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Full-Text Articles in Physical Sciences and Mathematics
Secondary Gravity Waves Generated By Breaking Mountain Waves Over Europe, Christopher J. Heale, Jonathan B. Snively, Katrina Bossert, S. L. Vadas, Lars Hoffmann, A. Dörnbrack, G. Stober, C. Jacobi
Secondary Gravity Waves Generated By Breaking Mountain Waves Over Europe, Christopher J. Heale, Jonathan B. Snively, Katrina Bossert, S. L. Vadas, Lars Hoffmann, A. Dörnbrack, G. Stober, C. Jacobi
Publications
A strong mountain wave, observed over Central Europe on 12 January 2016, is simulated in 2D under two fixed background wind conditions representing opposite tidal phases. The aim of the simulation is to investigate the breaking of the mountain wave and subsequent generation of nonprimary waves in the upper atmosphere. The model results show that the mountain wave first breaks as it approaches a mesospheric critical level creating turbulence on horizontal scales of 8–30 km. These turbulence scales couple directly to horizontal secondary waves scales, but those scales are prevented from reaching the thermosphere by the tidal winds, which act …
Regional Distribution Of Mesospheric Small‐Scale Gravity Waves During Deepwave, Pierre-Dominique Pautet, Michael J. Taylor, S. D. Eckermann, Neal R. Criddle
Regional Distribution Of Mesospheric Small‐Scale Gravity Waves During Deepwave, Pierre-Dominique Pautet, Michael J. Taylor, S. D. Eckermann, Neal R. Criddle
Publications
The Deep Propagating Gravity Wave Experiment project took place in June and July 2014 in New Zealand. Its overarching goal was to study gravity waves (GWs) as they propagate from the ground up to ~100 km, with a large number of ground‐based, airborne, and satellite instruments, combined with numerical forecast models. A suite of three mesospheric airglow imagers operated onboard the NSF Gulfstream V (GV) aircraft during 25 nighttime flights, recording the GW activity at OH altitude over a large region (>7,000,000 km2). Analysis of this data set reveals the distribution of the small‐scale GW mean power …
Localization Effects On The Dissipation Of Gravity Wave Packets In The Upper Mesophere And Lower Thermosphere, C. J. Heale, R. L. Walterscheid, J. B. Snively
Localization Effects On The Dissipation Of Gravity Wave Packets In The Upper Mesophere And Lower Thermosphere, C. J. Heale, R. L. Walterscheid, J. B. Snively
Publications
Gravity waves not subject to breaking or filtering will dissipate due to viscosity and thermal conduction in the thermosphere. However, the evolutions of wave packets, and the altitudes they reach, are highly dependent upon the spectral content. In this paper, a 2‐D numerical model is used to investigate the effect of spatial localization (and thus spectral content) of a wave packet on its dissipation, dispersion, and spectral evolution. It is found that most wave packets launched below the thermosphere evolve to smaller central vertical wavelengths as the faster, longer vertical wavelength components reach the dissipative thermosphere and are removed first, …
First Search For Nontensorial Gravitational Waves From Known Pulsars, B. P. Abbott, K. Aultoneal, S. Gaudio, K. Gill, B. Hughey, J. W. W. Pratt, E. Schmidt, S. G. Schwalbe, M. J. Szczepańczyk, M. Zanolin, Et Al.
First Search For Nontensorial Gravitational Waves From Known Pulsars, B. P. Abbott, K. Aultoneal, S. Gaudio, K. Gill, B. Hughey, J. W. W. Pratt, E. Schmidt, S. G. Schwalbe, M. J. Szczepańczyk, M. Zanolin, Et Al.
