A living catalog of stream interaction regions in the Parker Solar Probe era

R C Allen,D Odstrcil,D M Malaspina,M L Stevens,S K Vines,N Raouafi,C J Joyce,J C Kasper,L K Jian,C Möstl,D J Mccomas,M E Hill,N A Schwadron,S D Bale,G C Ho,K E Korreck,R Mcnutt,A W Case

doi:10.1051/0004-6361/202039833

Abstract

Stream interaction regions (SIRs) and corotating interaction regions (CIRs) are important phenomena in heliospheric physics. These large-scale structures vary temporally and spatially, both in latitude and with radial distance. The additions of Parker Solar Probe (PSP) and Solar Orbiter have allowed for investigations into the radial evolution of these structures over a wide range of heliocentric distances for the first time since the Helios era. To better enable investigations of SIRs and CIRs within the inner heliosphere, we have developed a living catalog of SIR and CIR observations by Parker Solar Probe with corresponding observations by STEREO-A as well as ACE and Wind at 1 au. The methodology used for the identification of events and the generation of this catalog, the initial catalog of PSP observations spanning orbits one through five along with corresponding 1 au observations, and information on accessing the living catalog for future studies is described. This list of SIR and CIR events from PSP and corresponding observations from other heliophysics missions will enable case studies utilizing unique orbital arrangements, as well as aid in future statistical studies to further understand the properties and evolution of these structures.

Highlights

Stream interaction regions (SIRs) form in interplanetary space where faster solar wind streams, originating from coronal holes, overtake the preceding slower solar wind streams (e.g., Belcher et al 1971; Pizzo 1978; Richardson 2018)
Data gaps often occur when Parker Solar Probe (PSP) is at larger heliospheric distances, especially for SPC, as well as during Ka-band downlinking intervals, and so this limits the time periods that are searchable for SIRs and corotating interaction regions (CIRs)
Apparent velocity enhancements that are not flagged as SIR and CIR events in Fig. 1 are found to correspond to interplanetary coronal mass ejections (ICMEs), sector boundary crossings, or slow velocity increases without the formation of a stream interface

Summary

Introduction

Stream interaction regions (SIRs) form in interplanetary space where faster solar wind streams, originating from coronal holes, overtake the preceding slower solar wind streams (e.g., Belcher et al 1971; Pizzo 1978; Richardson 2018). SIRs and CIRs can be highly geoeffective, triggering geomagnetic storms (e.g., Tsurutani & Gonzalez 1997; Turner et al 2006) and affecting the ionosphere and thermosphere of Earth (e.g., Chen et al 2014). These structures, and their associated shocks, can modulate the intensity of galactic cosmic rays from the inner heliosphere out to the very local interstellar medium (e.g., Hill et al 2020a)

Methods

Results

Conclusion