Abstract We present the first theoretical modeling of joint Parker Solar Probe (PSP)–Metis/Solar Orbiter (SolO) quadrature observations. The combined observations describe the evolution of a slow solar wind plasma parcel from the extended solar corona (3.5–6.3 R ⊙ ) to the very inner heliosphere (23.2 R ⊙ ). The Metis/SolO instrument remotely measures the solar wind speed finding a range from 96 to 201 km s −1 , and PSP measures the solar wind plasma in situ, observing a radial speed of 219.34 km s −1 . We find theoretically and observationally that the solar wind speed accelerates rapidly within 3.3–4 R ⊙ and then increases more gradually with distance. Similarly, we find that the theoretical solar wind density is consistent with the remotely and in-situ observed solar wind density. The normalized cross helicity and normalized residual energy observed by PSP are 0.96 and −0.07, respectively, indicating that the slow solar wind is very Alfvénic. The theoretical NI/slab results are very similar to PSP measurements, which is a consequence of the highly magnetic field-aligned radial flow ensuring that PSP can measure slab fluctuations and not 2D ones. Finally, we calculate the theoretical 2D and slab turbulence pressure, finding that the theoretical slab pressure is very similar to that observed by PSP.
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This content will become publicly available on July 1, 2024
Slow solar wind modeling of the Metis/Solar Orbiter – Parker Solar Probe quadrature
Abstract In January 2021, Metis/SolO and PSP formed a quadrature from which the slow solar wind was able to be measured from the extended solar corona (3.5 – 6.3 R ⊙ ) to the very inner heliosphere (23.2 R ⊙ ). Metis/SolO remotely measured the coronal solar wind, finding a speed of 96 – 201 kms −1 , and PSP measured the solar wind in situ, finding a speed of 219.34 kms −1 . Similarly, the normalized cross-helicity and the normalized residual energy measured by PSP are 0.96 and -0.07. In this manuscript, we study the evolution of the proton entropy and the turbulence cascade rate of the outward Elsässer energy during this quadrature. We also study the relationship between solar wind speed, density and temperature, and their relationship with the turbulence energy, the turbulence cascade rate, and the solar wind proton entropy. We compare the theoretical results with the observed results measured by Metis/SolO and PSP.
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- Award ID(s):
- 1655280
- NSF-PAR ID:
- 10448565
- Date Published:
- Journal Name:
- Journal of Physics: Conference Series
- Volume:
- 2544
- Issue:
- 1
- ISSN:
- 1742-6588
- Page Range / eLocation ID:
- 012007
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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