scholarly journals Contrasting Spatial and Seasonal Trends of Methylmercury Exposure Pathways of Arctic Seabirds: Combination of Large-Scale Tracking and Stable Isotopic Approaches

2020 ◽  
Vol 54 (21) ◽  
pp. 13619-13629
Author(s):  
Marina Renedo ◽  
David Amouroux ◽  
Céline Albert ◽  
Sylvain Bérail ◽  
Vegard S. Bråthen ◽  
...  
Keyword(s):  
Large Scale ◽  
Seasonal Trends ◽  
Exposure Pathways ◽  
Stable Isotopic ◽  
Methylmercury Exposure ◽  
Arctic Seabirds

scholarly journals Using blood and feathers to investigate large-scale Hg contamination in Arctic seabirds: A review

2019 ◽  
Vol 177 ◽  
pp. 108588 ◽  
Author(s):  
Céline Albert ◽  
Marina Renedo ◽  
Paco Bustamante ◽  
Jérôme Fort
Keyword(s):  
Large Scale ◽  
Arctic Seabirds

Stable isotopic composition of CO, H2 and CH4 in the troposphere and lower stratosphere: results from the ATom-WAS samples

2020 ◽  
Author(s):  
Maria Elena Popa ◽  
Carina van der Veen ◽  
Simone Meinardi ◽  
Donald R. Blake ◽  
Thomas Roeckmann
Keyword(s):  
Isotopic Composition ◽  
Large Scale ◽  
Lower Stratosphere ◽  
Global Scale ◽  
Atmospheric Composition ◽  
Air Sampler ◽  
Stable Isotopic Composition ◽  
Stable Isotopic ◽  
Different Seasons ◽  
Clean Air

<p>The NASA Atmospheric Tomography Mission (ATom) aimed to improve the understanding of atmospheric composition through global scale aircraft sampling campaigns in different seasons. The flights included continuous profiling between 0.2 and 12 km over the Atlantic and Pacific Oceans.</p><p>A large number of samples were taken using the Whole Air sampler (WAS, UC Irvine, CA). In a selection of these samples, we measured the stable isotopic composition of CO, H<sub>2</sub> and CH<sub>4</sub>. The samples cover remote clean air from different latitudes, from troposphere and lower stratosphere, and air influenced by specific (pollution) sources or processes.</p><p>We will give an overview of the data available and the main characteristics. We observe large variations in the isotopic composition, showing the large scale influence of tropospheric sources and sinks, but also stratospheric processing. The three gas species are mainly affected by the same sources and processes but in different ways, thus giving complementary information on the atmospheric processes.</p>

scholarly journals High-resolution ice-core stable-isotopic records from Antarctica: towards interannual climate reconstruction

2005 ◽  
Vol 41 ◽  
pp. 63-70 ◽  
Author(s):  
David P. Schneider ◽  
Eric J. Steig ◽  
Tas Van Ommen
Keyword(s):  
Large Scale ◽  
Ice Core ◽  
Multiple Linear Regression Model ◽  
Ice Cores ◽  
The United States ◽  
Seasonal Temperature ◽  
Stable Isotopic ◽  
Isotopic Records ◽  
The Antarctic ◽  
Ice Core Records

AbstractIce-core records are a key resource for reconstructing Antarctic climate. However, a number of physical processes preclude the simple interpretation of ice-core properties such as oxygen isotopic ratios in terms of climate variables like temperature or sea-level pressure. We show that well-dated, sub-annually resolved stable-isotopic records from the United States International Trans-Antarctic Scientific Expedition (US-ITASE) traverses and other sources have a high correlation with local seasonal temperature variation. However, this temporal relationship cannot be simply extended to quantitative interannual resolution reconstructions of site temperature. We suggest that a consistent and important target for ice-core calibrations is a composite of annual mean temperature records from Antarctic weather stations, which covaries strongly with the dominant mode (from principal component analysis) of temperature variability in the Antarctic. Significant correlations with this temperature index are found with individual ice-core records, with a composite of the ice cores, and through a multiple linear regression model with the ice cores as predictors. These results imply that isotopic signals, like the instrumental temperature mode itself, have a strong response to large-scale atmospheric circulation variability, which in the Antarctic region is dominated by the Southern Annular Mode.

