Ionization above theF2-peak,as affected by the interplanetary gas

Summary The atmospheres of the earth, the sun and other bodies are surrounded by gas that is nearly uniform in number densityn and kinetic temperatureT, over spaces much greater than those occupied by the atmospheres. This gas may be called theambium of the atmosphere. In total it is much more massive than the atmosphere it encloses. The conditions in the ambium must powerfully affect the state of the outer atmosphere. In particular, there must be a continuous transition of the values ofn andT between the ambium and the atmosphere. In the case of the earth, the sun and other hot stars, both the ambium and the outermost part of the atmosphere will consist of atomic hydrogen. The temperature of the ambium will determine whether this hydrogen and that of the outermost atmosphere are mainly ionized or neutral.The nature of the terrestrial ambium depends on the extension of the sun's atmosphere. This atmosphere is hot and highly ionized in its inner parts. At some radius not yet known, the solar atmospheric gas must become cool and neutral. The state of the earth's outermost atmosphere depends greatly on whether the earth lies in the ionized or the neutral part of the sun's atmosphere, or in the solar ambium.Evidence will be presented favoring the view that the earth's ambium consists of ionized solar atmospheric hydrogen. If this be so, the outermost part of the earth's atmosphere is likewise hot and ionized. It must enclose an extensive layer of mainly neutral atomic hydrogen.The part of this work done at High Altitude Observatory was supported by the National Bureau of Standards and the Air Force Cambridge Research Center.     

Recruitment patterns of Serpula vermicularis L. (Polychaeta, Serpulidae) in Loch Creran, Scotland

This study aimed to contribute to conservation management of reefs of Serpula vermicularis by increasing understanding of the factors influencing larval settlement. The study was carried out in Loch Creran, which supports the most extensive known development of S. vermicularis reefs in the world. Settlement plates were deployed to examine the influence of season, depth, reef density, substrate type and orientation. Monthly deployment of plates revealed settlement of S. vermicularis to occur predominantly from mid-June to mid-October, peaking in late August to early September. Settlement of Pomatoceros spp. peaked much earlier, in late May to early June. Deployment of plates at different depths revealed a marked reduction in S. vermicularis settlement intensity between 6 and 12 m. As this corresponds with the deeper limit of the peripheral fringe of serpulid reefs in the loch, it is suggested that this limit is imposed by a depth-correlated settlement response, rather than reduction in available substrata. Comparisons of various substrata showed a preference by S. vermicularis larvae for a slate over a scallop substrate and no evidence of enhanced recruitment to occupied or unoccupied tubes of S. vermicularis, suggesting that gregarious attraction is unlikely to be a factor causing reef formation. Settlement onto the upper side of a horizontal scallop substrate was found to be insignificant in comparison with the underside or a vertically orientated scallop. Evidence for the role of light in controlling the depth and substrate-orientation preferences of S. vermicularis larvae is discussed. Based on the results of this study, recommendations are made regarding remediation of areas suffering reef damage.     

Optimisation of a catalytic procedure for the determination of total iodine in seawater

A precise method for the determination of total iodine in seawater, which uses a Technicon Auto-Analyser II system and is based on Truesdale and Spencer's (1974) and Truesdale and Smith's (1975) earlier works with a catalytic procedure, is described. The procedure operates over a range of 30–80 μg1^?1 of iodine. As requested by Mark (1973), the way in which the procedure can be varied to suit other applications, and therefore ranges, is explained in detail. The standard deviation at the 50 μg1^?1 level was found to be 0.12 μ1^?1 showing that the method's precision exceeds most, if not all, previously published procedures for this variable. This high degree of resolution makes the procedure suitable for oceanic investigations. The effects of varying the reaction time, the temperature at which the reaction proceeds and the salinity of samples and standards are described. The advantages of using a Technicon Auto-Analyser II system rather than an Auto-Analyser I system are discussed. With slight modification the procedure can also be used in the measurement of river flow where sodium iodide is used as tracer in the dilution method.     

Effects of ship motion on a neutrally-stable towed fish

Digital computer simulation in two dimensions of a neutrally-stable fish towed on a faired cable has been used to investigate the response of the fish to disturbances in the ship motion. The numerical methods used are described broadly, excluding mathematical detail, and selected results are presented which indicate typical behaviour of the system.The free oscillations of the fish-cable system and its response to deterministic and random ship disturbances are investigated. This reveals the dynamic principles governing the motion and allows the formulation of simple rules to give a first approximation to the magnitude of the fish response. It is shown that, provided resonances of the ship and fish-cable system do not coincide, the overall amplitude of motion of the fish is proportional to the sine of the angle made by the top of the cable with the horizontal. Formulae are given for calculating approximately the resonant frequencies of the towed system.     

An analysis of 1983 observations of facular contrast with an extreme limb photometer

Analysis of facular contrast I/I _qs from Extreme Limb Photometer (ELP) data of the summer of 1983 yield a mean contrast of 0.91 ± 0.19% and 1.57 ± 0.16% for apertures 1 and 2 located at = 0.198 and at = 0.111, respectively. The ratio of the mean contrast in the outer aperture (closer to the limb) to that of the inner one is 1.71 ± 0.40, indicating an increase in the mean facular contrast toward the limb. This result is in agreement with observations made in 1975, 1979, and 1982. The errors are dominated by the random presence of solar active regions. The combined results from all seasons follow an approximately ^–1 curve. Facular excess solar oblateness signals for 1983 are 33.8 ± 6.6 arc ms and 16.5 ± 2.1 arc ms for ELP apertures 1 and 2, respectively, in reasonable agreement with the 1983 excess solar oblateness results of Dicke, Kuhn, and Libbrecht (1985).     

Solar gravitational redshift

Wavelengths of solar spectrum lines should be shifted toward the red by the Sun's gravitational field as predicted by metric theories of gravity according to the principle of equivalence. Photographic wavelengths of 738 solar Fe i lines and their corresponding laboratory wavelengths have been studied. The measured solar wavelength minus the laboratory wavelength (_observed) averaged for the strong lines agrees well with the theoretically predicted shift (_theoretical). Studies show that the departures depend on line strength. No dependence of the departures on wavelength was found within the existing data.By studying strong lines over a wide spectral range, velocity shifts caused by the complex motions in the solar atmosphere seem to affect the results in a minimal fashion.