An ultra-clean technique for accurately analysing Pb isotopes and heavy metals at high spatial resolution in ice cores with sub-pgg−1 Pb concentrations

Abstract. High resolution, downscaled climate model data are used in a wide variety of applications in environmental sciences. Here we present the CHELSA-TraCE21k downscaling algorithm to create global monthly climatologies for temperature and precipitation at 30 arcsec spatial resolution in 100 year time steps for the last 21,000 years. Paleo orography at high spatial resolution and at each timestep is created by combining high resolution information on glacial cover from current and Last Glacial Maximum (LGM) glacier databases with the interpolation of a dynamic ice sheet model (ICE6G) and a coupling to mean annual temperatures from CCSM3-TraCE21k. Based on the reconstructed paleo orography, mean annual temperature and precipitation was downscaled using the CHELSA V1.2 algorithm. The data were validated by comparisons with the glacial extent of the Laurentide ice shield based on expert delineations, proxy data from Greenland ice cores, historical climate data from meteorological stations, and a dynamic simulation of species a distribution throughout the Holocene. Validations show that CHELSA TraCE21k output creates a reasonable representation of the distribution of temperature and precipitation through time at a high spatial resolution, and simulations based on the data are capable of detecting effective LGM refugia of species.

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High spatial resolution AEM observations of yttrium segregation in chromia scales grown on Co-45%Cr

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100144103 ◽

1986 ◽

Vol 44 ◽

pp. 518-519

Author(s):

K. Przybylski ◽

A. J. Garratt-Reed ◽

G. J. Yurek

Keyword(s):

Spatial Resolution ◽

Outer Surface ◽

Maximum Concentration ◽

High Spatial Resolution ◽

Reactive Elements ◽

Chromia Scales

The addition of so-called “reactive” elements such as yttrium to alloys is known to enhance the protective nature of Cr2O3 or Al2O3 scales. However, the mechanism by which this enhancement is achieved remains unclear. An A.E.M. study has been performed of scales grown at 1000°C for 25 hr. in pure O2 on Co-45%Cr implanted at 70 keV with 2x1016 atoms/cm2 of yttrium. In the unoxidized alloys it was calculated that the maximum concentration of Y was 13.9 wt% at a depth of about 17 nm. SIMS results showed that in the scale the yttrium remained near the outer surface.

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Integration of Core-Edge Spectroscopy Methods for the Study of Polymers

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010016323x ◽

1996 ◽

Vol 54 ◽

pp. 154-155

Author(s):

E. G. Rightor

Keyword(s):

Excited State ◽

Polymer Blends ◽

Gas Phase ◽

Spatial Resolution ◽

High Spatial Resolution ◽

Electronic States ◽

Core Electron ◽

Bulk Solids ◽

Development Application

Core edge spectroscopy methods are versatile tools for investigating a wide variety of materials. They can be used to probe the electronic states of materials in bulk solids, on surfaces, or in the gas phase. This family of methods involves promoting an inner shell (core) electron to an excited state and recording either the primary excitation or secondary decay of the excited state. The techniques are complimentary and have different strengths and limitations for studying challenging aspects of materials. The need to identify components in polymers or polymer blends at high spatial resolution has driven development, application, and integration of results from several of these methods.

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