The heliospheric magnetic field

The heliospheric magnetic field (HMF) is the extension of the coronal magnetic field carried out into the solar system by the solar wind. It is the means by which the Sun interacts with planetary magnetospheres and channels charged particles propagating through the heliosphere. As the HMF remains rooted at the solar photosphere as the Sun rotates, the large-scale HMF traces out an Archimedean spiral. This pattern is distorted by the interaction of fast and slow solar wind streams, as well as the interplanetary manifestations of transient solar eruptions called coronal mass ejections. On the smaller scale, the HMF exhibits an array of waves, discontinuities, and turbulence, which give hints to the solar wind formation process. This review aims to summarise observations and theory of the small- and large-scale structure of the HMF. Solar-cycle and cycle-to-cycle evolution of the HMF is discussed in terms of recent spacecraft observations and pre-spaceage proxies for the HMF in geomagnetic and galactic cosmic ray records

Implications of the recent low solar minimum for the solar wind during the Maunder minimum

The behavior of the Sun and near-Earth space during grand solar minima is not understood; however, the recent long and low minimum of the decadal-scale solar cycle gives some important clues, with implications for understanding the solar dynamo and predicting space weather conditions. The speed of the near-Earth solar wind and the strength of the interplanetary magnetic field (IMF) embedded within it can be reliably reconstructed for before the advent of spacecraft monitoring using observations of geomagnetic activity that extend back to the mid-19th century. We show that during the solar cycle minima around 1879 and 1901 the average solar wind speed was exceptionally low, implying the Earth remained within the streamer belt of slow solar wind flow for extended periods. This is consistent with a broader streamer belt, which was also a feature of the recent low minimum (2009), and yields a prediction that the low near-Earth IMF during the Maunder minimum (1640-1700), as derived from models and deduced from cosmogenic isotopes, was accompanied by a persistent and relatively constant solar wind of speed roughly half the average for the modern era

Heliospheric modulation of galactic cosmic rays during grand solar minima: past and future variations

Galactic cosmic ray flux at Earth is modulated by the heliospheric magnetic field. Heliospheric modulation potential, Φ, during grand solar minima is investigated using an open solar flux (OSF) model with OSF source based on sunspot number, R, and OSF loss on heliospheric current sheet inclination. Changing dominance between source and loss means Φ varies in- (anti-) phase with R during strong (weak) cycles, in agreement with Φ estimates from ice core records of 10Be concentration, which are in-phase during most of the last 300 years, but anti-phase during the Maunder Minimum. Model results suggest “flat” OSF cycles, such as solar cycle 20 result from OSF source and loss terms temporarily balancing throughout the cycle. Thus even if solar activity continues to decline steadily, the long-term drop in OSF through SC21 to SC23 may plateau during SC24, though reemerge in SC25 with the inverted phase relation

Predicting space climate change

The recent decline in the open magnetic flux of the Sun heralds the end of the Grand Solar Maximum (GSM) that has persisted throughout the space age, during which the largest‐fluence Solar Energetic Particle (SEP) events have been rare and Galactic Cosmic Ray (GCR) fluxes have been relatively low. In the absence of a predictive model of the solar dynamo, we here make analogue forecasts by studying past variations of solar activity in order to evaluate how long‐term change in space climate may influence the hazardous energetic particle environment of the Earth in the future. We predict the probable future variations in GCR flux, near‐Earth interplanetary magnetic field (IMF), sunspot number, and the probability of large SEP events, all deduced from cosmogenic isotope abundance changes following 24 GSMs in a 9300‐year record

