Dissolved Folin Phenol Active Substances (Tannin and Lignin) in the Seawater along the West Coast of India

Information on the distribution of dissolved Folin phenol active substances (FPAS) such as tannin and lignin in the seawater along the west coast of India is provided. Notable amounts of FPAS (surface concentrations: 80 g/l to 147 g/l and bottom concentrations: 80 g/l to 116 g/l) were detected in the seawater along the coast. The distribution pattern brings about a general depth-wise decrease. A seaward decrease was observed in the southern stations whereas reverse was the case in northern stations. A significant negative correlation was observed between FPAS concentration and dissolved oxygen in sub-surface samples. The appreciable amounts of FPAS detected in the coastal waters indicate the presence of organic matter principally originating from terrestrial (upland and coastal marsh) ecosystems in the marine environment. In this context, they may be used as tracers to determine the fate of coastalborn dissolved organic matter in the ocean and to determine directly the relationship between allochthonous and autochthonous organic matter.     

Radio and visible-light observations of a coronal arcade transient

We discuss simultaneous visible-light and radio observations of a coronal transient that occurred on 9 April, 1980. Visible-light observations of the transient and the associated erupting prominence were available from the Coronagraph/Polarimeter carried aboard SMM, the P78-1 coronagraph, and from the Haleakala Observatory. Radio observations of the related type III-II-IV bursts were available from the Clark Lake and Culgoora Observatories. The transient was extremely complex; we suggest that an entire coronal arcade rather than just a single loop participated in the event. Type III burst sources observed at the beginning of the event were located along a nearby streamer, which was not disrupted, but was displaced by the outmoving loops. The type II burst showed large tangential motion, but unlike such sources usually do, it had no related herringbone structure. A moving type IV burst source can be associated with the most dense feature of the white-light transient.     

Vector magnetic fields in sunspots

Observations of a round, unipolar sunspot in the Zeeman triplet Fe i 6302.5 with the High Altitude Observatory Stokes Polarimeter are used to derive the vector magnetic field in the spot. The behavior of the magnitude, inclination, and azimuth of the field vector B across the spot is discussed. A linear relation is found between the continuum intensity I _c and the field magnitude B. Time series obtained in the umbra show significant power in the magnitude of the field at a period of t 180 s but the other components of the field vector do not display this behavior.The National Center for Atmospheric Research is sponsored by the National Science Foundation.     

Hyperspectral interpretation of selected drill cores from orogenic gold deposits in central Victoria,Australia

HyLogger hyperspectral data obtained from seven orogenic gold deposits in central Victoria, including Bendigo, Ballarat, Maldon, Fosterville, Costerfield, Castlemaine and Wildwood, are presented. The data demonstrate that fresh diamond drill core displays substantial mineralogical variation that can be attributed to the effects of cryptic hydrothermal alteration that might not otherwise be recognised. The most significant hyperspectral response lies in the white mica compositions, which vary in a systematic manner between high-Al muscovitic zones (Al–OH absorption around 2208 nm) that define a phyllic alteration halo around mineralised structures, and low-Al phengitic–chlorite zones (Al–OH absorption >2014 nm) inferred to represent either more distal alteration or possibly regional metamorphic background. An extensive ferroan dolomite alteration halo overlaps the phyllic and sulfidic alteration zones and extends beyond the sampled core in most instances. This ferroan dolomite halo has previously been defined petrographically, geochemically and using carbonate staining techniques, and is further characterised using thermal infrared hyperspectral data in drill core from the Ballarat goldfield. The mineralogical trends identified by the hyperspectral data are best developed in diamond drill core from the Costerfield, Fosterville and Ballarat goldfields, and are less pronounced at the other deposits. At Bendigo and Castlemaine the reasons for this are not immediately clear, but may be related to the close timing of gold mineralisation relative to peak metamorphism. The Maldon area lies within the contact aureole of the Harcourt Batholith and so has been thermally overprinted leading to the recrystallisation of earlier hydrothermal assemblages. The Wildwood deposit is similar to the Magdala deposit at Stawell and differs from the other goldfields in its geological setting, host rock lithologies and style of hydrothermal alteration, with the development of Fe-rich chlorite closely associated with gold mineralisation. The results demonstrate how hyperspectral data can be used to define large hydrothermal alteration footprints associated with orogenic gold mineralisation in central Victoria that are of direct benefit to mineral explorers, as well as independently characterising lithological variations in drill core.     

