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Found 20 entries in the Bibliography.
Showing entries from 1 through 20
| 2023 |
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Magnetic Reconnection as the Driver of the Solar Wind We present EUV solar observations showing evidence for omnipresent jetting activity driven by small-scale magnetic reconnection at the base of the solar corona. We argue that the physical mechanism that heats and drives the solar wind at its source is ubiquitous magnetic reconnection in the form of small-scale jetting activity (a.k.a. jetlets). This jetting activity, like the solar wind and the heating of the coronal plasma, is ubiquitous regardless of the solar cycle phase. Each event arises from small-scale reconnection of ... Raouafi, Nour; Stenborg, G.; Seaton, D.~B.; Wang, H.; Wang, J.; DeForest, C.~E.; Bale, S.~D.; Drake, J.~F.; Uritsky, V.~M.; Karpen, J.~T.; DeVore, C.~R.; Sterling, A.~C.; Horbury, T.~S.; Harra, L.~K.; Bourouaine, S.; Kasper, J.~C.; Kumar, P.; Phan, T.~D.; Velli, M.; Published by: \apj Published on: mar YEAR: 2023 DOI: 10.3847/1538-4357/acaf6c Parker Data Used; Solar corona; Solar wind; magnetic fields; Solar magnetic reconnection; 1483; 1534; 994; 1504; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
| 2022 |
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We report observations of reconnection exhausts in the Heliospheric Current Sheet (HCS) during Parker Solar Probe Encounters 08 and 07, at 16 R$_s$ and 20 R$_s$, respectively. Heliospheric current sheet (HCS) reconnection accelerated protons to almost twice the solar wind speed and increased the proton core energy by a factor of \ensuremath\sim3, due to the Alfv\ en speed being comparable to the solar wind flow speed at these near-Sun distances. Furthermore, protons were energized to super-thermal energies. During E08, energ ... Phan, T.~D.; Verniero, J.~L.; Larson, D.; Lavraud, B.; Drake, J.~F.; Oieroset, M.; Eastwood, J.~P.; Bale, S.~D.; Livi, R.; Halekas, J.~S.; Whittlesey, P.~L.; Rahmati, A.; Stansby, D.; Pulupa, M.; MacDowall, R.~J.; Szabo, P.~A.; Koval, A.; Desai, M.; Fuselier, S.~A.; Velli, M.; Hesse, M.; Pyakurel, P.~S.; Maheshwari, K.; Kasper, J.~C.; Stevens, J.~M.; Case, A.~W.; Raouafi, N.~E.; Published by: \grl Published on: may YEAR: 2022 DOI: 10.1029/2021GL096986 Parker Data Used; magnetic reconnection; Particle acceleration; Solar wind; parker solar probe; heliospheric current sheet |
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We present observations of \ensuremath\gtrsim10-100 keV nucleon$^-1$ suprathermal (ST) H, He, O, and Fe ions associated with crossings of the heliospheric current sheet (HCS) at radial distances of <0.1 au from the Sun. Our key findings are as follows: (1) very few heavy ions are detected during the first full crossing, the heavy-ion intensities are reduced during the second partial crossing and peak just after the second crossing; (2) ion arrival times exhibit no velocity dispersion; (3) He pitch-angle distributions track t ... Desai, M.~I.; Mitchell, D.~G.; McComas, D.~J.; Drake, J.~F.; Phan, T.; Szalay, J.~R.; Roelof, E.~C.; Giacalone, J.; Hill, M.~E.; Christian, E.~R.; Schwadron, N.~A.; McNutt, R.~L.; Wiedenbeck, M.~E.; Joyce, C.; Cohen, C.~M.~S.; Davis, A.~J.; Krimigis, S.~M.; Leske, R.~A.; Matthaeus, W.~H.; Malandraki, O.; Mewaldt, R.~A.; Labrador, A.; Stone, E.~C.; Bale, S.~D.; Verniero, J.; Rahmati, A.; Whittlesey, P.; Livi, R.; Larson, D.; Pulupa, M.; MacDowall, R.~J.; Niehof, J.~T.; Kasper, J.~C.; Horbury, T.