6,177 research outputs found
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AASE-II OBSERVATIONS OF TRACE CARBON SPECIES DISTRIBUTIONS IN THE MID TO UPPER TROPOSPHERE
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Airborne observations of the tropospheric CO2 distribution and its controlling factors over the South Pacific Basin
Highly precise measurements of CO2 mixing ratios were recorded aboard both the NASA DC-8 and P3-B aircraft during the Pacific Exploratory Mission-Tropics conducted in August-October 1996. Data were obtained at altitudes ranging from 0.1 to 12 km over a large portion of the South Pacific Basin representing the most geographically extensive CO2 data set recorded in this region. These data along with CO2 surface measurements from the National Oceanic and Atmospheric Administration/Climate Monitoring and Diagnostics Laboratory (NOAA/CMDL) and the National Institute of Water and Atmospheric Research (NIWA) were examined to establish vertical and meridional gradients. The CO2 spatial distribution in the southern hemisphere appeared to be largely determined by interhemispheric transport as air masses with depleted CO2 levels characteristic of northern hemispheric air were frequently observed south of the Intertropical Convergence Zone. However, regional processes also played a role in modulating background concentrations. Comparisons of CO2 with other trace gases indicated that CO2 values were influenced by continental sources. Large scale plumes from biomass burning activities produced enhanced CO2 mixing ratios within the lower to midtroposphere over portions of the remote Pacific. An apparent CO2 source was observed in the NOAA/ CMDL surface data between 15° N and 15° S and in the lower altitude flight data between 8° N and 8.5° S with a zone of intensity from 6.5° N to 1° S. Inferred from these data is the presence of a Southern Ocean sink from south of 15° S having two distinct zones seasonally out of phase with one another. Copyright 1999 by the American Geophysical Union
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Application of passive seismic to the detection of buried hollows
Pilot studies involving the use of passive seismic techniques in a range of geological settings and
applications, e.g., mapping bedrock, studies of soil erosion and Quaternary mapping have shown that it
is a versatile, non-invasive and economic technique. This paper presents the findings of three case studies
that trialled the use of passive seismic techniques for the detection and characterisation of buried hollows
in carbonate rocks, comprising: i) a buried hollow in the Cretaceous Chalk at Ashford Hill in the Kennet
Valley, a tributary of the River Thames, UK; ii) buried karst in the foundation excavations for wind turbines in Carboniferous Limestone at Brassington, Wirksworth, Derbyshire, UK, and iii) defining the extent of solution hollows that host terrestrial Miocene deposits, near Friden, Newhaven, Derbyshire, UK. Whilst case studies ii) and iii) are focused on areas of buried dolines, the geological context of the Ashford
Hill site is more complex; comprising a deformation hollow with an uplifted “pinnacle” of chalk bedrock at
the centre. The data were collected using a (Tromino), a three-component, broadband seismometer to measure background ambient noise (microtremors induced by wind, ocean waves, industrial machinery, road and rail traffic, etc.). The Tromino is small, portable with an operating range of 0.1 Hz to 1,024 Hz and interpreted using proprietary software (Grilla), which subjects the data to Fourier transformation and smoothing. Where possible, estimated shear wave velocities used in the
Grilla Software modelling, based on peaks identified on the H/V spectrum, have been calibrated using borehole data or parallel geophysical techniques. In each case, the karst features were defined by Nakamura’s
horizontal to vertical (H/V) spectral ratio technique, where microtremors are converted to show impedance
contrasts (velocity x density), or a pseudo layered seismic stratigraphy of the near surface along each
profile. An additional benefit of the use of this technique is its depth of penetration and potential for defining the
structural and lithological context of the hollows, thereby contributing to the process understanding associated with their formation. To this end the technique has helped define discontinuity (fault, joint or bedding) guidance of the hollows.S. Castellaro, Mrs J. Renwick, West Coast Energy Ltd (GDF Suez), Mr Roger Durrant (Raymond Brown Construction Ltd
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O-3, NOY, AND NOX/NOY IN THE UPPER TROPOSPHERE OF THE EQUATORIAL PACIFIC
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Aerosols from biomass burning over the tropical South Atlantic region: Distributions and impacts
The NASA Global Tropospheric Experiment (GTE) Transport and Atmospheric Chemistry Near the Equator-Atlantic (TRACE A) expedition was conducted September 21 through October 26, 1992, to investigate factors responsible for creating the seasonal South Atlantic tropospheric ozone maximum. During these flights, fine aerosol (0.1-3.0 μm) number densities were observed to be enhanced roughly tenfold over remote regions of the tropical South Atlantic and greater over adjacent continental areas, relative to northern hemisphere observations and to measurements recorded in the same area during Ac wet season. Chemical and meteorological analyses as well as visual observations indicate that the primary source of these enhancements was biomass burning occurring within grassland regions of north central Brazil and southeastern Africa. These fires exhibited fine aerosol (N) emission ratios relative to CO (dN/dCO) of 22.5 ± 9.7 and 23.6 ± 15.1 cm-3 parts per billion by volume (ppbv)-1 over Brazil and Africa, respectively. Convection coupled with counterclockwise flow around the South Atlantic subtropical anticyclone subsequently distributed these aerosols throughout the remote South Atlantic troposphere. We calculate that dilute smoke from biomass burning produced an average tenfold enhancement in optical depth over the continental regions as well as a 50% increase in this parameter over the middle South Atlantic Ocean; these changes correspond to an estimated net cooling of up to 25 W m-2 and 2.4 W m-2 during clear-sky conditions over savannas and ocean respectively. Over the ocean our analyses suggest that modification of CCN concentrations within the persistent eastern Atlantic marine stratocumulus clouds by entrainment of subsiding haze layers could significantly increase cloud albedo resulting in an additional surface radiative cooling potentially greater in magnitude than that caused by direct extinction of solar radiation by the aerosol particles themselves
Developing an inclusional pedagogy of the unique: how do I clarify, live and explain my educational influences in my learning as I pedagogise my healing nurse curriculum in a Japanese university?
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Is communications a strategic activity in UK Education?
This qualitative exploratory paper investigates whether communications/public relations is regarded by opinion formers in UK education as a strategic business activity or a tactical marketing tool. It is based upon depth interviews with 16 senior managers with strategic roles in UK higher or further education, or Government bodies, conducted between June and September 2004. The findings seem to suggest that communications/PR is ideally seen by leaders as a strategic function, but that there are limitations to this vision becoming a reality. The research goes on to offer initial conclusions on some of the issues surrounding perception, resource, and implementation of strategic communications/PR in UK education, with implications for practitioners considered
Psychosocial Contexts of Diabetes and Older Adulthood: Reciprocal Effects
The present study was conducted to assess the reciprocal effects between the psychosocial contexts of diabetes and older adulthood. Data were collected from 191 community-dwelling adults over the age of 60 with non-insulin-dependent diabetes mellitus. Results indicate that older adults with diabetes reported higher rates of selected chronic illnesses, lower self-rated physical health, and higher levels of depression than did comparison samples of older adults without diabetes. Compared with younger adults with NIDDM, the present sample of older adults perceived fewer impacts of diabetes, including fewer symptoms of poor metabolic control, less emotional impact, fewer barriers to adherence, and less complex regimens. Overall levels of social support and regimen adherence were high. Older adults in this sample reported wanting minimal help from their family and friends with self-management activities and receiving more help than desired with following a meal plan and taking medications. Implications of the unique context of older adulthood for diabetes self-management are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69058/2/10.1177_014572179101700507.pd
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