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.


Title: Halal et al. 2024 3D Dust Complexity Maps
The 3D dust complexity maps used in the main result of Section 4 <a href="https://arxiv.org/abs/2404.11009">"Imprints of the Local Bubble and Dust Complexity on Polarized Dust Emission," Halal et al. 2024</a>. Use of these data must cite that paper. We provide 12 maps, corresponding to the 12 posterior sample 3D dust extinction maps of <a href="https://www.aanda.org/articles/aa/full_html/2024/05/aa47628-23/aa47628-23.html">Edenhofer et al. 2023</a>, which extend radially out to 1.25 kpc. The maps we provide are in Galactic coordinates and are only defined over the masks described in <a href="https://arxiv.org/abs/2404.11009">Halal et al. 2024</a>.  more » « less
Award ID(s):
2106607
PAR ID:
10562789
Author(s) / Creator(s):
; ;
Publisher / Repository:
Harvard Dataverse
Date Published:
Subject(s) / Keyword(s):
Astronomy Astrophysics Dust Polarization Interstellar Medium
Format(s):
Medium: X Size: 4728960 Other: application/fits
Size(s):
4728960
Right(s):
Creative Commons Zero v1.0 Universal
Sponsoring Org:
National Science Foundation
More Like this
  1. The HI-based Stokes parameter maps used in (https://arxiv.org/abs/2306.10107) Filamentary Dust Polarization and the Morphology of HI Structures, Halal et al. 2023. Use of these data must cite that paper and (https://ui.adsabs.harvard.edu/abs/2019ApJ...887..136C/abstract) Clark & Hensley 2019. There are four sets of data cubes: one at Nside=1024 based on the 4' GALFA-HI data computed using the Spherical RHT algorithm, one at Nside=2048 based on the 4' GALFA-HI data smoothed to 7' computed using the Hessian algorithm, and two at Nside=1024 based on the 16.2' HI4PI data (one computed using the Spherical RHT algorithm and the other using the Hessian algorithm). A map based on the Hessian algorithm and the 16.2' HI4PI data, integrated over the velocity range -13 km/s to 16 km/s (Section 4.1 in Halal et al. 2023), is also available. The provided data cubes can be used to produce integrated maps over any velocity range desired. <br/><br/> These maps are given in units of K km/s and follow the Galactic IAU polarization convention. Multiply U by -1 to obtain maps corresponding to the COSMO convention as those provided by Planck. Multiply both Q and U by -1 to obtain maps corresponding to the magnetic field orientation in the IAU convention. <br/><br/> Please see (https://github.com/seclark/ClarkHensley2019) for code that demonstrates the use of data of the same format. The velocity binning of this data follows that of <a href="https://dataverse.harvard.edu/dataset.xhtml?persistentId=doi:10.7910/DVN/P41KDE">Clark & Hensley 2019</a> and can be found <a href="https://github.com/seclark/ClarkHensley2019/tree/master/data">here</a>. 
