skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: Coordinates and Dynamic Pressure of High-Speed Magnetosheath Jets Measured by THEMIS Satellites, 2012-2018
This dataset adds satellite parameters and dynamic pressure calculations to the event list at https://osf.io/7rjs4/ You can reference this data set as follows: Plaschke, F., Hietala, H., & LaMoury, A. T. (2020, October 27). THEMIS magnetosheath jet data set 2012-2018. Retrieved from osf.io/7rjs4. The description of the identification processes of the THEMIS data sets is published in: Plaschke, F., Hietala, H., and Angelopoulos, V.: Anti-sunward high-speed jets in the subsolar magnetosheath, Ann. Geophys., 31, 1877–1889, https://doi.org/10.5194/angeo-31-1877-2013, 2013. The original THEMIS list should be downloaded locally from the link above before running the python code in the Jupyter notebook. The columns contain:    column 1: jet number    column 2: observing spacecraft (A: THEMIS-A, ..., E: THEMIS-E)    column 3: start of identified jet interval in UT    column 4: time of maximum dynamic pressure ratio in UT    column 5: end of identified jet interval in UT In the final version of the list, the column is indexed by "Max" (col 4 in original), and the other columns are named 'Jet Number', 'Ref Spacecraft', 'Start', and 'End'. From CDAWeb, we add the following columns:     SM_LAT, SM_LON: Latitude and longitude in GSM coordinates    SM_X, SM_Y, SM_Z: Cartesian position in GSM coordinates    GEO_X_1, GEO_Y_1, GEO_Z_1: Cartesian position in geographic coordinates    DIST_FROM_P93_BOW_SHOCK: Distance from the P93 Bow Shock    DIST_FROM_MAGNETOPAUSE: Distance from the RS93 Magnetopause    DIST_FROM_T95_NS: Distance to the Tsyganenko 1995 model Neutral Sheet    L_VALUE: Dipole L value    INVAR_LAT: Dipole Invariant Latitude    MAGNETIC_STRENGTH: Magnetic Field Strength    Dynamic Pressure (nPa): Peak dynamic pressure of jet     Electron density:     Vx, Vy, Vz: Cartesian coordinates of ion velocity. Used in computing dynamic pressure These are pulled from orbit parameters and on-board moment data, using ai.cdas and the second using pyspedas respectively.  more » « less
Award ID(s):
2218996
PAR ID:
10562841
Author(s) / Creator(s):
Publisher / Repository:
Zenodo
Date Published:
Format(s):
Medium: X
Right(s):
Creative Commons Attribution 4.0 International
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; ; ; ; ; ; (, Journal of Geophysical Research: Space Physics)
    Abstract We use the three‐dimensional (3‐D) global hybrid code ANGIE3D to simulate the interaction of four solar wind tangential discontinuities (TDs) observed by ARTEMIS P1 from 0740 UT to 0800 UT on 28 December 2019 with the bow shock, magnetosheath, and magnetosphere. We demonstrate how the four discontinuities produce foreshock transients, a magnetosheath cavity‐like structure, and a brief magnetopause crossing observed by THEMIS and MMS spacecraft from 0800 UT to 0830 UT. THEMIS D observed entries into foreshock transients exhibiting low density, low magnetic field strength, and high temperature cores bounded by compressional regions with high densities and high magnetic field strengths. The MMS spacecraft observed cavities with strongly depressed magnetic field strengths and highly deflected velocity in the magnetosheath downstream from the foreshock. Dawnside THEMIS A magnetosheath observations indicate a brief magnetosphere entry exhibiting enhanced magnetic field strength, low density, and decreased and deflected velocity (sunward flow). The solar wind inputs into the 3‐D hybrid simulations resemble those seen by ARTEMIS. We simulate the interaction of four oblique TDs with properties similar to those in the observation. We place virtual spacecraft at the locations where observations were made. The hybrid simulations predict similar characteristics of the foreshock transients, a magnetosheath cavity, and a magnetopause crossing with characteristics similar to those observed by the multi‐spacecraft observations. The detailed and successful comparison of the interaction involving multiple TDs will be presented. 
    more » « less
  2. ; ; ; ; ; (, Journal of Geophysical Research: Space Physics)
    Abstract South Pole Station, Antarctica (SPA, magnetic latitude = −74.5°, magnetic local time (MLT) = UT–3.5 h), is a unique observatory which can capture daytime auroral forms throughout austral winter season. We have studied the properties and origin of ultralow‐frequency (ULF) range modulation of daytime diffuse aurora, using data acquired on June 23, 2017 by multi‐instrument measurements at SPA and in situ measurements in the dayside outer magnetosphere. At 1500–1600 UT, monochromatic Pc5‐range pulsations (period ∼10 min) emerged in the midday diffuse auroral region. The sequential 2‐D images reveal that the auroral pulsations result from the repetitive formation of faint, diffuse auroral patches, propagating poleward at a speed of ∼1.5 km s−1. Interestingly, no obviously similar magnetic pulsations were found at SPA. The results differ fundamentally from the ground optical and magnetic signatures expected for a standing field line resonance. On the other hand, the co‐located riometer and VLF receiver observed clearly synchronized pulsations, suggesting that tens‐of‐keV electrons interact with modulated chorus waves and then are scattered down to the auroral pulsation region. During the same interval, the THEMIS‐D spacecraft detected corresponding Pc5 oscillations in the dayside outer magnetosphere (9–10REand ∼15 MLT). The compressional component of the magnetospheric Pc5 waves, presumably driven by an external source, exhibited a good correspondence to the daytime Pc5 auroral pulsations. The simultaneous SPA–THEMIS observations highlight the role of compressional Pc5 pulsations in the dayside outer magnetosphere in determining the periodicity of daytime high‐latitude diffuse auroral pulsations. 
