A 17 June 2011 polar jet and its presence in the background solar wind

Abstract

High‐speed jet responses in the polar solar wind are enigmatic. Here we measure a jet response that emanates from the southern polar coronal hole on 17 June 2011 at the extreme speed of over 1200 km/s. This response was recorded from the Sun‐Earth line in Solar Dynamics Observatory/Atmospheric Imaging Assembly (SDO/AIA) and Large Angle and Spectrometric Coronagraph/C2 and both Solar TErrestrial RElations Observatory Extreme Ultraviolet Imager and COR2 coronagraphs when the three spacecraft were situated ~90° from one another. These certify the coronal 3‐D location of the response that is associated with an existing solar plume structure and show its high speed to distances of over 14 RS. This jetting is associated with magnetic flux changes in the polar region as measured by the SDO/Helioseismic and Magnetic Imager instrumentation over a period of several hours. The fastest coronal response observed can be tracked to a time near the period of greatest flux changes and to the onset of the brightest flaring in AIA. This high‐speed response can be tracked directly as a small patch of outward moving brightness in coronal images as in Yu et al. (2014) where three slower events were followed from the perspective of Earth. This accumulated jet response has the largest mass and energy we have yet seen in 3‐D reconstructions from Solar Mass Ejection Imager observations, and its outward motion is certified for the first time using interplanetary scintillation observations. This jet response is surrounded by similar high‐speed patches, but these are smoothed out in Ulysses polar measurements, we speculate about how these dynamic activities relate to solar wind acceleration.

CESE‐HLL Magnetic Field‐Driven Modeling of the Background Solar Wind During Year 2008

“…In situ observations from the Ulysses spacecraft reveal that the solar wind emanating from the polar coronal hole is extremely uniform (McComas et al, , ), which is consistent with our result. However, analyses of remote sensing observations show that the solar wind speed above polar coronal holes is intermittent and highly variable (Jackson et al, ; Yu et al, , ). For the period investigated, our modeled results miss such variable microstructures of the solar wind over the poles.…”

Validation for global solar wind prediction using Ulysses comparison: Multiple coronal and heliospheric models installed at the Community Coordinated Modeling Center

“…IPS observations over the north and south ecliptic poles are generally obtained close to the solar surface. Coronagraph and IPS studies suggest that the polar solar wind can be highly variable near the Sun at solar minimum [Jackson et al, 2014;Yu et al, 2016] requiring averaging not yet available in the time-dependent tomography. Jian et al [2015].…”

“…Because of poor solar magnetic field observation in the polar region, the Enlil model at the CCMC, by default, provides the solar wind simulation only within ±60° in latitude, although it can, in principle, model the solar wind up to higher latitudes. On the other hand, the interplanetary scintillation (IPS) observations at high latitudes are coarse and generally obtained close to the solar surface where the polar wind can be highly variable at solar minimum [ Jackson et al ., ; Yu et al ., ], requiring averaging not yet available in the time‐dependent tomography. Thus, we limit the comparison with Ulysses data in Carrington rotations (CRs) 2056–2062, as in Jian et al .…”

Iterative Tomography: A Key to Providing Time-Dependent 3-D Reconstructions of the Inner Heliosphere and the Unification of Space Weather Forecasting Techniques

“…SMEI was shut down after more than eight years of operation in September 2011 (Howard et al, 2013). Some data analysis from SMEI has continued with studies of solar jetting (Yu et al, 2016). The SMEI data still exist, and recently with advent of NASA funding for the Small Explorer Spacecraft PUNCH, there has been an interest in the resurrection of tests of these data sets for its 3-D reconstruction application with this new system.…”

“…In the iterative tomography, brightness alone can provide a LOS location of bright structures since the modeled outflow can only be present over a limited range of speeds and accelerations. Additionally, there have been other attempts to provide digital velocities from the smaller-scale heliospheric background solar wind features directly (e.g., Jackson et al, 2014;Yu et al, 2014;Yu et al, 2016), and while as yet untried using heliospheric imagery, this information is expected to be used to provide Thomson scattering velocities more directly as is used for the IPS from small-scale features at different LOS locations in these tomographic analyses.…”