[P-EM14] Frontiers in solar physics

[PEM14-P04] A New Solar Radio Polarimeter in Yokosuka - Yokosuka Radio Polarimeter (YoRP)

*Kyoko Watanabe¹, Kazumasa Iwai², Masumi Shimojo³ (1.National Defense Academy of Japan, 2.ISEE, Nagoya University, 3.National Astronomical Observatory of Japan)

Keywords:Solar microwave emission, Radio Polarimeter, Space Weather

Extreme ultraviolet (EUV) emission from the Sun, which is the main contributor to the space weather environment, is known to correlate well with microwaves, which can also be observed on the ground. In fact, we confirmed that there is a good correlation between solar EUV and microwave emissions, not only for variations of these emissions in solar cycle, but also for variations of these emissions due to solar flares. In our previous study, we mainly used EUV spectra observed by the TIMED/SEE and SDO/EVE, and microwave data obtained by the Nobeyama Radio Polarimeters (NoRP). For the solar cycle variations, it was found that among the microwave emissions, low-frequency microwave emissions such as 1 and 2 GHz contributed to the reproduction of the EUV emission spectrum. On the other hand, for solar flare emissions, microwave emissions with higher frequencies such as 17 and 35 GHz were found to correlate well with the EUV emission spectra.
Microwave data with wide range of frequencies needed to understand space weather conditions in detail. In Japan, microwave emissions have been observed at Toyokawa and Nobeyama for more than 70 years (Shimojo and Iwai, 2023), but the observed frequencies are limited to seven: 1, 2, 3.75, 9.4, 17, 35, and 80 GHz. Not only to observe these microwave emissions continuously, but also to obtain dynamic spectra of microwave emissions including these frequencies, we installed a microwave observation system in our institute at Yokosuka. In this paper, we introduce the Yokosuka Radio Polarimeter (YoRP) and report the latest data acquisition status.