Now showing items 1-20 of 25

    • The 04 – 10 September 2017 Sun–Earth Connection Events: Solar Flares, Coronal Mass Ejections/Magnetic Clouds, and Geomagnetic Storms 

      Wu, Chin-Chun; Liou, Kan; Lepping, Ronald P.; Hutting, Lynn (Springer Netherlands, 2019-08-23)
      In early September 2017, a series of solar flares and coronal mass ejections (CMEs) erupted from the Sun. The Cor2a coronagraph, a unit of the Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI), onboard ...
    • An analysis of the Trouvelot’s Auroral Drawing on 1/2 March 1872: Plausible Evidence for Recurrent Geomagnetic Storms 

      Bhaskar, Ankush; Hayakawa, Hisashi; Oliveira, Denny M.; Blake, Sean; Silverman, Sam M.; Ebihara, Yusuke (AGU Pubication, 2020-06-22)
      This work examines Trouvelot’s observations and drawing of an auroral display during the night of 1 March 1872. It is known that the auroral oval moves equatorward to mid‐ and even low‐latitudes during large geomagnetic ...
    • Assessment of observational evidence for direct convective hydration of the lower stratosphere 

      Jensen, E. J.; Pan, Laura L.; Honomichl, Shawn; Diskin, Glenn S.; Krämer, Martina; Spelten, Nicole; Günther, Gebhard; Hurst, Dale F.; Fujiwara, Masatomo; Vömel, Holger; Selkirk, Henry B.; Suzuki, Junko; Schwartz, Michael J.; Smith, Jessica B. (AGU Pubication, 2020-06-23)
      In situ and remote‐sensing observations of water vapor are analyzed to assess the evidence for direct convective hydration of the lower stratosphere. We have examined several hundred balloon‐borne and airborne in situ ...
    • Developing the Physical Understanding of Intermediate Polars: An X-Ray Study of TV Col and V2731 Oph 

      Oliveira, R. Lopes de; Mukai, K. (IOP Publishing, 2019-08-02)
      The X-rays in intermediate polars (IPs) originate in a compact region near the surface of a magnetic white dwarf (WD) and interact with the complex environment surrounding the emission region. Here we report a case study ...
    • Electron vorticity indicative of the electron diffusion region of magnetic reconnection 

      Hwang, K.‐J.; Choi, E.; Dokgo, K.; Burch, J. L.; Sibeck, D. G.; Giles, B. L.; Goldstein, M. L.; Paterson, W. R.; Pollock, C. J.; Shi, Q. Q.; Fu, H.; Hasegawa, H.; Gershman, D. J.; Khotyaintsev, Y.; Torbert, R. B.; Ergun, R. E.; Dorelli, J. C.; Avanov, L.; Russell, C. T.; Strangeway, R. J. (American Geophysical Union, 2019-06-27)
      Abstract While vorticity defined as the curl of the velocity has been broadly used in fluid and plasma physics, this quantity has been underutilized in space physics due to low time resolution observations. We report ...
    • EMIC waves converted from equatorial noise due to M/Q = 2 ions in the plasmasphere: Observations from Van Allen Probes and Arase 

      Miyoshi, Y.; Matsuda, S.; Kurita, S.; Nomura, K.; Keika, K.; Shoji, M.; Kitamura, N.; Kasahara, Y.; Matsuoka, A.; Shinohara, I.; Shiokawa, K.; Machida, S.; Santolik, O.; Boardsen, S. A.; Horne, R. B.; Wygant, J. F. (American Geophysical Union, 2019-06-07)
      Abstract Equatorial noise (EN) emissions are observed inside and outside the plasmapause. EN emissions are referred to as magnetosonic mode waves. Using data from Van Allen Probes and Arase, we found conversion from EN ...
    • Geomagnetically induced currents caused by interplanetary shocks with different impact angles and speeds 

