A Catalog of Type II Radio Bursts Observed by Wind/WAVES and their Statistical Properties

TL;DR

This paper presents a comprehensive catalog of solar type II radio bursts observed by Wind/WAVES, analyzing their statistical properties and associations with solar eruptions, CMEs, and space weather phenomena over solar cycles.

Contribution

It provides a detailed, publicly accessible catalog of type II radio bursts with associated solar activity data and analyzes their statistical and solar cycle variations.

Findings

Type II burst occurrence varies with solar cycle.

Strong correlation between type II bursts and CMEs.

Type II bursts at low frequencies indicate energetic, Earth-impacting CMEs.

Abstract

Solar type II radio bursts are the signature of particle acceleration by shock waves in the solar corona and interplanetary medium. The shocks originate in solar eruptions involving coronal mass ejections (CMEs) moving at super-Alfvenic speeds. Type II bursts occur at frequencies ranging from hundreds of MHz to tens of kHz, which correspond to plasma frequencies prevailing in the inner heliosphere from the base of the solar corona to the vicinity of Earth. Type II radio bursts occurring at frequencies below the ionospheric cutoff are of particular importance, because they are due to very energetic CMEs that can disturb a large volume of the heliosphere. The underlying shocks accelerate not only electrons that produce the type II bursts, but also protons and heavy ions that have serious implications for space weather. The type II radio burst catalog (https://cdaw.gsfc.nasa.gov/CME_list/radio/waves_type2.html) presented here provides detailed information on the bursts observed by the Radio and Plasma Wave Experiment (WAVES) on board the Wind Spacecraft. The catalog is enhanced by compiling the associated flares, CMEs, solar energetic particle (SEP) events including their basic properties. We also present the statistical properties of the radio bursts and the associated phenomena, including solar-cycle variation of the occurrence rate of the type II bursts.