Changes in atmospheric water content associated with an unusual high snowfall during June 2004 at Maitri station (Schirmacher Oasis, East Antarctica) and the role of South West Indian ridge geodynamics

Abstract

We study changes in the atmospheric water vapour associated with the unusual snowfall during June 2004 polar night at the Indian Antarctica station Maitri (MAIT), located *70 km inland of the East Antarctic north coast. The GPS-derived Zenith Total Delay data for the 2004 polar night are used to evaluate the atmospheric water content at four GPS locations along the northern margin of East Antarctica. Stations Maitri and Syowa (SYOG) showed significant increase in atmospheric water vapour from GPS day 162 (10 June 2004) to 176 (24 June 2004) and correlate well with the duration of heavy snowfall at MAIT. The precipitable water vapour values computed for IGS station SYOG confirm high water vapour during this high snowfall period. Such an anomalous water vapour over East Antarctica in this peak winter time, characterized by the complete absence of solar radiations, suggests a link between this phenomenon and the high evaporation rate over South West Indian Ridge triggered by the geothermal heat radiated to the sea bottom through active magma spreading.