Article
Mechanics
Jim Thomas, Don Daniel
Summary: A study on the interaction between internal gravity waves and geostrophic balanced flow in the world's oceans reveals significant variability in energy balance, with wave-dominated regions showing an overtaking of the wave spectrum over the balanced flow at mesoscales. The research demonstrates that in high wave energy regions, waves can reverse the direction of geostrophic energy flux, leading to enhanced geostrophic energy dissipation.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Lin-Fan Zhang, Jin-Han Xie
Summary: This paper investigates the impact of near-inertial waves (NIWs) on zonal jets on a beta-plane. It finds that NIWs inhibit jet formation and can lead to the annihilation of zonal jets when their strength increases. The study also shows that NIWs induce spatial asymmetry in jet dynamics and modify the migration velocity of the jets.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
Houssam Yassin
Summary: Surface buoyancy gradients create latitudinally inhomogeneous mixing with eastward jets centered at sharp buoyancy gradients and weaker westward flows in between. The dynamics of this mixing depend on the vertical stratification, where decreasing stratification leads to longer interaction range and highly dispersive Rossby waves, and increasing stratification leads to shorter interaction range and weakly dispersive Rossby waves. The zonal-to-meridional speeds ratio and spacing between jets also vary with stratification.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
Michael R. R. Cox, Hossein A. A. Kafiabad, Jacques Vanneste
Summary: The dispersion of three-dimensional inertia-gravity waves by a turbulent geostrophic flow leads to a diffusion process in wavevector space. Previous studies have obtained the diffusivity tensor assuming a time-independent geostrophic flow. This study relaxes this assumption and examines how the weak diffusion of wave action affects the distribution of wave energy due to the slow time dependence of the geostrophic flow. The results show that the wave-energy spectrum is localized within a thin boundary layer around the constant-frequency cone, with its thickness controlled by the acceleration spectrum of the geostrophic flow.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Geosciences, Multidisciplinary
R. Bandyopadhyay, D. J. McComas, J. R. Szalay, F. Allegrini, S. J. Bolton, R. W. Ebert, R. J. Wilson, D. J. Gershman
Summary: Power spectra of magnetic-field fluctuations near Jupiter have been analyzed since the early days of space exploration with Voyager and Ulysses flyby of Jupiter. However, power spectra of velocity and density fluctuations have not been as well studied, due to the lack of high-resolution measurements required to resolve a significant fraction of the inertial range. The investigation of fluid-scale turbulence in Jupiter's magnetosheath using measurements from the Jovian Auroral Distributions Experiment (JADE) instrument onboard Juno spacecraft revealed nearly Kolmogorov scaling of ion density and velocity spectra, indicating weakly compressible fluctuations and the presence of a scale-invariant cascade through the inertial range. This specific case study suggests the existence of Alfvenic Kolmogorov-type turbulence in at least some locations in Jupiter's magnetosheath.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Engineering, Aerospace
Heather L. Roman-Stork, Bulusu Subrahmanyam, Corinne B. Trott
Summary: This study analyzed the mesoscale eddies in the Bay of Bengal, revealing seasonal differences in eddy characteristics and their impact on ocean heat content. Warm-core eddies were found to be associated with changes in OHC, while a significant relationship was observed between warm-core eddies and sea surface temperatures and outgoing longwave radiation during periods of strong ENSO and IOD forcing.
ADVANCES IN SPACE RESEARCH
(2021)
Article
Geosciences, Multidisciplinary
S. B. Xu, S. Y. Huang, Z. G. Yuan, H. H. Wu, K. Jiang, J. Zhang
Summary: This study investigates intermittent structures and intermittent heating in Saturn's magnetosphere based on observations from the Cassini spacecraft. Positive correlations are found between electron temperature and magnetic field intermittency, as well as between turbulence heating rate and the probability density of intermittent structures. These results suggest that intermittent structures contribute to turbulent heating in Saturn's magnetosphere.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geochemistry & Geophysics
L. Sachl, J. Velimsky, J. Fullea, Z. Martinec
Summary: In this paper, a new approach to the inverse problem of global electromagnetic induction is developed and tested, aiming to retrieve the 3-D structure of electrical conductivity in the suboceanic upper mantle using satellite-observed tidal magnetic field. Parametric studies and synthetic tests demonstrate the successful reconstruction of suboceanic upper mantle conductivity structure, with correlation coefficient greater than 0.8 in the ideal noise-free case.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Astronomy & Astrophysics
Senbei Du, Hui Li, Zhaoming Gan, Xiangrong Fu
Summary: Solar wind turbulence is weakly compressible and the understanding of density fluctuations is limited. Compressible magnetohydrodynamic simulations provide insights and the anisotropy effect is stronger at smaller scales and lower plasma beta. In situ measurements exhibit broad variations, so careful averaging is needed to reveal the scaling relations between density variations and other turbulence quantities.
ASTROPHYSICAL JOURNAL
(2023)
Article
Environmental Sciences
Xunwei Nie, Hao Liu, Tengfei Xu, Zexun Wei
Summary: The interannual-decadal variability in the upper-ocean salinity of the southeast Indian Ocean (SEIO) is highly correlated with the El Nino-Southern Oscillation (ENSO). This variability is mainly driven by meridional geostrophic velocity (MGV), which changes with the zonal pattern of the sea surface height (SSH). Previous studies have focused on the influence of local-wind forcing and eastern-boundary forcing on the SSH variability, but this study emphasizes the leading role of eastern-boundary forcing in the interannual variability of upper-ocean salinity in the SEIO.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Multidisciplinary Sciences
Dhruv Balwada, Jin-Han Xie, Raffaele Marino, Fabio Feraco
Summary: The ocean's turbulent energy cycle has a paradox of kinetic energy transferring between large and small scales, with the first observation of a dual kinetic energy cascade indicating a seasonal modulation in energy transfer.
