in SBS 0335-052. From model fits to the
radio spectral energy distribution, we infer a global mean density in the two
youngest clusters of n_e > 10^3-10^4 cm^-3. In addition, a comparison between
the compact and diffuse radio emission indicates that up to ~50% of the
ionizing flux could be leaking out of the compact HII regions.Comment: accepted AJ, 14 pages, 5 figure
Professional care workforce: a rapid review of evidence supporting methods of recruitment, retention, safety, and education
Background: Across the care economy there are major shortages in the health and care workforce, as well as high rates of attrition and ill-defined career pathways. The aim of this study was to evaluate current evidence regarding methods to improve care worker recruitment, retention, safety, and education, for the professional care workforce. Methods: A rapid review of comparative interventions designed to recruit, retain, educate and care for the professional workforce in the following sectors: disability, aged care, health, mental health, family and youth services, and early childhood education and care was conducted. Embase and MEDLINE databases were searched, and studies published between January 2015 and November 2022 were included. We used the Quality Assessment tool for Quantitative Studies and the PEDro tools to evaluate study quality. Results: 5594 articles were initially screened and after applying the inclusion and exclusion criteria, 30 studies were included in the rapid review. Studies most frequently reported on the professional nursing, medical and allied health workforces. Some studies focused on the single domain of care worker education (n = 11) while most focused on multiple domains that combined education with recruitment strategies, retention strategies or a focus on worker safety. Study quality was comparatively low with a median PEDro score of 5/10, and 77% received a weak rating on the Quality Assessment tool for Quantitative Studies. Four new workforce strategies emerged; early career rural recruitment supports rural retention; workload management is essential for workforce well-being; learning must be contextually relevant; and there is a need to differentiate recruitment, retention, and education strategies for different professional health and care workforce categories as needs vary. Conclusions: Given the critical importance of recruiting and retaining a strong health and care workforce, there is an immediate need to develop a cohesive strategy to address workforce shortfalls. This paper presents initial evidence on different interventions to address this need, and to inform care workforce recruitment and retention. Rapid Review registration PROSPERO 2022 CRD42022371721 Available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD4202237172
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Biotic and Human Vulnerability to Projected Changes in Ocean Biogeochemistry over the 21st Century
Ongoing greenhouse gas emissions can modify climate processes and induce shifts in ocean temperature, pH, oxygen concentration, and productivity, which in turn could alter biological and social systems. Here, we provide a synoptic global assessment of the simultaneous changes in future ocean biogeochemical variables over marine biota and their broader implications for people. We analyzed modern Earth System Models forced by greenhouse gas concentration pathways until 2100 and showed that the entire world's ocean surface will be simultaneously impacted by varying intensities of ocean warming, acidification, oxygen depletion, or shortfalls in productivity. In contrast, only a small fraction of the world's ocean surface, mostly in polar regions, will experience increased oxygenation and productivity, while almost nowhere will there be ocean cooling or pH elevation. We compiled the global distribution of 32 marine habitats and biodiversity hotspots and found that they would all experience simultaneous exposure to changes in multiple biogeochemical variables. This superposition highlights the high risk for synergistic ecosystem responses, the suite of physiological adaptations needed to cope with future climate change, and the potential for reorganization of global biodiversity patterns. If co-occurring biogeochemical changes influence the delivery of ocean goods and services, then they could also have a considerable effect on human welfare. Approximately 470 to 870 million of the poorest people in the world rely heavily on the ocean for food, jobs, and revenues and live in countries that will be most affected by simultaneous changes in ocean biogeochemistry. These results highlight the high risk of degradation of marine ecosystems and associated human hardship expected in a future following current trends in anthropogenic greenhouse gas emissions