Importance Of Space Weather Research Articles

Observational results of MUSER during 2014–2019

The solar radio signal that can be received by the ground-based telescopes covers a wide frequency range, allowing us to monitor the complex physical processes occurred from the solar surface to the vast interplanetary space. MingantU SpEctral Radioheliograph (MUSER), as the latest generation of solar dedicated radio spectral-imaging instrument in the centimeter-decimeter wavelengths, has accumulated a large number of observational data since its commissioning observation in 2014. This paper presents the main observational results identified by MUSER from 2014 to 2019, including the quiet Sun and 94 solar radio burst events. We find that there are 81 events accompanied with Geostationary Operational Environmental Satellites (GOES) soft X-ray (SXR) flares, among which the smallest flare class is B1.0. There are 13 events without accompanying any recorded flares, among which the smallest SXR intensity during the radio burst period is equivalent to level-A. The main characteristics of all radio burst events are presented, which shows the powerful ability of MUSER to capture the valuable information of the solar non-thermal processes and the importance for space weather. This work also provides a database for further in-depth research.

A Broad Perspective on Automated CME Tracking: Towards Higher Level Space Weather Forecasting

We discuss our current capabilities to deliver the CME parameters required for the space weather forecasting process. The ever growing importance of space weather has lead to new requirements on the timeliness and objectiveness of CME detection. It has become indispensable to report the occurrence of Earth-directed CMEs and to predict their possible impact on the geospace environment. Early 2005, we are on the eve of a new era in space weather forecasting. We point out the restricted accuracy on the current forecasts and discuss a chance for amelioration. This invokes data-driven models (empirical and numerical), triggered by a real-time CME disturbance, simulating the propagation and interaction of the ejection with the ambient solar wind. We discuss the link between the direct observable parameters (like the CME projected speed and angle around the occulter) and the required input parameters (like radial speed, direction, ...). The only way to guarantee the real-time value of the simulations is by employing software which autonomously detect CME parameters in a variety of data. This paper focusses on the automated CME detection algorithms that are currently available. Automated CME tracking is yet in its infancy, therefore this 'review' will be an outlook on the potential of this field rather than looking back on already achieved milestones.

The effect of upstream turbulence and its anisotropy on the efficiency of solar wind – magnetosphere coupling

Abstract. The importance of space weather and its forecasting is growing as interest in studying geoeffective processes in the Sun – solar wind – magnetosphere – ionosphere coupled system is increasing. This paper introduces the proper selection criteria for solar wind magnetic turbulence events during duskward electric field and southward Bz driven geomagnetic storms. Two measures for the strength of solar wind fluctuations were investigated: the standard deviations of magnetic field components and a proxy for the so-called Shebalin anisotropy angles. These measures were compared to the strength of geomagnetic storms obtained from a SYM-H index time series. We found a weak correlation between standard deviation of interplanetary magnetic field GSM component Bz and SYM-H index, and a strong correlation between Shebalin anisotropy angle and the SYM-H index, which can be the result of an increase of probability of magnetic reconnection in fluctuating magnetic fields.

The influence of solar wind turbulence on geomagnetic activity

Abstract. The importance of space weather and its forecasting is growing as interest in studying geoeffective processes in the Sun – solar wind – magnetosphere – ionosphere coupled system is increasing. In this paper higher order statistical moments of interplanetary magnetic field and geomagnetic SYM-H index fluctuations are compared. The proper description of fluctuations in the solar wind can elucidate important aspects of the geoeffectivity of upstream turbulence and contribute to our understanding of space weather. Our results indicate that quasi-stationary intervals during both quiet and stormy periods have to be investigated in order to find correlations between upstream and geomagnetic conditions. We found that the fourth statistical moment (kurtosis), which was not considered in previous studies, appears to be a new geoeffective parameter. Intermittency of the magnetic turbulence in the solar wind can influence the efficiency of the solar wind – magnetosphere coupling through affecting magnetic reconnection at the Earth's magnetopause.

The solar-terrestrial interaction and its importance for space weather

The solar-terrestrial interaction is dominated by reconnection between the IMF and the Earth's magnetic field and the consequences which follow from this. Momentum and energy transfer from the solar wind into the magnetosphere are controlled by the direction of the IMF. Other factors such as the magnitude and length of time in certain directions are also important. In this paper we discuss the role played by reconnection in the process and its importance for Space Weather.