~S.; Published by: \apj Published on: mar YEAR: 2022 DOI: 10.3847/1538-4357/ac4961 Parker Data Used; The Sun; Solar magnetic reconnection; Interplanetary particle acceleration; interplanetary magnetic fields; Heliosphere; 1693; 1504; 826; 824; 711; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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Slow Shock Formation Upstream of Reconnecting Current Sheets The formation, development, and impact of slow shocks in the upstream regions of reconnecting current layers are explored. Slow shocks have been documented in the upstream regions of magnetohydrodynamic (MHD) simulations of magnetic reconnection as well as in similar simulations with the kglobal kinetic macroscale simulation model. They are therefore a candidate mechanism for preheating the plasma that is injected into the current layers that facilitate magnetic energy release in solar flares. Of particular interest is their ... Arnold, H.; Drake, J.~F.; Swisdak, M.; Guo, F.; Dahlin, J.~T.; Zhang, Q.; Published by: \apj Published on: feb YEAR: 2022 DOI: 10.3847/1538-4357/ac423b Parker Data Used; 1504; 2086; 2089; 1544; Physics - Plasma Physics; Physics - Space Physics |
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Flux Rope Merging and the Structure of Switchbacks in the Solar Wind A major discovery of Parker Solar Probe (PSP) was the presence of large numbers of localized increases in the radial solar wind speed and associated sharp deflections of the magnetic field- switchbacks (SBs). A possible generation mechanism of SBs is through magnetic reconnection between open and closed magnetic flux near the solar surface, termed interchange reconnection, that leads to the ejection of flux ropes (FRs) into the solar wind. Observations also suggest that SBs undergo merging, consistent with an FR picture of t ... Agapitov, O.~V.; Drake, J.~F.; Swisdak, M.; Bale, S.~D.; Horbury, T.~S.; Kasper, J.~C.; MacDowall, R.~J.; Mozer, F.~S.; Phan, T.~D.; Pulupa, M.; Raouafi, N.~E.; Velli, M.; Published by: \apj Published on: feb YEAR: 2022 DOI: 10.3847/1538-4357/ac4016 Parker Data Used; 711; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
| 2021 |
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On the Origin of Switchbacks Observed in the Solar Wind The origin of switchbacks in the solar wind is discussed in two classes of theory that differ in the location of the source being either near the transition region near the Sun or in the solar wind itself. The two classes of theory differ in their predictions of the switchback rate (the number of switchbacks observed per hour) as a function of distance from the Sun. To distinguish between these theories, one-hour averages of Parker Solar Probe data were averaged over five orbits to find the following: (1) The hourly averaged ... Mozer, F.~S.; Bale, S.~D.; Bonnell, J.~W.; Drake, J.~F.; Hanson, E.~L.~M.; Mozer, M.~C.; Published by: \apj Published on: sep YEAR: 2021 DOI: 10.3847/1538-4357/ac110d Solar wind; Solar corona; Space plasmas; 1534; 1483; 1544; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics; Parker Data Used |
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One of the striking observations from the Parker Solar Probe (PSP) spacecraft is the prevalence in the inner heliosphere of large amplitude, Alfv\ enic magnetic field reversals termed switchbacks. These $\delta B_R/B\sim \mathcal O (1$ ) fluctuations occur over a range of timescales and in patches separated by intervals of quiet, radial magnetic field. We use measurements from PSP to demonstrate that patches of switchbacks are localized within the extensions of plasma structures originating at the base of the corona. These ... Bale, S.~D.; Horbury, T.~S.; Velli, M.; Desai, M.~I.; Halekas, J.~S.; McManus, M.~D.; Panasenco, O.; Badman, S.~T.; Bowen, T.~A.; Chandran, B.~D.~G.; Drake, J.~F.; Kasper, J.~C.; Laker, R.; Mallet, A.; Matteini, L.; Phan, T.~D.; Raouafi, N.~E.; Squire, J.; Woodham, L.