Pride Of My Heart And Home : Or You Can Guess The Rest

https://digitalcommons.library.umaine.edu/mmb-vp/4897/thumbnail.jp

Periodicities in the coronal rotation and sunspot numbers

The present study is an attempt to investigate the long term variations in coronal rotation by analyzing the time series of the solar radio emission data at 2.8 GHz frequency for the period 1947 - 2009. Here, daily adjusted radio flux (known as Penticton flux) data are used. The autocorrelation analysis shows that the rotation period varies between 19.0 to 29.5 sidereal days (mean sidereal rotation period is 24.3 days). This variation in the coronal rotation period shows evidence of two components in the variation; (1) 22-years component which may be related to the solar magnetic field reversal cycle or Hale's cycle, and (3) a component which is irregular in nature, but dominates over the other components. The crosscorrelation analysis between the annual average sunspots number and the coronal rotation period also shows evidence of its correlation with the 22-years Hale's cycle. The 22-years component is found to be almost in phase with the corresponding periodicities in the variation of the sunspots number.Comment: 9 pages, 5 figures, Accepted for publication in MNRA

The eventization of leisure and the strange death of alternative Leeds

The communicative potential of city spaces as leisure spaces is a central assumption of political activism and the creation of alternative, counter-cultural and subcultural scenes. However, such potential for city spaces is limited by the gentrification, privatization and eventization of city centres in the wake of wider societal and cultural struggles over leisure, work and identity formation. In this paper, we present research on alternative scenes in the city of Leeds to argue that the eventization of the city centre has led to a marginalization and of alternative scenes on the fringes of the city. Such marginalization has not caused the death of alternative Leeds or political activism associated with those scenes—but it has changed the leisure spaces (physical, political and social) in which alternative scenes contest the mainstream

FLUX MEASUREMENTS FROM A TALL TOWER IN A COMPLEX LANDSCAPE

The accuracy and representativeness of flux measurements from a tall tower in a complex landscape was assessed by examining the vertical and sector variability of the ratio of wind speed to momentum flux and the ratio of vertical advective to eddy flux of heat. The 30-60 m ratios were consistent with theoretical predictions which indicate well mixed flux footprints. Some variation with sector was observed that were consistent with upstream roughness. Vertical advection was negligible compared with vertical flux except for a few sectors at night. This implies minor influence from internal boundary layers. Flux accuracy is a function of sector and stability but 30-60 m fluxes were found to be generally representative of the surrounding landscape. This paper will study flux data from a 300 m tower, with 4 levels of instruments, in a complex landscape. The surrounding landscape will be characterized in terms of the variation in the ratio of mean wind speed to momentum flux as a function of height and wind direction. The importance of local advection will be assessed by comparing vertical advection with eddy fluxes for momentum and heat

Cosmic rays and the magnetic field in the nearby starburst galaxy NGC 253. II The magnetic field

Original article can be found at: http://www.aanda.org/ Copyright The European Southern Observatory (ESO) DOI: 10.1051/0004-6361/200911698Context. There are several edge-on galaxies with a known magnetic field structure in their halo. A vertical magnetic field significantly enhances the cosmic-ray transport from the disk into the halo. This could explain the existence of the observed radio halos. Aims. We observed NGC 253 that possesses one of the brightest radio halos discovered so far. Since this galaxy is not exactly edge-on (i = 78◦) the disk magnetic field has to be modeled and subtracted from the observations in order to study the magnetic field in the halo. Methods. We used radio continuum polarimetry with the VLA in D-configuration and the Effelsberg 100-m telescope. NGC253 has a very bright nuclear point-like source, so that we had to correct for instrumental polarization. We used appropriate Effelsberg beam patterns and developed a tailored polarization calibration to cope with the off-axis location of the nucleus in the VLA primary beams. Observations at λλ6.2 cm and 3.6 cm were combined to calculate the RM distribution and to correct for Faraday rotation. Results. The large-scale magnetic field consists of a disk (r, φ) and a halo (r, z) component. The disk component can be described as an axisymmetric spiral field pointing inwards with a pitch angle of 25◦ ± 5◦ which is symmetric with respect to the plane (even parity). This field dominates in the disk, so that the observed magnetic field orientation is disk parallel at small distances from the midplane. The halo field shows a prominent X-shape centered on the nucleus similar to that of other edge-on galaxies. We propose a model where the halo field lines are along a cone with an opening angle of 90◦ ± 30◦ and are pointing away from the disk in both the northern and southern halo (even parity). We can not exclude that the field points inwards in the northern halo (odd parity). The X-shaped halo field follows the lobes seen in Hα and soft X-ray emission. Conclusions. Dynamo action and a disk wind can explain the X-shaped halo field. The nuclear starburst-driven superwind may further amplify and align the halo field by compression of the lobes of the expanding superbubbles. The disk wind is a promising candidate for the origin of the gas in the halo and for the expulsion of small-scale helical fields as requested for efficient dynamo action.Peer reviewe

A disk-wind model with correct crossing of all MHD critical surfaces

The classical Blandford & Payne (1982) model for the magnetocentrifugal acceleration and collimation of a disk-wind is revisited and refined. In the original model, the gas is cold and the solution is everywhere subfast magnetosonic. In the present model the plasma has a finite temperature and the self-consistent solution of the MHD equations starts with a subslow magnetosonic speed which subsequently crosses all critical points, at the slow magnetosonic, Alfven and fast magnetosonic separatrix surfaces. The superfast magnetosonic solution thus satisfies MHD causality. Downstream of the fast magnetosonic critical point the poloidal streamlines overfocus towards the axis and the solution is terminated. The validity of the model to disk winds associated with young stellar objects is briefly discussed. ~Comment: 13 pages, MNRAS accepted for publicatio

Short Term Climatological Wind Data as a Tool for Wind Forecasting

Utilizing short-term climatological wind data can enhance wind speed and wind direction forecasts. An analysis of regional or tower-based wind rose summaries can be useful forecast guides especially when synoptic-scale pressure gradients are weak. Predictive data from multiple models can be plotted against short-term climatological wind data to assess deviations from expected norms and differences between forecast models. Site-specific comparisons between predicted data and observed climatological distributions can provide further insights to the forecaster. These methods can be applied to any location where sufficient climatological data (at least two years) is available

Electronic Liquid Crystal Physics of Underdoped Cuprates

Recent observations of broken symmetries have partly demystified the pseudogap phase. Here we review evidence for long-range intra-unit-cell(IUC) nematic order and its unexpectedly strong coupling to the phase of the fluctuating stripes in the pseudogap states of underdoped Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$. In particular, we focus on the analysis techniques that reveal this evidence in scanning tunneling spectroscopy data, the definition of the extracted IUC nematic order parameter, and a phenomenological theory of the coupling between the IUC nematic order and the previously reported coexisting fluctuating stripes. We also present a microscopic mechanism of IUC nematic order driven by on-site and near-neighbor repulsions. Finally we discuss open questions in the context of these results.Comment: 26 pages, 10 figures. To be published in Physica