The NASA MAVEN (Mars Atmosphere and Volatile Evolution) spacecraft, which is currently in orbit around Mars, has been taking daily (systematic) measurements of the densities and temperatures in the upper atmosphere of Mars between about 140 to 240 km above the surface. Wind measurement campaigns are also conducted once per month for 5-10 orbits. These densities, temperatures and winds change with time (e.g. 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. Such global dust storm period measurements can be compared to simulations from a computer model of the Mars atmosphere called M-GITM (Mars Global Ionosphere-Thermosphere Model), developed at U. of Michigan. This is an ongoing detailed comparison between direct global dust storm period measurements in the upper atmosphere of Mars and simulated MGITM fields and is important because it can help to inform us what physical processes are acting on the upper atmosphere during such large dust events. 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 key context for understanding how the atmosphere behaves as a whole system. A basic version of the M-GITM code can be found on Github as follows: https:/github.com/dpawlows/MGITM [less]
About 4 months of Neutral Gas and Ion Mass Spectrometer (NGIMS) measurements of densities and winds have been made by the MAVEN team during the summer of 2018 (Elrod et al., 2019; Roeten et al 2022). For this specialized archive (Elrod et al. 2023), one reference measurement interval during this 2018 global dust storm (30-31 August 2018) is selected for detailed study of helium distributions (Elrod et al. 2023). The Mars conditions for this last of nine intervals have been used to launch corresponding M-GITM code simulations, yielding 3-D neutral density, temperature and wind fields for comparison to these NGIMS measurements. This last interval is used to provide M-GITM datacubes to explicitly extract the helium density (plus corresponding temperatures and neutral winds) along the trajectory of each orbit path between 140 and 240 km . A general README file is also provided for this Deep Blue Data archive detailing the contents of each file, while also summarizing the inputs and outputs of the M-GITM code simulations for this study.
Elrod, M. K., S. W. Bougher, K. Roeten, R. Sharrar, J. Murphy, Structural and Compositional Changes in the Upper Atmosphere related to the PEDE-2018 Dust Event on Mars as Observed by MAVEN NGIMS, Geophys. Res. Lett., (2019). doi: 10.1029/2019GL084378. and Elrod, M. K., S. W. Bougher, K. Roeten and K. Arnold, Surprising Decrease in the Martian He Bulge during PEDE-2018 and Changes in Upper Atmospheric Circulation, J. Geophysical Research, (2023), doi:XXX
Each row in the file contains the museum ID (museum where the specimen is located and the accession number), the species name, and the values for centroid size, followed by the x,y coordinates for each landmark. Any program that can read in a csv file can read this file.
The data and scripts are meant to show how burster dynamics determine response to a single biphasic stimulus. The files include data which show trends in the propensity of termination for different burster types and the MATLAB scripts used to generate this data. The MATLAB scripts also allow the user to generate their own data sets for alternative bursting paths and stimulus parameter combinations. Furthermore, they allow the user to visually examine the effects of single stimuli in the voltage timeseries and in state space. How the user can access these features of the script is described in the file "ReadMe.pdf."
In this work, we perform Global Sensitivity Analysis (GSA) for the background solar wind in order to quantify contributions from uncertainty of different model parameters to the variability of in-situ solar wind speed and density at 1au, both of which have a major impact on CME propagation and strength. Scripts written in the Julia language are used to build the PCE and calculate the sensitivity results. Data is available in csv, NetCDF and JLD files. A `Project.toml` file is included to activate and install all required dependencies (See README for details).
The files here provide monthly averaged soil NOx emissions (units of ng N m^-2 s^-1) for the contiguous United States on a 0.25 degree x 0.25 degree grid for the years 2011-2020 .
Reconstructed CT slices for a right tusk of Loxodonta africana (University of Michigan Museum of Paleontology catalog number UMMP_VP_118186) as a series of TIFF images. Raw projections are not included in this dataset. The reconstructed slice data from the scan are offered here as a series of unsigned 16-bit integer TIFF images. The upper left corner of the first image (*_000.tif) is the XYZ origin.
