scholarly journals Effects of interplanetary magnetic clouds, interaction regions, and high-speed streams on the transient modulation of galactic cosmic rays

2007 ◽  
Vol 112 (A2) ◽  
pp. n/a-n/a ◽  
Author(s):  
Y. P. Singh ◽  
Badruddin
Keyword(s):  
Cosmic Rays ◽  
High Speed ◽  
Galactic Cosmic Rays ◽  
Magnetic Clouds ◽  
Interaction Regions

Solar wind temperature–velocity relationship over the last five solar cycles and Forbush decreases associated with different types of interplanetary disturbance

2020 ◽  
Vol 500 (3) ◽  
pp. 2786-2797
Author(s):  
A A Melkumyan ◽  
A V Belov ◽  
M A Abunina ◽  
A A Abunin ◽  
E A Eroshenko ◽  
...  
Keyword(s):  
Solar Wind ◽  
High Speed ◽  
Coronal Holes ◽  
Cosmic Ray ◽  
Magnetic Clouds ◽  
Solar Cycles ◽  
Forbush Decreases ◽  
Proton Temperature ◽  
Interaction Regions ◽  
Interplanetary Disturbance

ABSTRACT The behaviour of the solar wind (SW) proton temperature and velocity and their relationship during Forbush decreases (FDs) associated with various types of solar source – coronal mass ejections (CMEs) and coronal holes (CHs) – have been studied. Analysis of cosmic ray variations, SW temperature, velocity, density, plasma beta, and magnetic field (from 1965–2019) is carried out using three databases: the OMNI database, Variations of Cosmic Rays database (IZMIRAN) and Forbush Effects & Interplanetary Disturbances database (IZMIRAN). Comparison of the observed SW temperature (T) and velocity (V) for the undisturbed SW allows us to derive a formula for the expected SW temperature (Texp, the temperature given by a T–V formula, if V is the observed SW speed). The results reveal a power-law T–V dependence with a steeper slope for low speeds (V < 425 km s−1, exponent = 3.29 ± 0.02) and flatter slope for high speeds (V > 425 km s−1, exponent = 2.25 ± 0.02). A study of changes in the T–V dependence over the last five solar cycles finds that this dependence varies with solar activity. The calculated temperature index KT = T/Texp can be used as an indicator of interplanetary and solar sources of FDs. It usually has abnormally large values in interaction regions of different-speed SW streams and abnormally low values inside magnetic clouds (MCs). The results obtained help us to identify the different kinds of interplanetary disturbance: interplanetary CMEs, sheaths, MCs, corotating interaction regions, high-speed streams from CHs, and mixed events.

Cosmic ray modulation in high and middle latitudes during solar cycles 22 and 23

2015 ◽  
Vol 93 (1) ◽  
pp. 100-104 ◽  
Author(s):  
Kingsley Chukwudi Okpala ◽  
Francisca Nneka Okeke ◽  
Anselem Ikechukwu Ugwuoke
Keyword(s):  
Cosmic Rays ◽  
Dynamic Pressure ◽  
Cosmic Ray ◽  
Galactic Cosmic Rays ◽  
Proton Density ◽  
Solar Cycles ◽  
Middle Latitudes ◽  
Cosmic Ray Modulation ◽  
Interaction Regions

Galactic cosmic rays are modulated in the heliosphere primarily by the global merged interaction regions with intense magnetic fields, which leads to a decrease in galactic cosmic rays throughout the heliosphere. Using long-term averages of solar wind (SW) component parameters in addition to cosmic ray count rates of four neutron monitors with different rigidity cutoffs, we analyzed the effect of these SW components on the count rates under different interplanetary magnetic field (IMF) disturbance levels. From first-order partial correlation, we found that the IMF-B was the most dominant modulating parameter, especially during quiet conditions and the SW dynamic pressure was more effective during disturbed conditions. The influence of more subtle parameters like wind speed, Bz component, and proton density were masked by these dominant parameters: IMF total B, and SW dynamic pressure.

scholarly journals Galactic Cosmic Rays Modulation in the Vicinity of Corotating Interaction Regions: Observations During the Last Two Solar Minima

2019 ◽  
Vol 882 (1) ◽  
pp. 54 ◽  
Author(s):  
Keyvan Ghanbari ◽  
Vladimir Florinski ◽  
Xiaocheng Guo ◽  
Qiang Hu ◽  
Richard Leske
Keyword(s):  
Cosmic Rays ◽  
Galactic Cosmic Rays ◽  
Corotating Interaction Regions ◽  
Interaction Regions

The effect of solar wind high-speed streams on the galactic cosmic rays intensity

2016 ◽  
Vol 32 (6) ◽  
pp. 265-275
Author(s):  
Yu. L. Kolesnyk ◽  
A. I. Klyuyeva ◽  
B. A. Shakhov ◽  
Yu. I. Fedorov
Keyword(s):  
Solar Wind ◽  
Cosmic Rays ◽  
High Speed ◽  
Galactic Cosmic Rays
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