Metal concentrations in the upper atmosphere during meteor showers

Abstract. Using the nadir-viewing Global Ozone Measuring Experiment (GOME) UV/VIS spectrometer on the ERS-2 satellite, we investigate short term variations in the vertical magnesium column densities in the atmosphere and any connection to possible enhanced mass deposition during a meteor shower. Time-dependent mass influx rates are derived for all the major meteor showers using published estimates of mass density and temporal profiles of meteor showers. An average daily sporadic background mass flux rate is also calculated and used as a baseline against which calculated shower mass flux rates are compared. These theoretical mass flux rates are then compared with GOME derived metal vertical column densities of Mg and Mg+ from the years 1996–2001. There is no correlation between theoretical mass flux rates and changes in the Mg and Mg+ metal column densities. A possible explanation for the lack of a shower related increase in metal concentrations may be differences in the mass regimes dominating the average background mass flux and shower mass flux.

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Investigation of the Motion of Periodic Comet Giacobini-Zinner and the Origin of the Draconid Meteor Showers of 1926, 1933 and 1946

Symposium - International Astronomical Union ◽

10.1017/s0074180900006471 ◽

1972 ◽

Vol 45 ◽

pp. 173-180

Author(s):

Yu. V. Evdokimov

Keyword(s):

Meteor Shower ◽

Meteor Showers ◽

Orbital Elements ◽

Periodic Comet

Orbital elements of P/Giacobini-Zinner have been obtained from 577 observations at the eight apparitions 1900 to 1965 by linking apparitions in pairs. By this technique we established that the comet has a nongravitational secular deceleration amounting, on the average, to 0.081 day/(period)2. As a result of the comet's approach to Jupiter in 1969, a return of the Draconid meteor shower is possible on 1972 October 8d15h45m UT. The 1946 meteor shower was due to meteoroids ejected forward along the orbit of the comet in 1940 with velocities of 14 m s- 1. The meteor showers of 1933 and 1926 were apparently produced by meteoroids ejected in 1900 with velocities of 15.0 m s- 1 forward and 14.5 m s- 1 backward, respectively.

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A fragmentation model of dust grains in the inner coma of Halley. A possible explanation of the color effect

International Astronomical Union Colloquium ◽

10.1017/s0252921100501900 ◽

1996 ◽

Vol 150 ◽

pp. 387-390

Author(s):

B. Goidet-Devel ◽

J. Clairemidi ◽

G. Moreels ◽

P. Rousselot

Keyword(s):

Refractive Index ◽

Mass Density ◽

Scattered Light ◽

Particle Radius ◽

Fragmentation Model ◽

Dust Grains ◽

Color Effect ◽

Dependent Mass ◽

Good Agreement

AbstractA model to describe the intensity of dust scattered light observed by the spectrometer TKS during the Vega/Halley encounter is presented. Good agreement is obtained when using a particle radius dependent mass density. The color effect is reproduced if the refractive index of tholin is adopted.

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33. Meteor shower mass distribution from radar echo counts

Symposium - International Astronomical Union ◽

10.1017/s0074180900019902 ◽

1968 ◽

Vol 33 ◽

pp. 352-361

Author(s):

W. G. Elford

Keyword(s):

Mass Distribution ◽

Meteor Shower ◽

Inverse Power ◽

Meteor Showers ◽

Power Flux ◽

Wide Aperture ◽

Radar Echoes ◽

Radar Echo

Theoretical hourly rates of radar echoes from meteor showers observed with narrow- and wide-aperture systems are calculated in terms of equipment parameters and the distribution of the number of meteors as a function of mass. From a comparison of the echo rates in selected range intervals, it is shown that it is possible to determine the value of the exponent in a simple inverse power flux law.The effect on the echo rate of a change in the value of the exponent in the flux law with magnitude is described and the probability of detecting showers at different stations is discussed.It is suggested that simple radar echo counts in several range intervals can be used to determine the mass distribution of meteor showers over a range of two or three magnitudes above the limiting magnitude of the system. The analysis is applied to some observations made at Christchurch and Ottawa.

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MIRROR WORLD AND AXION: RELAXING COSMOLOGICAL BOUNDS

International Journal of Modern Physics A ◽

10.1142/s0217751x05024766 ◽

2005 ◽

Vol 20 (11) ◽

pp. 2454-2458 ◽

Cited By ~ 4

Author(s):

MAURIZIO GIANNOTTI

Keyword(s):

Mass Density ◽

Temperature Dependent ◽

Axion Mass ◽

Upper Limit ◽

Axion Field ◽

Dependent Mass

The cosmological (upper) limit on the Peccei-Quinn constant, related to the primordial oscillations of the axion field, can be relaxed for a mirror axion model. The simple reason is that the mirror world is colder and so the behavior of the axion temperature-dependent mass is dominated by the contribution from the mirror sector. So the coherent oscillations start earlier and correspondingly the axion mass density Ωah2 is reduced.

