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- Creator:
- McCuen, Brett A.
- Description:
- We present a comprehensive statistical analysis of high-frequency transient-large-amplitude (TLA) magnetic perturbation events that occurred at 12 high-latitude ground magnetometer stations throughout solar cycle 24 from 2009 to 2019. TLA signatures are defined as one or more second-timescale dB/dt interval with magnitude ≥ 6 nT/s within an hour event window. This study characterizes high-frequency TLA events based on their spatial and temporal behavior as well as relation to auroral substorms, geomagnetic storm phases and nighttime geomagnetic disturbance events events (GMD). We show that TLA events occur primarily at nighttime and solely in the high-latitude region above 60 degrees geomagnetic latitude. The largest TLA events occurred more often in the declining phase of the solar cycle when solar wind velocity was higher and ring current activity was lower, suggesting association to high-speed flows caused by coronal holes and subsequent corotating interaction regions reaching Earth. TLA perturbations often occurred preceding or within the most extreme nighttime geomagnetic disturbance (GMD) events with 5-10 minute timescales, but the TLA intervals were often even more localized than the ~300 km effective radius of GMDs: occurring at only some of the stations at which GMDs occurred. We show that TLA-related GMD events can result from dipolarization fronts in the magnetotail and fast flows toward Earth and are closely temporally associated to poleward boundary intensifications (PBI) and auroral streamers. The highly localized behavior and connection to the most extreme GMD events suggests that TLA intervals are a ground manifestation of the features within rapid and complex ionospheric structures that can drive GICs.
- Keyword:
- geomagnetic field, high frequency, space weather, transient-large-amplitude, TLA, high frequency dB/dt, dB/dt search algorithm
- Citation to related publication:
- McCuen, B. A., Moldwin, M. B., Engebretson, M. J., Weygand, J. G., Nishimura, Y. (2023). A Statistical Analysis of High-frequency Transient-Large-Amplitude Geomagnetic Disturbance. [To be submitted to] Journal of Geophysical Research: Space Physics
- Discipline:
- Science
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- Creator:
- Crisp, Dakota N., Saggio, Maria L., Scott, Jared, Stacey, William C., Nakatani, Mitsuyoshi, Gliske, Stephen V., and Lin, Jack
- Description:
- This data and scripts are meant to test and show seizure differentiation based on bifurcation theory. A zip file is included which contains real and simulated seizure waveforms, Matlab scripts, and metadata. The matlab scripts allow for visual review validation and objective feature analysis. The file “README.txt” provides more detail about each individual file within the zip file. and Data citation: Crisp, D.N., Saggio, M.L., Scott, J., Stacey, W.C., Nakatani, M., Gliske, S.F., Lin, J. (2019). Epidynamics: Navigating the map of seizure dynamics - Code & Data [Data set]. University of Michigan Deep Blue Data Repository. https://doi.org/10.7302/ejhy-5h41
- Keyword:
- Bifurcation, Epilepsy, Seizure, and Divergence
- Citation to related publication:
- Saggio, M.L., Crisp, D., Scott, J., Karoly, P.J., Kuhlmann, L., Nakatani, M., Murai, T., Dümpelmann, M., Schulze-Bonhage, A., Ikeda, A., Cook, M., Gliske, S.V., Lin, J., Bernard, C., Jirsa, V., Stacey, W., 2020. In pre-print. Epidynamics characterize and navigate the map of seizure dynamics. bioRxiv 2020.02.08.940072. https://doi.org/10.1101/2020.02.08.940072
- Discipline:
- Engineering, Science, and Health Sciences
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- Creator:
- Ding, J, Moore, TY, and Gan, Z
- Description:
- Jerboas (Jaculus jaculus) are bipedal hopping rodents that frequently transition between gaits (running, hopping, and skipping) throughout their entire speed range. It has been hypothesized that these non-cursorial bipedal gait transitions are likely to enhance their maneuverability and predator evasion ability. However, it is difficult to use the underlying dynamics of these locomotion patterns to predict gait transitions due to the large number of degrees of freedom expressed by the animals. To this end, we used empirical jerboa kinematics and dynamics to develop a unified Spring Loaded Inverted Pendulum model with defined passive swing leg motions. The simulated trajectories from the model precisely matched the experimental data. Jerboas were observed to apply different neutral swing leg angles during locomotion. By investigating the gait structure of the model with coupled and uncoupled neutral swing leg, we found two set of mechanism may explain the frequent gait transitions of jerboas.
