Chromospheric and photospheric evolution of an extremely active solar region in solar cycle 19

a comprehensive investigation was made of phenomena attending the disk passage, July 7 to 21, 1959, of active solar center HAO-59Q. At the photospheric level that comprised an aggregate of groups of sunspots of which one group, Mt. Wilson 14284, showed all the attributes deemed typical of solar regions associated with the production of major flares. A special characteristic of 59Q was its capability to eject dark material. Part of this material remained trapped in the strong magnetic fields above group 14284 where it formed a system of interrelated arches, the legs of which passed through components of the bright chromospheric network of the plage and were rooted in various underlying umbrae. Two apparently diffeent kinds of flare were identified in 59Q; namely, prominence flares (which comprised brightenings within part of the suspended dark prominence) and plage flares (which comprised brightenings within part of the chromospheric network). Prominence flares were of three varieties described as 'impact', 'stationary' and 'moving' prominence flares. Plage flares were accompanied in 3 percent of cases by Type III bursts. These latter radio events indicate the associated passage through the corona of energetic electrons in the approximate energy range 10 to 100 keV. At least 87.5 percent, and probably all, impulsive brightenings in 59Q began directly above minor spots, many of which satellites to major umbrae. Stationary and moving prominence flares were individually triggered at sites beneath which magnetic changes occurred within intervals which included each flare's flash phase

Pioneering Spirit in Space Exploration

,.o have a career in science is to live in an environment of great beauty and challenge and the excitement of it never fades", says Professor Susan McKenna-Lawlor, winner of the Irish Laureate - Woman of Europe Award in 1994 - for her pioneering work in space exploration. Dermot O'Leary, Chairman of CIE, sponsors of the Award, said that, ''the Laureate Award is designed to pay tribute to those women throughout Europe who have advanced the European ideal by their personal careers and have contributed, through their achievements to the development of a new Europe

Magnetohydrodynamic Simulation of the Interaction between Interplanetary Strong Shock and Magnetic Cloud and its Consequent Geoeffectiveness

Numerical studies have been performed to interpret the observed "shock overtaking magnetic cloud (MC)" event by a 2.5 dimensional magnetohydrodynamic (MHD) model in heliospheric meridional plane. Results of an individual MC simulation show that the MC travels with a constant bulk flow speed. The MC is injected with very strong inherent magnetic field over that in the ambient flow and expands rapidly in size initially. Consequently, the diameter of MC increases in an asymptotic speed while its angular width contracts gradually. Meanwhile, simulations of MC-shock interaction are also presented, in which both a typical MC and a strong fast shock emerge from the inner boundary and propagate along heliospheric equator, separated by an appropriate interval. The results show that the shock firstly catches up with the preceding MC, then penetrates through the MC, and finally merges with the MC-driven shock into a stronger compound shock. The morphologies of shock front in interplanetary space and MC body behave as a central concave and a smooth arc respectively. The compression and rotation of magnetic field serve as an efficient mechanism to cause a large geomagnetic storm. The MC is highly compressed by the the overtaking shock. Contrarily, the transport time of incidental shock influenced by the MC depends on the interval between their commencements. Maximum geoeffectiveness results from that when the shock enters the core of preceding MC, which is also substantiated to some extent by a corresponding simplified analytic model. Quantified by $Dst$ index, the specific result gives that the geoeffectiveness of an individual MC is largely enhanced with 80% increment in maximum by an incidental shock.Comment: 45 pages, 9 figure

A statistical study of the performance of the Hakamada-Akasofu-Fry version 2 numerical model in predicting solar shock arrival times at Earth during different phases of solar cycle 23