    more » « less
  3. ; (, Zenodo)
    This Python script queries the USGS StreamStats Service API for a list of available basin characteristics, and the values for those characteristics, for each input site. The script takes as input a matrix of site identifiers and location coordinates and returns 1) a matrix of values for available basin characteristics obtained from StreamStats for each input location and 2) a matrix of basin characteristic variable names and definitions. To run this script exactly as written, create 3 columns of data in comma-separated format: 1) 'Site,' which are the study site identifiers, 2) 'lonSS,' the longitudinal coordinates, and 3) 'latSS,' the latitudinal coordinates (in decimal degrees). Name the input file 'ssLocs.csv' and store it in a subfolder named 'Data.' Otherwise, the pathnames for input and output files can be modified within the script. The output files 'ssDats.csv' and 'Descriptions.csv' will also be saved to the subfolder 'Data'. Multiple code runs may be necessary to obtain information for all sites; as long as the output file 'ssDats.csv' remains in the 'Data' folder, the script will only query for sites with missing information. If the program returns an error or is unable to obtain data for a site after several attempts, it may be that the input coordinates do not point to a cell defined as water in the StreamStats application. A solution is to check the coordinates manually in the StreamStats web application (http://streamstats.usgs.gov). This script was developed as part of the analysis described in: URycki DR, Good SP, Crump BC, Chadwick J and Jones GD (2020) River Microbiome Composition Reflects Macroscale Climatic and Geomorphic Differences in Headwater Streams. Front. Water 2:574728. doi: 10.3389/frwa.2020.574728 
    more » « less
  4. ; ; ; ; ; (, Journal of Geophysical Research: Space Physics)
    Abstract The magnetotail lobe region at Mercury is characterized by low plasma density and low magnetic field variability compared to the nightside magnetosheath and central plasma sheet. At Mercury, as well as other planets, lobe magnetic fields play a crucial role in storing and releasing magnetic flux in response to changing upstream solar wind conditions such as interplanetary magnetic field (IMF) orientation and solar wind dynamic pressure (Pdyn). This makes the region significant for studying the magnetospheric interaction with the intense solar wind conditions at Mercury's orbit. Here, we identify and analyze magnetotail lobe observations made by the Mercury Surface, Space Environment, Geochemistry and Ranging (MESSENGER) spacecraft during its 4 years orbital phase. We empirically determined a set of criteria using magnetometer (MAG) and the Fast Imaging Plasma Spectrometer instruments onboard MESSENGER to identify lobe magnetic field intervals. From 3,332 MESSENGER orbits, we identify 1,242 lobe field intervals. We derive an expression for the average lobe magnetic field strength in nanotesla with respect to radial distance downtail:Blobe(r) = (135 ± 8) * r(−2.1±0.3) + (31 ± 8). The lobe magnetic field exhibits both small‐scale (∼3 min) and orbit‐to‐orbit (∼8–12 hr) variability in magnetic field strength compared to this averaged field strength expression. The orbit‐to‐orbit variability in lobe field strength is not significantly correlated with estimated IMF orientation, but is directly correlated withPdyn. Thus, our findings provide evidence for the pressure balance between the inward facingPdynon the nightside magnetopause and the outward facing magnetic pressure supplied by the lobes. 
    more » « less
  5. ; ; (, Frontiers in Astronomy and Space Sciences)
    Magnetopause location is an important prediction of numerical simulations of the magnetosphere, yet the models can err, either under-predicting or over-predicting the motion of the boundary. This study compares results from two of the most widely used magnetohydrodynamic (MHD) models, the Lyon–Fedder–Mobarry (LFM) model and the Space Weather Modeling Framework (SWMF), to data from the GOES 13 and 15 satellites during the geomagnetic storm on 22 June 2015, and to THEMIS A, D, and E during a quiet period on 31 January 2013. The models not only reproduce the magnetopause crossings of the spacecraft during the storm, but they also predict spurious magnetopause motion after the crossings seen in the GOES data. We investigate the possible causes of the over-predictions during the storm and find the following. First, using different ionospheric conductance models does not significantly alter predictions of the magnetopause location. Second, coupling the Rice Convection Model (RCM) to the MHD codes improves the SWMF magnetopause predictions more than it does for the LFM predictions. Third, the SWMF produces a stronger ring current than LFM, both with and without the RCM and regardless of the LFM spatial resolution. During the non-storm event, LFM predicts the THEMIS magnetopause crossings due to the southward interplanetary magnetic field better than the SWMF. Additionally, increasing the LFM spatial grid resolution improves the THEMIS predictions, while increasing the SWMF grid resolutions does not. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email