Numerical study of wind energy characteristics over heterogeneous terrain — Central Israel case study

A numerical mesoscale meteorological model has been applied over the heterogeneous terrain of central Israel in order to study wind energy characteristics of three typical synoptic situations. The supportive nature of this method for observationally oriented wind energy studies has been emphasized. Mesoscale forcing effects on the availability of wind energy and on the exponent, p, in the vertical wind power law are evaluated.     

Traveling screens as sampling gear for vertical distribution studies

A sampling technique has been developed for increasing the information gathered during routine monitoring of impingement at water intake structures. Samples from impingement catches on traveling screens were taken from the sluiceway of the Brunswick Steam Electric Plant near Southport, North Carolina during the screen wash process so as to divide the catch into vertical catch components. Each component represented 1.2 m of the water column. Results showed differences in day and night vertical distributions of impinged organisms according to the spatial preferences of each species. Impingement during daytime was lower than during night. Impingement of surface-oriented species during daytime occurred at mid-depth, midwater species near the bottom, and bottom species were seldom impinged. During the night surface-oriented species were impinged at the surface, midwater species at mid-depth, and bottom species near the bottom. Residue (animals and debris) which remained within the screen wash system from collection of the previous sample, and those organisms which became impinged on the screens during retrieval of the sample, were used to calculate the rate of “continuous impingement” on the traveling screens. These rates were compared to the impingement catch in order to determine biases in the vertical catch components. Comparison of these rates indicated that impingement estimates determined by routine monitoring methods may under-estimate true impingement rates for certain species. We have concluded that this sampling technique for monitoring impingement at intake structures will increase knowledge of the local biologic system while minimizing the cost of obtaining the information. The technique will also aid in pinpointing specific impingement problems which may be corrected through modifications to the design of the intake structure.     

Solar soft X-rays and solar activity

Flare-associated soft X-ray bursts (8–12 Å) are examined for 283 events observed by OSO-III. These bursts are shown to be predominantly thermal in nature. Their time-profiles are roughly similar to those of the associated H flares, although the X-ray burst begins about two minutes earlier, on the average. The strength of the soft X-ray burst is directly related to the area and brilliance of the flare, the age and flare-richness of the associated plage, and the general level of solar activity at the time of the burst. The peak enhancements in the soft X-ray and H emission rates during flares are of the same order of magnitude, as are the total flare energies radiated at these wavelengths. We estimate that soft X-radiation accounts for up to 10% of a flare's total electromagnetic emission.NRC/NAS Resident Research Associate.     

LOCATIONAL DECISION-MAKING IN A RESOURCE-BASED MANUFACTURING SECTOR: CASE STUDIES FROM THE PULP AND PAPER INDUSTRY OF BRITISH COLUMBIA*

Based on interviews with corporate executives, this paper examines several decisions to locate pulp and paper mills in British Columbia during the 1960's and early 1970's. It emphasizes locational evaluations of regions, communities, and sites interpreted as parts of wider investment decision processes and longer-run corporate strategies. Relationships between initial locational decisions and post-locational assessments and adjustments are also identified.     

A discussion of the solution for the motion of Pluto

In a previous paper, a semi-analytical solution for the long-term motion of Pluto was presented. The present paper contains: (1) a comparison of the present solution with the solution by Williams and Benson; (2) a discussion of the effect of the near resonance between Pluto and Uranus; and, (3) a calculation of the librational period of the eccentricity, inclination and perihelion.The semi-analytical solution is shown to agree very closely with the long-term solution for Pluto obtained by Williams and Benson using numerical integration of the averaged equations of motion. A small difference between the two solutions is attributed to neglecting the eccentricity and inclination of Neptune in the semi-analytical solution.     

Activity–composition relations for phases in petrological calculations: an asymmetric multicomponent formulation

For petrological calculations, including geothermobarometry and the calculation of phase diagrams (for example, P–T petrogenetic grids and pseudosections), it is necessary to be able to express the activity–composition (a–x) relations of minerals, melt and fluid in multicomponent systems. Although the symmetric formalism—a macroscopic regular model approach to a–x relations—is an easy-to-formulate, general way of doing this, the energetic relationships are a symmetric function of composition. We allow asymmetric energetics to be accommodated via a simple extension to the symmetric formalism which turns it into a macroscopic van Laar formulation. We term this the asymmetric formalism (ASF). In the symmetric formalism, the a–x relations are specified by an interaction energy for each of the constituent binaries amongst the independent set of end members used to represent the phase. In the asymmetric formalism, there is additionally a "size parameter" for each of the end members in the independent set, with size parameter differences between end members accounting for asymmetry. In the case of fluid mixtures, for example, H₂O–CO₂, the volumes of the end members as a function of pressure and temperature serve as the size parameters, providing an excellent fit to the a–x relations. In the case of minerals and silicate liquid, the size parameters are empirical parameters to be determined along with the interaction energies as part of the calibration of the a–x relations. In this way, we determine the a–x relations for feldspars in the systems KAlSi₃O₈–NaAlSi₃O₈ and KAlSi₃O₈–NaAlSi₃O₈–CaAl₂Si₂O₈, for carbonates in the system CaCO₃–MgCO₃, for melt in the melting relationships involving forsterite, protoenstatite and cristobalite in the system Mg₂SiO₄–SiO₂, as well as for fluids in the system H₂O–CO₂. In each case the a–x relations allow the corresponding, experimentally determined phase diagrams to be reproduced faithfully. The asymmetric formalism provides a powerful and flexible way of handling a–x relations of complex phases in multicomponent systems for petrological calculations.     

Mistreatment of the economic impacts of extreme events in the Stern Review Report on the Economics of Climate Change

The Stern Review on the Economics of Climate Change has focused debate on the costs and benefits of alternative courses of action on climate change. This refocusing has helped to move debate away from science of the climate system and on to issues of policy. However, a careful examination of the Stern Review's treatment of the economics of extreme events in developed countries, such as floods and tropical cyclones, shows that the report is selective in its presentation of relevant impact studies and repeats a common error in impacts studies by confusing sensitivity analyses with projections of future impacts. The Stern Review's treatment of extreme events is misleading because it overestimates the future costs of extreme weather events in developed countries by an order of magnitude. Because the Stern Report extends these findings globally, the overestimate propagates through the report's estimate of future global losses. When extreme events are viewed more comprehensively the resulting perspective can be used to expand the scope of choice available to decision makers seeking to grapple with future disasters in the context of climate change. In particular, a more comprehensive analysis underscores the importance of adaptation in any comprehensive portfolio of responses to climate change.     

Spectral Diagnostics of an Active Region Observed by the Solar EUV Rocket Telescope and Spectrograph (SERTS)

The EUV spectrum of a solar active region observed by SERTS-89 is used to estimate physical parameters such as electron density, elemental abundance and inhomogeneity in the emitting source. A total of 13 ions, namely, Neiv-vi, Mgv-ix, Sivii-x and Sx, are studied in the SERTS spectral range 170-450 Ú, providing plasma diagnostics at temperatures between10₅ –10⁶ K. Attention is called to results derived from ion pairs of different elements that are formed over similar temperature regimes, which allow special checks on the standard assumptions of spectral analyses. Some EUV lines, not originally reported in the SERTS-89 spectrum, are shown to have measureable intensities and are indicated for future observations.