- Keyword:
- jerboa, legged locomotion, gait transition, Legged Robots, Dynamics, Bipedal locomotion, and Non-cursorial locomotion
- Citation to related publication:
- Ding, Moore, Gan (submitted) A template model explains jerboa gait transitions across a broad range of speeds. Frontiers in Bioengineering And Biotechnology
- Discipline:
- Science and Engineering
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- Creator:
- Kort, EA, Gvakharia, A, Smith, ML, and Conley, S
- Description:
- Data is collected from research flights based in West Memphis, Arkansas, covering the Mississippi River Valley. The data file contains all merged flight data from each flight day.
- Keyword:
- Greenhouse gas
- Discipline:
- Science
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- Creator:
- Kort, Eric A., Plant, Genevieve, Smith, Mackenzie L., Brandt, Adam R., Chen, Yuanlei, Gorchov Negron, Alan M., Schwietzke, Stefan, and Zavala-Araiza, Daniel
- Description:
- As part of the Flaring & Fossil Fuels: Uncovering Emissions & Losses (F3UEL) project, in 2020 the aircraft measurement platform sampled offshore oil & gas facilities in the Gulf of Mexico to quantify facility-level emissions using the approach detailed in Conley et al. (2017). Onshore, the aircraft sampled downwind of flare combustion plumes in the Permian and Eagle Ford regions of Texas. Vertical profiles were conducted on each flight to capture the vertical structure and mixing depths of the atmosphere. The data file contains all merged flight data from each flight day. and Reference: Conley, S., Faloona, I., Mehrotra, S., Suard, M., Lenschow, D. H., Sweeney, C., Herndon, S., Schwietzke, S., Pétron, G., Pifer, J., Kort, E. A., and Schnell, R.: Application of Gauss’s theorem to quantify localized surface emissions from airborne measurements of wind and trace gases, Atmos. Meas. Tech., 10, 3345 – 3358, 2017.
- Keyword:
- Offshore Oil & Gas, Flaring, Methane, and Nitrogen Oxides
- Discipline:
- Science
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- Creator:
- Kort, Eric A., Plant, Genevieve, Brandt, Adam R., Chen, Yuanlei, Gorchov Negron, Alan M., Schwietzke, Stefan, Smith, Mackenzie L., and Zavala-Araiza, Daniel
- Description:
- As part of the Flaring & Fossil Fuels: Uncovering Emissions & Losses (F3UEL) project, in 2021 the aircraft measurement platform sampled offshore oil & gas facilities in Alaska and California to quantify facility-level emissions using the approach detailed in Conley et al. (2017). Onshore, the aircraft sampled downwind of flare combustion plumes in the Bakken region of North Dakota. Vertical profiles were conducted on each flight to capture the vertical structure and mixing depths of the atmosphere. The data file contains all merged flight data from each flight day. and Reference: Conley, S., Faloona, I., Mehrotra, S., Suard, M., Lenschow, D. H., Sweeney, C., Herndon, S., Schwietzke, S., Pétron, G., Pifer, J., Kort, E. A., and Schnell, R.: Application of Gauss’s theorem to quantify localized surface emissions from airborne measurements of wind and trace gases, Atmos. Meas. Tech., 10, 3345 – 3358, 2017.
- Keyword:
- Offshore Oil & Gas, Flaring, Methane, and Nitrogen Dioxides
- Discipline:
- Science
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- Creator:
- Kort, Eric A., Plant, Genevieve, and Dacic, Natasha
- Description:
- As part of the Measurement of Agriculture Illuminating farm-Zone Emissions of N2O (MAIZE) project, in 2021 the aircraft platform sampled the agriculture regions of Nebraska and Iowa. Vertical profiles were conducted on each flight to capture the vertical structure and mixing depths of the atmosphere. The data files contains the merged data for each individual file day.
