The MMS Dayside Magnetic Reconnection Locations During Phase 1 and Their Relation to the Predictions of the Maximum Magnetic Shear Model

Trattner, K. J.; Burch, J. L.; Ergun, R. E.; Eriksson, S.; Fuselier, S. A.; Giles, B. L.; Gomez, R. G.; Grimes, E. W.; Lewis, W. S.; Mauk, B. H.; Petrinec, S. M.; Russell, C. T.; Strangeway, R. J.; Trenchi, Lorenzo; Wilder, F. D.

doi:10.1002/2017ja024488

Cited by 29 publications

(55 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Here we use the maximum magnetic shear model by Trattner et al () to estimate the possible source region of FTE cascades. The FTE cascades in our study appear during those IMF conditions (southward IMF with a strong B y component) for which the maximum magnetic shear model gives an excellent agreement with observations of normal reconnection events (Trattner et al, , , , ).…”

Section: Discussionsupporting

confidence: 89%

“…There exist both observational studies (e.g., Trenchi et al, ) and magnetohydrodynamic simulations (Hoilijoki et al, ) confirming such a dipole tilt‐dependent shift of the reconnection line toward the winter hemisphere. Comparing the maximum magnetic shear model with reconnection signatures in Polar (Trattner et al, ), Time History of Events and Macroscale Interactions during Substorms (THEMIS) (Trattner et al, ), and Magnetic Multiscale Mission (MMS) data (Trattner et al, ) showed an excellent agreement with observations for a large majority of cases. Deviations between model and observations occur though for specific IMF conditions.…”

Section: Introductionmentioning

confidence: 83%

See 1 more Smart Citation

The Difference Between Isolated Flux Transfer Events and Flux Transfer Event Cascades

2019

View full text Add to dashboard Cite

This flux transfer event (FTE) study is based on 984 FTEs originally identified by Wang et al. (2005, https://doi:10.1029/2005JA011150) in Cluster data. Due to Cluster's orbit, the FTE list exclusively contains events detected at the high‐latitude dayside magnetopause and low‐latitude flanks. The focus of this study is on FTE separation time. The results show that FTEs appearing in cascades are mainly located at the northern dusk and southern dawn magnetopause, while isolated FTEs are equally spread over the region covered by Cluster. This difference may be explained by the different interplanetary magnetic field (IMF) conditions during which the subsets occur. For isolated FTEs, average IMF By is close to zero. During such conditions, FTEs are expected to form at arbitrary longitudes along an equatorial merging line. After formation, they propagate northward and southward, causing an equal distribution at higher latitudes. In contrast, FTE cascades typically occur during weakly southward IMF with a negative By component. Their asymmetric distribution at higher latitudes is consistent with both the component and the antiparallel merging model for nonzero By. In both scenarios, newly formed FTEs are expected to move to the northern dusk and southern dawn regions, as observed. Many FTE cascades appearing during northward IMF are located close to the low‐latitude flanks, confirming previous reports. We discovered that such FTEs appear during large IMF values. Another new result is that 16% of all isolated FTEs appear during small IMF cone angles, suggesting that these may form as a result of magnetosheath jets impacting on the magnetopause.

show abstract

Section: Discussionsupporting

confidence: 89%

Section: Introductionmentioning

confidence: 83%

The Difference Between Isolated Flux Transfer Events and Flux Transfer Event Cascades

2019

View full text Add to dashboard Cite

show abstract

“…The model also predicts that during IMF clock angles (arctan ( B Y / B Z ), where 0° is defined as pointing due north) within ±25° of a southward magnetic field or events occurring during a mainly radial magnetic field (IMF| B X |/ B > 0.7) the reconnection process reverts to an antiparallel reconnection scenario with no component reconnection tilted X‐line present. Several magnetopause reconnection studies and MHD simulations have successfully used and confirmed the model predictions (e.g., Dunlop et al, ; Fuselier et al, ; Komar et al, ; Petrinec et al, ; Trattner et al, 2012, Trattner, Thresher, et al, , Trattner, Burch, et al, ; Vines et al, ).…”

Section: Introductionmentioning

confidence: 84%

“…Figure shows the distance of the 302 MMS X‐line encounters observed during Phase 1a (Trattner, Burch, et al, ) from the predicted reconnection location versus the IMF clock angles of the events. While 80% of the events are within the model uncertainty of 2 R E (dotted line), the IMF clock angles around 120° and 240° showed larger errors and are associated with the fall and spring equinoxes, respectively.…”

