Results 11 to 20 of about 24,293 (260)

Polar cap hot patches: enhanced density structures different from the classical patches in the ionosphere [PDF]

Geophysical Research Letters, 2017
Based on in situ and ground-based observations, a new type of “polar cap hot patch” has been identified that is different from the classical polar cap enhanced density structure (cold patches).
B.-C. Zhang, Basu, Carlson, Carlson, Carter, Crowley, Crowley, D. R. Themens, Foster, J. C. Foster, J. Moen, Jayachandran, Jin, Jin, Jin, Knudsen, Lockwood, Lockwood, Lockwood, Lockwood, M. Lockwood, MacDougall, Maggiolo, Moen, Nishimura, Oksavik, P. T. Jayachandran, Q.-H. Zhang, Redmon, S.-R. Zhang, Themens, Themens, Thomas, Wang, Weber, Y. Wang, Y.-L. Zhang, Y.-Z. Ma, Z. Y. Xing, Zhang, Zhang, Zhang, Zhang, Zhang, Zhang, Zhang, Zhang, Q.-H., Zou   +47 more
core   +7 more sources

Do the Throat Auroras Create Polar Cap Patches?

Geophysical Research Letters, 2023
Throat auroras and polar cap patches are common phenomena in the polar ionosphere resulting from magnetosphere‐ionosphere coupling. A campaign was organized, with all‐sky imagers at Yellow River Station, the European Incoherent Scatter Svalbard Radar ...
Duan Zhang, Qing‐He Zhang, Kjellmar Oksavik, Tong Xu, Zan‐Yang Xing, L. R. Lyons, De‐Sheng Han, Hong‐Bo Zhang, Yu‐Zhang Ma, Ze‐Jun Hu, Jian‐Jun Liu, Yong Wang, Xiang‐Yu Wang   +12 more
doaj   +4 more sources

Polar cap patch transportation beyond the classic scenario [PDF]

Journal of Geophysical Research: Space Physics, 2016
AbstractWe report the continuous monitoring of a polar cap patch, encompassing its creation, and a subsequent evolution that differs from the classic behavior. The patch was formed from the storm‐enhanced density plume, by segmentation associated with a subauroral polarization stream generated by a substorm.
Qing‐He Zhang, Jøran Moen, Michael Lockwood, Ian McCrea, Bei‐Chen Zhang, Kathryn A. McWilliams, Qiu‐Gang Zong, Shun‐Rong Zhang, J. Michael Ruohoniemi, Evan G. Thomas, Malcolm W. Dunlop, Rui‐Yuan Liu, Hui‐Gen Yang, Hong‐Qiao Hu, Mark Lester   +14 more
openaire   +5 more sources

Polar Cap Patch Prediction in the Expanding Contracting Polar Cap Paradigm [PDF]

Space Weather, 2019
AbstractSpace weather can cause serious disturbances of global navigation satellite systems (GNSS) used for positioning and navigation purposes. This paper describes a new method to forecast space weather disturbances on GNSS at high latitudes, in which we describe the formation and propagation of polar cap patches and predict their arrival at the ...
A. Fæhn Follestad, L. B. N. Clausen, E. G. Thomas, Y. Jin, A. Coster   +4 more
openaire   +4 more sources

Earth's ion upflow associated with polar cap patches: global and in-situ observations [PDF]

Geophysical Research Letters, 2016
We report simultaneous global monitoring of a patch of ionization and in situ observation of ion upflow at the center of the polar cap region during a geomagnetic storm.
Dunlop, Malcolm W., Hairston, Marc, Heelis, Roderick A., Lester, Mark, Liang, Jun, Liu, Rui-Yuan, Liu, Yong C.-M., Lockwood, Michael, Ma, Yu-Zhang, McCrea, Ian, Moen, Jøran, Ruohoniemi, J. Michael, Thomas, Evan G., Zhang, Bei-Chen, Zhang, Qing-He, Zhang, Shun-Rong, Zhang, Yong-Liang, Zong, Qiu-Gang   +17 more
core   +3 more sources

Ionospheric patch formation: Direct measurements of the origin of a polar cap patch [PDF]

Geophysical Research Letters, 2004
We present the first direct measurements documenting the origin of an ionospheric patch, emerging into the polar cap from the noon dark cusp region of the dayside auroral oval. A series of such patches were observed. The observed patch‐formation signatures, in plasma density and velocity, ion and electron temperature, and optical transient signatures ...
Herbert C. Carlson, Kjellmar Oksavik, Joran Moen, Todd Pedersen   +3 more
openaire   +3 more sources

The Ion/Electron Temperature Characteristics of Polar Cap Classical and Hot Patches and Their Influence on Ion Upflow

Geophysical Research Letters, 2018
The term of “polar cap hot patch” is a newly identified high‐density plasma irregularity at high latitudes, which is associated with high electron temperature and particle precipitation, while a classical polar cap patch has lower electron temperature ...
Yu‐Zhang Ma, Qing‐He Zhang, Zan‐Yang Xing, Roderick A. Heelis, Kjellmar Oksavik, Yong Wang   +5 more
doaj   +2 more sources

In situ measurement of a newly created polar cap patch [PDF]

Journal of Geophysical Research: Space Physics, 2010
The Investigation of Cusp Irregularities 2 sounding rocket was launched 5 December 2008 at 1035 UT. We present an overview of the associated solar wind and auroral conditions, and we look in detail at the relationship between poleward moving auroral forms (PMAFs) and the creation of polar cap patches using ground‐based optical and radar data as well as
D. A. Lorentzen, J. Moen, K. Oksavik, F. Sigernes, Y. Saito, M. G. Johnsen   +5 more
openaire   +3 more sources

Multi‐instrument, high‐resolution imaging of polar cap patch transportation [PDF]

Radio Science, 2015
AbstractTransionospheric radio signals in the high‐latitude polar cap are susceptible to degradation when encountering sharp electron density gradients associated with discrete plasma structures, or patches. Multi‐instrument measurements of polar cap patches are examined during a geomagnetic storm interval on 22 January 2012.
E. G. Thomas, K. Hosokawa, J. Sakai, J. B. H. Baker, J. M. Ruohoniemi, S. Taguchi, K. Shiokawa, Y. Otsuka, A. J. Coster, J.‐P. St.‐Maurice, K. A. McWilliams   +10 more
openaire   +3 more sources

Association of radio polar cap brightening with bright patches and coronal holes [PDF]

The Astrophysical Journal, 2017
Radio-bright regions near the solar poles are frequently observed in Nobeyama Radioheliograph (NoRH) maps at 17 GHz, and often in association with coronal holes. However, the origin of these polar brightening has not been established yet. We propose that
Costa, Joaquim E. R., de Castro, C. G. Gimenez, Selhorst, Caius L., Silva, Alexandre J. Oliveira e, Simoes, Paulo J. A., Valio, Adriana   +5 more
core   +4 more sources