~D.; Woolley, T.; Published by: \apj Published on: dec YEAR: 2021 DOI: 10.3847/1538-4357/ac2d8c Parker Data Used; 1534; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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Prevalence of magnetic reconnection in the near-Sun heliospheric current sheet During three of its first five orbits around the Sun, Parker Solar Probe (PSP) crossed the large-scale heliospheric current sheet (HCS) multiple times and provided unprecedented detailed plasma and field observations of the near-Sun HCS. We report the common detections by PSP of reconnection exhaust signatures in the HCS at heliocentric distances of 29.5-107 solar radii during encounters 1, 4, and 5. Both sunward and antisunward-directed reconnection exhausts were observed. In the sunward reconnection exhausts, PSP detected ... Phan, T.; Lavraud, B.; Halekas, J.; Øieroset, M.; Drake, J.; Eastwood, J.; Shay, M.; Pyakurel, P.; Bale, S.; Larson, D.; Livi, R.; Whittlesey, P.; Rahmati, A.; Pulupa, M.; McManus, M.; Verniero, J.; Bonnell, J.; Schwadron, N.; Stevens, M.; Case, A.; Kasper, J.; MacDowall, R.; Szabo, P.; Koval, A.; Korreck, K.; de Wit, Dudok; Malaspina, D.; Goetz, K.; Harvey, P.; Published by: Astronomy and Astrophysics Published on: 06/2021 YEAR: 2021 DOI: 10.1051/0004-6361/202039863 Sun: magnetic fields; Sun: heliosphere; Solar wind; Sun: flares; Parker Data Used |
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Electron Acceleration during Macroscale Magnetic Reconnection The first self-consistent simulations of electron acceleration during magnetic reconnection in a macroscale system are presented. Consistent with solar flare observations, the spectra of energetic electrons take the form of power laws that extend more than two decades in energy. The drive mechanism for these nonthermal electrons is Fermi reflection in growing and merging magnetic flux ropes. A strong guide field suppresses the production of nonthermal electrons by weakening the Fermi drive mechanism. For a weak guide field t ... Arnold, H.; Drake, J.; Swisdak, M.; Guo, F.; Dahlin, J.; Chen, B.; Fleishman, G.; Glesener, L.; Kontar, E.; Phan, T.; Shen, C.; Published by: Physical Review Letters Published on: 04/2021 YEAR: 2021 DOI: 10.1103/PhysRevLett.126.135101 Parker Data Used; Physics - Plasma Physics; Astrophysics - High Energy Astrophysical Phenomena |
| 2020 |
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Switchbacks as signatures of magnetic flux ropes generated by interchange reconnection in the corona The structure of magnetic flux ropes injected into the solar wind during reconnection in the coronal atmosphere is explored with particle-in-cell simulations and compared with in situ measurements of magnetic switchbacks from the Parker Solar Probe. We suggest that multi-x-line reconnection between open and closed flux in the corona injects flux ropes into the solar wind and that these flux ropes convect outward over long distances before eroding due to reconnection. Simulations that explore the magnetic structure of flu ... Drake, J.; Agapitov, A.; Swisdak, M.; Badman, S.; Bale, S.; Horbury, T.; Kasper, Justin; MacDowall, R.; Mozer, F.; Phan, T.; Pulupa, M.; Szabo, A.; Velli, M.; Published by: Astronomy and Astrophysics Published on: jun YEAR: 2020 DOI: "10.1051/0004-6361/202039432" |
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Observations by the Parker Solar Probe mission of the solar wind at \~35.7 solar radii reveal the existence of whistler wave packets with frequencies below 0.1 fce (20-80 Hz in the spacecraft frame). These waves often coincide with local minima of the magnetic field magnitude or with sudden deflections of the magnetic field that are called switchbacks. Their sunward propagation leads to a significant Doppler frequency downshift from 200-300 to 20-80 Hz (from 0.2 to 0.5 fce). The polarization of these ... Agapitov, O.; de Wit, Dudok; Mozer, F.; Bonnell, J.; Drake, J.; Malaspina, D.; Krasnoselskikh, V.; Bale, S.; Whittlesey, P.; Case, A.; Chaston, C.; Froment, C.; Goetz, K.; Goodrich, K.; Harvey, P.; Kasper, J.; Korreck, K.; Larson, D.; Livi, R.; MacDowall, R.; Pulupa, M.; Revillet, C.; Stevens, M.; Wygant, J.; Published by: The Astrophysical Journal Published on: 03/2020 YEAR: 2020 DOI: 10.3847/2041-8213/ab799c Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Space Physics; Solar Probe Plus |