The performance of the Hakamada Akasofu-Fry, version 2 (HAFv.2) numerical model, which provides predictions of solar shock arrival times at Earth, was subjected to a statistical study to investigate those solar/interplanetary circumstances under which the model performed well/poorly during key phases (rise/maximum/decay) of solar cycle 23. In addition to analyzing elements of the overall data set (584 selected events) associated with particular cycle phases, subsets were formed such that those events making up a particular sub-set showed common characteristics. The statistical significance of the results obtained using the various sets/subsets was generally very low and these results were not significant as compared with the hit by chance rate (50%). This implies a low level of confidence in the predictions of the model with no compelling result encouraging its use. However, the data suggested that the success rates of HAFv.2 were higher when the background solar wind speed at the time of shock initiation was relatively fast. Thus, in scenarios where the background solar wind speed is elevated and the calculated success rate significantly exceeds the rate by chance, the forecasts could provide potential value to the customer. With the composite statistics available for solar cycle 23, the calculated success rate at high solar wind speed, although clearly above 50%, was indicative rather than conclusive. The RMS error estimated for shock arrival times for every cycle phase and for the composite sample was in each case significantly better than would be expected for a random data set. Also, the parameter "Probability of Detection, yes" (PODy) which presents the Proportion of Yes observations that were correctly forecast (i.e. the ratio between the shocks correctly predicted and all the shocks observed), yielded values for the rise/maximum/decay phases of the cycle and using the composite sample of 0.85, 0.64, 0.79 and 0.77, respectively. The statistical results obtained through detailed analysis of the available data provided insights into how changing circumstances on the Sun and in interplanetary space can affect the performance of the model. Since shock arrival predictions are widely utilized in making commercially significant decisions re. protecting space assets, the present detailed archival studies can be useful in future operational decision making during solar cycle 24. It would be of added value in this context to use Briggs-Rupert methodology to estimate the cost to an operator of acting on an incorrect forecast

Arrival times of Flare/Halo CME associated shocks at the Earth: comparison of the predictions of three numerical models with these observations

International audienceThe arrival times at L1 of eleven travelling shocks associated both with X-ray flaring and with halo CMEs recorded aboard SOHO/LASCO have been considered. Close to the Sun the velocities of these events were estimated using either Type II radio records or CME speeds. Close to the Earth the shocks were detected in the data of various solar wind plasma, interplanetary magnetic field (IMF) and energetic particle experiments aboard SOHO, ACE, WIND, INTERBALL-1 and IMP-8. The real-time shock arrival predictions of three numerical models, namely the Shock Time of Arrival Model (STOA), the Interplanetary Shock Propagation Model (ISPM) and the Hakamada-Akasofu-Fry Solar Wind Model (HAFv.2) were tested against these observations. This is the first time that energetic protons (tens of keV to a few MeV) have been used to complement plasma and IMF data in validating shock propagation models. The models were all generally successful in predicting shock arrivals. STOA provided the smallest values of the "predicted minus measured" arrival times and displayed a typical predictive precision better than about 8 h. The ratio of the calculated standard deviation of the transit times to Earth to the standard deviation of the measurements was estimated for each model (treating interacting events as composite shocks) and these ratios turned out to be 0.60, 1.15 and 1.02 for STOA, ISPM and HAFv.2, respectively. If an event in the sample for which the shock velocity was not well known is omitted from consideration, these ratios become 0.36, 0.76 and 0.81, respectively. Larger statistical samples should now be tested. The ratio of the in situ shock velocity and the "Sun to L1" transit velocity (Vsh /Vtr) was in the range of 0.7?0.9 for individual, non-interacting, shock events. HAFv.2 uniquely provided information on those changes in the COBpoint (the moving Connection point on the shock along the IMF to the OBserver) which directly influenced energetic particle rise times. This model also illustrated the non-uniform upstream conditions through which the various shocks propagated; furthermore it simulated shock deformation on a scale of fractions of an AU. On the spatial scale (300 RE ), where near-Earth spacecraft are located, the passing shocks, in conformity with the models, were found to be locally planar. The shocks also showed tilting relative to the Sun-Earth line, probably reflecting the inherent directionality associated with their solar origin. Key words. Interplanetary physics (energetic particles; interplanetary shocks; solar wind plasma

