Three 2-m deep snowpits sampled at South Pole in 1994 provide detailed (2-cm resolution) profiles of the concentrations of soluble ionic species for the period 1987 - 1994. The most prominent feature is a large concentration spike of SO4 = in snow deposited in 1992 reflecting fallout from the eruptions of Pinatubo and Hudson in 1991. Concentrations of MSA and values of the MSA/(non-sea-salt SO4 =) ratio are elevated for about three years centered on the prominent volcanic signal. These changes appear to be due to the extended 1991 - 1993 El Nino. The overlapping effects of the volcanic eruptions and El Nino circulation preclude partitioning the enhanced deposition of SO4 = into volcanic and biogenic fractions. Nitrate concentration profiles show no relation to the severity of O3 depletion in the Antarctic stratosphere during the period of record. Rather, the profiles show a progressive decline of the annual peak concentrations over the top 0.5 - 1.0 m of each pit. This behavior is attributed to post-deposition loss of NO3 -, presumably by re-emission of HNO3 into the atmosphere. Copyright 1996 by the American Geophysical Union.
Earth Sciences, Earth Systems Research Center
Geophysical Research Letters
Digital Object Identifier (DOI)
J. E. Dibb and S. I. Whitlow, "Recent climate anomalies and their impact on snow chemistry at south pole, 1987-1994," Geophysical Research Letters, vol. 23, no. 10, pp. 1115–1118, May 1996.
Copyright 1996 by the American Geophysical Union.