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Parker Solar Probe In Situ Observations of Magnetic Reconnection Exhausts during Encounter 1 Magnetic reconnection in current sheets converts magnetic energy into particle energy. The process may play an important role in the acceleration and heating of the solar wind close to the Sun. Observations from Parker Solar Probe (PSP) provide a new opportunity to study this problem, as it measures the solar wind at unprecedented close distances to the Sun. During the first orbit, PSP encountered a large number of current sheets in the solar wind through perihelion at 35.7 solar radii. We performed a comprehensive survey ... Phan, T.; Bale, S.; Eastwood, J.; Lavraud, B.; Drake, J.; Oieroset, M.; Shay, M.; Pulupa, M.; Stevens, M.; MacDowall, R.; Case, A.; Larson, D.; Kasper, J.; Whittlesey, P.; Szabo, A.; Korreck, K.; Bonnell, J.; de Wit, Dudok; Goetz, K.; Harvey, P.; Horbury, T.; Livi, R.; Malaspina, D.; Paulson, K.; Raouafi, N.; Velli, M.; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab55ee Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Solar Probe Plus |
| 2019 |
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Scattering of Energetic Electrons by Heat-flux-driven Whistlers in Flares Roberg-Clark, G.~T.; Agapitov, O.; Drake, J.~F.; Swisdak, M.; Published by: \apj Published on: 12/2019 YEAR: 2019 DOI: 10.3847/1538-4357/ab5114 Parker Data Used; solar flares; Plasma physics; 1496; 2089; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
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Highly structured slow solar wind emerging from an equatorial coronal hole During the solar minimum, when the Sun is at its least active, the solar wind is observed at high latitudes as a predominantly fast (more than 500 kilometres per second), highly Alfv\ enic rarefied stream of plasma originating from deep within coronal holes. Closer to the ecliptic plane, the solar wind is interspersed with a more variable slow wind of less than 500 kilometres per second. The precise origins of the slow wind streams are less certain; theories and observations suggest that they may originate at the tips of ... Bale, S.; Badman, S.; Bonnell, J.; Bowen, T.; Burgess, D.; Case, A.; Cattell, C.; Chandran, B.; Chaston, C.; Chen, C.; Drake, J.; de Wit, Dudok; Eastwood, J.; Ergun, R.; Farrell, W.; Fong, C.; Goetz, K.; Goldstein, M.; Goodrich, K.; Harvey, P.; Horbury, T.; Howes, G.; Kasper, J.; Kellogg, P.; Klimchuk, J.; Korreck, K.; Krasnoselskikh, V.; Krucker, S.; Laker, R.; Larson, D.; MacDowall, R.; Maksimovic, M.; Malaspina, D.; Martinez-Oliveros, J.; McComas, D.; Meyer-Vernet, N.; Moncuquet, M.; Mozer, F.; Phan, T.; Pulupa, M.; Raouafi, N.; Salem, C.; Stansby, D.; Stevens, M.; Szabo, A.; Velli, M.; Woolley, T.; Wygant, J.; Published by: Nature Published on: 12/2019 YEAR: 2019 DOI: 10.1038/s41586-019-1818-7 |
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Large-scale parallel electric fields and return currents in a global simulation model Arnold, H.; Drake, J.~F.; Swisdak, M.; Dahlin, J.; Published by: Physics of Plasmas Published on: 10/2019 YEAR: 2019 DOI: 10.1063/1.5120373 Parker Data Used; Physics - Plasma Physics; Physics - Space Physics |
