scholarly journals Atmospheric controls on hydrogen and oxygen isotope composition of meteoric and surface waters in Patagonia

2018 ◽  
Author(s):  
Christoph Mayr ◽  
Lukas Langhamer ◽  
Holger Wissel ◽  
Wolfgang Meier ◽  
Tobias Sauter ◽  
...  
Keyword(s):  
Isotope Composition ◽  
Isotope Effects ◽  
Atlantic Coast ◽  
Climate Data ◽  
Moisture Recycling ◽  
Moisture Sources ◽  
The Andes ◽  
The Pacific ◽  
Hydrogen And Oxygen Isotope ◽  
Lentic Waters

Abstract. The southern tip of South America, commonly referred to as Patagonia, is a key area to understand Southern Hemisphere Westerlies (SHW) dynamics and orographic isotope effects in precipitation. However, only few studies have addressed these topics. We evaluated the stable isotope (δ2H, δ18O) compositions of precipitation, lentic waters, and lotic waters in that area to characterize and understand isotope fractionation processes associated with orographic rainout, moisture recycling and moisture sources. Observational data were interpreted with the help of backward trajectory modelling of moisture sources using reanalysis climate data. While the Pacific serves as the exclusive moisture source for sites upwind of the Andes and on the immediate downwind area of the Andes, recycled moisture from the continent seems to be the main humidity source at the Patagonian Atlantic coast. In contrast, the Pampean Atlantic coast north of Patagonia obtains moisture from the Atlantic Ocean. In the core zone of the SHW at a latitude of 50° S, a depletion in the heavy isotopes of 10 ‰ and 85 ‰, for δ18O and δ2H, respectively, occurs due to orographic rainout corresponding to a drying ratio of 0.45.

Majolica in the Early Colonial Andes: The Role of Panamanian Wares

2001 ◽  
Vol 12 (1) ◽  
pp. 45-58 ◽  
Author(s):  
Ross W. Jamieson
Keyword(s):  
Spanish Colonial ◽  
Important Indicator ◽  
The Andes ◽  
Early Colonial ◽  
The Pacific ◽  
Elite Status ◽  
Set Up ◽  
The City ◽  
Made In

As one of the most common artifact categories found on Spanish colonial sites, the wheel-made, tin-glazed pottery known as majolica is an important chronological and social indicator for archaeologists. Initially imported from Europe, several manufacturing centers for majolica were set up in the New World by the late sixteenth century. The study of colonial majolica in the Viceroyalty of Peru, which encompassed much of South America, has received less attention than ceramic production and trade in the colonial Caribbean and Mesoamerica. Prior to 1650 the Viceroyalty of Peru was supplied with majolica largely produced in the city of Panama Vieja, on the Pacific. Panama Vieja majolica has been recovered from throughout the Andes, as far south as Argentina. Majolica made in Panama Vieja provides an important chronological indicator of early colonial archaeological contexts in the region. The reproduction of Iberian-style majolica for use on elite tables was symbolically important to the imposition of Spanish rule, and thus Panamanian majolicas also provide an important indicator of elite status on Andean colonial sites.

scholarly journals Nitrogen isotope effects can be used to diagnose N transformations in wastewater anammox systems

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Paul M. Magyar ◽  
Damian Hausherr ◽  
Robert Niederdorfer ◽  
Nicolas Stöcklin ◽  
Jing Wei ◽  
...  
Keyword(s):  
Isotope Effect ◽  
Isotope Composition ◽  
Isotope Effects ◽  
Nitrogen Isotope ◽  
Anammox Bacteria ◽  
Ammonium Oxidation ◽  
Experimental Conditions ◽  
N Transformations ◽  
Natural Systems ◽  
Inverse Isotope Effect

AbstractAnaerobic ammonium oxidation (anammox) plays an important role in aquatic systems as a sink of bioavailable nitrogen (N), and in engineered processes by removing ammonium from wastewater. The isotope effects anammox imparts in the N isotope signatures (15N/14N) of ammonium, nitrite, and nitrate can be used to estimate its role in environmental settings, to describe physiological and ecological variations in the anammox process, and possibly to optimize anammox-based wastewater treatment. We measured the stable N-isotope composition of ammonium, nitrite, and nitrate in wastewater cultivations of anammox bacteria. We find that the N isotope enrichment factor 15ε for the reduction of nitrite to N2 is consistent across all experimental conditions (13.5‰ ± 3.7‰), suggesting it reflects the composition of the anammox bacteria community. Values of 15ε for the oxidation of nitrite to nitrate (inverse isotope effect, − 16 to − 43‰) and for the reduction of ammonium to N2 (normal isotope effect, 19–32‰) are more variable, and likely controlled by experimental conditions. We argue that the variations in the isotope effects can be tied to the metabolism and physiology of anammox bacteria, and that the broad range of isotope effects observed for anammox introduces complications for analyzing N-isotope mass balances in natural systems.

