scholarly journals Solar cycle variations in the electron heat flux: Ulysses observations

2001 ◽  
Vol 28 (11) ◽  
pp. 2169-2172 ◽  
Author(s):  
Earl E. Scime ◽  
J. E. Littleton ◽  
S. Peter Gary ◽  
Ruth Skoug ◽  
Naiguo Lin
Keyword(s):  
Heat Flux ◽  
Solar Cycle ◽  
Electron Heat

The role of electron heat flux in guide-field magnetic reconnection

2004 ◽  
Vol 11 (12) ◽  
pp. 5387-5397 ◽  
Author(s):  
Michael Hesse ◽  
Masha Kuznetsova ◽  
Joachim Birn
Keyword(s):  
Heat Flux ◽  
Magnetic Reconnection ◽  
Guide Field ◽  
Electron Heat

scholarly journals The electron heat flux in the polar solar wind: Ulysses observations

1999 ◽  
Vol 26 (14) ◽  
pp. 2129-2132 ◽  
Author(s):  
Earl E. Scime ◽  
Allen E. Badeau ◽  
J. E. Littleton
Keyword(s):  
Heat Flux ◽  
Solar Wind ◽  
Electron Heat

scholarly journals Total ozone trends and variability during 1979–2012 from merged datasets of various satellites

2013 ◽  
Vol 13 (11) ◽  
pp. 30407-30452 ◽  
Author(s):  
W. Chehade ◽  
J. P. Burrows ◽  
M. Weber
Keyword(s):  
Heat Flux ◽  
Solar Cycle ◽  
Trend Analysis ◽  
Total Ozone ◽  
Montreal Protocol ◽  
The Other ◽  
The Arctic ◽  
Eddy Heat Flux ◽  
Other Hand

Abstract. The study presents a~long term statistical trend analysis of total ozone datasets obtained from various satellites. A multi-variate linear regression was applied to annual mean zonal mean data using various natural and anthropogenic explanatory variables that represent dynamical and chemical processes which modify global ozone distributions in a changing climate. The study investigated the magnitude and zonal distribution of the different atmospheric chemical and dynamical factors to long-term total ozone changes. The regression model included the equivalent effective stratospheric chlorine (EESC), the 11 yr solar cycle, the Quasi-Biennial Oscillation (QBO), stratospheric aerosol loading describing the effects from major volcanic eruptions, the El Niño/Southern Oscillation (ENSO), the Arctic and Antarctic Oscillation (AO/AAO), and accumulated eddy heat flux (EHF), the latter representing changes due to the Brewer–Dobson circulation. The total ozone column dataset used here comprises the SBUV/TOMS/OMI merged data (1979–2012) MOD V8.0, the SBUV/SBUV-2 merged V8.6 and the merged GOME/SCIAMACHY/GOME-2 (GSG) WFDOAS merged data (1995–2012). The trend analysis was performed for twenty six 5° wide latitude bands from 65° S to 65° N, the analysis explained most of the ozone variability. The results show that QBO dominates the ozone variability in the tropics (±7 DU) while at higher latitudes, the dynamical indices, AO/AAO and eddy heat flux, have substantial influence on total ozone variations by up to ±10 DU. Volcanic aerosols are only prominent during the eruption periods and these together with the ENSO signal are more evident in the Northern Hemisphere. The signature of the solar cycle is evident over all latitudes and contributes about 10 DU from solar maximum to solar minimum. EESC is found to be a main contributor to the long-term ozone decline and the trend changes after the end of 1990s. A positive significant trend in total ozone columns is found after 1997 (between 1 and 8.2 DU decade−1) which points at the slowing of ozone decline and the onset of ozone recovery. The EESC based trends are compared with the trends obtained from the statistical piecewise linear trend (PWLT or hockey stick) model with a turnaround in 1997 to examine the differences between both approaches. Similar and significant pre-turnaround trends are observed. On the other hand, our results do indicate that the positive PWLT turnaround trends are larger than indicated by the EESC trends, however, they agree within 2-sigma, thus demonstrating the success of the Montreal Protocol phasing out of the ozone depleting substances (ODS). A sensitivity study is carried out by comparing the regression results, using SBUV MOD 8.0 merged time series (1979–2012) and a merged dataset combining TOMS/SBUV (1979–June 1995) and GOME/SCIAMACHY/GOME-2 ("GSG") WFDOAS (Weighting Function DOAS) (July 1995–2012) as well as SBUV/SBUV-2 MOD 8.6 (1979–2012) in the regression analysis in order to investigate the uncertainty in the long-term trends due to different ozone datasets and data versions. Replacing the late SBUV merged data record with GSG data (unscaled and adjusted) leads to very similar results demonstrating the high consistency between satellite datasets. However, the comparison of the new SBUV merged Mod V8.6 with the V8.0 data showed somewhat smaller sensitivities with regard to several proxies, however, the EESC and PWLT trends are very similar. On the other hand, the new MOD 8.6 data in the PWLT model revealed a~reduced ODS related upward trend after 1997.

