Abstract Details
| Name: Susanta Kumar Bisoi Affiliation: Physical Research Laboratory, Ahmedabad Conference ID: ASI2015_725 Title : A possibility of an impending grand solar minimum: solar, solar wind and ionospheric signatures Authors and Co-Authors : P.Janardhan (Physical Research Laboratory, Ahmedabad) S. Ananthakrishnan (Pune University, Pune) Abstract Type : Abstract Category : Thesis Abstract : Our study of solar photospheric magnetic fields and solar wind micro-turbulence levels in the inner-heliosphere indicates a possibility of an impending grand solar minimum, that is – a long period of little/no sunspot activity. A detailed study of solar high latitude magnetic fields using ground based magnetograms has clearly shown a steady decline in polar field strength since mid-1990’s which has continued to until the present. The fact that cycle 24 is already past its peak implies that the high-latitude magnetic fields will continue to decline until ~2020. In addition, interplanetary scintillation observations of solar wind micro-turbulence levels in the inner heliosphere have also shown a steady decline in sync with the declining solar photospheric fields. Even the heliospheric magnetic fields has also declined much below the previously proposed floor level of 4.6 nT, instead our study indicates a floor level of HMF to be ~3.2 nT. An assessment of the possible impact of such an impending grand solar minimum on terrestrial ionospheric current systems based on the one-to-one correlation of sunspot number and night time F-region maximum electron density reveals that there will be no significant effect on such systems. Our results rather indicate that the period post 2020 will be very useful for undertaking systematic ground based low-frequency radio astronomy, as the night time ionospheric cutoff could be well below 10 MHz for a prolonged period of time. (submitted for poster presentation) |