scholarly journals Evidence for a Localized Source of the Argon in the Lunar Exosphere

2017 ◽  
Vol 122 (10) ◽  
pp. 2163-2181 ◽  
Author(s):  
Jacob A. Kegerreis ◽  
Vincent R. Eke ◽  
Richard J. Massey ◽  
Simon K. Beaumont ◽  
Rick C. Elphic ◽  
...  
Keyword(s):  
Localized Source ◽  
Lunar Exosphere

Untangling the Origin of Molecular Hydrogen in the Lunar Exosphere

2019 ◽  
Vol 887 (1) ◽  
pp. 27
Author(s):  
Parker B. Crandall ◽  
Jeffrey J. Gillis-Davis ◽  
Ralf I. Kaiser
Keyword(s):  
Molecular Hydrogen ◽  
Lunar Exosphere

scholarly journals The Kerr-Schild double copy in Lifshitz spacetime

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Gökhan Alkaç ◽  
Mehmet Kemal Gümüş ◽  
Mustafa Tek
Keyword(s):  
General Relativity ◽  
Gauge Theory ◽  
Charge Density ◽  
Localized Source ◽  
Curvature Term ◽  
Constant Charge Density ◽  
Arbitrary Dimensions ◽  
Double Copy ◽  
Theory Solution ◽  
Constant Charge

Abstract The Kerr-Schild double copy is a map between exact solutions of general relativity and Maxwell’s theory, where the nonlinear nature of general relativity is circumvented by considering solutions in the Kerr-Schild form. In this paper, we give a general formulation, where no simplifying assumption about the background metric is made, and show that the gauge theory source is affected by a curvature term that characterizes the deviation of the background spacetime from a constant curvature spacetime. We demonstrate this effect explicitly by studying gravitational solutions with non-zero cosmological constant. We show that, when the background is flat, the constant charge density filling all space in the gauge theory that has been observed in previous works is a consequence of this curvature term. As an example of a solution with a curved background, we study the Lifshitz black hole with two different matter couplings. The curvature of the background, i.e., the Lifshitz spacetime, again yields a constant charge density; however, unlike the previous examples, it is canceled by the contribution from the matter fields. For one of the matter couplings, there remains no additional non-localized source term, providing an example for a non-vacuum gravity solution corresponding to a vacuum gauge theory solution in arbitrary dimensions.

scholarly journals Impact of a Localized Source of Subglacial Discharge on the Heat Flux and Submarine Melting of a Tidewater Glacier: A Laboratory Study

2016 ◽  
Vol 46 (10) ◽  
pp. 3155-3163 ◽  
Author(s):  
Claudia Cenedese ◽  
V. Marco Gatto
Keyword(s):  
Free Surface ◽  
Laboratory Study ◽  
Heat Budget ◽  
Discharge Rate ◽  
Circulation Pattern ◽  
Freezing Temperature ◽  
Buoyant Plumes ◽  
Localized Source ◽  
Numerical Studies ◽  
Glacier Front

AbstractIdealized laboratory experiments have been conducted in a two-layer stratified fluid to investigate the leading-order dynamics that control submarine melting and meltwater export near a vertical ice–ocean interface as a function of subglacial discharge. In summer, the discharge of surface runoff at the base of a glacier (subglacial discharge) generates strong buoyant plumes that rise along the glacier front entraining ambient water along the way. The entrainment enhances the heat transport toward the glacier front and hence the submarine melt rate increases with the subglacial discharge rate. In the laboratory, the effect of subglacial discharge is simulated by introducing freshwater at freezing temperature from a point source at the base of an ice block representing the glacier. The circulation pattern observed both with and without subglacial discharge resembles those observed in previous observational and numerical studies. Buoyant plumes rise vertically until they find either their neutrally buoyant level or the free surface. Hence, the meltwater can deposit within the interior of the water column and not entirely at the free surface, as confirmed by field observations. The heat budget in the tank, calculated following a new framework, gives estimates of submarine melt rate that increase with the subglacial discharge and are in agreement with the directly measured submarine melting. This laboratory study provides the first direct measurements of submarine melt rates for different subglacial discharges, and the results are consistent with the predictions of previous theoretical and numerical studies.