Regulation of the solar wind electron heat flux from 1 to 5 AU: Ulysses observations

1994 ◽  
Vol 99 (A12) ◽  
pp. 23401 ◽  
Author(s):  
Earl E. Scime ◽  
Samuel J. Bame ◽  
William C. Feldman ◽  
S. Peter Gary ◽  
John L. Phillips ◽  
...  
Keyword(s):  
Heat Flux ◽  
Solar Wind ◽  
Electron Heat ◽  
Solar Wind Electron

A new MHD model for Io's and Europa's plasma interaction

2020 ◽  
Author(s):  
Aljona Blöcker ◽  
Lorenz Roth ◽  
Nickolay Ivchenko ◽  
Emmanuel Chané ◽  
Ronny Keppens
Keyword(s):  
Heat Flux ◽  
Electron Temperature ◽  
Inelastic Collisions ◽  
Magnetized Plasma ◽  
Plasma Interaction ◽  
Complex Plasma ◽  
Electron Heat ◽  
Self Consistent ◽  
Physical Effects ◽  
Auroral Emissions

<p>Io and Europa are embedded in Jupiter’s magnetosphere and the moons’ surfaces and atmospheres interact with the surrounding moving magnetized plasma forming a complex plasma interaction. The interaction scenarios for both moons are characterized by inhomogeneities in the atmospheres from local outgassing. These inhomogeneities affect the electromagnetic environment but can also lead to localized features in the moons' auroral emissions. The moons’ aurora in turn is sensitive to the energy or temperature of the exciting electrons in the plasma. To simulate the interaction scenarios including atmospheric inhomogeneities and aurora generation, we expand the magnetohydrodynamic code MPI-AMRVAC by implementing a self-consistent description of the electron temperature and the electron density where the cooling by inelastic collisions between the magnetospheric electrons and the atmosphere, and the electron heat flux from the magnetospheric plasma to the moons’ ionosphere are included. Furthermore, the numerical schemes of MPI-AMRVAC are able to handle discontinuities that arise from the atmospheric inhomogeneities. Here, we demonstrate the implementation of the physical effects and first modeling results of Io’s and Europa’s plasma interaction with the advanced MHD code.</p>

Core-edge 2D fluid modeling of full tokamak discharge with varying magnetic equilibrium: from WEST start-up to ramp-down

2022 ◽  
Author(s):  
Manuel Scotto d'Abusco ◽  
Giorgio Giorgiani ◽  
Jean-Francois Artaud ◽  
Hugo Bufferand ◽  
Guido Ciraolo ◽  
...  
Keyword(s):  
Heat Flux ◽  
Fluid Transport ◽  
Time Integration ◽  
Electron Heat ◽  
Start Up ◽  
Fusion Operation ◽  
Discharge Simulation ◽  
Plasma Core ◽  
First Time ◽  
Magnetic Equilibrium

Abstract In the present work we investigate for the first time the 2D fluid transport of the plasma in WEST during an entire discharge from the start-up to the ramp-down (shot #54487). The evolution of density profile, electron and ion temperatures together with the experimental magnetic equilibrium, total current and gas-puff rate is investigated. Comparisons with the interferometry diagnostic show a remarkable overall qualitative agreement during the discharge that can be quantitative at some locations in the plasma core. If at the onset of the X-points during the ramp-up the electron heat flux is dominant at the target, present results show that the ion heat flux becomes dominant during the stationary phase of the discharge. Using a simple model for erosion, present results assess the tungsten sputtering due to deuterium ions during the start-up and ramp-up phases of the discharge and confirms the need to consider full discharge simulation to accurately treat the W source of contamination. This work also demonstrates the interest of developing magnetic equilibrium free solver including efficient time integration to step toward predictive capabilities in the future for fusion operation.

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