skip to main content

Search for: All records

Creators/Authors contains: "Sangha, H."

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. Our research team is currently conducting an ethnographic investigation of a Science, Technology, and Society Living Learning Community (STS-LLC). Our investigation focuses on understanding how engineering students’ macro-ethical reasoning develops within the cultural practices of this community. Our approach to this investigation deliberately partners faculty research leads and a group of undergraduate research fellows (RFs) chosen based on their “insider” status within the STS-LLC cohort being investigated. This collaboration required building substantial infrastructure and routines for disrupting the usual hierarchies that exist between researchers and “participants.” This paper will share multiple perspectives, from both RFs and research leads, on the mutually beneficial relationships that emerged within this research collaboration. We will draw on research team meeting notes, research team meeting recordings, and formative feedback survey responses to support our claims. Research leads will share their perspectives on recruiting, onboarding and working with the RFs and describe some of the macro-ethical considerations that motivated their partnership with RFs. RFs will also describe the multiplicity of ways they have participated in and benefited from this research collaboration. This paper will share sociotechnical innovations that supported the development of effective co-learning and co-working processes. These innovations will be described both in terms of the activities, routines, and artifacts that structured our work and the purposes these activities served. Some innovations were constructed by the research leads in order to: (a) support collaboration and mutual engagement, (b) support engineering students in developing competence with ethnographic methods, (c) expand awareness of the engineering education research literature, (d) empower students to refine their own thinking about macroethics and the purpose of education, (e) recognize particular “knowledge-building” games within research activities, and (f) create space for students’ values and political agendas to shape the direction of the research. We will share some example innovations that were iteratively refined in dialogue with RFs and other example innovations that were developed through the process of coworking with RFs, such as GroupMe communication channels, multi-vocal field noting, and prompts for scaffolding reflections on classroom events. We will describe how the deliberate social and technical organization of this collaboration enabled particular forms of mutually beneficial relationships. 
    more » « less
  2. We present a statistical analysis of the occurrence of bifurcations of the Region 2 (R2) Field-Aligned Current (FAC) region, observed by the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE). Previously, these have been shown to occur as the polar cap contracts after substorm onset, the beginning of the growth phase. During this phase both the Region 1 (R1) and R2 currents move equatorwards as the polar cap expands. Following onset, the R1 FAC region contracts polewards but the R2 FAC continues to expand equatorwards before eventually fading. At the same time, a new R2 FAC develops equatorwards of the R1 FAC. We have proposed that the bifurcated FACs formed during substorms are associated with plasma injections from the magnetotail into the inner magnetosphere, and that they might be the FAC signature associated with Sub-Auroral Polarization Streams (SAPS). We investigate the seasonal dependence of the occurrence of bifurcations from 2010 to 2016, determining whether they occur predominantly at dawn or dusk. Region 2 Bifurcations (R2Bs) are observed most frequently in the summer hemisphere and at dusk, and we discuss the possible influence of ionospheric conductance. We also discuss a newly discovered UT dependence of the R2B occurrences between 2011 and 2014. This dependence is characterized by broad peaks in occurrence near 09 and 21 UT in both hemispheres. Reasons for such a preference in occurrence are explored. 
    more » « less
  3. Abstract

    The effects of a solar wind pressure pulse on the terrestrial magnetosphere have been observed in detail across multiple datasets. The communication of these effects into the magnetosphere is known as a positive geomagnetic sudden impulse (+SI), and are observed across latitudes and different phenomena to characterize the propagation of +SI effects through the magnetosphere. A superposition of Alfvén and compressional propagation modes are observed in magnetometer signatures, with the dominance of these signatures varying with latitude. For the first time, collocated lobe reconnection convection vortices and region 0 field aligned currents are observed preceding the +SI onset, and an enhancement of these signatures is observed as a result of +SI effects. Finally, cusp auroral emission is observed collocated with the convection and current signatures. For the first time, simultaneous observations across multiple phenomena are presented to confirm models of +SI propagation presented previously.

    more » « less
  4. Abstract

    Super Dual Auroral Radar Network (SuperDARN) ionospheric convection maps are a powerful tool for the study of solar wind‐magnetosphere‐ionosphere interactions. SuperDARN data have high temporal (approximately minutes) and spatial (∼45 km) resolution, meaning that the convection can be mapped on fine time scales that show more detail than the large‐scale changes in the pattern. The Heppner‐Maynard boundary (HMB) defines the low‐latitude limit of the convection region, and its identification is an essential component of the standard SuperDARN convection mapping technique. However, the estimation of the latitude of this boundary is dependent on ionospheric scatter availability. Consequentially it is susceptible to nonphysical variations as areas of scatter in different latitude and local time regions appear and disappear, often due to changing propagation conditions. In this paper, the HMB is compared to an independent field‐aligned current data set from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE). A linear trend is found between the HMB and the boundary between the AMPERE Region 1 and Region 2 field‐aligned currents in the Northern Hemisphere, at both solar minimum and solar maximum. The use of this trend and the AMPERE current data set to predict the latitude position of the HMB is found to improve the interpretation of the SuperDARN measurements in convection mapping.

    more » « less