PSTEP: project for solar–terrestrial environment prediction

Abstract

Although solar activity may significantly impact the global environment and socioeconomic systems, the mechanisms for solar eruptions and the subsequent processes have not yet been fully understood. Thus, modern society supported by advanced information systems is at risk from severe space weather disturbances. Project for solar–terrestrial environment prediction (PSTEP) was launched to improve this situation through synergy between basic science research and operational forecast. The PSTEP is a nationwide research collaboration in Japan and was conducted from April 2015 to March 2020, supported by a Grant-in-Aid for Scientific Research on Innovative Areas from the Ministry of Education, Culture, Sports, Science and Technology of Japan. By this project, we sought to answer the fundamental questions concerning the solar–terrestrial environment and aimed to build a next-generation space weather forecast system to prepare for severe space weather disasters. The PSTEP consists of four research groups and proposal-based research units. It has made a significant progress in space weather research and operational forecasts, publishing over 500 refereed journal papers and organizing four international symposiums, various workshops and seminars, and summer school for graduate students at Rikubetsu in 2017. This paper is a summary report of the PSTEP and describes the major research achievements it produced.

Full-disc Ca ii K observations—A window to past solar magnetism

“…being unaffected by Earth's atmosphere, allowing measurement of quantities sensible to the atmospheric absorption, one example being the Total Solar Irradiance (TSI, the total, spectrally-integrated solar radiative energy flux measured at the top of Earth's atmosphere). Current and future missions, such as the Solar Orbiter (Müller et al, 2020), Parker Solar Probe (Fox et al, 2016), Aditya-L1 (Seetha and Megala, 2017;Tripathi et al, 2017), Solar-C (Watanabe, 2014;Shimizu et al, 2020), and balloonborne Sunrise (Solanki et al, 2010;Solanki et al, 2017;Feller et al, 2020) will keep pushing our understanding of the physics of the Sun (Kusano et al, 2021).…”

Solar Energetic Particle Events with Short and Long Onset Times

“…We thank the reviewer for their helpful comments on the manuscript. This study is based on the discussion at the Coordinated Data Analysis Workshops held in 2018 and 2019 August held under the auspice of the Project for Solar-Terrestrial Environment Prediction (PSTEP; Kusano et al 2021). This work was supported by JSPS KAKENHI grant Nos.…”

Statistical analysis for EUV dynamic spectra and their impact on the ionosphere during solar flares

“…"FISM2". Kawai et al (2020) introduced a new method to reproduce the emission spectrum of EUV flares, which is called the solar flare emission model (Kusano et al 2021). In this paper, the solar flare emission model is referred to as the SFEM.…”