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Zhang, Qile; Drake, J.~F.; Swisdak, M.; Published by: Physics of Plasmas Published on: 10/2019 YEAR: 2019 DOI: 10.1063/1.5121782 Parker Data Used; Physics - Plasma Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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Zhang, Qile; Drake, J.~F.; Swisdak, M.; Published by: Physics of Plasmas Published on: 07/2019 YEAR: 2019 DOI: 10.1063/1.5104352 Parker Data Used; Physics - Plasma Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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A computational model for exploring particle acceleration during reconnection in macroscale systems Drake, J.~F.; Arnold, H.; Swisdak, M.; Dahlin, J.~T.; Published by: Physics of Plasmas Published on: 01/2019 YEAR: 2019 DOI: 10.1063/1.5058140 Parker Data Used; Astrophysics - Solar and Stellar Astrophysics; Astrophysics - High Energy Astrophysical Phenomena; Physics - Plasma Physics |
| 2016 |
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The FIELDS Instrument Suite for Solar Probe Plus NASA\textquoterights Solar Probe Plus (SPP) mission will make the first in situ measurements of the solar corona and the birthplace of the solar wind. The FIELDS instrument suite on SPP will make direct measurements of electric and magnetic fields, the properties of in situ plasma waves, electron density and temperature profiles, and interplanetary radio emissions, amongst other things. Here, we describe the scientific objectives targeted by the SPP/FIELDS instrument, the instrument design itself, and the instrument conce ... Bale, S.; Goetz, K.; Harvey, P.; Turin, P.; Bonnell, J.; de Wit, T.; Ergun, R.; MacDowall, R.; Pulupa, M.; Andre, M.; Bolton, M.; Bougeret, J.-L.; Bowen, T.; Burgess, D.; Cattell, C.; Chandran, B.; Chaston, C.; Chen, C.; Choi, M.; Connerney, J.; Cranmer, S.; Diaz-Aguado, M.; Donakowski, W.; Drake, J.; Farrell, W.; Fergeau, P.; Fermin, J.; Fischer, J.; Fox, N.; Glaser, D.; Goldstein, M.; Gordon, D.; Hanson, E.; Harris, S.; Hayes, L.; Hinze, J.; Hollweg, J.; Horbury, T.; Howard, R.; Hoxie, V.; Jannet, G.; Karlsson, M.; Kasper, J.; Kellogg, P.; Kien, M.; Klimchuk, J.; Krasnoselskikh, V.; Krucker, S.; Lynch, J.; Maksimovic, M.; Malaspina, D.; Marker, S.; Martin, P.; Martinez-Oliveros, J.; McCauley, J.; McComas, D.; McDonald, T.; Meyer-Vernet, N.; Moncuquet, M.; Monson, S.; Mozer, F.; Murphy, S.; Odom, J.; Oliverson, R.; Olson, J.; Parker, E.; Pankow, D.; Phan, T.; Quataert, E.; Quinn, T.; Ruplin, S.; Salem, C.; Seitz, D.; Sheppard, D.; Siy, A.; Stevens, K.; Summers, D.; Szabo, A.; Timofeeva, M.; Vaivads, A.; Velli, M.; Yehle, A.; Werthimer, D.; Wygant, J.; Published by: Space Science Reviews Published on: 12/2016 YEAR: 2016 DOI: 10.1007/s11214-016-0244-5 Coronal heating; Parker Data Used; parker solar probe; Solar Probe Plus |
| 2014 |
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DYNAMICS OF DOUBLE LAYERS, ION ACCELERATION, AND HEAT FLUX SUPPRESSION DURING SOLAR FLARES Observations of flare-heated electrons in the corona typically suggest confinement of electrons. The confinement mechanism, however, remains unclear. The transport of coronal hot electrons into ambient plasma was recently investigated by particle-in-cell (PIC) simulations. Electron transport was significantly suppressed by the formation of a highly localized, nonlinear electrostatic potential in the form of a double layer (DL). In this work large-scale PIC simulations are performed to explore the dynamics of DLs in larger ... Li, T.; Drake, J.; Swisdak, M.; Published by: The Astrophysical Journal Published on: 09/2014 YEAR: 2014 DOI: 10.1088/0004-637X/793/1/7 acceleration of particles; Astrophysics - Solar and Stellar Astrophysics; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Solar Probe Plus; Solar wind; Sun: corona; Sun: flares |
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