Lunar Exosphere

1974 ◽  
pp. 185-196
Author(s):  
Zdeněk Kopal
Keyword(s):  
Lunar Exosphere

Wellbeing, young people, and music scenes

2019 ◽  
pp. 187-196 ◽  
Author(s):  
Andy Bennett ◽  
Lisa Nikulinsky
Keyword(s):  
Young People ◽  
Empirical Data ◽  
Sense Of Self ◽  
Psychological Wellbeing ◽  
Localized Source ◽  
Music Scenes ◽  
Academic Scholarship ◽  
Self Worth ◽  
Research Findings ◽  
The Relationship

This chapter considers how young people’s involvement in a local or virtual music scene can be important in terms of providing them with a sense of self-worth and esteem. Although the topic of music scenes has been comprehensively researched in academic scholarship, the connection between scene membership and physical and psychological wellbeing has not to date been a topic of focus. The chapter draws on original empirical data generated during interviews with young people in Margaret River, Western Australia, in 2016–17. Although our research findings originate from a localized source, they can be extrapolated to broader debates concerning the relationship between young people, music, and wellbeing.

scholarly journals How marine emissions of bromoform impact the remote atmosphere

2019 ◽  
Vol 19 (17) ◽  
pp. 11089-11103 ◽  
Author(s):  
Yue Jia ◽  
Susann Tegtmeier ◽  
Elliot Atlas ◽  
Birgit Quack
Keyword(s):  
Dispersion Model ◽  
Hot Spot ◽  
Open Ocean ◽  
Advective Transport ◽  
Localized Source ◽  
Mixing Ratios ◽  
Low Wind Speed ◽  
Uniform Background ◽  
Lagrangian Dispersion ◽  
The Impact

Abstract. It is an open question how localized elevated emissions of bromoform (CHBr3) and other very short-lived halocarbons (VSLHs), found in coastal and upwelling regions, and low background emissions, typically found over the open ocean, impact the atmospheric VSLH distribution. In this study, we use the Lagrangian dispersion model FLEXPART to simulate atmospheric CHBr3 resulting from assumed uniform background emissions, and from elevated emissions consistent with those derived during three tropical cruise campaigns. The simulations demonstrate that the atmospheric CHBr3 distributions in the uniform background emissions scenario are highly variable with high mixing ratios appearing in regions of convergence or low wind speed. This relation holds on regional and global scales. The impact of localized elevated emissions on the atmospheric CHBr3 distribution varies significantly from campaign to campaign. The estimated impact depends on the strength of the emissions and the meteorological conditions. In the open waters of the western Pacific and Indian oceans, localized elevated emissions only slightly increase the background concentrations of atmospheric CHBr3, even when 1∘ wide source regions along the cruise tracks are assumed. Near the coast, elevated emissions, including hot spots up to 100 times larger than the uniform background emissions, can be strong enough to be distinguished from the atmospheric background. However, it is not necessarily the highest hot spot emission that produces the largest enhancement, since the tug-of-war between fast advective transport and local accumulation at the time of emission is also important. Our results demonstrate that transport variations in the atmosphere itself are sufficient to produce highly variable VSLH distributions, and elevated VSLHs in the atmosphere do not always reflect a strong localized source. Localized elevated emissions can be obliterated by the highly variable atmospheric background, even if they are orders of magnitude larger than the average open ocean emissions.

The Effect of Scattering on Solar Radio Sources at 80 MHz

1972 ◽  
Vol 2 (2) ◽  
pp. 98-100 ◽  
Author(s):  
A. C. Riddle
Keyword(s):  
Plasma Level ◽  
Electron Density ◽  
Solar Radio ◽  
Brightness Distribution ◽  
Time Profile ◽  
Radio Sources ◽  
Density Structure ◽  
Localized Source ◽  
Type Iii

Scattering of radiation from solar radio sources by in homogeneities in the electron density structure of the corona can have marked effects on the observed time profile and the brightness distribution. These effects are appreciable for any localized source emitting a brief burst of radiation and are most pronounced when the radiation propagates close to the plasma level; it is such sources, illustrated here by those of type III bursts, that will be considered in this paper.

Sign in / Sign up

Export Citation Format

Share Document