A generalization of the Kolmogorov-von Kármán relationship and some further implications on the values of the constants

A general relation between the Kolmogorov (₁) and von Kármán (k) constants appropriate to flows in the surface boundary layer is obtained by including stability and divergence dependent terms in the development. The result is used to show that the author's earlier inference of the valuek = 0.36 drawn from the observed value ,k ^4/3=0.141 cannot have been underestimated due to the neglect of stability or divergence effects. It is concluded that if k is to be 0.4, then ₁ must be 0.5.Work performed under the auspices of the U.S. Energy Research and Development Administration.     

Complex formation in the ternary system Mg(II)-CO2-H2O

The carbonato and hydrogencarbonato complexes of Mg²⁺ were investigated at 25 and 50° in solutions of the constant ClO₄^? molality (3 M) consisting preponderantly of NaClO₄. The experimental data could be explained assuming the following equilibria: Mg²⁺ + CO_2B + H₂O ag MgHCO⁺₃ + H⁺, $\text{log}{}^1\text{β}{}_1\text{= ?7.64}{}_4\text{± 0.01}{}_7\text{(25°), ?7.46}{}_2\text{± 0.01}{}_1\text{(50°)}$, Mg²⁺ + 2 CO_2g + 2 H₂Oag Mg(HCO₃)⁰₂ ± 2 H⁺, $\text{log}{}^1\text{β}{}_2\text{= ?15.00 ± 0.14 (25°)}$, ?15.37 ± 0.39 (50°), Mg²⁺ + CO_2g + H₂Oag MgCO⁰₃ + 2 H⁺, $\text{log}{}^1\text{k}{}_1\text{= ?15.64 ± 0.06 (25°)}$,?15.23 ± 0.02 (50°), with the assumption γ_MgCO3⁰ = γ_Mg(HCO3)⁰2, ΔG⁰(I = 0) for the reaction MgCO⁰₃ + CO_2g + H₂O = Mg(HCO₃)⁰₂ was estimated to be ?3.9₁ ± 0.8₆ and 0.6 ± 2.4 kJ/mol at 25 and 50°C, respectively. The abundance of carbonate linked Mg(II) species in fresh water systems is discussed.     

The tunica hills,Louisiana-Mississippi: Late glacial locality for spruce and deciduous forest species

Reinvestigation of Quaternary sediments in West Feliciana Parish, southeastern Louisiana, and adjacent Wilkinson County, southwestern Mississippi, has resulted in revision of previous terrace stratigraphy of this portion of the Gulf Coastal Plain. Plant-macrofossil and pollen assemblages incorporated in fluviatile terrace deposits in the study area are reexamined in light of the current stratigraphic understanding. Macrofossils identified as white spruce (Picea glauca), tamarack (Larix laricina), and northern white cedar (Thuja occidentalis), recovered from these terrace deposits along with fossil remains of distinctly southern plant species, were initially interpreted as the result of dynamic intermixing of aggressive boreal species within a southern forest during the early Wisconsin (Brown, 1938). Failure to distinguish chronologically separate fossiliferous deposits resulted in the conceptual “mixing” of northern and southern plant species which came from two distinct fluviatile terrace sequences. Terrace 2 is now believed to be a fluviatile and coastwise depositional terrace of Sangamon Interglacial age; deposits of terrace 2 contain a distinctly warm-temperate plant assemblage. Fluviatile terrace 1 dates from 12,740 ± 300 to 3457 ± 366 BP and is now considered to be related to late glacial and Holocene aggradation and lateral migration of the Mississippi River (the local base level for streams in the study area); basal portions of terrace 1 contain fossils of white spruce, tamarack, and many plant species today characteristic of the cool-temperate Mixed Mesophytic Forest Association. Terrace 1 fossil deposits occur in fluviatile terraces along tributary streams of the Mississippi River at elevations 15 to 30 m above the maximum recorded historic flood stage of the Mississippi River. The plant macrofossils represent remains of species that grew at or very near the site of deposition; they were not “rafted in” by floodwaters of the Mississippi River. We present quantitative data for plant macrofossils and pollen that support our hypothesis that at least local cooling along the Blufflands of Mississippi and Louisiana promoted southward migrations of mixed mesophytic forest species and certain boreal species along this major pathway during late Wisconsin continental glaciation.     

