Magnetic signatures for satellite anomalies

Abstract

Similarities have been found between the yearly trends of magnetic activity and the occurrences of electrostatic discharge events on a geosynchronous communication satellite from April 1983 to December 1987 in the declining portion of the 11-year solar cycle. The seasonal variations of magnetic activity and electrostatic discharge events show maxima around the equinoxes and minima during solstitial months. Detailed comparisons of the events with magnetograms from Yellowknife, Canada, near the footprint of the satellite, indicate that magnetic storms, substorms, and bays offer magnetic signatures for the discharge events with substorms playing a dominant role. A study of the occurrences of electrostatic discharge with respect to the magnetic perturbations indicates a variable time delay in the occurrence after the initiation of the magnetic disturbance. The local time variation pattern in the occurrence of electrostatic discharge shows preferred occurrences in the afternoon and evening sector. It is possible that a delay mechanism is operating, whereby the surface of the satellite is charged differentially in the midnight to dawn sector during substorm and discharged at some later time. It is also conceivable that the daytime anomalies are caused by buried charge processes. The occurrences of electrostatic discharge events in the traditional midnight to dawn sector and in the local time interval encompassing the Harang discontinuity appear to be immediate responses to the magnetic perturbations.

Diagnosing low earth orbit satellite anomalies using NOAA-15 electron data associated with geomagnetic perturbations

“…The largest numbers of anomalies appeared in two sectors: the noon-to-dusk and dusk-to-midnight sectors. This pattern is similar to that reported by Lam and Hruska (1991), who found anomalies mostly distributed within the noon-to-dusk and evening sectors. As previously discussed, the time delay between magnetic storms and anomalies may explain why the MLT of anomalies was predominantly spread within the above two sectors.…”

“…4b, c. This was also found in some anomaly cases studied by Farthing et al (1982), Lam and Hruska (1991), and Iucci et al (2006). 2.…”

“…We initially examined the strengths of geomagnetic disturbances affecting the properties of plasma in space. A previous study showed that the charge buildup on satellites as a trigger of anomalies did not originate from the magnetic perturbations but rather from energetic electrons affecting the satellite surfaces (Lam and Hruska 1991). The properties of energetic particles and plasma around Earth change in association with magnetic perturbations.…”

On the predictive potential of Pc5 ULF waves to forecast relativistic electrons based on their relationships over two solar cycles

“…Indeed, connection between geomagnetic parameters and relativistic electrons has been perused in studies involving global geomagnetic indices of Kp [ Nagai , ], AE and ∑ Kp [ Baker et al ., ], Dst [ Reeves , ], and local geomagnetic index of DRX [ Lam , ]. Because of the association between geomagnetic activity and relativistic electrons, the occurrences of satellite operational anomalies appear to correlate with geomagnetic activity [ Lam and Hruska , ].…”

On the prediction of relativistic electron fluence based on its relationship with geomagnetic activity over a solar cycle

“…Also, from a practical point of view, it is of interest to determine the relationship between geomagnetic activity and relativistic electrons for a long time span of a solar cycle because, firstly, high fluxes of relativistic electrons impinging on a geosynchronous satellite could cause internal charging with possible discharges that could result in satellite operational anomalies (e.g. Wrenn and Sims, 1996), and, secondly, the occurrences of satellite operational anomalies appear to correlate with geomagnetic activity (Lam and Hruska, 1991). The objective of this paper is to present such a relationship based on study using data from 1987 to 1997, spanning Cycle 22, and to explore the space weather forecasting possibility of predicting electron fluence from ground magnetic data.…”