      Oliveira, D. M.; Arel, D.; Raeder, J.; Zesta, E.; Ngwira, C. M.; Carter, B. A.; Yizengaw, E.; Halford, A. J.; Tsurutani, B. T.; Gjerloev, J. W. (AGU, 2018-05-15)
      The occurrence of geomagnetically induced currents (GICs) poses serious threats to modern technological infrastructure. Large GICs result from sharp variations of the geomagnetic field (dB/dt) caused by changes of large‐scale ...
    • Highly structured slow solar wind emerging from an equatorial coronal hole 

      Bale, S. D.; Badman, S. T.; Bonnell, J. W.; Bowen, T. A.; Burgess, D.; Case, A. W.; Cattell, C. A.; Chandran, B. D. G.; Chaston, C. C.; Chen, C. H. K.; Drake, J. F.; Dudok de Wit, T.; Eastwood, J. P.; Ergun, R. E.; Farrell, W. M.; Fong, C.; Goetz, K.; Goldstein, M.; Goodrich, K. A.; Harvey, P. R.; Horbury, T. S.; Howes, G. G.; Kasper, J. C.; Kellogg, P. J.; Klimchuk, J. A.; Korreck, K. E.; Krasnoselskikh, V. V.; Krucker, S.; Laker, R.; Larson, D. E.; MacDowall, R. J.; Maksimovic, M.; Malaspina, D. M.; Martinez-Oliveros, J.; McComas, D. J.; Meyer-Vernet, N.; Moncuquet, M.; Mozer, F. S.; Phan, T. D.; Pulupa, M.; Raouafi, N. E.; Salem, C.; Stansby, D.; Stevens, M.; Szabo, A.; Velli, M.; Woolley, T.; Wygant, J. R. (Nature, 2019-12-04)
      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 Alfvénic rarefied stream of plasma originating ...
    • How do interplanetary shock impact angles control the size of the geoeffective magnetosphere 

      Rudd, J.T.; Oliveira, D.M.; Bhaskar, A.; Halford, A.J. (Elsevier Ltd, 2018-09-09)
      In this paper, we investigate temporal and spatial magnetosphere response to the impact of interplanetary (IP) shocks with different inclinations and speeds on the Earth’s magnetosphere. A data set with more than 500 IP ...
    • J-PLUS: Two-dimensional analysis of the stellar population in NGC 5473 and NGC 5485 

      Roman, I. San; Sanchez-Blazquez, P.; Cenarro, A. J.; Diaz-Garcia, L. A.; Lopez-Sanjuan, C.; Varela, J.; Vilella-Rojo, G.; Akras, S.; Bonoli, S.; Chies Santos, A. L.; Coelho, P.; Cortesi, A.; Ederoclite, A.; Jiménez-Teja, Y.; Logroño-García, R.; Oliveira, R. Lopes de; Nogueira-Cavalcante, J. P.; Orsi, A.; Ramió, H. Vázquez; Viironen, K.; Cristóbal-Hornillos, D.; Dupke, R.; Marín-Franch, A.; Oliveira, C. Mendes de; Moles, M.; Sodré, L. (ESO, 2019-01-12)
      Context. The spatial variations of stellar population properties within a galaxy are intimately related to their formation process. Therefore, spatially resolved studies of galaxies are essential to uncover their formation ...
    • A Magnetic Pressure Front Upstream of the Heliopause and the Heliosheath Magnetic Fields and Plasma, Observed during 2017 

      Burlaga, L. F.; Ness, N. F.; Berdichevsky, D. B.; Jian, L. K.; Park, J.; Mostafavi, P.; Richardson, J. D. (IOP Publishing, 2019-05-21)
      Voyager 1 (V1), moving in the interstellar magnetic field, observed an increase in the daily averages of B beginning on day ≈346, 2016, rising to a local maximum on day ≈382, and declining nearly monotonically for the ...
    • A Merged Search-Coil and Fluxgate Magnetometer Data Product for Parker Solar Probe FIELDS 

      Bowen, Trevor A.; Bale, Stuart D.; Bonnell, John W.; Wit, Thierry Dudok de; Goetz, Keith; Goodrich, Katherine; Gruesbeck, Jacob; Harvey, Peter R.; Jannet, Guillaume; Koval, Andriy; MacDowall, Robert J.; Malaspina, David M.; Pulupa, Marc; Revillet, Claire; Sheppard, David; Szabo, Adam (2020-01-19)
      NASA’s Parker Solar Probe (PSP) mission is currently investigating the local plasma environment of the inner-heliosphere (<0.25R ) using both in-situ and remote sensing instrumentation. Connecting signatures of microphysical ...
    • Model Fitting of Wind Magnetic Clouds for the Period 2004 – 2006 

