Solar-wind predictions for the Parker Solar Probe orbit

Abstract

The scope of this study is to model the solar-wind environment for the Parker Solar Probe's unprecedented distances down to 9.86 Rs in its mission phase during 2018-2025. The study is performed within the CGAUSS project which is the German contribution to the PSP mission as part of the WISPR imager on PSP. We present an empirical solar-wind model for the inner heliosphere which is derived from OMNI and Helios data. The sunspot number (SSN) and its predictions are used to derive dependencies of solar-wind parameters on solar activity and to forecast them for the PSP mission. The frequency distributions for the solar-wind key parameters magnetic field strength, proton velocity, density, and temperature, are represented by lognormal functions, considering the velocity distribution's bi-componental shape. Functional relations to the SSN are compiled using OMNI data and based on data from both Helios probes, the parameters' frequency distributions are fitted with respect to solar distance. Thus, an empirical solar-wind model for the inner heliosphere is derived, accounting for solar activity and solar distance. The inclusion of SSN predictions and the extrapolation down to PSP's perihelion region enables us to estimate the solar-wind environment for PSP's planned trajectory during its mission duration. This empirical model yields estimated solar-wind values for PSP's 1st perihelion in 2018 at 0.16 au: 87 nT, 340 km s-1, 214 cm-3 and 503000 K. The estimates for PSP's first closest perihelion, occurring in 2024 at 0.046 au, are 943 nT, 290 km s-1, 2951 cm-3, and 1930000 K. Since the modeled velocity and temperature values below approximately 20 Rs appear overestimated in comparison with existing observations, this suggests that PSP will directly measure solar-wind acceleration and heating processes below 20 Rs as planned.

14 pages, 14 figures, 4 tables, accepted for publication in A&A

References in corpus (2)

• Predicting the Amplitude and Hemispheric Asymmetry of Solar Cycle 25 with Surface Flux Transport
• CME dynamics using STEREO & LASCO observations: the relative importance of Lorentz forces and solar wind drag

Cited by in corpus (24)

• Critical Science Plan for the Daniel K. Inouye Solar Telescope (DKIST)
• Detection of Ongoing Mass Loss from HD 63433c, a Young Mini Neptune
• Testing the background solar wind modelled by EUHFORIA
• Metastable Helium Absorptions with 3D Hydrodynamics and Self-Consistent Photochemistry I: WASP-69b, Dimensionality, XUV Flux Level, Spectral Types, and Flares
• Metastable Helium Absorptions with 3D Hydrodynamics and Self-Consistent Photochemistry II: WASP-107b, Stellar Wind, Radiation Pressure, and Shear Instability
• Strong Preferential Ion Heating is Limited to within the Solar Alfven Surface
• Bimodal distribution of the solar wind at 1 AU
• Exploring the radial evolution of Interplanetary Coronal Mass Ejections using EUHFORIA
• Properties of stream interaction regions at Earth and Mars during the declining phase of SC 24
• A mission architecture to reach and operate at the focal region of the solar gravitational lens
• The exoplanetary magnetosphere extension in Sun-like stars based on the solar wind -- solar UV relation
• Turbulent Proton Heating Rate in the Solar Wind from $5$ to $45R_{\odot }$
• Particle-In-Cell simulations of the parallel proton firehose instability influenced by the electron temperature anisotropy in solar wind conditions
• On the time lag between solar wind dynamic parameters and solar activity UV proxies
• Dissipation scale lengths of density turbulence in the inner solar wind
• Preparing for Solar and Heliospheric Science with the SKAO: An Indian Perspective
• Disentangling the solar activity-solar wind predictive causality at Space Climate scales
• Orbital Migration through Atmospheric Mass Loss
• Effect of Dust Rotational Disruption by Radiative Torques and Implications for F-corona decrease revealed by the Parker Solar Probe
• Space weather: the solar perspective -- an update to Schwenn (2006)
• Reconstructing the Sun's Alfvén surface and wind braking torque with Parker Solar Probe
• De-Biasing Structure Function Estimates From Sparse Time Series of the Solar Wind: A Data-Driven Approach
• Properties and Radial Evolution of Solar Wind Turbulence Near Mercury's Orbit
• Characteristics and evolution of sheath and leading edge structures of interplanetary coronal mass ejections in the inner heliosphere based on Helios and Parker Solar Probe observations