Associations between elevated atmospheric temperature and human mortality: a critical review of the literature

The effects of the anomalously warm European summer of 2003 highlighted the importance of understanding the relationship between elevated atmospheric temperature and human mortality. This review is an extension of the brief evidence examining this relationship provided in the IPCC’s Assessment Reports. A comprehensive and critical review of the literature is presented, which highlights avenues for further research, and the respective merits and limitations of the methods used to analyse the relationships. In contrast to previous reviews that concentrate on the epidemiological evidence, this review acknowledges the inter-disciplinary nature of the topic and examines the evidence presented in epidemiological, environmental health, and climatological journals. As such, present temperature–mortality relationships are reviewed, followed by a discussion of how these are likely to change under climate change scenarios. The importance of uncertainty, and methods to include it in future work, are also considered.     

Sub-micron scale distributions of trace elements in zircon

Sub-micron scale zoning of Ti concentrations and correlations between concentrations of Ti and other trace elements (P, Ce, and Y) and cathodoluminescent (CL) banding is observed in natural zircons. Ion images were made using the Caltech Microanalysis Center’s CAMECA NanoSIMS 50L with an O⁻ primary beam focused to ~300 nm on the sample surface. The high spatial resolution of this technique allows for interrogation of chemical variations at or below the scale of CL banding in natural zircons. Images produced in this manner display two types of correlations among Ti, P, Ce, and Y (which appears to be a proxy for CL intensity): strong (correlation coefficients >0.8) and subtle (correlation coefficients ~0.15–0.4). Strongly correlated images, which display Ti variations of ca. a factor of 3 between adjacent CL bands and overall elevated trace element concentrations in CL-dark bands, were found within an oscillatory-zoned, trace element enriched sector of a CL sector-zoned zircon. Three possible causes for such correlations include: temperature-dependent equilibrium partitioning, trace element partitioning limited by diffusion in the host melt and surface-controlled, non-equilibrium growth. Comparison of our data with the expected results of these processes suggests that: (1) Ti partitioning in zircon is dependent upon non-equilibrium effects in addition to temperature and/or (2) the incorporation of elements that co-vary with Ti in zircon (e.g., Y, P and Ce) is also temperature-dependent. Sub-micron scale, high-Ti regions are also found within Proterozoic Adirondack and >4 Ga Jack Hills zircons as well as trace element enrichments (including Ti) along cracks within Jack Hills zircons.     

Mapping Submerged Aquatic Vegetation with GIS in the Caloosahatchee Estuary: Evaluation of Different Interpolation Methods

This article evaluates different spatial interpolation methods for mapping submerged aquatic vegetation (SAV) in the Caloosahatchee Estuary, Florida. Data used for interpolation were collected by the Submersed Aquatic Vegetation Early Warning System (SAVEWS). The system consists of hydro-acoustic equipment, which operates from a slow-moving boat and records bottom depth, seagrass height, and seagrass density. This information is coupled with geographic location coordinates from a Global Positioning System (GPS) and stored together in digital files, representing SAV status at points along transect lines. Adequate spatial interpolation is needed to present the SAV information, including density, height, and water depth, as spatially continuous data for mapping and for comparison between seasons and years. Interpolation methods examined in this study include ordinary kriging with five different semivariance models combined with a variable number of neighboring points, the inverse distance weighted (IDW) method with different parameters, and the triangulated irregular network (TIN) method with linear and quintic options. Interpolation results were compared with survey data at selected calibration transects to examine the suitability of different interpolation methods. Suitability was quantified by the determination coefficient (R2) and the root-mean-square error (RMSE) between interpolated and observed values. The most suitable interpolation method was identified as the one yielding the highest R2 value and/or the lowest RMSE value. For different geographic conditions, seasons, and SAV parameters, different interpolation methods were recommended. This study identified that kriging was more suitable than the IDW or TIN method for spatial interpolation of all SAV parameters measured. It also suggested that transect data with irregular spatial distribution patterns such as SAV parameters are sensitive to interpolation methods. An inappropriate interpolation method such as TIN can lead to erroneous spatial representation of the SAV status. With a functional geographic system and adequate computing power, the evaluation and selection of interpolation methods can be automated and quantitative, leading to a more efficient and accurate decision.     

The Broken Hill ore body,Australia

The paper reviews recent works on the Broken Hill ore body to see what data is available on the origin and history of the ore. A high grade metamorphism is recognizable (the Willyama Metamorphism) and this was followed by a number of retrograde metamorphic events. The characteristics of these events is described and this is followed by an analysis of the hypothesis that there is a stratigraphic control of Broken Hill type mineralization. It is concluded that any control that does exist is of a regional nature and that the evidence is equally as good for a restriction of mineralization to areas of high grade metamorphism. Many of the isotopic and geochronological results for Broken Hill are not diagnostic as far as ore genesis is concerned. They do present an internally consistent set of data that records three major events, the Willyama Metamorphism and introduction of the Broken Hill type mineralization at 1700 m. y., the intrusion of the Mundi Mundi Granite and cross cutting pegmatites at 1560 m. y., and retrograde metamorphism and introduction of the Thackaringa Mineralization at or prior to 500 m.y. The sulphides have been deformed in the retrograde schist zones and the ore therefore predates this event. But there is no evidence at the moment that unambiguously establishes that the sulphides were present prior to the Willyama Metamorphism. If it was present prior to or during the Willyama Metamorphism and there is no period of deformation prior to the first recognizable folds at Broken Hill, then the sulphide mass was initially grossly discordant with bedding.

