Search Results

You are looking at 81 - 90 of 993 items for :

  • Isotopic analysis x
  • All content x
Clear All
Yuko M. Okumura, David Schneider, Clara Deser, and Rob Wilson

isotope anomalies in the peninsula and eastern West Antarctica are again associated with positive SST anomalies in the North Atlantic and negative SST anomalies in the South Atlantic. Compared to Fig. 6b , positive SST correlations in the northern tropical Pacific and negative SST correlations in the South Pacific and Indian Ocean are more pronounced in Fig. 7b while positive correlations in the northern tropical Atlantic weaken. The SVD analysis thus confirms the results of simple correlation

Full access
B. B. Hicks

beenneglected. Some justification for the neglect of scavenging of theradon and thoron daughters by falling raindrops canbe derived from the results of Greenfield (1957). Sincethe isotopes of interest here are largely associated withparticles having diameters < 1 ~m (Jacobi et al., 1959),the amount of radioactivity collected by impactionduring the descent of the rain should be sufficientlysmall to be disregarded in the present analysis. Consequently, the data'have been corrected for radioactivedecay

Full access
R. J. Francey, L. P. Steele, R. L. Langenfelds, and B. C. Pak

routinely provided to international databases. In Melbourne, 200 km to the north, CSIRO has established the Global Atmospheric Sampling Laboratory (GASLAB), which substantially enhances the Cape Grim trace gas program. GASLAB emphasizes the analysis of air collected in flasks at Cape Grim and other sites and extends the Cape Grim program by expanding the range of species measured, providing, in particular, isotopic measurements; forming the link to international calibration scales through the provision

Full access
David W. Lea

-sea temperature component of the V19-30 benthic oxygen isotope record and the CO 2 record using a similar analysis yielded a coherent 100-kyr amplitude of 1°C and 34 ppmv, respectively ( Shackleton 2000 ). The coherent 100-kyr amplitude in the Cocos Ridge SST record is likely to be a consequence of the influence of atmospheric CO 2 on tropical climate. It is important to note that the amplitude of SST change at 100 kyr is not unusually high at the Cocos Ridge site. For example, a longer record from the

Full access
R. E. M. Neubert, L. L. Spijkervet, J. K. Schut, H. A. Been, and H. A. J. Meijer

1. Introduction Sampling of atmospheric whole air into glass flasks for later laboratory analysis of trace gas concentrations and isotopic ratios (commonly known as flask sampling) has proven to be a tool of major importance in global carbon cycle research (e.g., Conway et al. 1994 ; Keeling et al. 1995 ; Francey et al. 1995 ). In this way, air samples can be taken even at remote places with little infrastructure (and thus anthropogenic influences), providing better observation coverage of

Full access
George I. Smith, Irving Friedman, Harold Klieforth, and Kenneth Hardcastle

. Frey, Eds.,Int. Assoc. Quat. Res., 7th Cong. Rev. Vol., 433-451.Mehringer, P. J., Jr., 1967: Pollen analysis of the Tule Springsarea, Nevada. Nevada State Anthropol. Pap., No. 13, pt. 3,130-200.Monteverdi, J. P., 1976: The single air mass disturbance andprecipitation characteristics at San Francisco. Mon. Wee.Rev., 104, 1289-1296.Mook, W. G., D. J. Groeneveld, A. E. Brown and A. J. VanGanswijk, 1974: Analysis of a run-off hydrograph by meansof natural 180: Isotope Techniques in Groundwater

Full access
Annie L. Putman, Xiahong Feng, Eric S. Posmentier, Anthony M. Faiia, and Leslie J. Sonder

, investigators interested in understanding isotopic ratios of precipitation will want to know the temperature of condensation/deposition (for equilibrium fractionation) or humidity at the cloud base (to assess the potential for subcloud evaporation). We expect that the vapor sources identified by back trajectories are sensitive to the choice of arrival heights, and so are the conclusions (e.g., meteorological conditions at the source) drawn from the analysis. Within the literature, there are many ways of

Full access
Per B. Storebø

found by measurementsof radioactivity in precipitation.Deposition of bomb debris from the stratosphere is examined by available world-wide measurements oflong-lived radioactive isotopes. The simple assumption that Sr" is more rapidly brought down to earth byprecipitation than is Cs'n is shown to be reasonable. This might explain Norwegian, Danish, and Britishmeasurements of the Cs*n/Srgo ratio in precipitation, provided that various climatic factors are taken in,toaccount. This interpretation of the

Full access
Francina Dominguez, Praveen Kumar, Xin-Zhong Liang, and Mingfang Ting

that atmospheric moisture storage plays in the recycling process. The study of precipitation recycling has been approached in a variety of ways, such as physical analysis using isotope data, numerical tracer experiments, and analytical theories. Analysis of isotopic data in rainfall provides information about the origin of the water molecules. Isotopic studies in the Amazon region are numerous and date back to the 1970s with the work of Salati et al. (1979) and Salati and Vose (1984) . These

Full access
David J. Gochis, Juan-Carlos Leal, W. James Shuttleworth, Christopher J. Watts, and Jaime Garatuza-Payan

enhancements will increase sampling in this interval. d. Coordinated isotopic sampling In addition to the automatic, tipping-bucket rain gauge network, 12 bulk rainfall collectors were deployed at selected sites for the collection and analysis of isotopes. Isotopes can potentially serve as atmospheric and terrestrial tracers of moisture sources, paths, and processes. These sites, shown as white squares on Fig. 1 , are intended to sample the longitudinal and elevational gradient of isotope content in

Full access