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Uniform exponential stabilisation of serially connected inhomogeneous Euler-Bernoulli beams

ESAIM Control Optimisation and Calculus of Variations ◽

10.1051/cocv/2020036 ◽

2020 ◽

Vol 26 ◽

pp. 110

Author(s):

Björn Augner

Keyword(s):

Boundary Conditions ◽

Modulus Of Elasticity ◽

Spatial Dependence ◽

Mass Density ◽

Coupled System ◽

The Other ◽

Exponential Energy Decay ◽

A Chain ◽

Dissipative Boundary ◽

Dependent Mass

We consider a chain of Euler-Bernoulli beams with spatial dependent mass density, modulus of elasticity and area moment which are interconnected in dissipative or conservative ways and prove uniform exponential energy decay of the coupled system for suitable dissipative boundary conditions at one end and suitable conservative boundary conditions at the other end. We thereby generalise some results of G. Chen, M.C. Delfour, A.M. Krall and G. Payre from the 1980’s to the case of spatial dependence of the parameters.

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SIZE-DEPENDENT MASS DENSITY OF NANOCRYSTALS

NANO ◽

10.1142/s1793292012500099 ◽

2012 ◽

Vol 07 (02) ◽

pp. 1250009 ◽

Cited By ~ 4

Author(s):

ALI SAFAEI

Keyword(s):

Experimental Data ◽

Particle Size ◽

Apparent Density ◽

Mass Density ◽

Ionic Crystals ◽

Size Dependent ◽

Metallic Oxides ◽

Simple Lattice ◽

Silica Nanopowder ◽

Dependent Mass

A new simple, lattice-type-sensitive model has been developed for the size-dependency of the mass density of individual elemental and compound nanocrystals. It has also been generalized for a multi-composition nanocrystal, and can be used for metallic oxides, ionic crystals and alloys. The model has been corroborated with the experimental data for the particle size-dependent apparent density (AD) of silica nanopowder.

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Meteor Showers: which ones are real and where do they come from?

Proceedings of the International Astronomical Union ◽

10.1017/s174392131400502x ◽

2012 ◽

Vol 10 (H16) ◽

pp. 142-142

Author(s):

Peter Jenniskens

Keyword(s):

Solar System ◽

Ground Truth ◽

Meteor Shower ◽

General Assembly ◽

Meteor Showers ◽

Orbital Elements ◽

Meteoroid Streams ◽

Zodiacal Cloud ◽

History Of ◽

To Receive

AbstractThe IAU Meteor Shower Working List contains 369 showers, of which only 64 are considered established (per February 28, 2012). In this invited review, we will give an overview of international efforts to validate the remaining showers. We report on the showers that were validated in this triennium and proposed to receive the predicate “established" at the present General Assembly. The meteoroid orbit surveys characterize the meteoroid streams in terms of orbital elements and their dispersions, which is ground truth for efforts to identify their parent comets, study the fragmentation history of the (mostly dormant) comet population in the inner solar system, and understand the origin of the zodiacal cloud.

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Mass transfer from a drop—II. Theoretical analysis of temperature dependent mass flux correlation

International Journal of Heat and Mass Transfer ◽

10.1016/0017-9310(94)00302-c ◽

1995 ◽

Vol 38 (9) ◽

pp. 1705-1708 ◽

Cited By ~ 32

Author(s):

Markku Kulmala ◽

Timo Vesala ◽

Jaroslav Schwarz ◽

Jiri Smolik

Keyword(s):

Mass Transfer ◽

Theoretical Analysis ◽

Mass Flux ◽

Temperature Dependent ◽

Dependent Mass

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Step-Mountain Technique Applied to an Atmospheric C-Grid Model, or How to Improve Precipitation near Mountains

Monthly Weather Review ◽

10.1175/2007mwr2048.1 ◽

2007 ◽

Vol 135 (12) ◽

pp. 4060-4076 ◽

Cited By ~ 12

Author(s):

Gary L. Russell

Keyword(s):

Mass Flux ◽

Atmospheric Model ◽

Variable Number ◽

Geostrophic Adjustment ◽

Vertical Column ◽

Numerical Errors ◽

Polar Cell ◽

Mass Fluxes ◽

Horizontal Flows ◽

Grid Scheme

Abstract Starting with Arakawa and Lamb’s second-order C-grid scheme, this paper describes the modifications made to the dynamics to create a C-grid atmospheric model with a variable number of cells for each vertical column. Where mountains exist, grid cells are discarded at the bottom of the column so that the mass per square meter of retained cells is more nearly equal to that of horizontally adjacent cells. This leads to the following chain of causes and effects: decreased mass variations reduce the numerically induced alternating patterns in the horizontal velocity components, which reduce erroneous vertical mass fluxes, which reduce erroneous precipitation. In addition, horizontal flows above mountains are smoother, the Ferrel cell is stronger, and the polar cell is better organized. The C-grid performs geostrophic adjustment best among the gridpoint schemes, being the most sensitive to condensation-released heating perturbations. It also overreacts more egregiously to numerical errors, particularly with respect to the vertical mass flux, and consequently is often not used. Mesinger et al. applied the step-mountain (eta coordinate) technique to an E-grid scheme with excellent results. Its application to the C-grid reduces numerical errors in the vertical mass flux resulting in improvements in precipitation and other quantities.

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