Association of Auroral Streamers and Bursty Bulk Flows During Different States of the Magnetotail: A Case Study

Abstract

In‐situ measurements in the magnetotail are sparse and limited to single points. On the other hand, there is a broad range of observations, including magnetometers, aurora imagers, and radars, in the ionosphere. Since the nightside ionosphere resembles the magnetotail plasma sheet dynamics projection, it can be used to monitor the tail's dynamics. A proper interpretation of the ionosphere and ground observations necessitates understanding the coupling processes between the ionosphere and the magnetosphere. Here, we use the global magnetohydrodynamic simulation model, OpenGGCM‐CTIM‐RCM, to investigate these coupling processes during periods when the magnetic flux is transported through the tail via narrow fast flow channels, typically called bursty bulk flows (BBFs). We consider three relevant states of the magnetotail: immediately before the substorm's onset, during the expansion of the substorm, and during a steady magnetic convection (SMC) event. The number of flow channels increases, and they penetrate closer to the Earth during SMC. The IMF By direction influences fast flows' location but not their orientation in the plasma sheet during this event. However, the dimension of fast flows and streamers do not depend on the IMF conditions and state of the magnetosphere.

Auroral Drivers of Large dB∕dt During Geomagnetic Storms

“…Streamers, also named as north‐south segments (Montbriand, 1971), equatorward‐diving arcs (Henderson et al., 1994), north‐south auroral forms (Henderson et al., 1994; Nakamura et al., 1993), and auroral fingers (Liu & Rostoker, 1993; Rostoker et al., 1987), are structures that originate from intense, transient auroral disturbances along the poleward boundary of the nightside auroral oval (i.e., poleward boundary intensifications, PBIs) and then propagate equatorward. They are auroral manifestations of earthward‐moving plasma‐bubble‐produced flow bursts and hence represent effective transport of mass, energy, and magnetic flux from the tail reconnection site to the near‐Earth region (Ferdousi et al., 2021; Lyons et al., 1999; Nakamura et al., 2001; Sergeev et al., 2000). They occur under all geomagnetic conditions, but the bright ones tend to occur during the substorm expansion and recovery phases.…”

Solar Minimum Exospheric Neutral Density Near the Subsolar Magnetopause Estimated From the XMM Soft X‐Ray Observations on 12 November 2008

“…In this paper, a stand-alone OpenGGCM model is used with the NASA WIND spacecraft data. More details and applications of the OpenGGCM model can be found in Raeder et al (2001Raeder et al ( , 2008; see also Connor et al (2012,2014,2015,2016,2021), Cramer et al (2017), Ferdousi and Raeder (2016), Ferdousi et al (2021), Jensen et al (2017, Kavosi et al (2018), Oliveira and Raeder (2015), and Shi et al (2017).…”

Unified Theory of the Arc Auroras: Formation Mechanism of the Arc Auroras Conforming General Principles of Convection and FAC Generation

“…The difficult point is to get higher resolution in the M‐I coupling process. The Lyon‐Fedder‐Mobarry (LFM) model (Ohma et al., 2021; Pham et al., 2016; Sorathia et al., 2020) has a considerable ability for the calculation of the ionospheric FAC, while others such as the Grand Unified Magnetosphere‐Ionosphere Coupling Simulation (GUMICS) (Lakka et al., 2018), Block Adaptive Tree Solar‐wind Roe‐type Upwind Scheme (BATSRUS) (Mukhopadhyay et al., 2022; Ozturk et al., 2017; Toth et al., 2011), and Open Geospace General Circulation Model (Cramer et al., 2017; Ferdousi et al., 2021; Kavosi et al., 2018; Li et al., 2017) provide minimum required reproduction of the ionospheric FAC to study auroral problems from comparison with observations. The REPPU code has pretty better performance in the M‐I coupling calculation than above models.…”