    more » « less
  2. <p>NSF COLDEX performed two airborne campaigns from South Pole Station over the Southern Flank of Dome A and 2022-23 and 2023-24, searching for a potential site of a continuous ice core that could sample the mid-Pleistocene transition. Ice thickness data extracted from the MARFA radar system has allow for a new understanding of this region.</p> <p>Here we generate crustal scale maps of ice thickness, bed elevation, specularity content, subglacial RMS deviation and fractional basal ice thickness with 1 km sampling, and 10 km resolution. We include both masked and unmasked grids.</p> <p> The projection is in the SCAR standard ESPG:3031 polar stereographic projection with true scale at 71˚S.</p> <p>These geotiffs were generated using performed using GMT6.5 (<a href="https://doi.org/10.1029/2019GC008515">Wessel et al., 2019</a>) using the pygmt interface, by binning the raw data to 2.5 km cells, and using the <a href="https://github.com/sakov/nn-c"> nnbathy </a> program to apply natural neighbor interpolation to 1 km sampling. A 10 km Gaussian filter - representing typical lines spacings - was applied and then a mask was applied for all locations where the nearest data point was further than 8 km. </p> Ice thickness, bed elevation and RMS deviation @ 400 m length scale (<a href="http://dx.doi.org/10.1029/2000JE001429">roughness</a>) data includes the following datasets: <ul> <li> UTIG/CRESIS <a href="https://doi.org/10.18738/T8/J38CO5">NSF COLDEX Airborne MARFA data</a></li> <li> British Antarctic Survey <a href="https://doi.org/10.5285/0f6f5a45-d8af-4511-a264-b0b35ee34af6">AGAP-North</a></li> <li> LDEO <a href="https://doi.org/10.1594/IEDA/317765"> AGAP-South </a></li> <li> British Antarctic Survey <a href="https://doi.org/10.5270/esa-8ffoo3e">Polargap</a></li> <li> UTIG Support Office for Airborne Research <a href="https://doi.org/10.15784/601588">Pensacola-Pole Transect (PPT) </a></li> <li> NASA/CReSIS <a href="https://doi.org/10.5067/GDQ0CUCVTE2Q"> 2016 and 2018 Operation Ice Bridge </a> </li> <li> ICECAP/PRIC <a href="https://doi.org/10.15784/601437"> SPICECAP Titan Dome Survey </a> </ul> <p>Specularity content (<a href="https://doi.org/10.1109/LGRS.2014.2337878">Schroeder et al. 2014</a>) is compiled from <a href="https://doi.org/10.18738/T8/KHUT1U"> Young et al. 2025a </a> and <a href="https://doi.org/10.18738/T8/6T5JS6"> Young et al. 2025b</a>.</p> <p>Basal ice fractional thickness is complied from manual interpretation by Vega Gonzàlez, Yan and Singh. </p> <p>Code to generated these grids can be found at <a href="https://github.com/smudog/COLDEX_dichotomy_paper_2025"> at github.com </a></p> 
    more » « less
  3. <p><b> Introduction </b> <br> The National Science Foundations Center for Oldest Ice Exploration (<a href="https://www.coldex.org">NSF COLDEX</a>) is a Science and Technology Center working to extend the record of atmospheric gases, temperature and ice sheet history to greater than 1 million years. As part of this effort, NSF COLDEX has been searching for a site for a continuous ice core extending through the mid-Pleistocene transition. Two seasons of airborne survey were conducted from South Pole Station across the southern flank of Dome A. </p> <p><b> 2023-2024 Field Season </b> <br> In the 2023-2024 field season (CXA2), and using a BT-67 Basler, NSF COLDEX conducted 17 flights from South Pole Station toward the southern flank of Dome C. Three test flights were conducted from McMurdo Station. Instrumentation included the <a href="https://doi.org/10.18738/T8/J38CO5">60 MHz MARFA ice penetrating radar </a> from the University of Texas Institute for Geophysics, a <a href="https://doi.org/10.1109/IGARSS53475.2024.10640448">UHF ice penetrating radar </a> from the Center for Remote Sensing and Integrated Systems; an GT-2 Gravimeter, and LD-90 laser altimeter and an G-823 Magnetometer. </p> <p><b> Basal specularity content </b> <br> These basal specularity content were derived from comparing 1D and 2D focused MARFA data (<a href="http://doi.org/10.1109/TGRS.2007.897416">Peters et al., 2007</a>). By comparing bed echo strengths for different focusing apertures, and accounting for the ranges and angles involved, we can derive the "specularity content" of the bed echo, a proxy for small scale bed roughness and a good indicator for subglacial water pressure in regions of distributed subglacial water (<a href="https://doi.org/10.1109/LGRS.2014.2337878">Schroeder et al., 2014, IEEE GRSL </a>, <a href="https://doi.org/10.1016/j.epsl.2019.115961">Dow et al., 2019, EPSL </a>) and smooth deforming bed material (<a href="http://doi.org/10.1002/2014GL061645">Schroeder et al., 2014, GRL</a>, <a href="http://dx.doi/org/10.1098/rsta.2014.0297">Young et al., 2016, PTRS</a>. Specularity data are inherently noisy, so these products have been smoothed with a 1 km filter.</p> 
