Long term storage of relativistic particles in the solar corona

A model is presented which shows that large numbers of energetic electrons (0.3-> 10 MeV) and protons (1–30 MeV) can be stored in the solar corona at altitudes around 3 × 10⁵ km for periods in excess of 5 days. Specific reference is made to the time period July 6–16 1968 as an excellent example of energetic solar particle storage. Time histories of interplanetary charged particle intensities observed by the IMP-4 and Pioneer 8 satellites are used to substantiate this contention. Detailed reference is also made to solar X-ray, optical and radio data obtained during the period in question, in addition to interplanetary magnetometer data. This model provides a unique solution to many hitherto unexplained solar particle events, and can also account for the lack of prompt particle emission from certain large solar flares recorded in the past.     

Impact of copper smelting on lakes in the southern Ural Mountains,Russia, inferred from chironomids

Karabash (52°2 N, 60°10 E) is a copper smelting town in the southern Ural Mountains of Russia. The town is affected by sulphur dioxide emissions and deposition of metal-rich particulates from the smelter, acid drainage from old mine workings, and leachates from disused waste dumps and tailings dams. The close proximity of houses to these sources of pollution is of concern to human health and has devastated terrestrial vegetation in the environs. The environmental impact of the smelter on lakes in the area has been assessed using chironomids. Short sediment cores were taken from 16 lakes within a 50 km radius of the smelter and the composition of the chironomid fauna from the bottom of each core, representing conditions prior to the commissioning of the smelter in 1910, was compared with the present chironomid fauna in the surface sediments. Redundancy analysis (RDA) showed that changes in the chironomid fauna of most lakes were driven by trophic change, independent of the industrial activity. Lakes and ponds adjacent to the smelter and waste dumps, which directly receive contaminated waters were devoid of macro- and mesofauna and flora, but there is no evidence that other lakes have been severely impacted by smelter emissions. Local geology ensures that the lakes are well-buffered to the effects of acid deposition which will limit the bioavailability of metals in the water column and sediment.     

Some aspects of flare properties versus magnetic boundary morphology

Flares often begin near lines of zero-longitudinal magnetic field. These boundary lines between opposite polarities can have the magnetic field either parallel to or transverse to the boundary. A study of 75 flares associated with one or the other type of boundary indicates that the difference in boundary morphology is not reflected in the frequency or properties of the associated flares.     

The changing distribution of sex ratios in the british urban system

The preponderance of females in society has steadily decreased since the last war. This paper uses Metropolitan Economic Labour Areas to examine the differential effect of these changes and suggests associations with retirement migration and increasing female economic activity rates.     

Comet Bowell (1980b): Measurement of the optical thickness of the coma and particle albedo from a stellar occultation

Comet Bowell (1980b) was observed to pass within 0.25 ± 0.09 arc sec of a star (about 540 km at the comet), where the absorption of starlight by the dust coma was found to be 3% (±1%). The implied optical thickness of 0.03 differs greatly from other determinations and gives a mass of 3 × 10¹³ g for the coma within 1 × 10⁴ km of the nucleus. Coupled with absolute continuum filter photometry, these results indicate a very low particle albedo consistent with fluffy carbonaceous material. This experiment indicates the need to observe nearly central occulations by several observers to measure the optical thickness profile of a comet. The advantages of using a charge-coupled device area photometer for such observations are discussed.     

Triggering of El Niño by westerly wind events in a coupled general circulation model

Two ten-members ensemble experiments using a coupled ocean-atmosphere general circulation model are performed to study the dynamical response to a strong westerly wind event (WWE) when the tropical Pacific has initial conditions favourable to the development of a warm event. In the reference ensemble (CREF), no wind perturbation is introduced, whereas a strong westerly wind event anomaly is introduced in boreal winter over the western Pacific in the perturbed ensemble (CWWE). Our results demonstrate that an intense WWE is capable of establishing the conditions under which a strong El Niño event can occur. First, it generates a strong downwelling Kelvin wave that generates a positive sea surface temperature (SST) anomaly in the central-eastern Pacific amplified through a coupled ocean-atmosphere interaction. This anomaly can be as large as 2.5°C 60 days after the WWE. Secondly, this WWE also initiates an eastward displacement of the warm-pool that promotes the occurrence of subsequent WWEs in the following months. These events reinforce the initial warming through the generation of additional Kelvin waves and generate intense surface jets at the eastern edge of the warm-pool that act to further shift warm waters eastward. The use of a ten-members ensemble however reveals substantial differences in the coupled response to a WWE. Whereas four members of CWWE ensemble develop into intense El Niño warming as described above, four others display a moderate warming and two remains in neutral conditions. This diversity between the members appears to be due to the internal atmospheric variability during and following the inserted WWE. In the four moderate warm cases, the warm-pool is initially shifted eastward following the inserted WWE, but the subsequent weak WWE activity (when compared to the strong warming cases) prevents to further shift the warm-pool eastwards. The seasonal strengthening of trade winds in June–July can therefore act to shift warm waters back into the western Pacific, reducing the central-eastern Pacific warming. This strong sensitivity of the coupled response to WWEs may therefore limit the predictability of El Niño events, as the high frequency wind variability over the warm pool region remains largely unpredictable even at short time lead.     

Using the geologic setting of talc deposits as an indicator of amphibole asbestos content

This study examined commercial talc deposits in the U.S. and their amphibole-asbestos content. The study found that the talc-forming environment directly influenced the amphibole and amphibole-asbestos content of the talc deposit. Large talc districts in the U.S. have mined hydrothermal talcs that replaced dolostone. Hydrothermal talcs, created by siliceous fluids heated by magmas at depth, consistently lack amphiboles as accessory minerals. In contrast, mineable talc deposits that formed by contact or regional metamorphism consistently contain amphiboles, locally as asbestiform varieties. Examples of contact metamorphic deposits occur in Death Valley, California; these talc-tremolite deposits contain accessory amphibole-asbestos. Talc bodies formed by regional metamorphism always contain amphiboles, which display a variety of compositions and habits, including asbestiform. Some industrial mineral deposits are under scrutiny as potential sources of accessory asbestos minerals. Recognizing consistent relations between the talc-forming environment and amphibole-asbestos content may be used in prioritizing remediation or monitoring of abandoned and active talc mines.     

Magnetic cleansing of weathered/tarry oiled feathers--the role of pre-conditioners

Iron powder has previously been demonstrated to be effective in the removal, via magnetic harvesting, of a wide variety of oil contaminants from feathers and plumage. This study investigates the efficacy of magnetic cleansing for the removal from feathers of tarry contamination that has been allowed to weather. Clusters of feathers from Mallard duck (Anas platyrhnchos) and Little Penguin (Eudyptula minor) were completely immersed in a tarry contaminant and allowed to weather from one to fourteen days. The contaminant was removed using a magnetic cleansing protocol and the removal efficacy assessed gravimetrically. For one, seven and fourteen days of weathering, a final removal (after fourteen treatments) of more than 99% and 97% was achieved for duck feathers and penguin feathers, respectively. Repeating the experiments (for a seven-day weathering period) for both duck and penguin feathers, with the judicious application of a pre-conditioner (olive oil), further improved removal efficacy. A convenient method to screen for improved pre-conditioning agents is suggested.