Published August 1, 2021 | Version v1
Journal article

Is Solar Minimum 24/25 Another Unusual One?

  • 1. Institute of Space Science and Applied Technology, Harbin Institute of Technology, Shenzhen, Shenzhen 518055 (China)

Description

Solar minimum 23/24 is considered to be unusual because it exhibits features that differ notably from those commonly seen in previous minima. In this Letter, we analyze the solar polar magnetic field, the potential-field solution of the solar corona, and the in situ solar wind measurements to see if the recent solar minimum 24/25 is another unusual one. While the dipolar configuration that is commonly seen during minimum 22/23 and earlier minima persist for about half a year after the absolute minimum of solar cycle 24, the corona has a morphology that is more complex than a simple dipole before the absolute minimum. The fast solar wind streams are less dominant than minimum 23/24. The interplanetary magnetic field strength, density, and mass flux that are historically low in the minimum 23/24 are regained during minimum 24/25, but still do not reach the minimum 22/23 level. From the analysis of this Letter, it seems that the minimum 24/25 is only partly unusual, and the recovery of the commonly minimum features may result from the enhancement of the polar field.

Availability note (English)

Available from http://dx.doi.org/10.3847/2041-8213/ac13a6

Additional details

Identifiers

Publishing Information

Journal Title
Astrophysical Journal Letters
Journal Volume
917
Journal Issue
2
Journal Page Range
[8 p.]
ISSN
2041-8205

INIS

Country of Publication
United Kingdom
Country of Input or Organization
International Atomic Energy Agency (IAEA)
INIS RN
53072117
Subject category
S79: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY;
Descriptors DEI
INTERPLANETARY MAGNETIC FIELDS; SOLAR CORONA; SOLAR CYCLE; SOLAR WIND
Descriptors DEC
ATMOSPHERES; MAGNETIC FIELDS; SOLAR ACTIVITY; SOLAR ATMOSPHERE; STELLAR ACTIVITY; STELLAR ATMOSPHERES; STELLAR CORONAE; STELLAR WINDS