Solar-Terrestrial Sciences

New insights to the north-south asymmetries of auroral features

Jone Peter Reistad February 14, 2019

Aurora Borealis above the EISCAT Svalbard Radar. Credit: Jone Peter Reistad

Recent research on the simultaneous displays of aurora in both hemispheres have lead to new knowledge of how large-scale asymmetries in the global magnetic field configuration can arise and be mitigated. This new understanding is contrary to what has been the consensus in the field, and was recently highlighted in a press release from the American Geophysical Union, followed by attention from nume ...[Read More]

Web-based Tools for Forecasting Solar Particle Events and Flares

Athanasios Papaioannou January 14, 2019

The effect of particles in the Bastille day event. Credit: http://sidc.be/news/233/welcome.html

The presence of Solar Energetic Particles (SEPs) poses a serious health risk to humans in space, can result in increased radiation doses for high-latitude aircraft flights and constitutes a serious hazard for the micro-electronics and other hardware elements of satellites, aircraft and launchers. These groups of end users need reliable forecasts of possible enhancements in the radiation flux level ...[Read More]

A close-up journey to the Sun: The Parker Solar Probe Mission

Athanasios Papaioannou October 24, 2018

Artist’s concept of the Parker Solar Probe spacecraft approaching the sun. Credit: NASA/Johns Hopkins APL/Steve Gribben

Almost two months ago, in August 12, 2018 Parker Solar Probe (PSP) launched by NASA on a Delta IV Heavy rocket from Cape Canaveral, Florida. This is a long-awaited mission from the Heliospheric community. The first to explore the Sun within distances of ~0.167 AU (or 25 million kilometers) at its perihelia. Its ancestors were the successful Helios -A and -B spacecraft, a pair of probes launched in ...[Read More]

Cosmogenic Radionuclides – The quest of studying the solar activity of thousands of years

Athanasios Papaioannou September 18, 2018

Figure 1: Sketch of the processes involved in order to model the atmospheric production of the cosmogenic radionuclides. Courtesy K. Herbst

Thanks to the invention of the Neutron Monitor in 1948 and multiple spacecraft which monitor the cosmic ray environment since 1970’s we now have a constant record of the solar activity over almost 70 years. Information prior to this space era, however, are rare and take us back in time only to the late 1930s, when ionization chambers have been introduced. This of course allows us only a narr ...[Read More]

SunPy: a Python solar data analysis environment

Kamalam August 16, 2018

Introduction For many years now we know that our star the Sun influences the Earth in many different ways, via the total solar irradiance, solar energetic particles and coronal mass ejections. Understanding the influence of the Sun on the Earth requires many different types of measurements. For example, NASA’s Solar Dynamics Observatory (SDO) spacecraft, produces over 1 terabyte of data per day (P ...[Read More]

Cosmic rays – messengers from space

Athanasios Papaioannou March 19, 2018

Artistic representation of cosmic rays entering the Earth's atmosphere (Credit: Asimmetrie/INFN).

Cosmic rays (CRs), are not actually rays, but highly energetic charged particles of extraterrestrial origin. The life cycle of a cosmic ray particle starts with its birth at some point in the Universe, its travel at nearly the speed of light and finally with its death ( e.g. at a detector). These highly energetic particles strike our planet from all directions and thus provide a constant backgroun ...[Read More]

How do we study the magnetosphere?

Jone Peter Reistad January 15, 2018

The Sun-Earh system. Credit: NASA

Our closest star, the Sun, is constantly emitting hot gas in all directions as its upper atmosphere, the corona, expands. This is known as the Solar Wind, also carrying with it an embedded magnetic field, the Interplanetary Magnetic Field (IMF). The IMF originates at the Sun and forms an enormous spiral throughout the solar system as the solar wind escapes radially, while the magnetic field-line ...[Read More]

Eyes on the Sun

Kamalam October 31, 2017

Fig. 1: The Sun’s layers in different wavelengths. Credits NASA/GSFC/SDO

The Sun is a complex, dynamic ball of plasma which influences our lives. Studying the Sun is challenging because each of its layers have different composition, physics and wavelengths of emssion. Moving outwards from the photosphere (visible surface of the Sun), we have the chromosphere and the corona (hottest outermost layer). The solar plasma is in constant motion much like fiercely boiling wate ...[Read More]

Capturing a Whole Total Eclipse of the Sun: Megamovie

Hugh S Hudson July 25, 2017

The Eclipse Megamovie Project (from https://eclipsemega.movie/)

by Hugh S Hudson (U. of Glasgow and UC Berkeley) Normally solar eclipses give an observer only a fleeting moment (minutes at most) to enjoy the solar corona. We aim to amplify that considerably in the August 21 eclipse across North America. The plan is simple: Megamovie will capture everybody’s images, especially those from a group of 1,000 photographc volunteers, and compile them into an op ...[Read More]