This animation summarizes the new heliospheric scenario and the formation of the "sea" of bubbles in the heliosheath. The sun's magnetic field points toward the sun in the northen hemisphere and away from the sun in the southern (shown in red and blue). These oppositely pointing magnetic fields are separated by a layer of current called the heliospheric current sheet. Due to the tilt of the magnetic axis in relation to the axis of rotation of the sun, the heliospheric current sheet flaps like a flag in the wind. The flapping current sheet separates regions of oppositely pointing magnetic field, called sectors. As the solar wind speed decreases past the termination shock, the sectors squeeze together, bringing regions of opposite magnetic field closer to each other. When the separation of sectors becomes very small, the sectored magnetic field breaks up into a sea of nested "magnetic bubbles" in a phenomenon called magnetic reconnection. The region of nested bubbles is carried by the solar wind to the north and south, filling out the entire front region of the heliopause and the sector region in the heliosheath.
This animation depicts the effect of the new scenario on galactic cosmic rays. The heliospheric boundaries are very important in shielding the inner solar system from the galactic cosmic ray flux. The heliopause, the last region that separates us from the rest of the galaxy, acts more like a membrane that is permeable to galactic cosmic rays than a shield that deflects those energetic particles. The galactic cosmic rays slowly wander into the heliosphere and can get trapped in the sea of magnetic bubbles. Eventually they access the solar magnetic field lines that connect back to the sun, and can move quickly towards the sun and Earth.
This animation shows the Voyager 2 observations of energetic electrons. Voyager 2 detected a dramatic drop of the flux of electrons as it left the sector region. The intense flux came back as soon as Voyager 2 was inside the sector region again. Energetic particles have a hard time "navigating" through the sea of bubbles. The bubbles act like traps for these particles. When particles escape the sea of bubbles and access the field lines that connect back to the sun, they quickly escape along the magnetic field lines, very much like entering a highway. These observations were the unexpected signature of the new scenario.
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 22.214.171.124.0