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Recent climate anomalies and their impact on snow chemistry at South Pole, 1987‐1994
Author(s) -
Dibb Jack E.,
Whitlow Sallie I.
Publication year - 1996
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/96gl01039
Subject(s) - volcano , snow , stratosphere , atmospheric sciences , atmosphere (unit) , nitrate , deposition (geology) , climatology , geology , environmental science , period (music) , oceanography , chemistry , meteorology , geochemistry , geography , geomorphology , physics , organic chemistry , sediment , acoustics
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 SO 4 = 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 SO 4 = ) 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 SO 4 = into volcanic and biogenic fractions. Nitrate concentration profiles show no relation to the severity of O 3 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 NO 3 − , presumably by reemission of HNO 3 into the atmosphere.