Search Constraints
Number of results to display per page
View results as:
Search Results
-
- Creator:
- Malhotra, Garima and Ridley, Aaron
- Description:
- This research aims to understand the importance of lower thermospheric atomic oxygen on the upper thermosphere. O number densities between 95-100 km from WACCM-X are much closer to the observations from SABER instrument on TIMED satellite as compared to those from MSIS. We show in this study that the correction of the lower boundary atomic oxygen yields better agreement between GITM and GUVI O/N2 in the upper thermosphere .
- Keyword:
- Lower Thermosphere Atomic Oxygen, Thermospheric Dynamics, Thermospheric composition and mixing, Lower-Upper Thermosphere Vertical Coupling, GITM - WACCMX coupling, and Global Ionosphere Thermosphere Model
- Citation to related publication:
- Malhotra, G., Ridley, A. J., Marsh, D. R., Wu, C., Paxton, L. J., & Mlynczak, M. G. (2020). Impacts of Lower Thermospheric Atomic Oxygen on Thermospheric Dynamics and Composition Using the Global Ionosphere Thermosphere Model. Journal of Geophysical Research: Space Physics, e2020JA027877. https://doi.org/10.1029/2020JA027877
- Discipline:
- Science
-
- Creator:
- Hemphill, Libby
- Description:
- Social media data offer a rich resource for researchers interested in public health, labor economics, politics, social behaviors, and other topics. However, scale and anonymity mean that researchers often cannot directly get permission from users to collect and analyze their social media data. This article applies the basic ethical principle of respect for persons to consider individuals’ perceptions of acceptable uses of data. We compare individuals' perceptions of acceptable uses of other types of sensitive data, such as health records and individual identifiers, with their perceptions of acceptable uses of social media data. Our survey of 1018 people shows that individuals think of their social media data as moderately sensitive and agree that it should be protected. Respondents are generally okay with researchers using their data in social research but prefer that researchers clearly articulate benefits and seek explicit consent before conducting research. We argue that researchers must ensure that their research provides social benefits worthy of individual risks and that they must address those risks throughout the research process.
- Keyword:
- social media, data ethics, and data reuse
- Discipline:
- Social Sciences
-
- Creator:
- Niemi, Nathan A. and Abbey, Alyssa L.
- Description:
- These data were produced in the scope of research into the timing, rate, and magnitude of extensional exhumation along the length of the Rio Grande Rift in Colorado and New Mexico. The low-temperature (apatite and zircon (U-Th)/He) thermochronometric ages presented in this data set are sensitive to near-surface temperatures (~80C and 180C, respectively) and record the progressive exhumation of the rock mass from which the samples were collected towards the Earth's surface. These thermochronometric ages, and the differences between them, provide insight into the absolute timing, exhumation rate and total magnitude of exhumation on the normal faults that bound the Rio Grande Rift. and The QTQt program mentioned (Version QTQt64R5.6.2a was used for the data presented in this deposit) is not openly available for download, but is described in the Gallagher 2012 publication referenced, and can be requested from its author. For more information on the request process and a user guide, see http://www.iearth.org.au/codes/QTQt/
- Keyword:
- thermochronology, helium dating, (U-Th)/He, Rio Grande Rift, New Mexico, Colorado, and extensional tectonics
- Citation to related publication:
- Abbey, A. L., & Niemi, N. A. (2020). Perspectives on Continental Rifting Processes From Spatiotemporal Patterns of Faulting and Magmatism in the Rio Grande Rift, USA. Tectonics, 39(1), e2019TC005635. https://doi.org/10.1029/2019TC005635
- Discipline:
- Science
-
- Creator:
- Shane, Alexander
- Description:
- This data set was created with the purpose to study the electron pitch angle distributions on dayside closed crustal fields at Mars and to compare with theoretical predictions made by numerical modeling. Analyzing the plasma environment of the crustal fields was another point of study to determine if whistler waves can interact with high energy superthermal electrons.
- Keyword:
- Mars, superthermal electron, pitch angle distribution, and crustal magnetic field
- Discipline:
- Science
-
- Creator:
- Attari, Ali
- Description:
- Please refer to the "README.txt" for more details., MATLAB R2018a (Mathworks, Natick, MA, USA) was used to process this data., and Excel (Microsoft Office) was used to store survey data on the comfort of both systems and also to provide absolute and relative intraobserver variablities for the DM device.
