Convection in the Magnetosphere-Ionosphere System: a Multi-Mission Survey of its Response to IMF By Reversals

The By-component of the interplanetary magnetic field (IMF) has consistently been shown to exert significant influence on the variability of the coupled solar wind-magnetosphere-ionosphere system. Through multiple superposed epoch analyses, we have identified some of the timings involved in the SW-M-I system's response to reversals in the orientation of the IMF By component. Data from the Cluster Electron Drift Instrument indicates that the lobes respond quickly, with initial changes starting in as a little as 5 min after a reversal and an end state being reached within 30-40 min. Data from the ground-based SuperDARN radar network show that the corresponding ionospheric flows (≥75° MLAT) also respond on these prompt timescales. However, at least on these short timescales, plasma flows recorded by a range of spacecraft in the plasmasheet do not show a clear response to the IMF By reversals and nor do the counterpart flows in the SuperDARN data (60-65° MLT). We discuss the significance of these results in terms of the different driving mechanisms that may be at play

Aurorasaurus and the St Patrick’s Day storm

The recent St. Patrick's Day geomagnetic storm provided a rare chance for the public to witness a dazzling auroral display, even from mid-latitudes. An unprecedented number of citizen scientists reported their sightings to Aurorasaurus, offering an exciting opportunity for future scientific study

A comparison of modeled auroral boundaries with observations from citizen scientists

Over the past year, the citizen science project Aurorasaurus has collected new, globally-distributed, ground-based observations of the aurora and has integrated them with space-based estimates of auroral activity. A case study of these observations were compared to the OVATION Prime model of aurora, run by the NOAA Space Weather Prediction Center (SWPC). The observations were comprised of positive and negative sightings directly reported to Aurorasaurus, along with verified tweets, which are positive sightings reported on Twitter and verified by Aurorasaurus users. The observations were collected during March and April 2015, a period spanning three large geomagnetic storms, and covered a wide range of latitudes. The observations demonstrated that, during these events, over 60% of the positive aurora observations (which includes those reported directly to Aurorasaurus and the verified tweets) occurred at latitudes equatorward of the SWPC predicted "view line". New scaling parameters were determined from the relationship of the differences in latitude between the positive observations and the view line, and the maximum probability of visible aurora. Future work testing these scaling parameters and using them in the Aurorasaurus real-time alert system will be presented

Solar wind-magnetosphere interactions:a statistical analysis of spacecraft measurements

When investigating solar wind-magnetosphere-ionosphere coupling, it is important to understand how the solar wind, and the interplanetary magnetic field (IMF) frozen into it, behaves as it reaches the Earth. Magnetic reconnection, for example, is a phenomenon whose morphology is governed by the IMF orientation and wields a large influence over many of the processes occurring within the magnetosphere. Exploiting nearly a decade of spacecraft data, primarily from ESA's Cluster mission and NASA's ACE mission, the three studies presented in this thesis aim to help improve the specification of the IMF at the magnetopause

Using citizen science reports to define the equatorial extent of auroral visibility

An aurora may often be viewed hundreds of kilometers equatorward of the auroral oval owing to its altitude. As such, the NOAA Space Weather Prediction Center (SWPC) Aurora Forecast product provides a “view line” to demonstrate the equatorial extent of auroral visibility, assuming that it is sufficiently bright and high in altitude. The view line in the SWPC product is based upon the latitude of the brightest aurora, for each hemisphere, as specified by the real-time oval variation, assessment, tracking, intensity, and online nowcasting (OVATION) Prime (2010) aurora precipitation model. In this study, we utilize nearly 500 citizen science auroral reports to compare with the view line provided by an updated SWPC aurora forecast product using auroral precipitation data from OVATION Prime (2013). The citizen science observations were recorded during March and April 2015 using the Aurorasaurus platform and cover one large geomagnetic storm and several smaller events. We find that this updated SWPC view line is conservative in its estimate and that the aurora is often viewable further equatorward than is indicated by the forecast. By using the citizen reports to modify the scaling parameters used to link the OVATION Prime (2013) model to the view line, we produce a new view line estimate that more accurately represents the equatorial extent of visible aurora. An OVATION Prime (2013) energy flux-based equatorial boundary view line is also developed and is found to provide the best overall agreement with the citizen science reports, with an accuracy of 91%

Field Day Success Loop

Field days continue to be useful for Extension professionals conducting outreach with farmers, so long as those events incorporate an interpersonal, farmer-led instructional style and are followed up with an evaluation strategy that documents the long-term influences field day attendees have on their peers. At Iowa Learning Farms, we have formulated a successful method for conducting field days that has led to a set of progressive impacts we refer to as the field day success loop. By drawing on the multifaceted approach to evaluation that contributes to the success loop, Extension professionals can strengthen their own field days and track the long-term impact of farmers\u27 influence on their peers regarding implementing conservation practices

A real-time hybrid aurora alert system:combining citizen science reports with an auroral oval model

Accurately predicting when, and from where, an aurora will be visible is particularly difficult, yet it is a service much desired by the general public. Several aurora alert services exist that attempt to provide such predictions but are, generally, based upon fairly coarse estimates of auroral activity (e.g. Kp or Dst). Additionally, these services are not able to account for a potential observer's local conditions (such as cloud cover or level of darkness). Aurorasaurus, however, combines data from the well-used, solar wind driven, OVATION Prime auroral oval model with real-time observational data provided by a global network of citizen scientists. This system is designed to provide more accurate and localized alerts for auroral visibility than currently available. Early results are promising and show that over 100,000 auroral visibility alerts have been issued, including nearly 200 highly localized alerts, to over 2,000 users located right across the globe

Determining the accuracy of crowdsourced tweet verification for auroral research

The Aurorasaurus citizen science project harnesses volunteer crowdsourcing to identify sightings of an aurora (or the "northern/southern lights") posted by citizen scientists on Twitter. Previous studies have demonstrated that aurora sightings can be mined from Twitter but with the caveat that there is a high level of accompanying non-sighting tweets, especially during periods of low auroral activity. Aurorasaurus attempts to mitigate this, and thus increase the quality of its Twitter sighting data, by utilizing volunteers to sift through a pre-filtered list of geo-located tweets to verify real-time aurora sightings. In this study, the current implementation of this crowdsourced verification system, including the process of geo-locating tweets, is described and its accuracy (which, overall, is found to be 68.4%) is determined. The findings suggest that citizen science volunteers are able to accurately filter out unrelated, spam-like, Twitter data but struggle when filtering out somewhat related, yet undesired, data. The citizen scientists particularly struggle with determining the real-time nature of the sightings and care must therefore be taken when relying on crowdsourced identification