# Charge States and FIP Bias of the Solar Wind from Coronal Holes, Active Regions, and Quiet Sun

## TL;DR

This study analyzes the properties of solar wind originating from different solar regions, revealing distinct speed and composition patterns that support specific solar wind generation models.

## Contribution

It provides a comprehensive statistical comparison of solar wind from coronal holes, active regions, and quiet Sun, linking observed properties to theoretical models.

## Key findings

- Coronal hole wind has a bimodal speed distribution with peaks at ~400 km/s and ~600 km/s.
- An anti-correlation exists between solar wind speed and O7+/O6+ ion ratio across all source regions.
- N_Fe/N_O and FIP bias decrease with increasing solar wind speed, with differences among source regions.

## Abstract

Connecting in-situ measured solar-wind plasma properties with typical regions on the Sun can provide an effective constraint and test to various solar wind models. We examine the statistical characteristics of the solar wind with an origin in different types of source regions. We find that the speed distribution of coronal hole (CH) wind is bimodal with the slow wind peaking at ~400 km/s and a fast at ~600 km/s. An anti-correlation between the solar wind speeds and the O7+/O6+ ion ratio remains valid in all three types of solar wind as well during the three studied solar cycle activity phases, i.e. solar maximum, decline and minimum. The N_Fe/N_O range and its average values all decrease with the increasing solar wind speed in different types of solar wind. The N_Fe/N_O range (0.06-0.40, FIP bias range 1-7) for AR wind is wider than for CH wind (0.06-0.20, FIP bias range 1-3) while the minimum value of N_Fe/N_O (0.06) does not change with the variation of speed, and it is similar for all sourceregions. The two-peak distribution of CH wind and the anti-correlation between the speed and O7+/O6+ in all three types of solar wind can be explained qualitatively by both the wave-turbulence-driven (WTD) and reconnection-loop-opening (RLO) models, whereas the distribution features of N_Fe/N_O in different source regions of solar wind can be explained more reasonably by the RLO models.