Center for Computational Heliophysics

Intelligent Databases and Analysis Tools for Geospace Data
(https://www.earthcube.org/group/intelligent-databases-analysis-tools-geospace-data)

Alexander Kosovichev, Gelu Nita, Vincent Oria, Viacheslav Sadykov

To facilitate interdisciplinary research on solar influences, this project will develop a unique data environment that will integrate new and archived satellite and ground-based observational data. The integrated data environment will allow researchers to efficiently access solar and geospace data and use them for studying fundamental problems of solar activity and variability and their impacts on Earth systems, as well as for developing new predictive capabilities.

The innovative interdisciplinary approach for building an intelligent integrated database, developed in collaboration between heliophysicists and computer scientists, will contribute to knowledge discovery in the EarthCube and associated fields.

Global Solar MHD Modeling
(https://www.nas.nasa.gov/publications/articles/feature_solar_simulations_Stejko.html)

Alexander Kosovichev and Andrey Stejko

In this project, the 3D global MHD model is used to accurately reproduce the structure and long-term pattern of the solar magnetic dynamo. To simulate the motion of plasma on the Sun, Stejko and Kosovichev ran a complex set of calculations on up to 512 parallel nodes (8 cores per processor and 16 cores per node) of Pleiades, simulating 100 years of solar evolution in just 3 weeks—a process that would have taken a decade on regular computers. Higher resolution simulations that were used for hyperwall visualizations took 10 times longer and needed hundreds of gigabytes of memory to store in NAS’s mass storage system.

The NAS Data Analysis and Visualization team used this data to produce high-resolution videos and images that give the NJIT researchers an incredibly detailed look at how turbulence inside the Sun can create magnetic structures. The visualizations helped the researchers track the magnetic field over several centuries, and improved their understanding of where and how it evolves in the Sun.

The high-resolution videos and images are being used to further improve the NJIT team’s numerical methods, in order to generate realistic models that can be used to predict the effects of space weather on Earth. However, many puzzles remain to be solved about what happens inside the Sun’s deep interior. Stejko says the team is now applying what they have learned to build a new model that will give even more precise results and link the modeled interior flows to measurements of the actual flows obtained from NASA’s Solar Dynamics Observatory, with the ultimate goal of developing a model that will work exactly like the Sun.

Interactive Multi-Instrument Database for Studying Solar Flares 
(http://solarflare.njit.edu)

Viacheslav Sadykov, Rishabh Gupta, Alexander Kosovichev, Gelu Nita, Vincent Oria and Denis Akhmetov

Solar flares are the most powerful events in the Heliosphere. High-energy radiation and particles generated during the flares affect the Earth’s space environment, technological and biological systems. The radiation from the solar flares cover the whole range of electromagnetic spectrum, from radio- to gamma-rays, opening a broad observational opportunities for the space missions and ground-based observatories. We develop a multi-instrument database of solar flares. Our database integrates flare reports from various sources (e.g. GOES event list, RHESSI event list, SDO/HEK flares) and allows to group (match) the reports physically representing the same flare events based on their time and position on the solar disc. For the interaction with users, we have developed a web-based interface allowing the users to search events based on their physical characteristics (e.g. the flare duration, X-ray class temperature and emission measure etc.), browse them and identify the corresponding data products (GOES and SDO/EVE light curves, SDO images etc.). The database provides an important tool for studying the physics of solar flares and developing physics-based flare forecasts.
 

Integrated Global-Sun Model of Magnetic Flux Emergence and Transport

Alexander Kosovichev and Andrey Stejko

The proposal is a part of a large collaborative project led by Dr Nagi Mansour (NASA). The proposed effort of the NJIT in collaboration with Stanford helioseismology group will be focused on the development of helioseismology data analysis methods, helioseismology modeling and data assimilation for providing robust observational data and their interpretation for these objectives. This project includes the following tasks:
A. Detailed analysis of the cross-correlation function of solar oscillations for optimal detection of the emerging flux signal, development of a fast optimal measurement scheme and travel-time fitting method, investigation of systematic and random errors;
B. Statistical analysis of the emerging flux signals, determination of the emergence detection criteria and threshold, characterization of the emerging flux data in terms of the travel-time anomaly strength, spatial and temporal behavior, distortion of the cross-correlation function, and also in terms of the relationship to the structure, evolution and activity of magnetic region after the mergence;
C. Development of numerical MHD simulations of helioseismology data for realistic models of emerging magnetic flux (including variation of the thermodynamic parameters, magnetic field and associated plasma flows), validation and testing the helioseismology data analysis procedures and codes using the numerical simulation data;
D. Investigation of the relationship between the helioseismology results and emerging flux properties for constraining the models of emerging flux and determining the model state for mathematical data assimilation methods;
E. Improvement of far-side imaging technique by implementing and optimizing the time-distance helioseismology method; verification and testing of the far imaging by using the numerical MHD simulations; comparison with the traditional holography technique;
F. Characterization of the subsurface flow maps in terms of the magnetic flux transport, comparison with the surface flux transport data from correlation tracking analysis of magnetic features; determination of the meridional circulation and zonal flows; investigation of systematic and random errors and providing the flow data for the global MHD flux transport modeling.

Characterization of Sunquake Signatures in Terms of Energy and Momentum, and Their Relationship with the Flare Impulsive Phase

Alexander Kosovichev and Viacheslav Sadykov

The sunquakes, observed in the form of expanding wave ripples, in the solar photosphere represent packets of acoustic waves that are excited by flare impacts and travel through the solar interior. The excitation impacts strongly correlate with the impulsive flare phase and are caused by the energy and momentum transport from the flare magnetic energy released sites. However, the exact mechanism of the energy and momentum transport are not known. Solving the problem of the sunquake mechanism will substantially improve our understanding of the flare energy release
in the form of energetic particles, wave and mass motions and radiation. This project represents a comprehensive investigation of the sunquake properties and their relationship to the physical processes of the impulsive phase, using observational data from the SDO, RHESSI, Hinode, SOHO, and GONG, and numerical modeling.