Abstract:
This paper studies the effects of galactic cosmic rays on clouds and snow-fall rates in Antarctica using nine years of data
(2001-2009) covering the long deep solar minimum (2007-2009) for the first time. Measurements of the fair-weather air
earth current (Jz
) at the Indian Antarctic station Maitri (70º45'S, 11º43’E), and equivalent galactic cosmic ray (GCR) flux
from the neutron monitor measurements made at the American station McMurdo (77º51’S, 166º40’E) are used for the
study. Meteorological data from the Antarctic stations Maitri, Vostok (78º27’S,106º52’E), Scott Base (77º51’S, 166º46’E)
and Antarctic Data base are also used. The results show that low level cloud coverage (pressure >680 hPa) is positively
correlated to GCR flux with the maximum correlation (31%) being at the long solar minimum (2007-2009) when snow-fall
increased by 14%. The observed link between cosmic rays and climate in Antarctica is discussed in terms of ion-aerosol
clear-sky hypothesis and ion-aerosol near-cloud hypothesis. GCR enhanced the cloud formation, and the increased low
level clouds have invigoration to reflect more heat back to space.
