Reliability of inexpensive charcoal and alpha-track radon monitors

A comparison between single short-term radon measurements and annual radon measurements in basements shows that significant uncertainties should be associated with the short-term measurements. Activated charcoal radon monitors which measure radon over a 3 to 7 day interval yield measurements that should carry a ± 90% uncertainty in terms of estimating annual radon concentration. Alpha-track radon monitors which measure radon over a 3 month interval should carry a ± 30% uncertainty. Decisions about home purchases, home remediation and the development of risk characterizations may often be incorrect if currently popular but unrealistically low estimates of uncertainty are applied to short-term radon measurements. Optimal results are obtained from year-long alpha-track measurements.     

Age and paleoclimatic significance of the Stansbury shoreline of Lake Bonneville, Northeastern Great Basin

The Stansbury shoreline, one of the conspicuous late Pleistocene shorelines of Lake Bonneville, consists of tufa-cemented gravel and barrier beaches within a vertical zone of about 45 m, the lower limit of which is 70 m above the modern average level of Great Salt Lake. Stratigraphic evidence at a number of localities, including new evidence from Crater Island on the west side of the Great Salt Lake Desert, shows that the Stansbury shoreline formed during the transgressive phase of late Pleistocene Lake bonneville (sometime between about 22,000 and 20,000 yr B.P.). Tufa-cemented gravel and barrier beaches were deposited in the Stansbury shorezone during one or more fluctuations in water level with a maximum total amplitude of 45 m. We refer to the fluctuations as the Stansbury oscillation. The Stansbury oscillation cannot have been caused by basin-hypsometric factors, such as stabilization of lake level at an external overflow threshold or by expansion into an interior subbasin, or by changes in drainage basin size. Therefore, changes in climate must have caused the lake level to reverse its general rise, to drop about 45 m in altitude (reducing its surface area by about 18%, 5000 km²), and later to resume its rise. If the sizes of Great Basin lakes are controlled by the mean position of storm tracks and the jetstream, which as recently postulated may be controlled by the size of the continental ice sheets, the Stansbury oscillation may have been caused by a shift in the jetstream during a major interstade of the Laurentide ice sheet.     

Modeling basin-scale hydrology in support of physical climate and global biogeochemical studies: An example using the Zambezi River

Human activity is an important agent defining the contemporary hydrologic cycle. We have documented the potential impacts of impoundment, land use change and climate change on the Zambezi River system in southern Africa and found that they can be substantial. A full analysis requires construction and parameterization of a simulation for the entire catchment. This paper develops a strategy for implementing catchment-scale models of the major hydrologic processes operating within the basin. A coherent data set for calibrating the models has also been assembled. The algorithms consist of a Water Balance (WBM) and a Water Transport (WTM) operating at 1/2^o spatial scale and at monthly timesteps. These models transform complex patterns of regional climatology into estimates of soil water, evapotranspiration, runoff, and discharge through rivers of various size. The models are dependent on the characteristics of the terrestrial surface, principally soil texture and land cover. A simulated river network is also required. Additional tabular data sets are essential for model testing and calibration. These include subcatchment areas; observed river discharge at selected points; flooding, storage and loss characteristics of major wetlands; floodwave translation; and, volume, surface area, withdrawal and evaporative losses from impoundments. An important design consideration for the numerous impoundments in the Zambezi requires an understanding of the seasonal variation in discharge, in particular how it might respond to climate and land use change. The research strategy offered here lays a framework for addressing such issues. Although the primary focus of this work is hydrologic, we discuss how the model can be extended to consider constituent transport and biogeochemical cycling issues at the continental scale.     

