Momentum dependent mean-fields of (anti)hyperons

Abstract Identical composite analysis of midlatitude cyclones over oceanic regions has been carried out on both output from the NCAR Community Atmosphere Model, version 3 (CAM3) and multisensor satellite data. By focusing on mean fields associated with a single phenomenon, the ability of the CAM3 to reproduce realistic midlatitude cyclones is critically appraised. A number of perturbations to the control model were tested against observations, including a candidate new microphysics package for the CAM. The new microphysics removes the temperature-dependent phase determination of the old scheme and introduces representations of microphysical processes to convert from one phase to another and from cloud to precipitation species. By subsampling composite cyclones based on systemwide mean strength (mean wind speed) and systemwide mean moisture the authors believe they are able to make meaningful like-with-like comparisons between observations and model output. All variations of the CAM tested overestimate the optical thickness of high-topped clouds in regions of precipitation. Over a system as a whole, the model can both over- and underestimate total high-topped cloud amounts. However, systemwide mean rainfall rates and composite structure appear to be in broad agreement with satellite estimates. When cyclone strength is taken into account, changes in moisture and rainfall rates from both satellite-derived observations and model output as a function of changes in sea surface temperature are in accordance with the Clausius–Clapeyron equation. The authors find that the proposed new microphysics package shows improvement to composite liquid water path fields and cloud amounts.

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From Mixing to the Large Scale Circulation: How the Inverse Cascade Is Involved in the Formation of the Subsurface Currents in the Gulf of Guinea

Fluids ◽

10.3390/fluids5030147 ◽

2020 ◽

Vol 5 (3) ◽

pp. 147 ◽

Cited By ~ 2

Author(s):

Fernand Assene ◽

Yves Morel ◽

Audrey Delpech ◽

Micael Aguedjou ◽

Julien Jouanno ◽

...

Keyword(s):

Large Scale ◽

Spatial And Temporal Variability ◽

Gulf Of Guinea ◽

Equatorial Undercurrent ◽

Zonal Jets ◽

Mean Fields ◽

The Mean ◽

North And South ◽

And Diffusion ◽

Meridional Advection

In this paper, we analyse the results from a numerical model at high resolution. We focus on the formation and maintenance of subsurface equatorial currents in the Gulf of Guinea and we base our analysis on the evolution of potential vorticity (PV). We highlight the link between submesoscale processes (involving mixing, friction and filamentation), mesoscale vortices and the mean currents in the area. In the simulation, eastward currents, the South and North Equatorial Undercurrents (SEUC and NEUC respectively) and the Guinea Undercurrent (GUC), are shown to be linked to the westward currents located equatorward. We show that east of 20° W, both westward and eastward currents are associated with the spreading of PV tongues by mesoscale vortices. The Equatorial Undercurrent (EUC) brings salty waters into the Gulf of Guinea. Mixing diffuses the salty anomaly downward. Meridional advection, mixing and friction are involved in the formation of fluid parcels with PV anomalies in the lower part and below the pycnocline, north and south of the EUC, in the Gulf of Guinea. These parcels gradually merge and vertically align, forming nonlinear anticyclonic vortices that propagate westward, spreading and horizontally mixing their PV content by stirring filamentation and diffusion, up to 20° W. When averaged over time, this creates regions of nearly homogeneous PV within zonal bands between 1.5° and 5° S or N. This mean PV field is associated with westward and eastward zonal jets flanking the EUC with the homogeneous PV tongues corresponding to the westward currents, and the strong PV gradient regions at their edges corresponding to the eastward currents. Mesoscale vortices strongly modulate the mean fields explaining the high spatial and temporal variability of the jets.