Publications
We present results from the first directed search for nontensorial gravitational waves. While general relativity allows for tensorial (plus and cross) modes only, a generic metric theory may, in principle, predict waves with up to six different polarizations. This analysis is sensitive to continuous signals of scalar, vector, or tensor polarizations, and does not rely on any specific theory of gravity. After searching data from the first observation run of the advanced LIGO detectors for signals at twice the rotational frequency of 200 known pulsars, we find no evidence of gravitational waves of any polarization. We report the first upper …
Unexpected Occurrence Of Mesospheric Frontal Gravity Wave Events Over The South Pole (90 Degrees S), P.-D. Pautet, M. J. Taylor, J. B. Snively, C. Solorio
Unexpected Occurrence Of Mesospheric Frontal Gravity Wave Events Over The South Pole (90 Degrees S), P.-D. Pautet, M. J. Taylor, J. B. Snively, C. Solorio
Publications
Since 2010, Utah State University has operated an infrared Advanced Mesospheric Temperature Mapper at the Amundsen–Scott South Pole station to investigate the upper atmosphere dynamics and temperature deep within the vortex. A surprising number of “frontal” gravity wave events (86) were recorded in the mesospheric OH(3,1) band intensity and rotational temperature images (typical altitude of ~87 km) during four austral winters (2012–2015). These events are gravity waves (GWs) characterized by a sharp leading wave front followed by a quasi-monochromatic wave train that grows with time. A particular subset of frontal gravity wave events has been identified in the past (Dewan …
Nonlinear Gravity Wave Forcing As A Source Of Acoustic Waves In The Mesosphere, Thermosphere, And Ionosphere, J. B. Snively
Nonlinear Gravity Wave Forcing As A Source Of Acoustic Waves In The Mesosphere, Thermosphere, And Ionosphere, J. B. Snively
Publications
Numerical simulations demonstrate theoretical predictions that gravity waves with short periods (∼4–8 min) in the mesosphere and lower thermosphere may force secondary acoustic waves, with harmonic periods (∼2-4 minutes), that can reach detectable amplitudes in the thermosphere and ionosphere. The mechanism is through their vertical fluxes of vertical momentum, which lead to forcing as they are disrupted by varying stratification or instability. This is shown likely to occur where horizontally or radially opposing gravity waves interact at large amplitudes, such as above large convective sources, and after overturning. Evanescence and reflection of the waves can lead to further enhancements of …
Gw170817: Observation Of Gravitational Waves From A Binary Neutron Star Inspiral, B. P. Abbott, K. Aultoneal, S. Gaudio, K. Gill, E. M. Gretarsson, B. Hughey, M. Muratore, J. W. W. Pratt, S. G. Schwalbe, K. Staats, M. J. Szczepańczyk, M. Zanolin, Et Al.
Gw170817: Observation Of Gravitational Waves From A Binary Neutron Star Inspiral, B. P. Abbott, K. Aultoneal, S. Gaudio, K. Gill, E. M. Gretarsson, B. Hughey, M. Muratore, J. W. W. Pratt, S. G. Schwalbe, K. Staats, M. J. Szczepańczyk, M. Zanolin, Et Al.
Publications
On August 17, 2017 at 12∶41:04 UTC the Advanced LIGO and Advanced Virgo gravitational-wave detectors made their first observation of a binary neutron star inspiral. The signal, GW170817, was detected with a combined signal-to-noise ratio of 32.4 and a false-alarm-rate estimate of less than one per 8.0 × 104 years. We infer the component masses of the binary to be between 0.86 and 2.26 M⊙, in agreement with masses of known neutron stars. Restricting the component spins to the range inferred in binary neutron stars, we find the component masses to be in the range 1.17–1.60 M⊙, with the total …
Directly Comparing Gw150914 With Numerical Solutions Of Einstein's Equations For Binary Black Hole Coalescence, B. P. Abbott, K. Gill, B. Hughey, M. J. Szczepańczyk, M. Zanolin, Et Al.
Directly Comparing Gw150914 With Numerical Solutions Of Einstein's Equations For Binary Black Hole Coalescence, B. P. Abbott, K. Gill, B. Hughey, M. J. Szczepańczyk, M. Zanolin, Et Al.
Publications
We compare GW150914 directly to simulations of coalescing binary black holes in full general relativity, including several performed specifically to reproduce this event. Our calculations go beyond existing semianalytic models, because for all simulations—including sources with two independent, precessing spins—we perform comparisons which account for all the spin-weighted quadrupolar modes, and separately which account for all the quadrupolar and octopolar modes. Consistent with the posterior distributions reported by Abbott et al. [Phys. Rev. Lett. 116, 241102 (2016)] (at the 90% credible level), we find the data are compatible with a wide range of nonprecessing and precessing simulations. Follow-up simulations performed …