Measurements of stratospheric ozone at a mid-latitude observing station Valentia, Ireland (51.94° N, 10.25° W), using ground-based and ozonesonde observations from 1994 to 2009     

Om P. Tripathi  S. G. Jennings  C. D. O’Dowd  K. P. Lambkin  E. Moran 《Journal of Atmospheric Chemistry》2013,70(4):297-316

Sixteen years (1994 – 2009) of ozone profiling by ozonesondes at Valentia Meteorological and Geophysical Observatory, Ireland (51.94^° N, 10.23^° W) along with a co-located MkIV Brewer spectrophotometer for the period 1993–2009 are analyzed. Simple and multiple linear regression methods are used to infer the recent trend, if any, in stratospheric column ozone over the station. The decadal trend from 1994 to 2010 is also calculated from the monthly mean data of Brewer and column ozone data derived from satellite observations. Both of these show a 1.5 % increase per decade during this period with an uncertainty of about ±0.25 %. Monthly mean data for March show a much stronger trend of?~?4.8 % increase per decade for both ozonesonde and Brewer data. The ozone profile is divided between three vertical slots of 0–15 km, 15–26 km, and 26 km to the top of the atmosphere and a 11-year running average is calculated. Ozone values for the month of March only are observed to increase at each level with a maximum change of +9.2?±?3.2 % per decade (between years 1994 and 2009) being observed in the vertical region from 15 to 26 km. In the tropospheric region from 0 to 15 km, the trend is positive but with a poor statistical significance. However, for the top level of above 26 km the trend is significantly positive at about 4 % per decade. The March integrated ozonesonde column ozone during this period is found to increase at a rate of ~6.6 % per decade compared with the Brewer and satellite positive trends of ~5 % per decade.  相似文献   

Seasonal POC fluxes at BATS estimated from 210Po deficits     

Gillian M. Stewart  S. Bradley Moran  Michael W. Lomas 《Deep Sea Research Part I: Oceanographic Research Papers》2010,57(1):113-124

In this study at the Bermuda Atlantic Time-series Study (BATS) site we demonstrate that the polonium–lead disequilibrium system may perform better as a tracer of organic carbon export under low-flux conditions (in this case, <2.5 mmol C m^?2 d^?1) than under bloom conditions in an oligotrophic setting. With very few exceptions, the POC flux predictions calculated from the water-column ²¹⁰Po deficit were within a factor of 2 of the POC flux caught in surface-tethered sediment traps. However, we found higher correlation between size-fractionated particulate ²¹⁰Po activity and POC concentration in November 2006 (r=0.93) than in January (r=0.79) and during the spring bloom in March 2007 (r=0.80). We suggest that this is due to the ability of polonium to distinguish between bulk mass flux and organic carbon export under oligotrophic and lithogenic-driven flux regimes. Further, we found that the POC/Po ratio on particles was largely independent of size class between 10 and 100 μm (P=0.13) during each season, supporting the notion that export in this oligotrophic system is driven by sinking aggregates of smaller cells and not by large, individual cells.  相似文献   

The systemic velocities of four long-period cataclysmic variable stars     

R. C. North  T. R. Marsh  U. Kolb  V. S. Dhillon  C. K. J. Moran 《Monthly notices of the Royal Astronomical Society》2002,337(4):1215-1223

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Land Value, Distance, and Productivity on the Auckland Urban Periphery     

Warren Moran 《New Zealand geographer》1978,34(2):85-96

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A grid search for families of periodic orbits in the restricted problem of three bodies     

V. V. Markellos  W. Black  P. E. Moran 《Celestial Mechanics and Dynamical Astronomy》1974,9(4):507-512

A method is described for the numerical determination of families of periodic orbits in the planar restricted problem of three bodies. The families are sought in their representation as curves in a two-dimensional space of parameters. A grid search is applied to the study of the evolution of satellite motion when the mass parameter is varied. Only that part of the space of parameters is investigated for which one of them, the relative energy constant, takes values larger than that corresponding to the inner Lagrangian pointL ₂. Critical values of the mass parameter are determined for which new families of simple or double periodic orbits appear inside the closed ovals of zero velocity.  相似文献   

Growth,feed conversion and faecal discharge of yellowtail kingfish (Seriola lalandi) fed three commercial diets     