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Zusammenfassung Die Arbeit bringt Ergebnisse der neuesten Untersuchungen über die Broken-Hill-Lagerstätte anschließend an einen Überblick früherer Arbeiten. Der intensiven Willyama-Metamorphose folgen verschiedene retrograde Vorgänge, über die Einzelheiten mitgeteilt werden. Ferner wird die Hypothese einer stratigraphischen Kontrolle der Vererzung einer Prüfung unterzogen und festgestellt, daß die maßgeblichen Frakturen regionaler Natur sein müssen und daß die Beobachtungen somit eine Annahme der Vererzung der hochmetamorphen Gebiete ebenso stark stützt. Viele Resultate von Isotopenzusammensetzungen und geochronologischen Untersuchungen sind für Broken Hill nicht diagnostisch, wenigstens was die Erzgenese betrifft. Sie belegen 3 Hauptereignisse: die Willyama-Metamorphose und den Beginn der Vererzung um 1700.10⁶a, die Intrusion des Mundi Mundi Granits und querschlägiger Pegmatite um 1560.10⁶a und eine retrograde Metamorphose und den Eintritt der Thackaringa-Vererzung um oder vor 500.10⁶a. Die Sulfide sind in der Zone der retrograden Schiefer deformiert worden, was beweist, daß die Vererzung älter ist als dieses Ereignis. Es gibt aber z. Z. keinen Beweis, daß die Sulfide vor der Willyama Metamorphose vorhanden gewesen sind. Wenn sie vor oder während dieses Ereignisses vorhanden gewesen sind und wenn vor der Zeit der ersten deutlichen Falten in Broken Hill keine Deformation stattgefunden hat, dann war die Sulfidmasse ursprünglich in der Schichtung stark diskordant.

     

Late quaternary paleoclimatic reconstructions for interior Alaska based on paleolake-level data and hydrologic models

Hydrologic models are developed for two lakes in interior Alaska to determine quantitative estimates of precipitation over the past 12,500 yrs. Lake levels were reconstructed from core transects for these basins, which probably formed prior to the late Wisconsin. Lake sediment cores indicate that these lakes were shallow prior to 12,500 yr B.P. and increased in level with some fluctuation until they reached their modern levels 4,000-8,000 yr B.P. Evaporation (E), evapotranspiration (ET), and precipitation (P) were adjusted in a water-balance model to determine solutions that would maintain the lakes at reconstructed levels at key times in the past (12,500, 9,000 and 6,000 yr B.P.). Similar paleoclimatic solutions can be obtained for both basins for these times. Results indicate that P was 35-75% less than modern at 12,500 yr B.P., 25-45% less than modern at 9,000 yr B.P. and 10-20% less than modern at 6,000 yr B.P. Estimates for E and ET in the past were based on modern studies of vegetation types indicated by fossil pollen assemblages. Although interior Alaska is predominantly forested at the present, pollen analyses indicate tundra vegetation prior to about 12,000 yr B.P. The lakes show differing sensitivities to changing hydrologic parameters; sensitivity depends on the ratio of lake area (AL) to drainage basin (DA) size. This ratio also changed over time as lake level and lake area increased. Smaller AL to DA ratios make a lake more sensitive to ET, if all other factors are constant.     

Acceleration of energetic particles of the outer regions of planetary magnetospheres: Inferences from laboratory and space experiments

High energy particles, with energies above those attainable by adiabatic or steady-state electric field acceleration, have been observed in and around the outer regions of planetary magnetospheres. Acceleration by large amplitude sporadic cross-tail electric fields over an order of magnitude greater than steady-state convection fields is proposed as a source of these particles. It is suggested that such explosive electric fields will occur intermittently in the vicinity of the tail neutral line in the expansive phases of substorms. We use laboratory Double Inverse Pinch Device (DIPD) and satellite evidence to estimate this electric potential for substorms at Earth; values of 500 kV to 2 MV are calculated, in agreement with particle observations. It is further suggested that these particles, which have been accelerated in the night side magnetosphere, drift to the dayside on closed field lines, and under certain interplanetary conditions can escape to regions upstream of the bow shock.     

New 1982 — 1990 photometry of λ Andromedae and its 11-year cycle

We present photoelectric photometry of λ And never before published, obtained between February 1982 and December 1990 at 29 different observatories. Then we combine it with all other photometry available to us (previously published, contained in the I.A.U. Commission 27 Archives, and obtained with the Vanderbilt 16-inch automatic telescope but not yet published), to yield a 14.8-year data base. Analysis reveals a long-term cycle in mean brightness, with a full range of 0^m.15 and a period of 11.4 ± 0.4 years. Because most of our new photometry was concentrated in the 1983-84 observing season, we analyze that one well-defined light curve with a two-spot model. Spot A keeps a 0^m.04 amplitude throughout four rotation cycles whereas the amplitude of spot B diminishes from 0^m.09 down almost to 0^m.03. The spot rotation periods were 55^d.9 ± 0^d.6 and 520^d.8 ± 1^d.0, respectively.