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RANDOMLY INTERACTING BOSONS, MEAN-FIELDS AND L = 0 GROUND STATES

Nuclear Structure Physics ◽

10.1142/9789812811233_0016 ◽

2001 ◽

Author(s):

R. BIJKER ◽

A. FRANK

Keyword(s):

Ground States ◽

Mean Fields

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Measurement of mean fields in the intermediate wake of a heated cylinder

Transactions of the JSME (in Japanese) ◽

10.1299/transjsme.19-00355 ◽

2020 ◽

Vol 86 (881) ◽

pp. 19-00355-19-00355 ◽

Cited By ~ 1

Author(s):

Hideaki WATANABE ◽

Hideharu MAKITA ◽

Makoto TAGO

Keyword(s):

Heated Cylinder ◽

Mean Fields

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The Effect of Hydrometeors on MSU/AMSU Temperature Observations over the Tropical Ocean

Journal of Atmospheric and Oceanic Technology ◽

10.1175/jtech-d-17-0190.1 ◽

2018 ◽

Vol 35 (5) ◽

pp. 1141-1150 ◽

Cited By ~ 1

Author(s):

Hamid A. Pahlavan ◽

Qiang Fu ◽

John M. Wallace

Keyword(s):

Regression Coefficient ◽

Temperature Fields ◽

Tropospheric Temperature ◽

Tropical Ocean ◽

Microwave Sounding Unit ◽

Mean Fields ◽

Microwave Sounding ◽

Temperature Observations ◽

The Difference ◽

Grid Points

AbstractThe temperature of Earth’s atmosphere has been monitored continuously since late 1978 by the Microwave Sounding Unit (MSU) and the Advanced Microwave Sounding Unit (AMSU) flown on polar-orbiting weather satellites. It is well known that these measurements are affected by the scattering and emission from hydrometeors, including cloud water, precipitation, and ice particles. In this study the hydrometeor effects on MSU/AMSU temperature observations are investigated by comparing satellite-observed temperature of the middle troposphere (TMT) with synthetic TMT constructed using temperature fields from ECMWF Interim [ERA-Interim (ERA-I)]. Precipitation data have been used to estimate how much of the difference between these two TMT fields is due to hydrometeor contamination effects. It is shown that there exists a robust linear proportionality between TMT deficit (i.e., the measured TMT minus the synthetic TMT) and precipitation at individual grid points in monthly mean fields. The linear correlation is even stronger in the annual mean and seasonally varying climatology and also in the spatial pattern of ENSO-related anomalies. The linear regression coefficient obtained in all of these analyses is virtually identical: −0.042 K (mm day−1)−1. The channel that senses lower-tropospheric temperature (TLT) is more sensitive to precipitation than the TMT channel: the regression coefficient is −0.059 K (mm day−1)−1. It is shown that correcting the TMT or TLT monthly anomalies by removing the hydrometeor contamination does not significantly influence estimates of tropical mean temperature trends, but it could affect the pattern of temperature trend over the tropical oceans.

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Reflections on the origin of the EMC effect

International Journal of Modern Physics E ◽

10.1142/s0218301318400013 ◽

2018 ◽

Vol 27 (12) ◽

pp. 1840001 ◽

Cited By ~ 3

Author(s):

Anthony W. Thomas

Keyword(s):

Short Range ◽

Mean Field ◽

Atomic Nuclei ◽

Lorentz Scalar ◽

Valence Structure ◽

Mean Fields ◽

European Muon Collaboration ◽

The Mean ◽

Emc Effect ◽

Short Range Correlations

In the 35 years since the European Muon Collaboration announced the astonishing result that the valence structure of a nucleus was very different from that of a free nucleon, many explanations have been suggested. The first of the two most promising explanations is based upon the different effects of the strong Lorentz scalar and vector mean fields known to exist in a nucleus on the internal structure of the nucleon-like clusters which occupy shell model states. The second links the effect to the modification of the structure of nucleons involved in short-range correlations, which are far off their mass shell. We explore some of the methods which have been proposed to give complementary information on this puzzle, especially the spin-dependent EMC effect and the isovector EMC effect, both proposed by Cloët, Bentz and Thomas. It is shown that the predictions for the spin-dependent EMC effect, in particular, differ substantially within the mean-field and short-range correlation approaches. Hence, the measurement of the spin-dependent EMC effect at Jefferson Lab should give us a deeper understanding of the origin of the EMC effect and, indeed, of the structure of atomic nuclei.

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