Gefüge und Entstehung der Ringdünen in den grauen Tuffen des Laacher Vulkans

The last products of the pleistocene Laach volcano (Eifel, about 40 kms SW of Bonn, Germany) are grey tuffs. Outcrops in the rim show characteristic cross-bedding in these tuffs. It is in discussion whether these structures are produced by wind or by phreato-magmatic outbursts. At all larger outcrops in the rim we measured numerous depositional elements of the tuffs, and analyzed their geometrical structure. So we are able to reconstruct shape, structure and orientation of dunes in the tuffs. They show transport vectors in centrifugal orientation, radially to the vent. The dunes are orientated concentrically to the vent, we intruduce the term “concentrical dune” for this dune type. This points out that the dunes in the Laach tuffs are of volcanic origin. But our geometrical results give no authorization to assume phreato-magmatic processes during the activity of the Laach volcano. We think that the grey Laach tuffs are no base surge deposits, but products of gas-rich eruptions in the phase of decreasing volcanic energy.     

Weather forecasting for dinosaurs

A weather forecast for 22 September 150 million years ago: 'Most of Britain will continue to enjoy a sunny end to the summer. Winds remain calm, but some cloud may develop by the end of the day. Further afield, India and Australia are experiencing some stormy weather with severe gales across the northern coast of India.'     

Conservation as disturbance: Upheaval and livelihood diversification near Tarangire National Park,northern Tanzania

Recent studies have identified poverty reduction near parks and protected areas, findings that challenge an extensive literature on the social burdens associated with protected areas. These studies move the discussion on the social dynamics of conservation forward, however, they do not offer insight into the underlying mechanisms that shape household-level outcomes such as income and wealth. By focusing on protected areas as centers of uncertainty, upheaval, and disturbance, this study examines the character and incidence of livelihood diversification within communities near Tarangire National Park in northern Tanzania compared to communities far from the park. Livelihood diversification is well understood as a coping and/or risk mitigation strategy pursued in response to various types of shocks, and uncertainty more generally. This study draws on mixed methodologies to construct multivariate statistical models to estimate the effect of proximity to the park on measures of livelihood diversification. The results indicate that proximity to park is strongly correlated with livelihood diversification, suggesting that households near the park are adapting to opportunities and constraints and may be seeking to reduce variance in income and wealth in response to disturbances and uncertainty associated with the park.     

Rapid change in early Holocene environments inferred from Lake Pupuke,Auckland City,New Zealand

Sediment cores from Lake Pupuke in Auckland City, New Zealand, contain a high‐resolution millennial to centennial‐scale record of changing climate and catchment hydrology spanning the past ca. 10 000 years. Here, we focus on the period between 9500 ± 25 and 7000 ± 155 cal. yr BP during which grain size, diatom palaeoecology, biogenic silica concentrations, sediment elemental and carbon isotope geochemistry reflect changes in sediment sources and lake conditions, with a significant event commencing at ca. 8240 cal. yr BP, commensurate with a lowering of lake level, faster erosion rates and increased sediment influx with a duration of ca. 360 yrs. However, the changes in the lake are not reflected in the terrestrial vegetation, where the pollen record indicates that podocarp forest dominated the Auckland region, with apparent environmental stability during this part of the early Holocene. The synchronous change in most of the proxies between ca. 8240 and 7880 cal. yr BP at Lake Pupuke indicates the presence of a sustained episode of relatively low lake level and concomitant increased rate of erosion in the early Holocene that appears to be at least partly coeval with the 8200 cal. yr BP meltwater event proposed for the North Atlantic region. Copyright © 2008 John Wiley & Sons, Ltd.