A comparison between large‐scale irregularities and scintillations in the polar ionosphere

Abstract

A comparison tool has been developed by mapping the global GPS total electron content (TEC) and large coverage of ionospheric scintillations together on the geomagnetic latitude/magnetic local time coordinates. Using this tool, a comparison between large‐scale ionospheric irregularities and scintillations is pursued during a geomagnetic storm. Irregularities, such as storm enhanced density, middle‐latitude trough, and polar cap patches, are clearly identified from the TEC maps. At the edges of these irregularities, clear scintillations appeared but their behaviors were different. Phase scintillations (σφ) were almost always larger than amplitude scintillations (S4) at the edges of these irregularities, associated with bursty flows or flow reversals with large density gradients. An unexpected scintillation feature appeared inside the modeled auroral oval where S4 were much larger than σφ, most likely caused by particle precipitations around the exiting polar cap patches.

Experimental Evidence on the Dependence of the Standard GPS Phase Scintillation Index on the Ionospheric Plasma Drift Around Noon Sector of the Polar Ionosphere

“…The adopted altitude of ionospheric pierce points of these indices is 350 km, roughly indicating the F 2 region of ionosphere. This particular method for projecting GPS scintillations has been adapted by Wang et al (). For comparison with the 2 min resolution plasma drift data from radars, related scintillation data are taken at the middle time of each velocity interval.…”

Polar Ionospheric Large‐Scale Structures and Dynamics Revealed by TEC Keogram Extracted From TEC Maps

“…Similarly, longer period signifies slower moving speed. Furthermore, the southward IMF B z has been widely reported to trigger the magnetic reconnection in the dayside magnetopause, not only driving the antisunward convection pattern but also possibly producing polar cap patches (e.g., Carlson, 2012;Lockwood & Carlson, 1992;Wang et al, 2016;. Note that the percentage scales in the three vertical axes of Figure 8 are the ratios of the patch numbers for each IMF component within 3-nT intervals to the total number of patches in the corresponding IMF component.…”

“…Recently, measurement of total electron content (TEC) has become a very popular tool due to its capability of continuous monitoring and global coverage (e.g., Foster, 1993;Foster et al, 2005;Oksavik et al, 2006;Pi et al, 1997;Prikryl et al, 2016;Thomas et al, 2013;Zhang et al, 2017;Zou et al, 2013). By using the TEC maps, the large-scale structures were identified and their scintillation behaviors were unveiled (e.g., Wang et al, 2016). Following this, reported the full cycle of convection flow by tracking the movement of polar cap patches from a time series of TEC maps.…”

Jim Dungey, The Open Magnetosphere, and Space Weather

“…These effects influence the orbital decay of satellites and space junk [ Doornbos and Klinkrad , ], with implications for mission planning, deorbiting of satellites, and for the detection of over‐the‐horizon (OTH) radar targets against the background noise of echoes from satellites and space debris. Pulses in magnetopause reconnection rate produce dense “patches” in the polar cap F region [ Lockwood and Carlson , ] which influence satellite communications [ Wang et al, ], GPS navigation systems [ Kintner et al , ], and OTH radar echo location [ Wheadon et al , ].…”