Metadata as produced by the Aracor system are included in *.IM$LA text files in IM$LA.zip.
This dataset contains three data files and three corresponding metadata files used in Bressler, A., and J. Blesh. 2023. A grass-legume cover crop maintains nitrogen inputs and nitrous oxide fluxes from an organic agroecosystem. Ecosphere. The file “N2O_Flux.xls” contains daily nitrous oxide data organized by replicate block, treatment, and date. The file “Soil_N.xls” contains nitrate and ammonium data organized by replicate block, treatment, and date. The file “Cover_crop_corn_soil.xls” contains baseline soil fertility characteristics, cover crop and corn biomass, nitrogen and carbon content, legume BNF, and cumulative N2O content organized by replicate block and treatment. The corresponding metadata files: “N2O_Flux_metadata.xls”, “Soil_N_metadata.xls”, and “Cover_crop_corn_soil_metadata.xls” provide detailed descriptions of all variables in each data set and any abbreviations used.
Bressler, A., and J. Blesh. 2023. A grass-legume cover crop maintains nitrogen inputs and nitrous oxide fluxes from an organic agroecosystem. Ecosphere. 14(2): e4428. https://doi.org/10.1002/ecs2.4428
It is commonly thought that volcanic glass only records volatile loss during the eruptions in the Moon. However, our recent work shows that Na, K and Cu (moderately volatile elements) in lunar 74220 orange glass beads are enriched near the bead surfaces and depleted in the bead interiors, forming an overall “U-shaped” profile. The “U-shaped” profile means that rather than being “lost” into space, Na, K and Cu were “gained” into the volcanic glass during the eruption, which is contrary to the “volatile loss” story. Three different instruments (EMP, SIMS and LA-ICP-MS) were used to verify the discovery. We propose that such U-shaped Na, K and Cu profiles were formed by initial outgassing and subsequent in-gassing of Na, K and Cu when the beads were flying from the vent onto the surface through the cooling volcanic gas plume. Hence, in-gassing and the formation of surface coatings are two processes that are genetically linked during the pyroclastic eruption and evolution of the gas cloud. To quantify the processes that formed the U-shaped profiles, we developed a diffusion and surface-equilibrium model using available literature data on Na and Cu diffusivity in basaltic melts. The model reproduced U-shaped Na and Cu concentration profiles with outgassing at high temperature and subsequent in-gassing as beads cooled. By fitting the measured Na and Cu profiles, we found that the cooling time scales of individual orange glass beads range from 48 to 179 s. This is the first time that both outgassing and in-gassing were modeled and the cooling time scales of individual 74220 volcanic orange glass beads were estimated. The discovery of the U-shaped profiles of moderately volatile elements inside volcanic beads provides significant constraints on partial pressures of relevant volcanic gas species in the eruption plume.
Su, X., Zhang, Y., Liu, Y. and Holder, R.M. (2023) Outgassing and in-gassing of Na, K and Cu in lunar 74220 orange glass beads. Earth and Planetary Science Letters 602. https://doi.org/10.1016/j.epsl.2022.117924
Reconstructed CT slices for UMMP VP 118710 Mammuthus primigenius proximal tusk segment as a series of TIFF images. Raw projections are not included in this dataset. The reconstructed slice data from the scan are offered here as a series of unsigned 16-bit integer TIFF images. The upper left corner of the first image (*_0000.tif) is the XYZ origin.
Reconstructed CT slices for UMMP VP 118186 Loxodonta africana tusk core as a series of TIFF images. Raw projections are not included in this dataset. The reconstructed slice data from the scan are offered here as a series of unsigned 16-bit integer TIFF images. The upper left corner of the first image (*_0000.tif) is the XYZ origin.
