scholarly journals Validating satellite altimeter measurements of internal tides with long‐term TAO/TRITON buoy observations at 2°S–156°E

2015 ◽  
Vol 42 (10) ◽  
pp. 4040-4046 ◽  
Author(s):  
Xiao‐Hui Zhou ◽  
Dong‐Ping Wang ◽  
Dake Chen
Keyword(s):  
Internal Tides ◽  
Satellite Altimeter ◽  
Triton Buoy

scholarly journals Barotropic and Baroclinic M2 Tides in the Monterey Bay Region

2010 ◽  
Vol 40 (8) ◽  
pp. 1766-1783 ◽  
Author(s):  
G. S. Carter
Keyword(s):  
Submarine Canyon ◽  
Equation Model ◽  
Internal Tides ◽  
Continental Margins ◽  
Monterey Bay ◽  
Multiple Sources ◽  
Primitive Equation ◽  
High Level ◽  
Flux Energy

Abstract A high-resolution (250 m) primitive equation model is used to simulate the depth-averaged and baroclinic M2 tides in the Monterey Bay region. The model shows a high level of skill in comparisons with sea level observations. ADCP current observations within the submarine canyon are reasonably well reproduced. The modeled depth-averaged currents have a complex spatial pattern with magnitudes in excess of 0.1 m s−1 near Moss Landing. During the second half of flood (ebb) tide, the flow is into (out of) the bay through the canyon but out of (into) the bay over the shelf regions. This depth-averaged flow pattern is not evident in a diagnostic run, implying a feedback between the internal tides and the pressure gradient in the bay. The depth-integrated baroclinic (total minus depth-averaged) energy fluxes show a complex beamlike pattern due to the interaction of energy from multiple sources. The beams have magnitudes up to 1 kW m−1 interspersed with regions of near-zero depth-integrated flux. Energy entering the bay propagates northward from generation regions along the continental margins to the south of the bay (notably on the flanks of Sur Platform) and is steered into the canyon. A localized increase in depth-integrated baroclinic flux magnitude (up to 5 times the values elsewhere in the domain) closely follows the canyon axis near the mouth of the bay, presumably due to topographic focusing. Upper ocean velocities from a long-term surface mooring (MBARI M1) are used to assess the temporal variability of the M2 tide outside the canyon.

scholarly journals M2 Internal Tides and Their Observed Wavenumber Spectra from Satellite Altimetry

2016 ◽  
Vol 46 (1) ◽  
pp. 3-22 ◽  
Author(s):  
R. D. Ray ◽  
E. D. Zaron
Keyword(s):  
Internal Tide ◽  
Internal Tides ◽  
Altimeter Data ◽  
Satellite Altimeter ◽  
Wave Dynamics ◽  
Spectral Signatures ◽  
Tasman Sea ◽  
Mode 2 ◽  
Satellite Altimeter Data ◽  
Good Agreement

AbstractA near-global chart of surface elevations associated with the stationary M2 internal tide is empirically constructed from multimission satellite altimeter data. An advantage of a strictly empirical mapping approach is that results are independent of assumptions about ocean wave dynamics and, in fact, can be used to test such assumptions. A disadvantage is that present-day altimeter coverage is only marginally adequate to support mapping such short-wavelength features. Moreover, predominantly north–south ground-track orientations and contamination from nontidal oceanographic variability can lead to deficiencies in mapped tides. Independent data from Cryosphere Satellite-2 (CryoSat-2) and other altimeters are used to test the solutions and show positive reduction in variance except in regions of large mesoscale variability. The tidal fields are subjected to two-dimensional wavenumber spectral analysis, which allows for the construction of an empirical map of modal wavelengths. Mode-1 wavelengths show good agreement with theoretical wavelengths calculated from the ocean’s mean stratification, with a few localized exceptions (e.g., Tasman Sea). Mode-2 waves are detectable in much of the ocean, with wavelengths in reasonable agreement with theoretical expectations, but their spectral signatures grow too weak to map in some regions.

Observations of Eddy-Modulated Turbulent Mixing in the Southern Bay of Bengal

2021 ◽  
Author(s):  
C. A. Luecke ◽  
H. W. Wijesekera ◽  
E. Jarosz ◽  
D. W. Wang ◽  
J. C. Wesson ◽  
...  
Keyword(s):  
Sri Lanka ◽  
Bay Of Bengal ◽  
Turbulent Mixing ◽  
Dissipation Rate ◽  
Southwest Monsoon ◽  
Energy Dissipation Rate ◽  
Internal Tides ◽  
Eddy Diffusivities ◽  
Intraseasonal Oscillations