- Keyword:
- Greenhouse Gas, Agriculture , and Nitrous Oxide
- Citation to related publication:
- Gvakharia A, Kort EA, Smith M, Conley S, Testing and evaluation of a new airborne system for continuous N2O, CO2, CO, and H2O measurements: the Frequent Calibration High-performance Airborne Observation System (FCHAOS), Atmos. Meas. Tech. 11, 6059-6074, https://doi.org/10.5194/amt-11-6059-2018, 2018, Conley S, Faloona I.C, Lenschow D.H, Karion A, Sweeney S, (2014) A low-cost system for measuring horizontal winds from single-engine aircraft, Journal of Atmospheric and Oceanic Technology, 31(6), 1312-1320, https://doi.org/10.1175/JTECH-D-13-00143.1, Airborne measurements reveal high spatiotemporal variation and the heavy-tail characteristic of nitrous oxide emissions in Iowa" by Natasha Dacic, Genevieve Plant, and Eric A Kort. Journal of Geophysical Research: Atmospheres. Submitted., and 2022 dataset: Kort, E. A., Plant, G., Dacic, N. (2024). Aircraft Data (2022) for Measurement of Agriculture Illuminating farm-Zone Emissions of N2O (MAIZE) [Data set], University of Michigan - Deep Blue Data. https://doi.org/10.7302/tmfd-nw87
- Discipline:
- Science
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- Creator:
- Kort, Eric A., Plant, Genevieve, Brandt, Adam R., Chen, Yuanlei, Gorchov Negron, Alan M., and Smith, Mackenzie L.
- Description:
- As part of the Flaring & Fossil Fuels: Uncovering Emissions & Losses (F3UEL) project, in 2022 the aircraft measurement platform sampled offshore oil & gas facilities in the US Gulf of Mexico to quantify facility-level emissions using the approach detailed in Conley et al. (2017). Vertical profiles were conducted on each flight to capture the vertical structure and mixing depths of the atmosphere. The data file contains all merged flight data from each flight day. Reference: Conley, S., Faloona, I., Mehrotra, S., Suard, M., Lenschow, D. H., Sweeney, C., Herndon, S., Schwietzke, S., Pétron, G., Pifer, J., Kort, E. A., and Schnell, R.: Application of Gauss’s theorem to quantify localized surface emissions from airborne measurements of wind and trace gases, Atmos. Meas. Tech., 10, 3345 – 3358, 2017.
- Keyword:
- Offshore Oil & Gas, Methane, Nitrogen Oxides, and Gulf of Mexico
- Discipline:
- Science
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- Creator:
- Kort, Eric A, Plant, Genevieve, and Dacic, Natasha
- Description:
- As part of the Measurement of Agriculture Illuminating farm-Zone Emissions of N2O (MAIZE) project, in 2022 an aircraft platform sampled atmospheric concentrations of nitrous oxide (N2O) in the agriculture regions of Iowa. Vertical profiles were conducted on each flight to capture the vertical structure and mixing depths of the atmosphere. The data files contain the merged data for each individual flight day.
- Keyword:
- Greenhouse Gases, Nitrous Oxide, and Agricultural soils
- Citation to related publication:
- Airborne measurements reveal high spatiotemporal variation and the heavy-tail characteristic of nitrous oxide emissions in Iowa" by Natasha Dacic, Genevieve Plant, and Eric A Kort. Journal of Geophysical Research: Atmospheres. Submitted. and 2021 dataset: Kort, E. A., Plant, G., Dacic, N. (2022). Aircraft Data (2021) for Measurement of Agriculture Illuminating farm-Zone Emissions of N2O (MAIZE) [Data set], University of Michigan - Deep Blue Data. https://doi.org/10.7302/0jvh-0c91
- Discipline:
- Science
-
- Creator:
- Gorchov Negron, Alan M., Kort, Eric A., Conley, Stephen A., and Smith, Mackenzie L.
- Description:
- This data-set contains data used in the publication "Airborne Assessment of Methane Emissions from Offshore Platforms in the U.S. Gulf of Mexico" by Gorchov Negron et al. (2020). There are 46,032 rows and 45 columns in the data. and The aircraft sampled offshore facilities with two unique sampling strategies: facility-level samples and regional box samples. Gorchov Negron et al. used facility-level samples to calculate facility-level fluxes and regional box samples, in conjunction with vertical profiles, to calculate regional-level fluxes. Meteorological parameters in the data were evaluated to discern when assumptions for each method were met. The facility-level fluxes were used to generate a facility-level aerial measurement-based inventory that was scaled up for comparison with regional-level fluxes.
- Keyword:
- Methane Emissions, Offshore Oil and Gas Platforms, Airborne Measurements, Greenhouse Gas Mitigation, and Gulf of Mexico
- Citation to related publication:
- Alan M. Gorchov Negron, Eric A. Kort, Stephen A. Conley, Mackenzie L. Smith. "Airborne Assessment of Methane Emissions from Offshore Platforms in the U.S. Gulf of Mexico". Environ. Sci. Technol. 2020. http://dx.doi.org/10.1021/acs.est.0c00179
- Discipline:
- Science