Stable isotopic and geochemical characterisation of precipitation and riverine waters in the Eastern Carpathians and links with large-scale drivers

2021 ◽  
pp. SP507-2020-154
Author(s):  
Carmen-Andreea Bădăluță ◽  
Dumitru Mihăilă ◽  
Doina Mihăilă ◽  
Gheorghe Bădăluță ◽  
Petruț Ionel Bistricean
Keyword(s):  
Surface Water ◽  
Isotopic Composition ◽  
Industrial Development ◽  
Large Scale ◽  
Precipitation Amount ◽  
Hydrological Processes ◽  
Ecological State ◽  
Eastern Carpathians ◽  
Stable Isotopic

AbstractWater, the vital element of the environment, considered for long time an inexhaustible and renewable resource, can have a limiting or favourable potential in the socio-economic development of a region. Given the fact that Romania's NE (Eastern Carpathians and the north-western part of Moldova Plateau) is undergoing increased competition for water resources, triggered by the intensification of agriculture and industrial development, better knowledge of the hydrological processes and the quality of surface water is required. The main purpose of the present study is to identify the hydrological processes that determine the quality of surface waters based on analyses of the stable isotopic composition of water (from precipitation, rivers and lakes) and their quality parameters. For this, water samples were collected from 29 river sections, two lakes and a precipitation monitoring point over a period of 12 months (January to December 2019). Results show that the changes in the isotopic composition of precipitation and surface water are mainly controlled by air temperature, which, in turn, is influenced by the large-scale atmospheric circulation and other factors (e.g. precipitation amount, season, altitude). At the same time, the chemical analyses indicate that the water resource of the study area is predominantly characterized by a good chemical and ecological state, except for two sampling points with a moderate state and three with a poor ecological state.

What drives the isotopic composition of vapor, precipitation and surface snow in a coastal site of East Anrctica: Adelie Land

2020 ◽  
Author(s):  
Christophe Leroy-Dos Santos ◽  
Amaelle Landais ◽  
Elise Fourre ◽  
Cecile Agosta ◽  
Mathieu Casado ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Large Scale ◽  
Hydrological Cycle ◽  
Specific Humidity ◽  
Data Series ◽  
Blowing Snow ◽  
Transport Pathway ◽  
Stable Isotopic Composition ◽  
Stable Isotopic ◽  
Surface Snow

<p>Studying the drivers of the water stable isotopic composition at coastal Antarctic sites is useful for the interpretation of coastal ice-core signal or the analysis of recent mass balance evolution. In addition to the classical fingerprint of temperature, the water isotopic composition in water vapor and snow carries a fingerprint of the humidity transport pathway, from evaporation to precipitation. Blowing snow in very windy coastal regions is also expected to carry a particular signature affected by snow-air exchanges as observed for surface snow on the East Antarctic plateau.</p><p>Since November 2018, we have been continuously measuring the water stable isotopic composition of vapor at Dumont D’Urville station (Adélie Land) using laser spectrometers in addition to isotopic composition of precipitation, blowing snow and surface snow samples. We present here the full 2019 data series. We focus on the two main weather regimes, in summer and winter, that affect the local hydrological cycle. In summer, temperature and specific humidity signals are characterized by large diurnal cycles due to katabatic winds. Winter variability is largely influenced by large scale synoptic events. We also investigate a few specific cases of precipitation/sublimation and compare two summer periods with opposite sea-ice conditions.</p>

Some comments about observations and image processing of comet 29P/Schwassmann-Wachmann 1

1999 ◽  
Vol 173 ◽  
pp. 243-248
Author(s):  
D. Kubáček ◽  
A. Galád ◽  
A. Pravda
Keyword(s):  
Image Processing ◽  
Large Scale ◽  
Harvard College ◽  
Oak Ridge ◽  
Large Scale Structures ◽  
Short Period Comet ◽  
Short Period ◽  
Scale Structures ◽  
Harvard College Observatory ◽  
Period Comet

AbstractUnusual short-period comet 29P/Schwassmann-Wachmann 1 inspired many observers to explain its unpredictable outbursts. In this paper large scale structures and features from the inner part of the coma in time periods around outbursts are studied. CCD images were taken at Whipple Observatory, Mt. Hopkins, in 1989 and at Astronomical Observatory, Modra, from 1995 to 1998. Photographic plates of the comet were taken at Harvard College Observatory, Oak Ridge, from 1974 to 1982. The latter were digitized at first to apply the same techniques of image processing for optimizing the visibility of features in the coma during outbursts. Outbursts and coma structures show various shapes.

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

Large-scale Motion of Solar Filaments

2000 ◽  
Vol 179 ◽  
pp. 205-208
Author(s):  
Pavel Ambrož ◽  
Alfred Schroll
Keyword(s):  
Magnetic Flux ◽  
Proper Motion ◽  
Time Scale ◽  
Large Scale ◽  
Accuracy Of Measurements ◽  
Solar Filaments ◽  
General Movement ◽  
Scale Motion ◽  
Velocity Scatter

AbstractPrecise measurements of heliographic position of solar filaments were used for determination of the proper motion of solar filaments on the time-scale of days. The filaments have a tendency to make a shaking or waving of the external structure and to make a general movement of whole filament body, coinciding with the transport of the magnetic flux in the photosphere. The velocity scatter of individual measured points is about one order higher than the accuracy of measurements.

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