Filters: Tags: Deuterium (X)29 results (68ms)
Changes in the isotopic and chemical composition of ground water resulting from a recharge pulse from a sinking stream
This product consists of one tabular dataset and associated metadata of water quality information related to rivers, streams, and reservoirs in the Upper Mississippi River watershed between 2012 and 2016. This data release is a part of a national assessment of freshwater aquatic carbon fluxes. Data consist of organic and inorganic carbon related species, carbon dioxide and methane gas fluxes calculated from manual chamber measurements, nitrogen species, carbon isotopes, oxygen isotopes, cations, anions, trace metals, and various in situ measurements including: pH, water temperature, air temperature, barometric pressure, dissolved oxygen, turbidity, fluorescent dissolved organic matter, and specific conductance....
Carbon acquisition and water use in a Northern Utah Juniperus osteosperma (Utah juniper) population.
Water use and carbon acquisition were examined in a northern Utah population of Juniperus osteosperma (Torr.) Little. Leaf-level carbon assimilation, which was greatest in the spring and autumn, was limited by soil water availability. Gas exchange, plant water potential and tissue hydrogen stable isotopic ratio (deltaD) data suggested that plants responded rapidly to summer rain events. Based on a leaf area index of 1.4, leaf-level water use and carbon acquisition scaled to canopy-level means of 0.59 mm day(-1) and 0.13 mol m(-2) ground surface day(-1), respectively. Patterns of soil water potential indicated that J. osteosperma dries the soil from the surface downward to a depth of about 1 m. Hydraulic redistribution...
The drilling project at Owens Lake commenced in April,1991. This Open-File Report represents an effort to makeavailable to other researchers our preliminary datacollected during the first year of study followingcompletion of the core-drilling phase. Nineteen datacollections and preliminary interpretations are presentedin the following sections. They are the work of fifteenfirst-authors and their numerous co-authors. Broadly,their topics include a field log of the core(1 contribution), sedimentological analyses (1), clay-mineral identification (1), geochemical analyses (5),dating and age estimates of the cored sediments (4), andidentifications of fossil materials (7).
Understanding the role of fog in forest hydrology: stable isotopes as tools for determining input and partitioning of cloud water in montane forests
Understanding the hydrology of tropical montane cloud forests (TMCF) has become essential as deforestation of mountain areas proceeds at an increased rate worldwide. Passive and active cloud-water collectors, throughfall and stemflow collectors, visibility or droplet size measurements, and micrometeorological sensors are typically used to measure the fog water inputs to ecosystems. In addition, stable isotopes may be used as a natural tracer for fog and rain. Previous studies have shown that the isotopic signature of fog tends to be more enriched in the heavier isotopes 2H and 18O than that of rain, due to differences in condensation temperature and history. Differences between fog and rain isotopes are largest...
From accumulation to discharge: modification of stable isotopes during glacial and post-glacial processes
Deuterium content and salinity of the present free waters from the Rodna-Bargau Mountains, Romania: an assessment for their origin and underground dynamics
Stable isotopic composition of precipitation in the semi-arid north-central portion of the US Great Plains
This product consists of multiple tabular datasets and associated metadata of water quality information related to rivers, streams, and lakes in the Yukon River watershed between 2014 and 2018. This data release is apart of the National Aeronautics and Space Administration (NASA) funded Arctic-Boreal Vulnerability Experiment (ABoVE) and is an assessment of water quality and greenhouse gas fluxes within the interior of Alaska. Sampling frequency varied across locations, with some sites sampled twice a year or more. Data consist of: organic and inorganic carbon related species, carbon dioxide and methane gas fluxes calculated from manual chamber measurements, nitrogen species, carbon isotopes, oxygen and deuterium...
Seasonal variations in isotopic content ( super(18)O- super(2)H) of rainfall over an intertropical humid island (Reunion Island, southwest Indian Ocean)
Isotopic and chemical signatures of low-temperature sulfurous mineral waters (Northern Portugal): Preliminary results
Isotopic ( delta super(18)O) characteristics of weekly precipitation collected across the USA: an initial analysis with application to water source studies
Extreme changes in stable hydrogen isotopes and precipitation characteristics in a landfalling Pacific storm
With a new automated precipitation collector we measured a remarkable decrease of 51‰ in the hydrogen isotope ratio (δ 2H) of precipitation over a 60-minute period during the landfall of an extratropical cyclone along the California coast on 21 March 2005. The rapid drop in δ 2H occurred as precipitation generation transitioned from a shallow to a much deeper cloud layer, in accord with synoptic-scale ascent and deep “seeder-feeder” precipitation. Such unexpected δ 2H variations can substantially impact widely used isotope-hydrograph methods. From extreme δ 2H values of −26 and −78‰, we calculate precipitation temperatures of 9.7 and −4.2°C using an adiabatic condensation isotope model, in good agreement with temperatures...