- Keyword:
- Digital Manometry
- Citation to related publication:
- Comparison of anorectal function measured using wearable digital manometry and a high resolution manometry system Attari A, Chey WD, Baker JR, Ashton-Miller JA (2020) Comparison of anorectal function measured using wearable digital manometry and a high resolution manometry system. PLOS ONE 15(9): e0228761. https://doi.org/10.1371/journal.pone.0228761
- Discipline:
- Engineering, Science, and Health Sciences
-
- Creator:
- Saylor, Kate M., Arring, Noël M., Aduse-Poku, Livingstone, Jiagge, Evelyn, Walker, Eleanor, White-Perkins, Denise, Israel, Barbara, Hinebaugh, Analise, Harb, Rayya, DeWitt, Jillian, Molnar, Maxim, Wilson-Powers, Eliza, and Brush, Barbara L.
- Description:
- The search data supports a literature review project on Strategies to Increase Black Enrollment and Retention in Cancer Clinical Trials. This dataset includes the reproducible search strategies (txt file) and the exported results of all citations from all databases (txt, ris, and.nbib files). These searches and exported result files contain all citations originating from the database searches that were considered for inclusion.
- Keyword:
- African American, Cancer, Neoplasm, clinical trials, and Minority Recruitment
- Discipline:
- Health Sciences
-
- Creator:
- Tye, Alexander R, Niemi, Nathan A, Safarov, Rafig T, Kadirov, Fakhraddin A, Babayev, Gulam R
- Description:
- The Eastern Greater Caucasus is a mountain belt in western Asia that formed as an accretionary prism above an active subduction zone. Because of the bedrock exposure in the range, it offers a unique opportunity to research deformation processes in accretionary prisms, which are ubiquitous above the Earth's many subduction zones but are typically submarine and difficult to investigate. The data presented here result from field geologic mapping in several swaths roughly perpendicular to the mountain range that together span the entire range across strike. The data serve will serve as the basis for inference of the deep structural architecture of the range and characterization of the styles of deformation present in the range.
- Keyword:
- structural geology, Greater Caucasus, tectonics, geologic mapping, and accretionary prism
- Citation to related publication:
- Tye, A. R., Niemi, N. A., Safarov, R. T., Kadirov, F. A., & Babayev, G. R. (2021). Sedimentary response to a collision orogeny recorded in detrital zircon provenance of Greater Caucasus foreland basin sediments. Basin Research, 33(2), 933–967. https://doi.org/10.1111/bre.12499
- Discipline:
- Science
-
- Creator:
- Bougher, S. W. (CLaSP Department, University of Michigan)
- Description:
- The NASA MAVEN (Mars Atmosphere and Volatile Evolution) spacecraft, which is currently in orbit around Mars, has been taking systematic measurements of the densities and deriving temperatures in the upper atmosphere of Mars between about 140 to 240 km above the surface since late 2014. Wind measurement campaigns are also conducted once per month for 5-10 orbits. These densities, temperatures and winds change with time (e.g. solar cycle, season, local time) and location, and sometimes fluctuate quickly. Global dust storm events are also known to significantly impact these density, temperature and wind fields in the Mars thermosphere. For the current project, the inert light species helium is used to trace the circulation patterns and constrain wind magnitudes throughout the Mars thermosphere. Presently, more than 6 years of Neutral Gas and Ion Mass Spectrometer (NGIMS) measurements of helium densities have been obtained by the MAVEN team (e.g. Elrod et al., 2017; 2021; Gupta et al., 2021). Measured helium distributions are compared to simulations from a computer model of the Mars atmosphere called M-GITM (Mars Global Ionosphere-Thermosphere Model), developed at U. of Michigan. Since the global circulation plays a role in the structure, variability, and evolution of the atmosphere, understanding the processes that drive the winds in the upper atmosphere of Mars also provides the needed context for understanding helium distributions and how the atmosphere behaves as a whole system. Three dimensional M-GITM simulations for the Mars four cardinal seasons (Ls = 0, 90, 180, 270, for Mars Year 33) were conducted for detailed comparisons with NGIMS helium and CO2 distributions (Gupta et al. 2021). The M-GITM datacubes used to extract these densities (plus winds) along the trajectory of each orbit path between 140 and 240 km, are provided in this Deep Blue Data archive. README files are also provided for each datacube, detailing the contents of each file. In addition, a general README file is provided that summarizes the inputs and outputs of the M-GITM code simulations for this study. Finally, a basic version of the M-GITM code can be found on Github at https:/github.com/dpawlows/MGITM.
