Global Sensitivity Analysis and Uncertainty Quantification for Background Solar Wind Using the Alfvén Wave Solar Atmosphere Model

Abstract

Coronal mass ejections (CMEs) are large-scale eruptions of the solar coronal plasma and magnetic fields expelled into the solar wind. CMEs can create magnetic storms in the Earth's magnetosphere that are responsible for severe geomagnetic effects ranging from breakdown in radio communications to damage of sensitive electronics on satellites and even disrupting the power grid. Therefore it is imperative to obtain reliable long-term predictions of space weather events driven by CMEs.Current state-of-the-art modeling capabilities involve numerical simulations using coupled first-principles and/ or empirical models. A prominent example is the Space Weather Modeling Framework (SWMF) (Gombosi et al., 2021;Tóth et al., 2005Tóth et al., , 2012) that models domains from the upper solar chromosphere to the Earth's atmosphere and/or the outer heliosphere using efficient coupling between multiple models and is capable of full Sun-to-Earth simulations. Typically, as shown in Figure 1, the model chain consists of obtaining the background solar wind in Stage 1, generating and propagating a CME through the heliosphere to Earth in Stage 2, and finally calculating the magnetospheric impact via geospace models in Stage 3. Along the way, various observational data (in the blue boxes) are also available to calibrate or validate the model. The SWMF offers predictions for several macroscopic plasma quantities, including those that critically impact the magnetosphere and the resulting

Investigating a Solar Wind Stream Interaction Region using Interplanetary Spacecraft Radio Signals: A Magnetohydrodynamic Simulation Study

“…Coronal mass ejections, for example, are expected to have a completely different FETCH signature (Jensen et al 2023). As FETCH data sets are accumulated, modern deep-learning algorithms and guided machine-learning techniques in heliophysics (Dorelli et al 2022;Jivani et al 2023) could play a role in improving classifications, predictions, and parameter estimates. The proposed FETCH system does have limitations.…”

Bayesian Inference and Global Sensitivity Analysis for Ambient Solar Wind Prediction

“…A sensitivity analysis study by Jivani et al. (2022) estimated the Sobol' sensitivity indices associated with uncertain parameters in the MHD Alfvén Wave Solar atmosphere Model (van der Holst et al., 2014). A recent study by Reiss et al.…”

“…We use variance-based global sensitivity analysis by estimating Sobol' sensitivity indices (Sobol', 2001). A sensitivity analysis study by Jivani et al (2022) estimated the Sobol' sensitivity indices associated with uncertain parameters in the MHD Alfvén Wave Solar atmosphere Model (van der Holst et al, 2014). A recent study by Reiss et al (2020) used Morris screening (Morris, 1991), a hybrid local/global sensitivity analysis method, to identify the most influential parameters in the WSA model.…”

Quantifying Uncertainties in the Quiet‐Time Ionosphere‐Thermosphere Using WAM‐IPE

“…Uncertainty quantification (UQ) is an emerging field that aims to compute the amount of uncertainty associated with particular quantities of interest (QoIs) in a physical system (i.e., Licata et al, 2022;Jivani et al, 2023). One technique widely used in UQ is to approximate the QoI in a series of orthogonal polynomials known as polynomial chaos expansion (PCE) (Doostan & Owhadi, 2011;Ghanem & Spanos, 2002;Xiu, 2010) and estimate the QoI low-order statistics or the sensitivity of QoI to the input through the expansion coefficients (Crestaux et al, 2009).…”

“…One technique widely used in UQ is to approximate the QoI in a series of orthogonal polynomials known as polynomial chaos expansion (PCE) (Doostan & Owhadi, 2011;Ghanem & Spanos, 2002;Xiu, 2010) and estimate the QoI low-order statistics or the sensitivity of QoI to the input through the expansion coefficients (Crestaux et al, 2009). PCE has been applied in a recent space weather study by Jivani et al (2023) to identify the important model parameters that affect the solar wind prediction with the Alfven Wave Solar atmosphere Model (AWSoM).…”