The 3-D Sun and heliosphere at solar maximum

Bob Forsyth and Andy Breen report from the RAS G Discussion Meeting at the Geological Society on 11 January 2002. Presentations came from both the solar and heliospheric communities, on the 3-D structure and dynamics of the solar corona and heliosphere and their inter-relation during the present maximum in the solar activity cycle.     

Effects of oil pollution on breeding Grey Seals

Marine mammals are probably frequently exposed to floating oil but little is known about the effect oil pollution has on them. Oil stranded on the shore in Pembrokeshire, West Wales in September 1974 coincided with the start of the Grey Seal breeding season there. Observations have been made on the effect the oil had on the newborn pups and their mothers.     

Surveillance for previously unmonitored organic contaminants in the San Francisco Estuary

The San Francisco Estuary Regional Monitoring Program initiated surveillance monitoring to identify previously unmonitored synthetic organic contaminants in the San Francisco Estuary. Organic extracts of water samples were analyzed using gas chromatography-mass spectrometry in full scan mode. The major contaminant classes identified in the samples were fire retardants, pesticides, personal care product ingredients, and plasticizers. Evidence from the literature suggests that some of these contaminants can persist in the environment, induce toxicity, and accumulate in marine biota and in higher food chain consumers. The major sources of these contaminants into the marine environment are the discharge of municipal and industrial wastewater effluents, urban stormwater, and agricultural runoff. As a proactive effort, it is suggested that surveillance studies be used routinely in monitoring programs to identify and prevent potential problem contaminants from harming the marine environment.     

Possible configurations of the magnetic field in the outer magnetosphere during geomagnetic polarity reversals

Possible configurations of the magnetic field in the outer magnetosphere during geomagnetic polarity reversals are investigated by considering the idealized problem of a magnetic multipole of order m and degree n located at the centre of a spherical cavity surrounded by a boundless perfect diamagnetic medium. In this illustrative idealization, the fixed spherical (magnetopause) boundary layer behaves as a perfectly conducting surface that shields the external diamagnetic medium from the compressed multipole magnetic field, which is therefore confined within the spherical cavity. For a general magnetic multipole of degree n, the non-radial components of magnetic induction just inside the magnetopause are increased by the factor 1 + [(n + 1)/n] relative to their corresponding values in the absence of the perfectly conducting spherical magnetopause. An exact equation is derived for the magnetic field lines of an individual zonal (m = 0), or axisymmetric, magnetic multipole of arbitrary degree n located at the centre of the magnetospheric cavity. For such a zonal magnetic multipole, there are always two neutral points and n – 1 neutral rings on the spherical magnetopause surface. The two neutral points are located at the poles of the spherical magnetopause. If n is even, one of the neutral rings is coincident with the equator; otherwise, the neutral rings are located symmetrically with respect to the equator. The actual existence of idealized higher-degree (n > 1) axisymmetric magnetospheres would necessarily imply multiple (n + 1) magnetospheric cusps and multiple (n) ring currents. Exact equations are also derived for the magnetic field lines of an individual non-axisymmetric magnetic multipole, confined by a perfectly conducting spherical magnetopause, in two special cases; namely, a symmetric sectorial multipole (m = n) and an antisymmetric sectorial multipole (m = n – 1). For both these non-axisymmetric magnetic multipoles, there exists on the spherical magnetopause surface a set of neutral points linked by a network of magnetic field lines. Novel magnetospheric processes are likely to arise from the existence of magnetic neutral lines that extend from the magnetopause to the surface of the Earth. Finally, magnetic field lines that are confined to, or perpendicular to, either special meridional planes or the equatorial plane, when the multipole is in free space, continue to be confined to, or perpendicular to, these same planes when the perfectly conducting magnetopause is present.Also Honorary Research Associate, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX, UK and Visiting Reader in Physics. University of Sussex, Falmer, Brighton BN1 9QH, UK     

Supraglacial weathering crust dynamics inferred from cryoconite hole hydrology

Water levels in cryoconite holes were monitored at high resolution over a 3‐week period on Austre Brøggerbreen (Svalbard). These data were combined with melt and energy balance modelling, providing insights into the evolution of the glacier's near‐surface hydrology and confirming that the hydrology of the near‐surface, porous ice known as the ‘weathering crust’ is dynamic and analogous to a shallow‐perched aquifer. A positive correlation between radiative forcing of melt and drainage efficiency was found within the weathering crust. This likely resulted from diurnal contraction and dilation of interstitial pore spaces driven by variations in radiative and turbulent fluxes in the surface energy balance, occasionally causing ‘sudden drainage events’. A linear decrease in water levels in cryoconite holes was also observed and attributed to cumulative increases in near‐surface ice porosity over the measurement period. The transport of particulate matter and microbes between cryoconite holes through the porous weathering crust is shown to be dependent upon weathering crust hydraulics and particle size. Cryoconite holes therefore yield an indication of the hydrological dynamics of the weathering crust and provide long‐term storage loci for cryoconite at the glacier surface. This study highlights the importance of the weathering crust as a crucial component of the hydrology, ecology and biogeochemistry of the glacier ecosystem and glacierized regions and demonstrates the utility of cryoconite holes as natural piezometers on glacier surfaces. Copyright © 2015 John Wiley & Sons, Ltd.     

著名科学家莱昂·诺波夫(Leon Knopoff)逝世

莱昂·诺波夫(1925~2011),是一位对物理学、地震学和音乐领域做出贡献的国际著名科学家,于2011年1月20日在妻子和3个孩子的陪伴下于家中辞世。莱昂·诺波夫1949年在加州理工学院获得物理学和数学博士学位,翌年开始在洛杉矶加州大学任教。1960年洛杉矶加州     

Climate Change and the Disappearance of Malaria from England

As the world's climate continues to change there is concern that this may cause malaria to spread to new areas. Here we examine whether past changes in temperature, in addition to social changes, may have affected malaria in England. Our analysis indicates that cold summers experienced during the 1800s may have contributed to the disappearance of this disease from the country. As our summers become progressively warner it is unlikely that malaria will become firmly re-established on these shores, although the possibility of future outbreaks should not be ignored.