The potential of massive corals for the study of high-resolution climate variation in the past millennium

AbstractWe examined the hydroclimatic signal in a record of annual lamina (varve) thickness from High Arctic Lake A, Ellesmere Island (83°00.00′N, 75°30.00′W). In this unglacierized catchment, nival melt is the dominant source for meltwater and transport of sediment to the lake, and autumn snowfall is highly influential on varve thickness through the amount of snow available for melt in the following year. For the period during which climatic data are available, varve thickness in Lake A was significantly correlated (r = 0.50, p < 0.01) with the cumulative snowfall from August to October (ASO) during the previous year and to a lesser extent, ASO mean daily temperature (r = 0.39, p < 0.01) at Alert, Nunavut (175 km east). The varve thickness record, interpreted as a proxy record of ASO snowfall and by extension, ASO temperature, indicated above-mean conditions during five periods of the past millennium, including most of the 20th century. These results corresponded well to other available high-resolution proxy climate records from the region, with some discrepancies prior to AD 1500 and during the period AD 1700–1900.

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The Contribution of Intermediate-Voltage, High-Resolution Electron Microscopy In Materials Science: An Appraisal

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100181142 ◽

1990 ◽

Vol 48 (1) ◽

pp. 478-479

Author(s):

John L. Hutchison

Keyword(s):

High Resolution ◽

Materials Science ◽

High Resolution Electron Microscopy ◽

Optical Diffraction ◽

The Past ◽

Resolution Electron ◽

Extreme Sensitivity ◽

Electron Microscopes ◽

New Generation ◽

Small Metal Particles

Over the past five years or so the development of a new generation of high resolution electron microscopes operating routinely in the 300-400 kilovolt range has produced a dramatic increase in resolution, to around 1.6 Å for “structure resolution” and approaching 1.2 Å for information limits. With a large number of such instruments now in operation it is timely to assess their impact in the various areas of materials science where they are now being used. Are they falling short of the early expectations? Generally, the manufacturers’ claims regarding resolution are being met, but one unexpected factor which has emerged is the extreme sensitivity of these instruments to both floor-borne and acoustic vibrations. Successful measures to counteract these disturbances may require the use of special anti-vibration blocks, or even simple oil-filled dampers together with springs, with heavy curtaining around the microscope room to reduce noise levels. In assessing performance levels, optical diffraction analysis is becoming the accepted method, with rotational averaging useful for obtaining a good measure of information limits. It is worth noting here that microscope alignment becomes very critical for the highest resolution.In attempting an appraisal of the contributions of intermediate voltage HREMs to materials science we will outline a few of the areas where they are most widely used. These include semiconductors, oxides, and small metal particles, in addition to metals and minerals.

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The Contribution of Phonon-Scattered Electrons to High-Resolution Electron Micrographs of Crystals

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100179063 ◽

1990 ◽

Vol 48 (1) ◽

pp. 62-63

Author(s):

H. Kohl

Keyword(s):

High Resolution ◽

Spherical Aberration ◽

High Resolution Electron Microscopy ◽

Static Potential ◽

Qualitative Comparison ◽

The Past ◽

Resolution Electron ◽

High Resolution Images ◽

High Resolution Electron Micrographs ◽

Extract Information

High-Resolution Electron Microscopy is able to determine structures of crystals and interfaces with a spatial resolution of somewhat less than 2 Å. As the image is strongly dependent on instrumental parameters, notably the defocus and the spherical aberration, the interpretation of micrographs necessitates a comparison with calculated images. Whereas one has often been content with a qualitative comparison of theory with experiment in the past, one is currently striving for quantitative procedures to extract information from the images [1,2]. For the calculations one starts by assuming a static potential, thus neglecting inelastic scattering processes.We shall confine the discussion to periodic specimens. All electrons, which have only been elastically scattered, are confined to very few directions, the Bragg spots. In-elastically scattered electrons, however, can be found in any direction. Therefore the influence of inelastic processes on the elastically (= Bragg) scattered electrons can be described as an attenuation [3]. For the calculation of high-resolution images this procedure would be correct only if we had an imaging energy filter capable of removing all phonon-scattered electrons. This is not realizable in practice. We are therefore forced to include the contribution of the phonon-scattered electrons.

