A Comparison Study of Extrapolation Models and Empirical Relations in Forecasting Solar Wind

Abstract

Coronal mass ejections and high speed solar streams serve as perturbations to the background solar wind that have major implications in space weather dynamics. Therefore, a robust framework for accurate predictions of the background wind properties is a fundamental step toward the development of any space weather prediction toolbox. In this pilot study, we focus on the implementation and comparison of various models that are critical for a steady state, solar wind forecasting framework. Specifically, we perform case studies on Carrington rotations 2,053, 2,082, and 2,104, and compare the performance of magnetic field extrapolation models in conjunction with velocity empirical formulations to predict solar wind properties at Lagrangian point L1. Two different models to extrapolate the solar wind from the coronal domain to the inner-heliospheric domain are presented, namely, a) Kinematics based [Heliospheric Upwind eXtrapolation (HUX)] model, and b) Physics based model. The physics based model solves a set of conservative equations of hydrodynamics using the PLUTO code and can additionally predict the thermal properties of solar wind. The assessment in predicting solar wind parameters of the different models is quantified through statistical measures. We further extend this developed framework to also assess the polarity of inter-planetary magnetic field at L1. Our best models for the case of CR2053 gives a very high correlation coefficient (∼0.73–0.81) and has an root mean square error of (∼75–90 km s−1). Additionally, the physics based model has a standard deviation comparable with that obtained from the hourly OMNI solar wind data and also produces a considerable match with observed solar wind proton temperatures measured at L1 from the same database.

A Parametric Study of Performance of Two Solar Wind Velocity Forecasting Models During 2006–2011

“…Our simulated velocity profiles at L1 are smoother than the observed because of the fact that the HUX extrapolation method ignores pressure gradient term along with the gravity. One expects to get results that match better, if one incorporates 2D pressure gradient term (Kumar et al., 2020).…”

Predicting Solar Wind Streams from the Inner-Heliosphere to Earth via Shifted Operator Inference

“…The HUX (Heliospheric Upwinding eXtrapolation) model developed by [52,48] is a two-dimensional time-stationary model that predicts the heliospheric solar wind speed. The HUX model has been incorporated into operational and ensemble-based space weather programs [27,5] as a MHD surrogate model to study retrospective time periods as well as real-time predictions. It has also been used to map streams directly from in-situ spacecraft observations (e.g.…”

SWASTi-SW: Space Weather Adaptive Simulation Framework for Solar Wind and Its Relevance to the Aditya-L1 Mission

“…The MHD domain uses the PLUTO code (Mignone et al 2007) to compute the plasma properties in the inner heliosphere. An earlier assessment of usage of the PLUTO code for solar wind prediction was done in the two-dimensional pilot study by Kumar et al (2020), in which they compared the results with other extrapolation models using the WSA relation. In this three-dimensional work, a more generalized version of the WSA relation is used, along with the more robust and flexible coronal model.…”