    more » « less
  4. <p><b> Introduction </b> <br> The National Science Foundations Center for Oldest Ice Exploration (<a href="https://www.coldex.org">NSF COLDEX</a>) is a Science and Technology Center working to extend the record of atmospheric gases, temperature and ice sheet history to greater than 1 million years. As part of this effort, NSF COLDEX has been searching for a site for a continuous ice core extending through the mid-Pleistocene transition. Two seasons of airborne survey were conducted from South Pole Station across the southern flank of Dome A. </p> <p><b> 2022-2023 Field Season </b> <br> In the 2022-20223 field season (CXA1), and using a BT-67 Basler, NSF COLDEX conducted 13 full flights and one weather abort from South Pole Station toward the southern flank of Dome C; as well as 1 survey flight toward Hercules Dome in support of the Hercules Dome Drilling project. Three test flights were conducted from McMurdo Station. Instrumentation included the <a href="https://doi.org/10.18738/T8/J38CO5">60 MHz MARFA ice penetrating radar </a> from the University of Texas Institute for Geophysics, a <a href="https://doi.org/10.1109/IGARSS53475.2024.10640448">UHF ice penetrating radar </a> from the Center for Remote Sensing and Integrated Systems; an GT-2 Gravimeter, and LD-90 laser altimeter and an G-823 Magnetometer. </p> <p><b> Basal specularity content </b> <br> These basal specularity content were derived from comparing 1D and 2D focused MARFA data (<a href="http://doi.org/10.1109/TGRS.2007.897416">Peters et al., 2007</a>). By comparing bed echo strengths for different focusing apertures, and accounting for the ranges and angles involved, we can derive the "specularity content" of the bed echo, a proxy for small scale bed roughness and a good indicator for subglacial water pressure in regions of distributed subglacial water (<a href="https://doi.org/10.1109/LGRS.2014.2337878">Schroeder et al., 2014, IEEE GRSL </a>, <a href="https://doi.org/10.1016/j.epsl.2019.115961">Dow et al., 2019, EPSL </a>) and smooth deforming bed material (<a href="http://doi.org/10.1002/2014GL061645">Schroeder et al., 2014, GRL</a>, <a href="http://dx.doi/org/10.1098/rsta.2014.0297">Young et al., 2016, PTRS</a>. Specularity data are inherently noisy, so these products have been smoothed with a 1 km filter.</p> 
    more » « less
  5. <p>This is an example line of NSF COLDEX MARFA ice penetrating radar data (CLX/MKB2o/R66a) that has been processed to provide azimuthal information about radar echos from below, and to the front and back of the aircraft. The input was 1 meter slow time resampled coherent range record with phase intact. The data were pulse compressed and an azimuth fast Fourier transform was used to convert to azimuth angles in 1 km chunks, then slices at -19°, +19˚ and nadir were selected for these numpy arrays. These can be displayed as an RGB image with Blue = nadir, red = forward and green = rear</p> <p>The nadir slice should dominate specular echos, as seen with englacial reflecting horizons; where this trades to more balanced returns across all three channels, scattering dominates, as with rough bed rock or volume scattering. A gmt text file contains information about where this transition occurs in the ice column.</p> <p>Details in delay Doppler processing can be found in <a href="http://pds-geosciences.wustl.edu/mro/mro-m-sharad-5-radargram- v1/mrosh_2001/document/rgram_processing.pdf">Campbell et al., 2014</a>; the idea for using this approach for looking at englacial structure was discussed by <a href="https://doi.org/10.5194/egusphere-egu23-2856">Arenas-Pingarrón, Á. et al., 2023</a>. Details of HiCARs/MARFA focused processing can be found in <a href="http://dx.doi.org/10.1109/TGRS.2007.897416">Peters et al., 2007</a>.</p> 
    more » « less