patras

• Mahoudian, A.; Patra, Swadesh; Kia, Fatemeh Sadeghi & Aliparast, P. (2020). First mesospheric in-situ measurement in Iran using sounding rockets and plasma impedance probe (PIP). Fīzīk-i zamīn va faz̤ā. ISSN 2538-371X. 45(4), s. 237–244. doi: 10.22059/jesphys.2019.269440.1007063. Fulltekst i vitenarkiv
• Spencer, Edmund; Vadepu, Sai Krishna; Srinivas, Pavithra; Patra, Swadesh & Horton, Wendell (2018). The dynamics of geomagnetic substorms with the WINDMI model. Earth, Planets and Space. ISSN 1343-8832. 70(1). doi: 10.1186/s40623-018-0882-9. Fulltekst i vitenarkiv Vis sammendrag

  The global dynamics of substorms are controlled by several key magnetospheric parameters. In this work we obtain quantitative measures of these parameters from a low-order nonlinear model of the nightside magnetosphere called WINDMI. The model uses solar wind and IMF measurements from the ACE spacecraft as input into a system of 8 nonlinear ordinary diferential equations. The state variables of the diferential equations represent the energy stored in the geomagnetic tail, central plasma sheet, ring current and feld-aligned currents. The output from the model is the geomagnetic westward auroral electrojet (AL) index and the Dst index. Intermediate variables of the model are the plasma sheet pressure, geotail current, cross-tail electric feld, parallel ion velocity and the pressure gradient current. The values of these variables are controlled by physical parameters of the model, consisting of spatially averaged quantities that are analogous to electric circuit elements. We tune the model to re-produce substorm events, comparing model capability against observations of auroral brightening and the auroral electrojet indices AL from WDC Kyoto and SML from SuperMAG. The model is capable of capturing events within a 10–12-min interval of occurrence, with level of activity comparable to the measured indices.

• Spencer, E. & Patra, Swadesh (2015). Ionosphere plasma electron parameters from radio frequency sweeping impedance probe measurements. Radio Science. ISSN 0048-6604. 50(9), s. 853–865. doi: 10.1002/2015RS005697. Fulltekst i vitenarkiv
• Patra, Swadesh & Spencer, E. (2015). The effect of changing solar wind conditions on the inner magnetosphere and ring current: A model data comparison. Journal of Geophysical Research (JGR): Biogeosciences. ISSN 2169-8953. 120(8), s. 6528–6540. doi: 10.1002/2015JA021299. Fulltekst i vitenarkiv
• Goodwin, Lindsay; Iserhienrhien, Blessing; Miles, David M.; Patra, Swadesh; Meeren, Christer van der & Buchert, Stephan C. [Vis alle 11 forfattere av denne artikkelen] (2015). Swarm in situ observations of F region polar cap patches created by cusp precipitation. Geophysical Research Letters. ISSN 0094-8276. 42(4), s. 996–1003. doi: 10.1002/2014GL062610. Fulltekst i vitenarkiv Vis sammendrag

  High-resolution in situ measurements from the three Swarm spacecraft, in a string-of-pearls configuration, provide new insights about the combined role of flow channel events and particle impact ionization in creating F region electron density structures in the northern Scandinavian dayside cusp. We present a case of polar cap patch formation where a reconnection-driven low-density relative westward flow channel is eroding the dayside solar-ionized plasma but where particle impact ionization in the cusp dominates the initial plasma structuring. In the cusp, density features are observed which are twice as dense as the solar-ionized background. These features then follow the polar cap convection and become less structured and lower in amplitude. These are the first in situ observations tracking polar cap patch evolution from creation by plasma transport and enhancement by cusp precipitation, through entrainment in the polar cap flow and relaxation into smooth patches as they approach the nightside auroral oval.

Se alle arbeider i NVA

• Patra, Swadesh & Moen, Jøran Idar (2015). High latitude scintillations during the ICI-4 rocket campaign. Fulltekst i vitenarkiv
• Goodwin, Lindsay; Iserhienrhien, Blessing; Miles, David M.; Patra, Swadesh; Meeren, Christer van der & Buchert, S. C. [Vis alle 11 forfattere av denne artikkelen] (2014). Swarm in situ observations of F-region polar cap patches created by cusp precipitation. Fulltekst i vitenarkiv
• Goodwin, Lindsay; Iserhienrhien, Blessing; Miles, David M.; Patra, Swadesh; Meeren, Christer van der & Buchert, S. C. [Vis alle 11 forfattere av denne artikkelen] (2014). In situ Swarm observations of polar cap patches created by cusp precipitation. Fulltekst i vitenarkiv

Se alle arbeider i NVA