AbstractLong-term measurements of turbulent kinetic-energy dissipation rate (ε), and turbulent temperature-variance dissipation rate (χT) in the thermocline, along with currents, temperature, and salinity were made at two subsurface moorings in the southern Bay of Bengal (BoB). This is a part of a major international program, conducted between July 2018 and June 2019, for investigating the role of the BoB on the monsoon intraseasonal oscillations. One mooring was located on the typical path of the Southwest Monsoon Current (SMC), and the other was in a region where the Sri Lanka Dome is typically found during the summer monsoon. Microstructure and finescale estimates of vertical diffusivity revealed the long-term subthermocline mixing patterns in the southern BoB. Enhanced turbulence and large eddy diffusivities were observed within the SMC during the passage of a subsurface-intensified anticyclonic eddy. During this time, background shear and strain appeared to influence high-frequency motions such as near-inertial waves and internal tides, leading to increased mixing. Near the Sri Lanka Dome, enhanced dissipation occurred at the margins of the cyclonic feature. Turbulent mixing was enhanced with the passage of Rossby waves and eddies. During these events, values of χT exceeding 10−4 °C2 s−1 were recorded concurrently with ε values exceeding 10−5 W kg −1. Inferred diffusivity peaked well above background values of 10−6 m2 s−1, leading to an annually-averaged diffusivity near 10−4 m2 s−1. Turbulence appeared low throughout much of the deployment period. Most of the mixing occurred in spurts during isolated events.

Therapy and prevention for mental health: What if mental diseases are mostly not brain disorders?

2019 ◽  
Vol 42 ◽  
Author(s):  
John P. A. Ioannidis
Keyword(s):  
Mental Health ◽  
Mental Disease ◽  
Brain Disorders ◽  
Social Stressors ◽  
Labor Education ◽  
Mental Diseases ◽  
Long Term Follow Up ◽  
Political Decisions

AbstractNeurobiology-based interventions for mental diseases and searches for useful biomarkers of treatment response have largely failed. Clinical trials should assess interventions related to environmental and social stressors, with long-term follow-up; social rather than biological endpoints; personalized outcomes; and suitable cluster, adaptive, and n-of-1 designs. Labor, education, financial, and other social/political decisions should be evaluated for their impacts on mental disease.

Conceptual short-term memory (CSTM) supports core claims of Christiansen and Chater

2016 ◽  
Vol 39 ◽  
Author(s):  
Mary C. Potter
Keyword(s):  
Working Memory ◽  
Rapid Serial Visual Presentation ◽  
Language Comprehension ◽  
Short Term Memory ◽  
Visual Presentation ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Use Of Knowledge

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.

Brief summary of Kleť photographic search programme for minor planets

1999 ◽  
Vol 173 ◽  
pp. 189-192
Author(s):  
J. Tichá ◽  
M. Tichý ◽  
Z. Moravec
Keyword(s):  
Ccd Camera ◽  
Minor Planet ◽  
Minor Planets ◽  
Main Belt

AbstractA long-term photographic search programme for minor planets was begun at the Kleť Observatory at the end of seventies using a 0.63-m Maksutov telescope, but with insufficient respect for long-arc follow-up astrometry. More than two thousand provisional designations were given to new Kleť discoveries. Since 1993 targeted follow-up astrometry of Kleť candidates has been performed with a 0.57-m reflector equipped with a CCD camera, and reliable orbits for many previous Kleť discoveries have been determined. The photographic programme results in more than 350 numbered minor planets credited to Kleť, one of the world's most prolific discovery sites. Nearly 50 per cent of them were numbered as a consequence of CCD follow-up observations since 1994.This brief summary describes the results of this Kleť photographic minor planet survey between 1977 and 1996. The majority of the Kleť photographic discoveries are main belt asteroids, but two Amor type asteroids and one Trojan have been found.

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

Long-term Cyclic Variations of Prominences, Green and Red Coronae over Solar Cycles

2000 ◽  
Vol 179 ◽  
pp. 201-204
Author(s):  
Vojtech Rušin ◽  
Milan Minarovjech ◽  
Milan Rybanský
Keyword(s):  
Emission Lines ◽  
High Latitudes ◽  
Green Line ◽  
Solar Cycles ◽  
The South ◽  
Coronal Emission ◽  
Local Maxima ◽  
The North ◽  
Cyclic Variations

AbstractLong-term cyclic variations in the distribution of prominences and intensities of green (530.3 nm) and red (637.4 nm) coronal emission lines over solar cycles 18–23 are presented. Polar prominence branches will reach the poles at different epochs in cycle 23: the north branch at the beginning in 2002 and the south branch a year later (2003), respectively. The local maxima of intensities in the green line show both poleward- and equatorward-migrating branches. The poleward branches will reach the poles around cycle maxima like prominences, while the equatorward branches show a duration of 18 years and will end in cycle minima (2007). The red corona shows mostly equatorward branches. The possibility that these branches begin to develop at high latitudes in the preceding cycles cannot be excluded.

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