Calculation of the electrostatic field within a structure of uniformly spaced coaxial conducting loops

Summary Structures of two or more conducting loops which are at evenly incremented voltages have been used to create electrostatic fields for experimental studies in atmospheric cloud particle interactions. Methods are described which may be used to calculate the uniformity of these fields over a given volume within the structure. The methods of calculation are described for two different cases: (1) A method using elliptic integrals is used for a finite set of round loops of circular cross section, and (2) a solution of Laplace's equation with approximate boundary conditions is used for an infinite set of square loops of elliptical cross section. The effects of changing the number of conductors, their spacing, size and shape are considered.National Center for Atmospheric Research Boulder, Colorado, 80302 (The National Center for Atmospheric Research is sponsored by the National Science Foundation).     

Typical influences of moisture on profile measurements in the marine atmospheric surface layer

Under a wide variety of meteorological conditions in a coastal environment, 250 cases were studied to determine the typical influences of moisture in calculating the gradient Richardson number stability and the fluxes of heat, humidity, and momentum with the profile method. Although the stability calculation was altered in some cases up to 95% by the moisture correction, the typical influence in computing the fluxes was found to be less than 10% when the humidity flux was upward and less then 25% when the humidity flux was downward.     

Suspension Properties of Various Phyletic Groups of Phytoplankton and Tintinnids in an Oligotrophic, Subtropical System

Abstract. The sinking rate (ψ) characteristics of a natural community of phytoplankton in the size range from 5 to 102 μn were determined. The following trends in ψ were observed: coc-colithophorids > dinoflagellates > diatoms; large cells > small cells; attenuate shapes < other geometries; community i|) rate based on cell numbers > chlorophyll-based rate; arenaceous tintinnids > organic-loricate tintinnids. Dtnoflagellate swimming rates appear to be considerably greater than their sinking rates.     

Adaptive Ecology, Growth Strategies and the Global Bloom Expansion of Dinoflagellates

Dinoflagellates exhibit unique differences from diatoms in their adaptive ecologies that may be favoring their increasingly successful exploitation of coastal waters and global bloom expansion. Dinoflagellates behave as annual species, bloom soloists, are ecophysiologically diverse and habitat specialists, whereas diatoms behave as perennial species, guild members and are habitat cosmopolites. Diatoms have a relatively uniform bloom strategy based on species-rich pools and exhibit limited habitat specialization. Dinoflagellates have multiple life-form strategies consistent with their diverse habitat specializations, but rely on impoverished bloom species pools. Niche structure and dinoflagellate competition for niche space are considered. The “open niche period” formulated originally for Narragansett Bay is extrapolated as a general bloom paradigm. It is suggested that successful niche occupancy leading to blooms involves adaptive strategies at three heirarchic taxonomic elements: phylogenetic, generic and species-specific, and in that sequence. Transoceanic expatriation of emigrant species leading to indigenous status and blooms requires completion of a three-stage colonization process. Anthropogenic seedings are not, in themselves, bloom stimulation events; they are only the first phase of a multiple-step process. The organismal and niche features required for a hidden flora member to become a bloom species are considered, and the interplay between niche structure, habitat carrying capacity, colonization requirements and stochasticity as factors in the changing global bloom behavior of dinoflagellates discussed. The question is posed whether traditional perspectives of phytoplankton behavior apply completely to dinoflagellates. This revised version was published online in August 2006 with corrections to the Cover Date.     

Interaction Between Macrophytobenthic Groups on the Sublittoral Belt of a Greek Island

Abstract. The interrelationships between the main phytobenthic groups of Chlorophyceae, Phaeophyceae, and Rhodophyceae around Milos Island, Central Aegean Sea, were studied using standard ecological and mathematical methods. The analysis was based on seasonal sampling of 114 different macrophytobenthic species.
The employed ecological indices revealed that the sampling areas located on the north, south, and east side of Milos Island show similar annual fluctuations in abundance and species diversity. The resemblance was particularly high between all stations in October-February, between south and east stations during May, and between north and east stations during July.
Additionally, an annual cycle of group interaction with regard to species diversity and abundance exists between the Chlorophyceae, Rhodophyceae, and Phaeophyceae. The Rhodophyceae are the most abundant and dominant group throughout the year, showing percentages in the samples higher than 70% in all sampling areas.     

Accumulation of plastic litter on beaches of Amchitka Island,Alaska

Between 1972 and 1974 plastic marine litter on ten 1-km beaches at Amchitka Island increased from 2,221 to 5,367 items—a 2·4 x increase in a two-year period. Most litter originated from Japanese and Soviet fishing vessels, but some items were from the Asian coast, at least 1,150 km distant. In 1974 there were 345 kg of common items of plastic litter per kilometre of beach. In 1972, an estimated 1,664 metric tons of plastic litter was lost or dumped from fishing vessels in the Bering Sea and North Pacific Ocean. Stranded plastic litter persists indefinitely but rapidly becomes buried in beach material or is blown inland and covered with vegetation. The most serious environmental impact is probably entanglement of marine mammals and birds in some types of litter. The accelerating accumulation of litter could be reduced through unilateral action by countries that regulate coastal fishing privileges if these countries make litter control a condition for permission to fish.     

The electron density in the direction of ζ Oph

It is shown that photoionization of vibrationally excited H₂ and photodissociation of the H ₂ ⁺ ions produced thereby constitute a significant electron production route in high UV flux situations. A significant fraction of the electron density in the direction of ζ Oph (?15 km s^?1 cloud) deduced from observations may be expected to arise in this way.     

Transformation from proper time on Earth to coordinate time in solar system barycentric space-time frame of reference

In order to obtain accurate computed values of Earth-based range and Doppler observables of a beep space probe, an expression is required for the time differencet–, wheret is coordinate time in the solar system barycentric space-time frame of reference and is proper time recorded on a fixed atomic clock on earth. This paper is part 1 of a two-part article which obtains an expression fort– which is suitable for use in obtaining computed values of observations of a spacecraft or celestial body located anywhere in the solar system. The expression can also be used in the computation of Very Long Baseline Interferometry data types. Part 1 obtains an expression fort– which is a function of position and velocity vectors of the major celestial bodies of the solar system and the atomic clock on Earth which reads . In Part 2, this expression will be transformed to a function of time and the Earth-fixed coordinates of the atomic clock.This paper presents the results of one phase of research carried out at the Jet Propulsion Laboratory, California Institute of Technology, under NASA Contract No. NAS 7-100.