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- Creator:
- Umaña, María Natalia, Zambrano, Jenny, Weemstra, Monique, and Allen, Dave
- Description:
- The objective of this research was to improve our understanding of tree growth from underlying variation in leaf and root functional traits. This knowledge ultimately enhances our knowledge of the above- and belowground processes that are involved in structuring forest communities. To this end, we determine which, how and to what degree (combinations of) leaf and root traits influence growth rates across ten temperate tree species along a soil carbon (C) and N gradient growing at the Big Woods plot at the E.S. George Reserve, Pickney, MI. This plot is part of the Smithsonian Institution's Forest Global Earth Observatory (ForestGEO) global network of forest research sites. https://forestgeo.si.edu/ and This dataset contains data on the leaf and root traits of several individuals from tree species, as well as on the soil properties at the Big Woods plots at the E.S. George Reserve, Pickney, MI. Data were collected in June 2019, and used to explain and predict the growth rates of the trees at Big Woods. [Growth data were obtained from Allen et al., 2019, https://doi.org/10.7302/wx55-kt18]. Each file contains data on leaf traits, root traits, and soil properties. Trait data are presented per individual tree for each of the 10 study species. Soil data are represented per soil sample, with four soil samples collected per subplot throughout the Big Woods plot (see legend, and publication for explanation). Descriptions and units per variable/column are provided in the legend tab in each file.
- Keyword:
- ecology, forests, Michigan, ForestGEO, Big Woods, Roots, Leaves, Tree growth, and Forest soils
- Citation to related publication:
- M. Weemstra, J. Zambrano, D. Allen, MN Umaña. (In press) Tree growth increases through opposing above- and belowground resource strategies. Journal of Ecology. https://doi.org/10.1111/1365-2745.13729
- Discipline:
- Science
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- Creator:
- Yuan, Ye, Currie, William S., Sharp, Sean J. , Martina, Jason P. , and Elgersma, Kenneth J.
- Description:
- This archived dataset includes all of the input files that were used to run the model for all the runs in this set, including files containing model parameters and drivers. This dataset also includes all of the model output files from model runs in this set.
- Keyword:
- wetland, Great Lakes, greenhouse gas, climate change, and ecosystem model
- Citation to related publication:
- Yuan, Y., S. J. Sharp, J. P. Martina, K. J. Elgersma, and W. S. Currie. Sustained-flux global warming potential driven by nitrogen inflow and hydroperiod in a model of Great Lakes coastal wetlands. JGR Biogeosciences in review.
- Discipline:
- Science
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- Creator:
- Vo, Thi and Glotzer, Sharon C.
- Description:
- The goal of this project is to develop a first principle driven approach for predicting the self-assembly behavior of entropically driven crystallization. We first developed a set of mean-field theoretical framework that captures the relevant energetic contributions to the assembly process and then evaluate relevant terms within our framework to determine the excess free energy of formation for each lattice (matlab/octave codes). We then validate theoretical predictions of relevant features like shape and bonding orbitals using standard MD simulations using HOOMD-Blue (simulation scripts). and This research was supported by the Office of the Undersecretary of Defense for Research and Engineering (OUSD(R&E)), Newton Award for Transformative Ideas during the COVID-19 Pandemic, Award number HQ00342010030.
- Keyword:
- Self-Assembly, Entropy, Thermodynamics, Simulations, and Theory
- Citation to related publication:
- Vo, T., & Glotzer, S. C. (2021). Microscopic Theory of Entropic Bonding for Colloidal Crystal Prediction. ArXiv:2107.02081 [Cond-Mat]. http://arxiv.org/abs/2107.02081
- Discipline:
- Science
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- Creator:
- Liu, Meichen
- Description:
- The Brune source model is widely used in studies of complex earthquakes with multiple episodes of high moment release (i.e., multiple subevents). In this study, we investigate how corner frequency estimates of earthquakes with multiple subevents are biased if they are based on the Brune source model. By assuming complex sources as a sum of multiple Brune sources, we analyze 1,640 source time functions (STFs) of Mw 5.5-8.0 earthquakes in the SCARDEC catalog to estimate the corner frequencies, onset times, and seismic moments of subevents. We identify more subevents for strike-slip earthquakes than dip-slip earthquakes, and the number of resolvable subevents increases with magnitude. We find that earthquake corner frequency correlates best with the corner frequency of the subevent with the highest moment release (i.e., the largest subevent). This suggests that, when the Brune model is used, the estimated corner frequency and therefore the stress drop of a complex earthquake is determined primarily by the largest subevent rather than the total rupture area. and Our results imply that the stress variation of asperities, rather than the average stress change of the whole fault, contributes to the large variance of stress drop estimates.