Stable Hydrogen and Oxygen Isotope Composition of Waters from Mine Tailings in Different Climatic Environments

2007 ◽  
Vol 41 (6) ◽  
pp. 1870-1876 ◽  
Author(s):  
Jorge E. Spangenberg ◽  
Bernhard Dold ◽  
Marie-Louise Vogt ◽  
Hans-Rudolf Pfeifer
Keyword(s):  
Oxygen Isotope ◽  
Mine Tailings ◽  
Isotope Composition ◽  
Oxygen Isotope Composition ◽  
Hydrogen And Oxygen Isotope

scholarly journals Moisture Recycling in the Andes of Colombia

2021 ◽  
Author(s):  
Juan Mauricio Bedoya-Soto ◽  
German Poveda
Keyword(s):  
Moisture Recycling ◽  
The Andes

scholarly journals Distribution, fluxes and balance of particulate organic carbon in the Arctic ocean

2019 ◽  
Vol 59 (4) ◽  
pp. 544-552
Author(s):  
A. A. Vetrov ◽  
E. A. Romankevich
Keyword(s):  
Organic Carbon ◽  
Arctic Ocean ◽  
Particulate Organic Carbon ◽  
The Arctic ◽  
Climate Data ◽  
Arctic Seas ◽  
The Pacific ◽  
The Arctic Ocean ◽  
Main Component ◽  
Depth Horizon

Particulate organic carbon (POC) is one of main component of carbon cycle in the Ocean. In this study an attempt to construct a picture of the distribution and fluxes of POC in the Arctic Ocean adjusting for interchange with the Pacific and Atlantic Oceans has been made. The specificity of this construction is associated with an irregular distribution of POC measurements and complicated structure and hydrodynamics of the waters masses. To overcome these difficulties, Multiple Linear Regression technic (MLR) was performed to test the significant relation between POC, temperature, salinity, as well depth, horizon, latitude and offshore distance. The mapping of POC distribution and its fluxes was carrying out at 38 horizons from 5 to 4150 m (resolution 1°×1°). Data on temperature, salinity, meridional and zonal components of current velocities were obtained from ORA S4 database (Integrated Climate Data Center, http://icdc.cen.uni-hamburg.de/las). The import-export of POC between the Arctic, Atlantic and Pacific Oceans as well as between Arctic Seas was precomputed by summer fluxes. The import of POC in the Arctic Ocean is estimated to be 38±8Tg Cyr-1, and the export is -9.5±4.4Tg Cyr-1.

scholarly journals Seasonal variations in nitrate isotope composition of three rivers draining into the North Sea

2010 ◽  
Vol 7 (4) ◽  
pp. 6051-6088 ◽  
Author(s):  
A. Deek ◽  
K. Emeis ◽  
U. Struck
Keyword(s):  
Isotopic Composition ◽  
North Sea ◽  
Isotope Composition ◽  
Atmospheric Oxygen ◽  
Isotope Effects ◽  
Nitrate Sources ◽  
Particulate Nitrogen ◽  
Soil Nitrification ◽  
Mean Values ◽  
Δ 15N

Abstract. Nitrate loading of coastal ecosystems by rivers that drain industrialised catchments continues to be a problem in the South Eastern North Sea, in spite of significant mitigation efforts over the last 2 decades. To identify nitrate sources, sinks, and turnover in three German rivers that discharge into the German Bight, we determined δ 15N-NO3- and δ18O- NO3- in nitrate and δ 15N of particulate nitrogen for the period 2006–2009 (biweekly samples). The nitrate loads of Rhine, Weser and Ems varied seasonally in magnitude and δ 15N-NO3- (6.5–21‰), whereas the δ 18O-NO3- (-0.3–5.9‰) and δ 15N-PN (4–14‰) were less variable. Overall temporal patterns in nitrate mass fluxes and isotopic composition suggest that a combination of nitrate delivery from nitrification of soil ammonia in the catchment and assimilation of nitrate in the rivers control the isotopic composition of nitrate. Nitrification in soils as a source is indicated by low δ 18O-NO3- in winter, which traces the δ 18O of river water. Mean values of δ 18O-H2O were between –9.4‰ and –7.3‰; combined in a ratio of 2:1 with the atmospheric oxygen δ 18O of 23.5‰ agrees with the found δ 18O of nitrate in the rivers. Parallel variations of δ 15N-NO3- and δ 18O-NO3- within each individual river are caused by isotope effects associated with nitrate assimilation in the water column, the extent of which is determined by residence time in the river. Assimilation is furthermore to some extent mirrored both by the δ 15N of nitrate and particulate N. Although δ 15-NO3- observed in Rhine, Weser and Ems are reflected in high average δ 15N-PN (between 6‰ and 9‰, both are uncorrelated in the time series due to lateral and temporal mixing of PN. That a larger enrichment was consistently seen in δ 15N-NO3- relative to δ 18O-NO3- is attributed to constant additional diffuse nitrate inputs deriving from soil nitrification in the catchment area. A statistically significant inverse correlation exists between increasing δ 15N-NO3- values and decreasing NO3- concentrations. This inverse relationship – observed in each seasonal cycle – together with a robust relationship between human dominated land use and δ 15N-NO3- values demonstrates a strong influence of human activities and riverine nitrate consumption efficiency on the isotopic composition of riverine nitrate.