Early X-ray/UV Line Signatures of GRB Progenitors and Hypernovae

We calculate the X-ray/UV spectral line signatures expected from the interaction of a gamma-ray burst afterglow and a dense pre-burst environment produced by the progenitor. We explore the conditions under which Fe line and edge equivalent widths of $\sim$ 1 keV can arise, and discuss the possibility of gaining information about possible progenitor scenarios using X-ray metal line spectra in the first few days of a burst. A wind or supernova shell around the burst produces an X-ray absorption line spectrum and later emission lines, while a hypernova funnel model produces mainly emission lines. The Fe \ked can in some cases be more prominent than the Fe \kal line. Under simple assumptions for the input continuum luminosity, current reports of observed Fe line luminosities are compatible with an Fe-enriched funnel model, while lower values are expected in shell models.Comment: revisions to ApJ ms first submitted 8/21/99; uses a higher and flatter input spectrum, with modified implications suggesting preference for funnel model

Solar angular momentum loss over the past several millennia

The Sun and Sun-like stars lose angular momentum to their magnetized stellar winds. This braking torque is coupled to the stellar magnetic field, such that changes in the strength and/or geometry of the field modifies the efficiency of this process. Since the space age, we have been able to directly measure solar wind properties using in situ spacecraft. Furthermore, indirect proxies such as sunspot number, geomagnetic indices, and cosmogenic radionuclides, constrain the variation of solar wind properties on centennial and millennial timescales. We use near-Earth measurements of the solar wind plasma and magnetic field to calculate the torque on the Sun throughout the space age. Then, reconstructions of the solar open magnetic flux are used to estimate the time-varying braking torque during the last nine millennia. We assume a relationship for the solar mass-loss rate based on observations during the space age which, due to the weak dependence of the torque on mass-loss rate, does not strongly affect our predicted torque. The average torque during the last nine millennia is found to be 2.2 × 1030 erg, which is comparable to the average value from the last two decades. Our data set includes grand minima (such as the Maunder Minimum), and maxima in solar activity, where the torque varies from ~1 to 5 × 1030 erg (averaged on decadal timescales), respectively. We find no evidence for any secular variation of the torque on timescales of less than 9000 yr

Adolescents leaving mental health or social care services: predictors of mental health and psychosocial outcomes one year later.

BACKGROUND: UK service structure necessitates a transition out of youth services at a time of increased risk for the development and onset of mental disorders. Little is currently known about the mental health and psychosocial outcomes of leaving services at this time. The aim of this study was to determine predictors of mental health and social adjustment in adolescents leaving mental health or social care services. METHODS: A cohort (n = 53) of 17 year olds were interviewed and assessed when preparing to leave adolescent services and again 12 months later. Their mental health and psychosocial characteristics were compared to a same-age community sample group (n = 1074). RESULTS: At discharge 34 (64%) met DSM IV criteria for a current psychiatric diagnosis and only 3 (6%) participants met operational criteria for successful outcomes at follow-up. Impairments in mental health, lack of employment, education or training and low preparedness were associated with poor outcomes. CONCLUSIONS: The findings suggest the current organisation of mental health and care services may not be fit for purpose and even unwittingly contribute to persistent mental illness and poor psychosocial outcomes. A redesign of services should consider a model where the timing of transition does not fall at the most hazardous time for young people, but is sufficiently flexible to allow young people to move on when they are personally, socially and psychologically most able to succeed. Assessment of a young person's readiness to transition might also be useful. A youth focused service across the adolescent and early adult years may be better placed to avoid young people falling through the service gap created by poor transitional management.This work was completed within the NIHR Collaborations for Leadership in Applied Health Research and Care (CLAHRC) for Cambridgeshire and Peterborough (now CLAHRC East of England). The CLAHRC is hosted by the University of Cambridge and the Cambridge and Peterborough NHS Foundation Trust. This work was partially supported by a Wellcome Trust programme grant (grant no. 74296) for the ROOTS data collection awarded to Ian Goodyer.This is the final version of the article. It first appeared from BioMed Central via http://dx.doi.org/10.1186/s12913-015-0853-