Section: Observationsmentioning

confidence: 99%

The Transition Between Antiparallel and Component Magnetic Reconnection at Earth's Dayside Magnetopause

et al. 2018

Self Cite

View full text Add to dashboard Cite

Magnetic reconnection at Earth's magnetopause is usually described by two different scenarios, antiparallel and component reconnection. The Maximum Magnetic Shear model combines these two scenarios at specific connection points known as the Knee regions. Using a database of confirmed magnetopause reconnection locations observed during Phase 1a of the Magnetospheric Multiscale mission, a recent study showed that the model predicts the reconnection locations correctly within 2 Earth radii 80% of the time. The study also revealed and confirmed the existence of anomalies, that is, a specific set of conditions/parameters for which the observed reconnection locations are significantly different than the predicted locations. The first anomaly, described in an earlier study, occurs during the equinoxes for events with interplanetary magnetic field (IMF) clock angles around 120° and 240°. Another previously unknown anomaly was found for events observed around December that also occurs for the same IMF clock angle ranges as the first anomaly. Several of the anomalous December events were observed in the dawn sector Knee region and show that a combination of a large dipole tilt with an IMF clock angle of about 140° causes the magnetopause antiparallel reconnection region to line up along the draped IMF. That causes a deflection of the Knee points and the predicted reconnection location. These events demonstrate that magnetic reconnection at the Earth's dayside magnetopause preferentially occurs in the antiparallel locations and only occurs along component reconnection line segments when the draped IMF field lines at the magnetopause no longer contact an antiparallel reconnection region.

show abstract

“…One empirical model that has been very successful in predicting where reconnection X‐lines occur and where there is antiparallel and component reconnection is the maximum shear reconnection model (Trattner et al, , ). This model was developed from a large number of measurements in the Earth's magnetospheric cusps and has been tested successfully using in situ observations at the Earth's magnetopause (Dunlop et al, ; Fuselier et al, ; Petrinec et al, ; Trattner et al, ; Trattner et al, ) and using energetic neutral atom observations to remotely image the magnetospheric cusps (Petrinec et al, ). The model was used successfully to predict the reconnection diffusion region encounters by the Magnetospheric Multiscale (MMS) mission (Fuselier et al, ).…”

Section: Introductionmentioning

confidence: 99%

Stationarity of the Reconnection X‐Line at Earth's Magnetopause for Southward IMF

et al. 2019

Self Cite

View full text Add to dashboard Cite

When the interplanetary magnetic field (IMF) is southward and has a substantial Y component, reconnection at the magnetopause occurs at low latitudes. Under these conditions, the maximum magnetic shear model for the reconnection X-line at the magnetopause predicts a continuous X-line stretching from the dawn to dusk terminators. During the solstices, the X-line is not at the subsolar point and may be located in a region where the magnetosheath bulk flow is super-Alfvenic. For a fixed IMF direction, the maximum shear model also predicts a stationary X-line. In response to IMF clock angle changes on the timescale of minutes, the X-line moves on the same timescale. The stationarity of the reconnection X-line is testable observationally under certain, restrictive conditions. This stationarity is tested using observations from the Magnetospheric Multiscale mission. For two events, the distance from the Magnetospheric Multiscale spacecraft to the X-line is constant over several minutes (within relatively large error bars) and the X-line is also near the location predicted by the maximum magnetic shear model. Thus, the reconnection X-line at the magnetopause appears to be quasi-stationary for constant IMF clock angle. These observations also place constraints on the formation and motion of multiple X-lines at the magnetopause.

show abstract

The MMS Dayside Magnetic Reconnection Locations During Phase 1 and Their Relation to the Predictions of the Maximum Magnetic Shear Model

Cited by 29 publications

References 64 publications

The Difference Between Isolated Flux Transfer Events and Flux Transfer Event Cascades

The Difference Between Isolated Flux Transfer Events and Flux Transfer Event Cascades

The Transition Between Antiparallel and Component Magnetic Reconnection at Earth's Dayside Magnetopause

Stationarity of the Reconnection X‐Line at Earth's Magnetopause for Southward IMF

Contact Info

Product

Resources

About