Heliosphere
===========

2D slice animations of the heliospheric MHD solution.
Each row shows one quantity for equatorial and meridional cuts. For time-dependent runs the MHD solution evolves
each frame, while for steady-state runs the background is fixed and spacecraft
positions change through it.
Density and radial field are scaled by :math:`r^2` to remove the geometric
:math:`1/r^2` falloff, revealing intrinsic structure in the solar wind.

.. admonition:: Run
   :class: note

   **bgtest_superlowres** — CR2121,
   MAST3, Steady-State

----

.. raw:: html

   <style>
     /* ---- controls (hidden for single-frame/steady-state runs) ---- */
     .hel-controls { display: flex; flex-direction: column; gap: 8px; margin-bottom: 14px; }
     .hel-row-ctrl { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }

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   <div class="hel-controls">
     <div class="hel-row-ctrl">
       <div class="hel-slider-wrap">
         <input type="range" id="hel-seek" min="0" max="71" value="0"
                oninput="helSeekToStep(+this.value)">
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     <div class="hel-row-ctrl">
       <button class="hel-play-btn" id="hel-play-btn" onclick="helTogglePlay()">&#9654; Play</button>
     </div>
   </div>

   <div class="hel-grid">

     <!-- column headers -->
     <div></div>
     <div class="hel-col-hdr">Equatorial</div>
     <div class="hel-col-hdr">Meridional</div>

     <!-- one row per variable -->
     <div class="hel-row-lbl">V<sub>r</sub></div>
     <figure class="hel-cell">
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         <source src="_static/videos/heliosphere/hel_vr_equatorial.mp4" type="video/mp4">
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       <figcaption>Vr — Equatorial</figcaption>
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         <source src="_static/videos/heliosphere/hel_vr_meridional.mp4" type="video/mp4">
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       <figcaption>Vr — Meridional</figcaption>
     </figure>
     <div class="hel-row-lbl">n<sub>e</sub>&thinsp;r<sup>2</sup></div>
     <figure class="hel-cell">
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         <source src="_static/videos/heliosphere/hel_rho_equatorial.mp4" type="video/mp4">
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       <figcaption>ne r² — Equatorial</figcaption>
     </figure>
     <figure class="hel-cell">
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         <source src="_static/videos/heliosphere/hel_rho_meridional.mp4" type="video/mp4">
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       <figcaption>ne r² — Meridional</figcaption>
     </figure>
     <div class="hel-row-lbl">r<sup>2</sup>&thinsp;B<sub>r</sub></div>
     <figure class="hel-cell">
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         <source src="_static/videos/heliosphere/hel_br_equatorial.mp4" type="video/mp4">
       </video>
       <figcaption>r²Br — Equatorial</figcaption>
     </figure>
     <figure class="hel-cell">
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         <source src="_static/videos/heliosphere/hel_br_meridional.mp4" type="video/mp4">
       </video>
       <figcaption>r²Br — Meridional</figcaption>
     </figure>

   </div>

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