The Vehicle, Spring 1996

Vol. 37, No. 2 Table of Contents Poetry AnyoneKeith Owenspage 2 Of Words and WidgetsJ. Dylan McNeillpage 3 HouseplantsPeter W. Katespage 4 IcarusJeff Vande Zandepage 5 UntitledPatrick F. Kellypage 7 CommuteWhitty Whitesellpage 8 During Graduate SchoolJeff Vande Zandepage 9 NeuteredJason S. Loguepage 10 Bitter WritingJ. Dylan McNeillpage 11 Song to Unknown SoldiersM. Olatoye Bayieupage 12 SoftAmy Haynespage 13 Mother\u27s Crossword PuzzlesMatthew J. Nelsonpage 14 Prose Cold ShowerMatt Parkspage 17 Your Title HereKeith Owenspage 20 Biographies Authorspage 27https://thekeep.eiu.edu/vehicle/1067/thumbnail.jp

The solar wind angular momentum flux as observed by Parker solar probe

The long-term evolution of the Sun's rotation period cannot be directly observed, and is instead inferred from trends in the measured rotation periods of other Sun-like stars. Assuming the Sun spins down as it ages, following rotation rate ∝ age−1/2, requires the current solar angular momentum (AM) loss rate to be around 6 × 1030 erg. Magnetohydrodynamic models, and previous observations of the solar wind (from the Helios and Wind spacecraft), generally predict a values closer to 1 × 1030 erg or 3 × 1030 erg, respectively. Recently, the Parker Solar Probe (PSP) observed tangential solar wind speeds as high as ~50 km s−1 in a localized region of the inner heliosphere. If such rotational flows were prevalent throughout the corona, it would imply that the solar wind AM-loss rate is an order of magnitude larger than all of those previous estimations. In this Letter, we evaluate the AM flux in the solar wind, using data from the first two orbits of PSP. The solar wind is observed to contain both large positive (as seen during perihelion), and negative AM fluxes. We analyze two solar wind streams that were repeatedly traversed by PSP; the first is a slow wind stream whose average AM flux fluctuates between positive and negative values, and the second is an intermediate speed stream that contains a positive AM flux (more consistent with a constant flow of AM). When the data from PSP are evaluated holistically, the average equatorial AM flux implies a global AM-loss rate of around (2.6–4.2) × 1030 erg (which is more consistent with observations from previous spacecraft)

Biomass production of herbaceous energy crops in the United States: field trial results and yield potential maps from the multiyear regional feedstock partnership

Current knowledge of yield potential and best agronomic management practices for perennial bioenergy grasses is primarily derived from small-scale and short-term studies, yet these studies inform policy at the national scale. In an effort to learn more about how bioenergy grasses perform across multiple locations and years, the U.S. Department of Energy (US DOE)/Sun Grant Initiative Regional Feedstock Partnership was initiated in 2008. The objectives of the Feedstock Partnership were to (1) provide a wide range of information for feedstock selection (species choice) and management practice options for a variety of regions and (2) develop national maps of potential feedstock yield for each of the herbaceous species evaluated. The Feedstock Partnership expands our previous understanding of the bioenergy potential of switchgrass, Miscanthus, sorghum, energycane, and prairie mixtures on Conservation Reserve Program land by conducting long-term, replicated trials of each species at diverse environments in the U.S. Trials were initiated between 2008 and 2010 and completed between 2012 and 2015 depending on species. Field-scale plots were utilized for switchgrass and Conservation Reserve Program trials to use traditional agricultural machinery. This is important as we know that the smaller scale studies often overestimated yield potential of some of these species. Insufficient vegetative propagules of energycane and Miscanthus prohibited farm-scale trials of these species. The Feedstock Partnership studies also confirmed that environmental differences across years and across sites had a large impact on biomass production. Nitrogen application had variable effects across feedstocks, but some nitrogen fertilizer generally had a positive effect. National yield potential maps were developed using PRISM-ELM for each species in the Feedstock Partnership. This manuscript, with the accompanying supplemental data, will be useful in making decisions about feedstock selection as well as agronomic practices across a wide region of the country