Unique Observations of a Geomagnetic SI^+ -- SI^- Pair: Solar Sources and Associated Solar Wind Fluctuations

The paper describes the occurrence of a pair of oppositely directed sudden impulses (SI), in the geomagnetic field ($\Delta$X), at ground stations, called SI${^{+}}$ -- SI${^{-}}$ pairs, that occurred between 1835 UT and 2300 UT on 23 April 1998. The SI${^{+}}$ -- SI${^{-}}$ pair, was closely correlated with corresponding variations in the solar wind density, while solar wind velocity and the southward component of the interplanetary magnetic field (Bz) did not show any correspondence. Further, this event had no source on the visible solar disk. However, a rear-side partial halo coronal mass ejection (CME) and an M1.4 class solar flare behind the west limb, took place on 20 April 1998, the date corresponding to the traceback location of the solar wind flows. This event presents empirical evidence, which to our knowledge, is the best convincing evidence for the association of specific solar events to the observations of an SI${^{+}}$ -- SI${^{-}}$ pair. In addition, it shows that it is possible for a rear side solar flare to propagate a shock towards the earth.Comment: The paper has just been accepted in the Journal of Geophysical Research (Space Physics) on 20 September 2010. It is 17 pages with 4 figure

Primary Care Staff's Views and Experiences Related to Routinely Advising Patients about Physical Activity. A Questionnaire Survey

Background: United Kingdom public health policy has recently re-emphasised the role of primary health care professionals in tackling increasing levels of physical inactivity within the general population. However, little is known about the impact that this has had in practice. This study explores Scottish primary care staff's knowledge, attitudes and experiences associated with advising patients about physical activity during routine consultations. Methods: A cross-sectional questionnaire survey of general practitioners (or family physicians), practice nurses and health visitors based in four health regions was conducted during 2004. The main outcome measures included: i) health professionals' knowledge of the current physical activity recommendations; (ii) practice related to routine physical activity advising; and (iii) associated attitudes. Results: Questionnaires were returned by 757 primary care staff (response rate 54%). Confidence and enthusiasm for giving advice was generally high, but knowledge of current physical activity recommendations was low. In general, respondents indicated that they routinely discuss and advise patients about physical activity regardless of the presenting condition. Health visitors and practice nurses were more likely than general practitioners to offer routine advice. Lack of time and resources were more likely to be reported as barriers to routine advising by general practitioners than other professional groups. However, health visitors and practice nurses were also more likely than general practitioners to believe that patients would follow their physical activity advice giving. Conclusion: If primary health care staff are to be fully motivated and effective in encouraging and supporting the general population to become more physically active, policymakers and health professionals need to engage in efforts to: (1) improve knowledge of current physical activity recommendations and population trends amongst frontline primary care staff; and (2) consider the development of tools to support individual assessment and advice giving to suit individual circumstances. Despite the fact that this study found that system barriers to routine advising were less of a problem than other previous research has indicated, this issue still remains a challenge

Iterative inversion of global magnetospheric ion distributions using energetic neutral atom (ENA) images recorded by the NUADU/TC2 instrument

A method has been developed for extracting magnetospheric ion distributions from Energetic Neutral Atom (ENA) measurements made by the NUADU instrument on the TC-2 spacecraft. Based on a constrained linear inversion, this iterative technique is suitable for use in the case of an ENA image measurement, featuring a sharply peaked spatial distribution. The method allows for magnetospheric ion distributions to be extracted from a low-count ENA image recorded over a short integration time (5 min). The technique is demonstrated through its application to a set of representative ENA images recorded in energy Channel~2 (hydrogen: 50–81 keV, oxygen: 138–185 keV) of the NUADU instrument during a geomagnetic storm. It is demonstrated that this inversion method provides a useful tool for extracting ion distribution information from ENA data that are characterized by high temporal and spatial resolution. The recovered ENA images obtained from inverted ion fluxes match most effectively the measurements made at maximum ENA intensity