Crystal field stabilization energies of almandine-pyrope and almandine-spessartine garnets determined by FTIR near infrared measurements

The band positions of three partially overlapping Fe²⁺ spin-allowed transitions located between 4000 and 9000 cm^–1 in almandine-pyrope and almandinespessartine garnets solid solutions were measured using near-infrared (NIR) spectroscopy. The crystal field stabilization energies (CFSE) along both binaries were calculated assuming a splitting of 1100 cm^–1 for the lower orbitals. The CFSE show a slight increase along the almandine-spessartine binary from 3730 to 3810 cm^–1 and a larger increase from 3730 to 3970 cm^–1 for the almandine-pyrope binary. Dodecahedral Fe²⁺-site distortion increases with an increase in spessartine component and decreases with increasing pyrope component, in agreement with average dodecahedral site distortions determined from diffraction experiments. The excess CFSE's along both joins are negative. For the almandinespessartine binary they are small, but are about 3.5 times larger in magnitude along the join almandine-pyrope, where an interaction parameter of W= -2.9 KJ/mole has been derived from a symmetric mixing model. The excess CFSE are relatively small compared to the magnitudes of the excess enthalpies of mixing that have been assigned to garnet solid solutions. Moreover, they give no indication which could support the positive and asymmetric excess enthalpies of mixing that have been proposed for almandine-pyrope solid solutions.     

Parameterization of meridional energy flux in a one-dimensional climate model

Summary The zonally averaged meridional energy transport is parameterized in terms of the zonally averaged temperature gradient and its radiative equilibrium value. Two climate regimes are identified: radiative equilibrium and isothermal climates. The transport and temperature gradient are intermediate between corresponding quantities of these two climates. The parameterization assumes a linear increase of transport as temperature gradient departs from its radiative equilibrium value. The parameterization is formulated using a one-dimensional climate model. Ice-albedo feedback provides the mechanism for climate changes. The parameterization works well for climates associated with seasonal changes.

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Parameterisierung des meridionalen Energiestromes in einem eindimensionalen Klimamodell

Zusammenfassung Der zonal gemittelte, meridionale Energietransport wird in Abhängigkeit vom zonal gemittelten Temperaturgradienten und seinem Strahlungsgleichgewicht parameterisiert. Zwei Klimaregime können identifiziert werden: Strahlungsgleichgewicht und isothermes Klima. Der Transport und der Temperaturgradient befinden sich zwischen den korrespondierenden Werten dieser zwei Klimate. Die Parameterisierung nimmt eine lineare Zunahme des Transportes mit der Abweichung des Temperaturgradienten vom seinem Strahlungsgleichgewichtswert an. Die Parameterisierung wird unter Verwendung eines eindimensionalen Klimamodelles formuliert. Die Eis-Albedo-Rückkopplung liefert den Mechanismus für Klimadnderungen. Die Parameterisierung funktioniert gut fur Klimate, welche jahreszeitliche Anderungen beinhalten.

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With 4 Figures     

Application of the technique to ellipitical markers deformed by pressure-solution

Compression and extension axes are deduced from quartz deformation lamellae in a quartzite and a graywacke folded into an asymetrical syncline. Deformation lamellae fabrics in the two sandstones are distinctly different. In the graywacke, regardless of bedding orientation or position on the fold, compression axes are normal or nearly normal to the axial planar rough cleavage. Extension axes generally lie in the cleavage plane, parallel to dip. In most quartzite samples, compression axes are parallel or subparallel to bedding, at high angles to the fold axis and extension axes are normal to bedding. Two samples from the very base of the formation indicate compression parallel to the fold axis with extension parallel to bedding, at high angles to the fold axis. One of these two shows both patterns. The lamellae fabric geometry in these two samples suggests the presence of a neutral surface in the quartzite. The lamellae-derived compression and extension axes are in good agreement with the buckling behavior of a viscous layer (quartzite) embedded in a less viscous medium (graywacke and shale below and shale and carbonate above).     

Rapid sampling of organic matter in flooded soils and sediments

Estuaries and Coasts - A coring system using a compressed air supply and a sediment shaking procedure using a soil dispersant are described which greatly simplify and shorten the task of...     

使用微机的自动气象站

本文综述了应用微型计算机作为自动气象站的核心部分应考虑的要点。阅读本文并不要求读者掌握微机的基本知识。本文所描述的原理涉及来自气象感应元件的信号处理、计算机硬件性能的选择、编制程序的语言和技术、最终结果的输出方法等。作为一个实例,本文介绍了一个用于向公众展示当天气象要素及气候统计资料的自动气象站。