- Citation to related publication:
- Meichen Liu, Yihe Huang, Jeroen Ritsema. 2021. Characterizing Multi-Subevent Earthquakes Using the Brune Source Model [Preprint]. https://essoar.org (2021) DOI: doi.org/10.1002/essoar.10507564.1
- Discipline:
- Science
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- Creator:
- Umaña, María Natalia and Arellano, Gabriel
- Description:
- The objective of this study was to examine the existence of congruent tree growth responses to different extreme climatic events –hurricanes and drought–affecting tropical wet forests.
- Keyword:
- Dendrometers , El Niño Southern Oscillation (ENSO), Hurricane Maria, Puerto Rico, and Tropical Forests
- Citation to related publication:
- Umaña, M.N.and Arellano G. In press. Legacy effects of drought on tree growth responses to hurricanes. Ecography. https://doi.org/10.1111/ecog.05803
- Discipline:
- Science
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Biologically Inspired Robotics and Dynamical Systems (BIRDS) Lab
User Collection- Creator:
- Revzen, Shai
- Description:
- Professor Revzen and his team at the Biologically Inspired Robotics and Dynamical Systems (BIRDS) Lab are working on discovering, modeling, and reproducing the strategies animals use when interacting with physical objects. This work consists of collaboration with biomechanists to analyze experimental data, developing new mathematical tools for modeling and estimation of model parameters, and construction of robots which employ the new principles.
- Discipline:
- Science
7Works -
- 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
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- 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
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- Creator:
- Lynch, Erin and van der Pluijm, Ben
- Description:
- High-resolution, low-angle XRD analysis of oriented clay samples (.txt files) and TC/EA, Mass Spectronometric analysis of oxygen and hydrogen isotopes (.xslx files)
- Keyword:
- fault gouge and geofluids
- Citation to related publication:
- In submission
- Discipline:
- Science
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- Creator:
- Fuller, Jennifer, Rowan, Erin, Landgraf, Ava, Alofs, Karen, Foufopoulos, Johannes, and Gronewold, Andrew
- Description:
- This study investigates the rapid decline of black tern (Chlidonias niger) over eight years in one of Michigan’s largest colonies, Lake St. Clair. 1. Nesting Success Model: A multiple logistic regression with a binomial (logit-link) fit using the glm() function from the ‘stats’ package in R (55) to determine the influence of habitat and biological predictors on nesting survival. 2. ArcMap visualization of Nesting Success: To visualize the geographic extent of the habitat’s potential to predispose nests’ vulnerability, the coefficients and intercept from our selected GLM were applied to raster layers in ArcMap using the Raster Calculator Tool. 3. Population Change & Habitat Extent: To quantify sub-colony breeding pair population size and their response to changes in sub-colony habitat in the geospatial model, we applied a general linear mixed model (GLMM) using the lmer() function from the ‘lme4’ package in R (55). Predictor variables were chosen a priori, and included the area of open water, uninhabitable vegetation (NDVI>0.72), any habitable area, and area with >50% hatch success.
- Keyword:
- black terns, wetlands, ecology, climate change, lake levels, Great Lakes, waterbirds, ornithology, general linear model, geospatial, GIS, nesting success, avian, and breeding
- Citation to related publication:
- Fuller, J., Rowan, E., Landgraf, A., Alofs, K., Foufopoulos, J., Gronewold, A., (2021). Collapse of a Black Tern Colony (Chlidonias niger) as a Result of Climate Change Driven Lake-Level Extremes and Anthropogenic Habitat Alteration [Data set]. University of Michigan - Deep Blue. and Fuller, J., et al. (2021). Shorebird colony collapses under climate driven lake-level rise and anthropogenic stressors. Forthcoming.
- Discipline:
- Science