Eric A. Oches

Malacological and sedimentological evidence for “warm” glacial climate from the Irig loess sequence, Vojvodina, Serbia

Four loess units and three paleosol layers are preserved in the Irig brickyard, Vojvodina, Serbia. Amino acid geochronology provides stratigraphic correlations between loess units V-L1 and V-L2 at the Irig section with loess of glacial cycles B and C, respectively, described from other central European localities. Luminescence dating results for the upper loess layers V-L1L1 and V-L1S1L1 confirm the geological interpretations, although in samples below paleosol V-L1S1S2, the age increase with depth is less than in our proposed age model. Magnetic susceptibility and sedimentological evidence from the Irig loess-paleosol sequence show general similarities with the MIS 6-1 pattern of the SPECMAP oxygen-isotope curve. Malacogical investigations at the Irig site reveal the continuous presence of the Chondrula tridens and Helicopsis striata faunal assemblages throughout the last glacial and final part of the penultimate glacial loess. The loess snail fauna, which is characterized by the complete absence of cold-resistant species, suggests a stable, dry, and relatively warm glacial climate, compared with other central European loess localities. Furthermore, these data suggest that the southern slope of Fruska Gora was a refugium for warm-loving and xerophilus mollusc taxa during the otherwise unfavorable glacial climates of the Late Pleistocene.

Aeolian dust dynamics in central Asia during the Pleistocene: Driven by the long‐term migration, seasonality, and permanency of the Asiatic polar front

Loess-paleosol sequences preserve detailed archives of climate change, reflecting the dynamics of aeolian dust sedimentation and the paleodust content of the atmosphere. The detailed investigation of particle size distributions (PSDs) of windblown sediments is an increasingly used approach to assess the paleorecord of aeolian dust dynamics. The central Asian loess belt offers the potential to reconstruct Pleistocene atmospheric circulation patterns along an adjacent west-east transect within interior Eurasia through granulometric studies. In this study we present the aeolian dust record of the loess sequence at Remisowka (SE Kazakhstan), which reflects a detailed signal of glacial-interglacial climate and atmospheric dynamics in central Asia. On the basis of radiocarbon and amino acid geochronologic data, long-term semicontinuous trends in the aeolian dust record of the Last Glacial Cycle are observed and interpreted to reveal their paleoclimate signal. In consideration of the modern synoptical atmospheric circulation patterns and aeolian dust transport in central Asia, it is likely that the observed trends reflect the long-term migration, seasonal duration, and permanency of the polar front during the late Pleistocene. Previously published models, which focused on the reciprocal glacial-interglacial influence of the zonal Westerlies and the Asiatic high on the aeolian dust transport in central Asia, were overly simplified and should be modified to include the major influence of the Asiatic polar front. As the polar front activity is intimately connected with the development and position of the interhemispherically active, high-level planetary frontal zone (HPFZ), the presented data give insight to long-term aeolian dust dynamics and climate variability of interior Eurasia, which are linked with interhemispheric climates.

Historical developments and recent advances in amino acid geochronology applied to loess research: examples from North America, Europe, and China

Abstract Amino acid geochronology provides important chronostratigraphic insight in the regional correlation and paleoclimatic evaluation of loess–paleosol sequences in the midwestern US, throughout western, central, and eastern Europe, and in China. In general, loess of the last four glacial cycles, corresponding to marine oxygen-isotope stages (OIS) 2–4, 6, 8, and 10, respectively, can be distinguished on the basis of alloisoleucine/isoleucine (A/I) ratios measured in fossil gastropod shells preserved in the loess. The racemization reaction is much slower in older samples, resulting in decreased temporal resolution. In the midwestern US and Europe, it is not possible to confidently subdivide the last glacial cycle on the basis of aminostratigraphic data. However, in China, where effective temperatures were higher during the Late Pleistocene, loess above and below L1SS1, the OIS-3 interstadial paleosol, can be distinguished using amino acid racemization data. With improvements in analytical methods, multiple amino acid d / l- enantiomers are now being measured using reverse-phase liquid chromatography. Aspartic acid racemizes at a higher rate than the traditionally measured alloisoleucine/isoleucine diastereomers and can be measured more rapidly. This development offers hope for better temporal resolution and enhanced stratigraphic subdivision of loess units than has been achieved previously.

Millennial-scale climatic change during the Last Interglacial Period: Superparamagnetic sediment proxy from Paleosol S1, western Chinese Loess Plateau

Detailed magnetic analyses of samples from the Jiuzhoutai well section on the western Chinese Loess Plateau reveal high-resolution signals of summer monsoon change. The last interglacial period is represented here by the 8-meter thick S1 paleosol complex. We have used low-temperature remanence studies to analyze variations in the concentration of Superparamagnetic (SP) grains, which previous studies have shown to be largely of pedogenic origin. The SP concentration, interpreted as a proxy for the extent of pedogenesis, shows millennial scale variations within S1. We conclude that the last interglacial period in Asia was characterized by rapid climate fluctuations, with at least one brief return to near-glacial conditions in the middle of oxygen-isotope substage 5e.

Speaking Out or Staying Quiet on Climate Change: Broadcast Meteorologists Influenced by the Need to Be Pithy, Popular and Politically Cautious

Broadcast meteorologists are in a position to convey knowledge about climate change to the public. These media professionals make deliberate choices about what information to omit or present to their audiences. Interviews with broadcast meteorologists revealed a wide range of attitudes about conveying climate science to their viewers. Three significant concerns emerged from conversations with participants: on-air time constraints are non-negotiable, pressure to be a “popular” personality is constant, and there is an enduring apprehension about taking a position associated with a perceived controversial topic or political viewpoint. Discomfort with these constraints affects the content choices of broadcast meteorologists who might otherwise take a stand representing the scientific consensus on climate change.

A Picture is Worth a Thousand Words: Commentary of Broadcast Meteorologists on the Visual Presentation of Climate Change

Broadcast meteorologists are trusted by the general public to convey knowledge on climate change and they make choices about what information to present to their viewing audiences. Interviews with broadcast meteorologists revealed a wide range in their knowledge base and confidence in conveying climate science to their audiences. However, all interviewees agreed that visual images are an essential means for communicating with their viewers. Three major themes emerged from interviews with participants: visual imagery is important, dramatic images are powerful motivators, and the new visual presentation technologies have great value.

Business Education in an Age of Science and Technology

In a 1994 interview, Carl Sagan described the relationship between science and society thus: ‘We live in a society absolutely dependent on science and technology and yet have cleverly arranged things so that almost no one understands science and technology. That’s a clear prescription for disaster’ (Kalosh, 1994). This view of a world dependent on, yet largely ignorant of, science and technology is an apt description of the situation facing business today. The global economy is increasingly dependent on science and technology. Joseph McCann, Dean of the Sykes College of Business at the University of Tampa in Florida, has written in BizEd that the ‘Next Economy’ is a ‘science and knowledge economy’ in which ‘industries revolve around the convergence of technologies such as computing, communications, and engineering, and the growing importance of life sciences such as physics, biology, and chemistry.’ (2006, pp. 40–41). In part, this transition reflects the commercial opportunities afforded by the persistent, exponential progress of scientific and technical innovation in fields such as computers, communications, genomics, genetic engineering, and nanotechnology. In part, it is also necessitated by circumstance, as our societies and economies confront the multifaceted challenges of stagnant economic growth, globalization, global climate change, and feeding and meeting the resource demands of a world population expected to reach 9 billion individuals by mid-century.