Reproductive biology of the mackerel scad Decapterus macarellus from Cabo Verde and the implications for its fishery management

The mackerel scad Decapterus macarellus is of great social and economic importance to Cabo Verde citizens; however, in recent years catches have shown an unexplained decline. The harvest is regulated by way of a minimum legal size and a seasonal closure, with both measures based on the results of reproductive studies that did not consider the microscopic characteristics of the gonads. This study aimed to analyse the gonads microscopically in order to classify the sexual development stage of individuals and to estimate the size at first maturity and the reproductive season. This information was then used to analyse the match between the reproductive parameters and the management measures. The samples comprised 284 females (20–36 cm fork length [FL]) and 85 males (21–35 cm FL). The annual variation in gonadosomatic index and the monthly frequencies of mature phases suggest that the reproductive season occurs from March to October, with two spawning peaks, one in March and another from July to October. The current seasonal closure (from July to September) covers the main reproductive period. However, the species has a long spawning period and the timing of peaks can vary between years; hence, a reassessment of this management measure is recommended. The sizes at first maturity were estimated at 24.1 cm FL for females, and 26.6 cm FL for males. These values are higher than the minimum legal size (20 cm FL) currently established for management of the species at Cabo Verde; thus, we strongly recommend an increase in the minimum legal size in an attempt to reduce catches of immature individuals.     

A white-light/Fe X/Hα coronal transient observation to 10 solar RadII

Multi-telescope observations of the coronal transient of 15–16 April, 1980 provide simultaneous data from the Solar Maximum Mission Coronagraph/Polarimeter, the Solwind Coronagraph, and the new Emission Line Coronagraph of the Sacramento Peak Observatory. An eruptive prominence-associated white light transient is for the first time seen as an unusual wave or brightening in Fe x gl6374 (but not in Fe xiv gl5303). Several interpretations of this fleeting enhancement are offered.The prominence shows a slowly increasing acceleration which peaks at the time of the Fe event. The white light loop transient surrounding the prominence expands at a well-documented constant speed to 10R , with an extrapolated start time at zero height coincident with the surface activity.This loop transient exemplifies those seen above 1.7R in that leading the disturbance is a bright (N _e-enhanced) loop rather than dark. This is consistent with a report of the behavior of another eruptive event observed by Fisher and Poland (1981) which began as a density depletion in the lower corona, with a bright loop forming at greater altitudes. The top of the bright loop ultimately fades in the outer corona while slow radial growth continues in the legs.The National Center for Atmospheric Research is sponsored by the National Science Foundation.     

The determination of vector magnetic fields from stokes profiles

The application of Unno's (1956) solution of the transfer equation for polarized radiation to the determination of thevector magnetic field is investigated. An analysis procedure utilizing non-linear least squares techniques is developed that allows one to automate the reduction of measured spectral profiles of the Stokes parameters to determine the field angles, strength as well as other parameters. The method is applied to synthetic spectra generated using a model solar atmosphere and yields results of remarkably high accuracy. The influence of additional factors upon determination of the vector field are also considered. These factors include effects of asymmetric profiles, magneto-optical effects, magnetic field gradients, unresolved field elements, scattered light, and instrumental noise.The National Center for Atmospheric Research is sponsored by the National Science Foundation.Operated by the Association of Universities for Research in Astronomy, Inc., under contract with the National Science Foundation.     

The High Altitude Observatory Coronagraph/Polarimeter on the Solar Maximum Mission

The High Altitude Observatory Coronagraph/Polarimeter, to be flown on the National Aeronautics and Space Administration's Solar Maximum Mission satellite, is designed to produce images of the solar corona in seven wavelength bands in the visible spectral range. The spectral bands have been chosen to specifically exclude or include chromospheric spectral lines, so as to allow discrimination between ejecta at high (coronal) and low (chromospheric) temperatures, respectively. In addition, the instrument features spectral filters designed to permit an accurate color separation of the F and K coronal components, and a narrow band (5.5 Å) filter to observe the radiance and polarization of the Fe xiv 5303 Å line. The effective system resolution is better than 10 arc sec and the instrument images a selected quadrant (or smaller field) on an SEC vidicon detector. The total height range that may be recorded encompasses 1.6 to more than 6.0R (from Sun center). The instrument is pointed independently of the SMM spacecraft, and its functions are controlled through the use of a program resident within the onboard spacecraft computer. Major experimental goals include: (a) Observation of the role of the corona in the flare process and of the ejecta from the flare site and the overlying corona; (b) the study of the direction of magnetic fields in stable coronal forms, and, perhaps, ejecta; and (c) examination of the evolution of the solar corona near the period of solar maximum activity.The National Center for Atmospheric Research is sponsored by the National Science Foundation.