Damian Moran  Stephen J. Pether  Peter S. Lee 《新西兰海洋与淡水研究杂志》2013,47(4):917-927

Abstract

A study was undertaken to provide data on growth, feed conversion ratio (FCR) and faecal discharge of yellowtail kingfish (Seriola lalandi) fed three commercial diets used previously to culture this species in New Zealand. Fish were raised in tanks from 0.4 to 1.2 kg over the spring (water temperature 14–17°C) and summer (17–22°C) periods. There were considerable differences in volumetric and mass‐specific feed intake, and energy intake amongst diets. Daily crude protein intake was similar amongst diets, although it increased from the cold (4.05–4.50 g protein kg^?1 day^?1) to warm period (6.48–7.67 g protein kg^?1 day^?1). The biological and economical FCR varied with diet (BFCR 1.22–2.17, EFCR 1.30–2.62), as did the cost of feed per unit biomass produced (NZ$38–3.78 kg^?1). Growth rates were broadly similar amongst diets, and the warmer summer temperature period greatly improved both growth (increase from 0.51–0.64% to 1.18–1.23% mass gain day^?1) and BFCR (decrease from 1.37–2.17 to 1.22–1.46). The Salmofood ESF diet resulted in only half of the faecal setüeable solids and settleable total nitrogen (T N) and total phosphorus (T P) output compared with Skretting NME, which was in turn only half or less of that of Reliance SF  相似文献   

Studies in the application of recurrence relations to special perturbation methods     

P. E. Moran 《Celestial Mechanics and Dynamical Astronomy》1973,7(1):122-135

Using the rectangular equations of motion for the restricted three-body problem a comparison is made of the Encke and Cowell methods of integration. Each set of differential equations is integrated using Taylor series expansions where the coefficients of the powers of time are determined by recurrence relationships. It is shown that for fairly highly eccentric orbits in which the perturbing force is less than one thousandth of the two-body force the Encke method achieves a considerable saving in machine time. This is also true for almost circular orbits when low or moderate accuracy is required. When very high accuracy is required, however, the Cowell method is faster unless the perturbing force is less than 10^–6 of the two-body force. There is little difference in the accuracy of the two methods, the Cowell method being slightly more accurate when a low or moderate accuracy criterion is imposed.  相似文献   

Highly perturbed periodic oscillations around a small primary     

V. V. Markellos  P. E. Moran  W. Black 《Astrophysics and Space Science》1975,33(2):385-419

A global picture of the families of simple periodic orbits in terms of their characteristics is given in the part of the plane (γ, ξ₁) of representation near the singularity corresponding to the small primary, for the case of the restricted problem with a small value of the mass parameter μ. The value used for μ is smaller than the critical value of Routh. The picture is found to be qualitatively different from the one corresponding to μ larger than the critical value. By means of the stability parameters four new families, consisting of asymmetric periodic orbits, are shown to exist as bifurcations of families of symmetric periodic orbits.  相似文献   

Studies in the application of recurrence relations to special perturbation methods     

A. E. Roy  P. E. Moran 《Celestial Mechanics and Dynamical Astronomy》1973,7(2):236-255

A set of differential equations is derived that has a number of advantages in special perturbation work. In particular, the equations remain valid for all values of the orbital eccentricity and inclination including zero. They are therefore applicable to parabolic- and hyperbolic-type orbits as well as elliptic-type; a scheme for use when the orbit is rectilinear or nearly so is provided. The equations are also much simpler in form than the Lagrange planetary equations and the transformations of the osculating elements to and from the rectangular coordinates are straightforward.  相似文献   

The 1999 eruption of Shishaldin Volcano, Alaska: monitoring a distant eruption     

C. Nye  T. Keith  J. Eichelberger  T. Miller  S. McNutt  S. Moran  D. Schneider  J. Dehn  J. Schaefer 《Bulletin of Volcanology》2002,64(8):507-519

Shishaldin Volcano, in the central Aleutian volcanic arc, became seismically restless during the summer of 1998. Increasing unrest was monitored using a newly installed seismic network, weather satellites, and rare local visual observations. The unrest culminated in large eruptions on 19 April and 22-23 April 1999. The opening phase of the 19 April eruption produced a sub-Plinian column that rose to 16 km before rapidly dissipating. About 80 min into the 19 April event we infer that the eruption style transitioned to vigorous Strombolian fountaining. Exceptionally vigorous seismic tremor heralded the 23 April eruption, which produced a large thermal anomaly observable by satellite, but only a modest, 6-km-high plume. There are no ground-based visual observations of this eruption; however we infer that there was renewed, vigorous Strombolian fountaining. Smaller low-level ash-rich plumes were produced through the end of May 1999. The lava that erupted was evolved basalt with about 49% SiO₂. Subsequent field investigations have been unable to find a distinction between deposits from each of the two major eruptive episodes.  相似文献