Article
Meteorology & Atmospheric Sciences
Brentha Thurairajah, Chihoko Yamashita Cullens
Summary: It is well known that stratospheric sudden warmings (SSWs) are a result of the interaction between planetary waves (PWs) and the stratospheric polar vortex. This study characterizes the downward progression of temperature anomalies in the stratosphere using 18 years of observations. The results show year-to-year variability in temperature anomalies and a correlation between increased gravity wave activity and the weakening and reversal of zonal winds.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2022)
Article
Astronomy & Astrophysics
Yu Khotyaintsev, D. B. Graham, A. Vaivads, K. Steinvall, N. J. T. Edberg, A. Eriksson, E. P. G. Johansson, L. Sorriso-Valvo, M. Maksimovic, S. D. Bale, T. Chust, V Krasnoselskikh, M. Kretzschmar, E. Lorfevre, D. Plettemeier, J. Soucek, M. Steller, S. Stverak, P. Travnicek, A. Vecchio, T. S. Horbury, H. O'Brien, V Evans, V Angelini, E. Lorfevre
Summary: The study aims to demonstrate the relationship between solar wind platform waves and plasma density fluctuations using measurements from Solar Orbiter, thus expanding the application of plasma measurement methods and providing new insights into solar wind physics.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Geosciences, Multidisciplinary
R. Bandyopadhyay, L. J. Begley, B. A. Maruca, D. J. McComas, J. R. Szalay, F. Allegrini, R. W. Ebert, D. J. Gershman, J. E. P. Connerney, S. J. Bolton
Summary: Most space plasmas are weakly collisional and exhibit non-Maxwellian velocity distributions and temperature anisotropy. Previous studies have shown that the range of ion temperature anisotropy becomes narrower as the parallel ion beta increases, attributed to the actions of kinetic microinstabilities. This study explores the beta-dependent limits on ion temperature anisotropy in Jupiter's magnetosheath.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Astronomy & Astrophysics
S. Q. Zhao, Huirong Yan, Terry Z. Liu, Mingzhe Liu, Mijie Shi
Summary: The study analyzed sub-Alfvenic magnetohydrodynamic perturbations in the low-beta radial-field solar wind using data from the Parker Solar Probe spacecraft. It found a high degree of Alfvenicity and the dominance of compressible modes in solar wind heating. The results suggest that the collisionless damping of compressible modes could play a significant role in heating effects at MHD scales in low-beta plasma.
ASTROPHYSICAL JOURNAL
(2021)
Article
Meteorology & Atmospheric Sciences
Andrey Y. Shcherbina, Miles A. Sundermeyer, Eric Kunze, Eric D'Asaro, Gualtiero Badin, Daniel Birch, Anne-Marie E. G. Brunner-Suzuki, Joern Callies, Brandy T. Kuebel Cervantes, Mariona Claret, Brian Concannon, Jeffrey Early, Raffaele Ferrari, Louis Goodman, Ramsey R. Harcourt, Jody M. Klymak, Craig M. Lee, M. -Pascale Lelong, Murray D. Levine, Ren-Chieh Lien, Amala Mahadevan, James C. McWilliams, M. Jeroen Molemaker, Sonaljit Mukherjee, Jonathan D. Nash, Tamay Oezgoekmen, Stephen D. Pierce, Sanjiv Ramachandran, Roger M. Samelson, Thomas B. Sanford, R. Kipp Shearman, Eric D. Skyllingstad, K. Shafer Smith, Amit Tandon, John R. Taylor, Eugene A. Terray, Leif N. Thomas, James R. Ledwell
BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY
(2015)
Article
Meteorology & Atmospheric Sciences
Ian Grooms, Andrew J. Majda, K. Shafer Smith
Article
Oceanography
Shane R. Keating, K. Shafer Smith
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2015)
Article
Geosciences, Multidisciplinary
Zouhair Lachkar, Shafer Smith, Marina Levy, Olivier Pauluis
GEOPHYSICAL RESEARCH LETTERS
(2016)
Article
Geochemistry & Geophysics
Ian Grooms, K. Shafer Smith, Andrew J. Majda
DYNAMICS OF ATMOSPHERES AND OCEANS
(2012)
Article
Oceanography
K. Shafer Smith, Raffaele Ferrari
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2009)
Article
Oceanography
Ross Tulloch, John Marshall, Chris Hill, K. Shafer Smith
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2011)
Article
Oceanography
Antoine Venaille, Geoffrey K. Vallis, K. Shafer Smith
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2011)
Article
Oceanography
Shane R. Keating, K. Shafer Smith, Peter R. Kramer
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2011)
Article
Oceanography
K. Shafer Smith, Jacques Vanneste
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2013)
Article
Oceanography
Ian Grooms, Louis-Philippe Nadeau, K. Shafer Smith
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2013)
Article
Meteorology & Atmospheric Sciences
Shane R. Keating, Andrew J. Majda, K. Shafer Smith
MONTHLY WEATHER REVIEW
(2012)
Article
Mechanics
Shane R. Keating, Peter R. Kramer, K. Shafer Smith
Article
Mechanics
K. S. Smith, E. Bernard