- Keyword:
- Mars, MAVEN Spacecraft Mission, Mars Thermosphere, Helium Density Distributions, and Neutral Gas and Ion Mass Spectrometer (NGIMS)
- Citation to related publication:
- Gupta, N., N. V. Rao, S. W. Bougher, and M. K. Elrod, Latitudinal and Seasonal Asymmetries of the Helium Bulge in the Martian Upper Atmosphere J. Geophys. Res., 126, XXXX-XXXX. doi:10.1002/2021JEXXXXXX
- Discipline:
- Engineering and Science
-
- Creator:
- Majeed, Tariq
- Description:
- We use our 1-D chemical diffusive model to quantify the physical processes necessary to interpret the day-side ionospheric measurements acquired with radio occultation techniques at the southern high-latitude region of Mars, where the crustal magnetic field is strong and near-vertical in orientation. To interpret the measured ionospheric structure at altitudes where plasma transport dominates, we find it is necessary to impose field-aligned vertical plasma drifts caused by the motion of neutral winds. The most interesting finding of this study is that both upward (between 110 m/s and 150 m/s) and downward (between -55 m/s and -120 m/s) drifts are required to maintain the topside Ne distribution comparable with the measured distribution. We also find that a fixed velocity boundary condition at the upper boundary with a sizeable upward ion velocity is needed to encounter any unexpected ion accumulation in the topside ionosphere to limit the Martian ion outflow. Given the complex nature of neutral dynamics and its relationship to plasma transport processes over magnetic anomalies, we consider that a simple model, such as we have developed, is still capable of yielding valuable insights relating to the neutral wind system at Mars.
- Keyword:
- Ionosphere of Mars
- Discipline:
- Science
-
- Creator:
- Hille, Madeline M., Clark, Marin K., Gronewold, Andrew D., West, A. Joshua, Zekkos, Dimitrios , and Chamlagain, Deepak
- Description:
- This dataset supports the findings of Hille et al. (2021, in review) in Geophysical Research Letters. In this article, we present a multivariate analysis of extreme storm events that occur during the Indian summer monsoon over the Himalayan Range in central Nepal. We resolve storm events at sub daily durations by merging NASA’s Global Precipitation Mission (GPM) Integrated Multi-satellitE Retrievals for GPM (IMERG) 30-minute, gridded 0.1x0.1-degree precipitation product with local rain gauges operated by the Nepal Department of Hydrology and Meteorology (DHM) and the International Centre for Integrated Mountain Development (ICIMOD). We quantify spatial variability in extreme rainfall by isolating storms over a specific intensity threshold and pairing a principal components analysis with a K-means clustering approach to group storms of similar characteristics. and We find that frequent and intense storms occur over the forefront of the central Himalayan range and coincide with a locus of monsoon-driven landslide density. This pattern agrees with observations of elevated annual precipitation volumes near the Himalayan physiographic transition from low to high relief (Bookhagen and Burbank, 2010), and is consistent with orographically-influenced rainfall over other mountain ranges (Marra et al., 2021). In addition to presenting novel methodology to quantifying storm variability, our results highlight the strong orographic effect on precipitation intensity and duration, as well as an association of shallow bedrock landsliding frequency with intense precipitation.
- Keyword:
- orographic rainfall, multivariate analysis, extreme rainfall events, and rainfall-triggered landslides
- Citation to related publication:
- Hille et al. (2021, in review). The orographic influence on storm variability, extreme rainfall characteristics and rainfall-triggered landsliding. Geophysical Research Letters. Forthcoming
- Discipline:
- Science