      Lepping, R. P.; Wu, C.-C.; Berdichevsky, D. B.; Szabo, A. (Springer Nature, 2020-06-22)
      We give the results of parameter fitting of the magnetic clouds (MCs) observed by the Wind spacecraft for the three year period – 2004 to the end of 2006 (the “Present period”) using the force-free MC model of Lepping, ...
    • Orbital Maintenance for the Wide Field Infrared Survey Telescope: The Effects of Solar Radiation Pressure and Navigation Accuracies on Station Keeping 

      Ariadna, Farres; Cassandra, Webster; Jennifer, Donaldson; Dave, Folta (2018-08-19)
      The Wide-Field Infrared Survey Telescope (WFIRST), a NASA observatory designed to investigate dark energy and astrophysics, is planned for a launch in 2025 to orbit the Sun-Earth L2 (SEL2) Libration Point. Due to the ...
    • A possible case of sporadic aurora observed at Rio de Janeiro 

      Oliveira, Denny M.; Hayakawa, Hisashi; Bhaskar, Ankush; Zesta, Eftyhia; Vichare, Geeta (Springer Open, 2020-06-06)
      Being footprints of major magnetic storms and hence major solar eruptions, mid- to low-latitude aurorae have been one of the pathways to understand solar–terrestrial environments. However, it has been reported that aurorae ...
    • Solar Radiation Pressure Effects on the Orbital Motion at SEL2 for the James Webb Space Telescope 

      Farres, Ariadna; Petersen, Jeremy (NASA Technical Reports Server, 2019-08-11)
      Due to James Webb Space Telescope’s large sunshield, which will always be facing the Sun to protect the observatory’s instruments, Solar Radiation Pressure (SRP) has an important effect on its orbital motion around SEL2. ...
    • Statistical survey of the terrestrial bow shock observed by the Cluster spacecraft 

      Kruparova, O.; Krupar, V.; Šafránková, J.; Němeček, Z.; Maksimovic, M.; Santolik, O.; Soucek, J.; Němec, F.; Merka, J. (American Geophysical Union, 2019-02-13)
      The terrestrial bow shock provides us with a unique opportunity to extensively investigate properties of collisionless shocks using in situ measurements under a wide range of upstream conditions. Here we report a statistical ...
    • Temporal and Spatial Evolutions of a Large Sunspot Groupand Great Auroral Storms around the Carrington Event in 1859 

      Hayakawa, Hisashi; Ebihara, Yusuke; Willis, David M.; Toriumi, Shin; Iju, Tomoya; Hattori, Kentaro; Wild, Matthew N.; Oliveira, Denny M.; Ermolli, Ilaria; Ribeiro, José R.; Correia, Ana P.; Ribeiro, Ana I.; Knipp, Delores J. (American Geophysical Union, 2019-08-29)
      The Carrington event is considered to be one of the most extreme space weather events in observational history within a series of magnetic storms caused by extreme interplanetary coronal mass ejections (ICMEs) from a large ...
    • Thermospheric heating and cooling times during geomagnetic storms, including extreme events 

      Zesta, Eftyhia; Oliveira, Denny M. (American Geophysical Union, 2019-11-29)
      We present the first quantitative calculations of thermospheric heating and cooling times for geomagnetic storms of different intensity, including extreme events. We utilize the neutral mass density database of the CHAllenging ...
    • Understanding the Role of α Particles in Oblique Heliospheric Shock Oscillations 

      Ofman, L.; Koval, A.; III, L. B. Wilson; Szabo, A. (American Geophysical Union, 2019-04-08)
      Recent observations by DSCOVR provide high temporal resolution (50 samples per second) magnetic vector field data that allows investigating the details of oblique heliospheric shock oscillations. It was found that some of ...