Comparison of 3-D Solar Wind of Solar Cycles between 22 and 24
Periasamy K MANOHARAN (Arecibo Observatory, University of Central Florida)
P K Manoharan Arecibo Observatory, University of Central Florida, Arecibo PR 00612, USA
In this talk, I will review the evolution and properties of large-scale structure of three-dimensional quasi-steady solar wind in the inner heliosphere between solar cycles 22 and 24. The solar wind data sets have been obtained from the interplanetary scintillation (IPS) measurements made with the Ooty Radio Telescope (at 327 MHz) and the Arecibo Radio Telescope (in the frequency range of 327 – 3000 MHz). Solar cycles 22 – 24 roughly decreased in density turbulence is consistent with the globular downward changes observed in the strength of the solar magnetic field in determining the dynamics of the solar wind as well as leading to a reduction in the supply of mass and energy at the base of the corona and into the heliosphere. However, the solar cycle 24 was the weakest cycle and the weak polar field during its minimum led to a weak and asynchronous reversal of polar fields and a large hemispheric asymmetry. Moreover, the observed storm strengths indicate that the cycle 24 is less geo-effective. The galactic cosmic ray from the neutron monitor at the end phase of cycle 24 is comparable to that of the similar phase of 23. The latitudinal extents of slow-speed solar wind close to low and mid-latitudes and their corresponding high-density turbulence regions at the minimums of solar cycles 22 – 24 have been compared.