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HURRICANE FREQUENCY NEAR CHESAPEAKE BAY DURING THE PAST MILLENNIUM

10.1130/abs/2019ne-328312 ◽

2019 ◽

Author(s):

Michael Toomey ◽

◽

Nicole D'Entremont ◽

Emma Armstrong ◽

Thomas Cronin ◽

...

Keyword(s):

Chesapeake Bay ◽

The Past ◽

Past Millennium

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Comparison of the HYDE cropland data over the past millennium with regional historical evidence from Germany

Regional Environmental Change ◽

10.1007/s10113-020-01735-1 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Diyang Zhang ◽

Xiuqi Fang ◽

Liang Emlyn Yang

Keyword(s):

Historical Evidence ◽

The Past ◽

Past Millennium

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Conceptualizing histories of multispecies entanglements: Ancient pathogen genomics and the case of Borrelia recurrentis

Journal of Social Archaeology ◽

10.1177/1469605321993942 ◽

2021 ◽

pp. 146960532199394

Author(s):

Venla Oikkonen

Keyword(s):

East Africa ◽

Ancient Dna ◽

Relapsing Fever ◽

Borrelia Recurrentis ◽

The Past ◽

Cultural Implications ◽

Past Millennium

This article explores the conceptual and cultural implications of using pathogen ancient DNA (aDNA) collected in archaeological contexts to understand the past. More specifically, it examines ancient pathogen genomics as a way of conceptualizing multispecies entanglements. The analysis focuses on the 2018 sequencing of Borrelia recurrentis bacteria retrieved from a medieval graveyard in Oslo, Norway. B. recurrentis is associated with louse-borne relapsing fever (LBRF), known to have killed several million people in Europe during the past millennium, and it is still encountered in parts of East Africa. The article demonstrates that while aDNA research often foregrounds multispecies entanglements, its epistemic tools cannot easily address the ontological blurriness of pathogens and their embeddedness in vibrant material processes. The article draws on feminist posthumanities work on microbes and materiality to highlight conceptual openings that a theorization of ancient pathogens could engender.

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d4PDF: large-ensemble and high-resolution climate simulations for global warming risk assessment

Progress in Earth and Planetary Science ◽

10.1186/s40645-020-00367-7 ◽

2020 ◽

Vol 7 (1) ◽

Author(s):

Masayoshi Ishii ◽

Nobuhito Mori

Keyword(s):

Risk Assessment ◽

Global Warming ◽

High Resolution ◽

Climate Changes ◽

Future Climate ◽

Atmospheric Models ◽

Large Ensemble ◽

Past Climate ◽

The Past ◽

Climate Simulations

Abstract A large-ensemble climate simulation database, which is known as the database for policy decision-making for future climate changes (d4PDF), was designed for climate change risk assessments. Since the completion of the first set of climate simulations in 2015, the database has been growing continuously. It contains the results of ensemble simulations conducted over a total of thousands years respectively for past and future climates using high-resolution global (60 km horizontal mesh) and regional (20 km mesh) atmospheric models. Several sets of future climate simulations are available, in which global mean surface air temperatures are forced to be higher by 4 K, 2 K, and 1.5 K relative to preindustrial levels. Nonwarming past climate simulations are incorporated in d4PDF along with the past climate simulations. The total data volume is approximately 2 petabytes. The atmospheric models satisfactorily simulate the past climate in terms of climatology, natural variations, and extreme events such as heavy precipitation and tropical cyclones. In addition, data users can obtain statistically significant changes in mean states or weather and climate extremes of interest between the past and future climates via a simple arithmetic computation without any statistical assumptions. The database is helpful in understanding future changes in climate states and in attributing past climate events to global warming. Impact assessment studies for climate changes have concurrently been performed in various research areas such as natural hazard, hydrology, civil engineering, agriculture, health, and insurance. The database has now become essential for promoting climate and risk assessment studies and for devising climate adaptation policies. Moreover, it has helped in establishing an interdisciplinary research community on global warming across Japan.

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