TWO NEW MEXICAN ISOTOGASTRURA (COLLEMBOLA: ISOTOGASTRURIDAE)

1998 ◽  
Vol 130 (2) ◽  
pp. 195-199 ◽  
Author(s):  
José G. Palacios-Vargas ◽  
Jean-Marc Thibaud
Keyword(s):  
New Species ◽  
Pacific Coast ◽  
Atlantic Coast ◽  
New Mexican ◽  
The Pacific ◽  
Two New Species

AbstractTwo new species of Isotogastrura, one from the Pacific coast and one from the Atlantic coast, are described: Isotogastrura ahuizotli sp.nov. and Isotogastrura veracruzana sp.nov. A key for the five species known at present is included.

scholarly journals On the Pleistocene Snow-Line Depression in the Arid Regions of the South American Andes

1971 ◽  
Vol 10 (59) ◽  
pp. 255-267
Author(s):  
Stefan L. Hastenrath
Keyword(s):  
Arid Regions ◽  
South American ◽  
The South ◽  
Temperate Latitude ◽  
The Andes ◽  
Western Cordillera ◽  
Snow Line ◽  
The Pacific ◽  
The Arid Regions ◽  
June July

AbstractField observations during a journey through the arid regions of the South American Andes in June-July 1969 are evaluated in conjunction with available air photographs and reports from adjacent regions of the High Andes. Results indicate an increase of the Pleistocene snow-line depression in the western Cordillera from about 700 m at lat. 12° S. to more than 1 500 m at lat. 30° S. The Pleistocene snow-line depression decreases from the Pacific to the Atlantic side of the Andes, but particularly strongly so on the poleward fringe of the arid region. From this geomorphic evidence it is suggested that the atmospheric circulation during the glacial period was characterized by an Equatorward displacement of the boundary between tropical easterlies and temperate-latitude westerlies.

Taxonomy of Centropomus Lacépède, 1802 (Perciformes: Centropomidae), with focus on the Atlantic species of the genus

Zootaxa ◽  
2021 ◽  
Vol 4942 (3) ◽  
pp. 301-338
Author(s):  
JESSÉ MIRANDA DE FIGUEIREDO-FILHO ◽  
ALEXANDRE P. MARCENIUK ◽  
ANDERSON FEIJÓ ◽  
RAQUEL SICCHA-RAMIREZ ◽  
GIOVANA S. RIBEIRO ◽  
...  
Keyword(s):  
Geometric Morphometrics ◽  
Pacific Coast ◽  
Atlantic Coast ◽  
Lateral View ◽  
Cytochrome C Oxidase I ◽  
Linear Measurements ◽  
Molecular Analyses ◽  
Needed Information ◽  
The Pacific ◽  
Pacific Species

Centropomus Lacépède, 1802 comprises 13 species of the fishes popularly knows as snooks, distributed in both Atlantic and Pacific coasts of America. Despite several studies on the group, conflicting taxonomic classifications still exist, including overlapping diagnostic characters, rendering species diagnoses extremely difficult. Herein, we review the taxonomy of Centropomus to elucidate species identities, redefine their diagnoses and to assess interspecific relationships based on the examination of 376 specimens. The study included complementary approaches, as analyses of external morphologic characters, linear and geometric morphometrics, and molecular analyses. Forty-nine characters were used for external morphology, 17 discrete plus 32 linear measurements. Shape and size were analyzed through geometric morphometrics of 185 specimens in lateral view. Partial sequences of the gene cytochrome c oxidase I were obtained for 129 specimens representing 11 species. Based on the consistent results retrieved from the morphologic and molecular analyses, we recognized six species of Centropomus from the Atlantic coast (C. ensiferus, C. irae, C. parallelus, C. pectinatus, C. poeyi and C. undecimalis). Centropomus mexicanus is treated as a junior synonym of C. parallelus. Six species from the Pacific coast are also tentatively recognized (C. armatus, C. medius, C. nigrescens, C. robalito, C. unionensis, and C. viridis), however further studies on the Pacific species are still needed. Information on type material, diagnosis, distribution, and taxonomic comments are provided for each species. An identification key to the species of Centropomus is presented. 

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