English
Related papers

Related papers: Parameter optimization for surface flux transport …

200 papers

We describe, test, and apply a technique to incorporate full-sun, surface flux evolution into an MHD model of the global solar corona. Requiring only maps of the evolving surface flux, our method is similar to that of Lionello et al.…

Solar and Stellar Astrophysics · Physics 2023-10-12 Roberto Lionello , Cooper Downs , Emily I. Mason , Jon A. Linker , Ronald M. Caplan , Pete Riley , Viacheslav S. Titov , Marc L. DeRosa

The Sun's surface field, especially the polar field, sets the boundary condition for the coronal and heliospheric magnetic fields, but also provides us insight into the dynamo process. The evolution of the polar fields results from the…

Solar and Stellar Astrophysics · Physics 2018-07-05 Jie Jiang , Jinbin Cao

Computational Fluid Dynamics (CFD)-based global solar coronal simulations are slowly making their way into the space weather modeling toolchains to replace the semi-empirical methods such as the Wang-Sheeley-Arge (WSA) model. However, since…

Solar and Stellar Astrophysics · Physics 2023-03-21 Michaela Brchnelova , Błażej Kuźma , Fan Zhang , Barbara Perri , Andrea Lani , Stefaan Poedts

In this work we describe a numerical optimization method for computing stationary MHD-equilibria. The newly developed code is based on a nonlinear force-free optimization principle. We apply our code to model the solar corona using synoptic…

Solar and Stellar Astrophysics · Physics 2020-11-11 Thomas Wiegelmann , Thomas Neukirch , Dieter H. Nickeler , Iulia Chifu

The solar activity cycle is successfully modeled by the flux transport dynamo, in which the meridional circulation of the Sun plays an important role. Most of the kinematic dynamo simulations assume a one-cell structure of the meridional…

Solar and Stellar Astrophysics · Physics 2014-02-05 Gopal Hazra , Bidya Binay Karak , Arnab Rai Choudhuri

This paper investigates the use of evolutionary optimisation techniques to register a template with a scene image. An error function is created to measure the correspondence of the template to the image. The problem presented here is to…

Computational Engineering, Finance, and Science · Computer Science 2007-05-23 Lukasz A Machowski , Tshilidzi Marwala

We discuss the potential use of an algebraic method to compute the value of the solar axial dipole moment at solar minimum, widely considered to be the most reliable precursor of the activity level in the next solar cycle. The method…

Solar and Stellar Astrophysics · Physics 2020-10-29 Kristóf Petrovay , Melinda Nagy , Anthony R. Yeates

It is increasingly common to encounter data from dynamic processes captured by static cross-sectional measurements over time, particularly in biomedical settings. Recent attempts to model individual trajectories from this data use optimal…

Machine Learning · Statistics 2020-07-28 Alexander Tong , Jessie Huang , Guy Wolf , David van Dijk , Smita Krishnaswamy

Reliable prediction of the solar cycle is a formidable challenge, yet it is increasingly vital in our technology-dependent society as solar activity drives space weather. Various methods, including precursors, nonlinear curve fitting and…

Solar and Stellar Astrophysics · Physics 2026-04-20 Bidya Binay Karak

Understanding subsurface ocean dynamics is essential for quantifying oceanic heat and mass transport, but direct observations at depth remain sparse due to logistical and technological constraints. In contrast, satellite missions provide…

This paper demonstrates a refined approach to solving dynamic optimization problems for underactuated marine surface vessels. To this end the differential flatness of a mathematical model assuming full actuation is exploited to derive an…

Systems and Control · Electrical Eng. & Systems 2021-11-01 Max Lutz , Thomas Meurer

This paper describes a new algorithm for solar energy forecasting from a sequence of Cloud Optical Depth (COD) images. The algorithm is based on the following simple observation: the dynamics of clouds represented by COD images resembles…

Optimization and Control · Mathematics 2017-10-03 Sergiy Zhuk , Tigran Tchrakian , Albert Akhriev , Siyuan Lu , Hendrik Hamann

The predictability, or lack thereof, of the solar cycle is governed by numerous separate physical processes that act in unison in the interior of the Sun. Magnetic flux transport and the finite time delay it introduces, specifically in the…

Astrophysics · Physics 2009-11-13 A. R. Yeates , D. Nandy , D. H. Mackay

We describe our first attempt to systematically simulate the solar wind during different phases of the last solar cycle with the Alfv\'en Wave Solar atmosphere Model (AWSoM) developed at the University of Michigan. Key to this study is the…

The Sun's axisymmetric flows, differential rotation and meridional flow, govern the dynamics of the solar magnetic cycle and variety of methods are used to measure these flows, each with its own strengths and weaknesses. Flow measurements…

Solar and Stellar Astrophysics · Physics 2021-09-08 Sushant S. Mahajan , David H. Hathaway , Andrés Muñoz-Jaramillo , Petrus C. Martens

We present the assessment of a diffusion-dominated mean field axisymmetric dynamo model in reproducing historical solar activity and forecast for solar cycle 25. Previous studies point to the Sun's polar magnetic field as an important proxy…

Solar and Stellar Astrophysics · Physics 2018-06-29 Alejandro Macario-Rojas , Katharine L. Smith , Peter C. E. Roberts

Investigating the solar magnetic field is crucial to understand the physical processes in the solar interior as well as their effects on the interplanetary environment. We introduce a novel method to predict the evolution of the solar…

We develop a helioseismic inversion algorithm that can be used to recover sub-surface vertical profiles of 2-dimensional supergranular flows from surface measurements of synthetic wave travel times. We carry out seismic wave-propagation…

Solar and Stellar Astrophysics · Physics 2017-11-29 Jishnu Bhattacharya , Shravan M. Hanasoge , Aaron C. Birch , Laurent Gizon

Computational models have become an essential part of exploratory protocols in cell biology, as a complement to in vivo or in vitro experiments. These virtual models have the twofold advantage of enabling access to new types of data and…

Medical Physics · Physics 2021-12-20 Maxime Vassaux , Laurent Pieuchot , Karine Anselme , Maxence Bigerelle , Jean-Louis Milan

Synoptic magnetograms provide us with knowledge about the evolution of magnetic fields on the solar surface and present important information for forecasting future solar activity. In this work, poloidal and toroidal magnetic field…

Solar and Stellar Astrophysics · Physics 2020-02-19 Irina N. Kitiashvili