Articles | Volume 35, issue 4
https://doi.org/10.5194/angeo-35-777-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/angeo-35-777-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Tracking patchy pulsating aurora through all-sky images
University of Calgary, Calgary, Alberta, Canada
Eric Donovan
University of Calgary, Calgary, Alberta, Canada
Kyle R. Murphy
NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
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Eric Grono and Eric Donovan
Ann. Geophys., 38, 1–8, https://doi.org/10.5194/angeo-38-1-2020, https://doi.org/10.5194/angeo-38-1-2020, 2020
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This is the first survey of pulsating auroras which is differentiated by type. Pulsating auroras are found to be almost always an early-morning phenomenon and are almost entirely lacking persistent structuring before midnight. Long-lived patches which are known to move with convection primarily appear after midnight. These patches are a less common form of pulsating aurora and are found to originate from the inner magnetosphere, in agreement with past observations of their source region.
Eric Grono and Eric Donovan
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-162, https://doi.org/10.5194/angeo-2019-162, 2020
Preprint withdrawn
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Pulsating auroras have recently begun to be reconsidered in the context of the conditions and mechanisms driving them. This research connects one type of pulsating aurora to specific plasma waves and uses in situ plasma observations to infer the source region of this aurora. Shortcomings of the available methods of associating in situ observations with specific auroral features are outlined and a key issue is identified which challenges our understanding of pulsating aurora formation.
Eric Grono and Eric Donovan
Ann. Geophys., 36, 891–898, https://doi.org/10.5194/angeo-36-891-2018, https://doi.org/10.5194/angeo-36-891-2018, 2018
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The solar wind reshapes Earth's magnetic field to create our magnetosphere and powers many dynamic processes in our plasma-filled environment, some of which produce the aurora. Networks of ground-based all-sky cameras are valuable tools that offer a large field-of-view with which to study the aurora. Using sequences of auroral images, this study defines criteria for differentiating an important type of aurora whose subcategories are often conflated.
Eric Grono and Eric Donovan
Ann. Geophys., 38, 1–8, https://doi.org/10.5194/angeo-38-1-2020, https://doi.org/10.5194/angeo-38-1-2020, 2020
Short summary
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This is the first survey of pulsating auroras which is differentiated by type. Pulsating auroras are found to be almost always an early-morning phenomenon and are almost entirely lacking persistent structuring before midnight. Long-lived patches which are known to move with convection primarily appear after midnight. These patches are a less common form of pulsating aurora and are found to originate from the inner magnetosphere, in agreement with past observations of their source region.
Eric Grono and Eric Donovan
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-162, https://doi.org/10.5194/angeo-2019-162, 2020
Preprint withdrawn
Short summary
Short summary
Pulsating auroras have recently begun to be reconsidered in the context of the conditions and mechanisms driving them. This research connects one type of pulsating aurora to specific plasma waves and uses in situ plasma observations to infer the source region of this aurora. Shortcomings of the available methods of associating in situ observations with specific auroral features are outlined and a key issue is identified which challenges our understanding of pulsating aurora formation.
Ching-Chang Cheng, Christopher T. Russell, Ian R. Mann, Eric Donovan, and Wolfgang Baumjohann
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2018-116, https://doi.org/10.5194/angeo-2018-116, 2018
Preprint withdrawn
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The comparison of geomagnetic active and quite events of double substorm onsets responsive to IMF variations shows that the occurrence sequence of all required substorm signatures looks the same and not different for small and large Kp. Double substorm onsets responsive to IMF variations can be characterized with two-stage magnetic dipolarizations in the magnetotail, two auroral breakups of which the first occurring at lower latitudes than the second, and two consecutive Pi2-Ps6 band pulsations.
Eric Grono and Eric Donovan
Ann. Geophys., 36, 891–898, https://doi.org/10.5194/angeo-36-891-2018, https://doi.org/10.5194/angeo-36-891-2018, 2018
Short summary
Short summary
The solar wind reshapes Earth's magnetic field to create our magnetosphere and powers many dynamic processes in our plasma-filled environment, some of which produce the aurora. Networks of ground-based all-sky cameras are valuable tools that offer a large field-of-view with which to study the aurora. Using sequences of auroral images, this study defines criteria for differentiating an important type of aurora whose subcategories are often conflated.
Bing Yang, Eric Donovan, Jun Liang, and Emma Spanswick
Ann. Geophys., 35, 217–225, https://doi.org/10.5194/angeo-35-217-2017, https://doi.org/10.5194/angeo-35-217-2017, 2017
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This is the first statistical study of the motion of patchy pulsating aurora (PPA). Our results show that PPA patches mainly drift eastward after midnight and westward before midnight, which suggests that the drifts of auroral patches could be a proxy for the ionospheric convection and provide a convenient and accurate method to remotely sense the magnetospheric convection. We also found that patch velocities do not seem to depend on AE index.
Brian J. Jackel, Craig Unick, Fokke Creutzberg, Greg Baker, Eric Davis, Eric F. Donovan, Martin Connors, Cody Wilson, Jarrett Little, M. Greffen, and Neil McGuffin
Geosci. Instrum. Method. Data Syst., 5, 493–512, https://doi.org/10.5194/gi-5-493-2016, https://doi.org/10.5194/gi-5-493-2016, 2016
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In order to compare auroral observations, it is necessary to ensure that all instruments are properly calibrated. This can be difficult to achieve with different instruments operated for extended intervals at remote field sites under harsh conditions. Astronomical sources can be used for independent absolute calibration procedures. Under ideal conditions Jupiter is an excellent source, as it can provide more light than the brightest star. We use Jupiter to calibrate an auroral MSP network.
D. Pokhotelov, I. J. Rae, K. R. Murphy, and I. R. Mann
Ann. Geophys., 33, 697–701, https://doi.org/10.5194/angeo-33-697-2015, https://doi.org/10.5194/angeo-33-697-2015, 2015
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Solar wind impacts the Earth’s magnetic cavity driving waves in the magnetosphere. The waves in the range of few mHz are important for the dynamics of energetic particles trapped inside the magnetosphere. The average solar wind parameters are known to control of magnetospheric wave power. Here the variability of solar wind parameters, rather than average properties, is analysed. It is shown that the magnetospheric wave power is most sensitive to variations in the interplanetary magnetic field.
J. Liang, F. Jiang, E. Donovan, E. Spanswick, V. Angelopoulos, and R. Strangeway
Ann. Geophys., 31, 1077–1101, https://doi.org/10.5194/angeo-31-1077-2013, https://doi.org/10.5194/angeo-31-1077-2013, 2013
Short summary
The spatial and temporal evolution of the aurora provides information about plasma dynamics throughout the magnetosphere. The THEMIS all-sky imager network has been operating for over 10 years and has accumulated millions of auroral images. To speed the extraction of information from this dataset, it is desirable to implement automated algorithms to track and classify the aurora. This paper demonstrates an automatic method of extracting the motion of the aurora from sequences of images.
The spatial and temporal evolution of the aurora provides information about plasma dynamics...