Climate sensitivity of the century-scale hydrogen peroxide (H2O2) record preserved in 23 ice cores from West Antarctica
Climate sensitivity of the century-scale hydrogen peroxide (H2O2) record preserved in 23 ice cores from West Antarctica
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西南极洲 23 个冰芯中保存的百年级过氧化氢 (H2O2) 记录的气候敏感性
DOI：
10.1029/2005jd006816
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发表时间：
2006
影响因子：
--
通讯作者：
J. McConnell
中科院分区：
文献类型：
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作者：
M. Frey;R. Bales;J. McConnell
作者：Frey，MM; Bales，RC; McConnell，JR|摘要：我们报告新世纪尺度的冰芯记录过氧化氢（H2 O2），一种主要的大气氧化剂，从23个地点横跨西南极冰盖（WAIS），并使用（多）年平均H2 O2浓度的空间变异性在雪和积雪调查冰芯H2 O2保存的敏感性，平均年温度和积累率。在协议的冰-空气平衡分配，H2 O2吸收在近地表积雪被认为是最大的在低温下，而沉积后的损失，从脱气增加的积累率降低。这导致在温暖的（g-25°C），低积累的网站（l13厘米yr-1），几乎完全损失的H2 O2，但良好的保存记录在寒冷，高积累的网站。一个双参数的半经验模型拟合到1911-1960年H2 O2的意思是在所有网站预测g94%的偏差，从冰-空气平衡在高积累的网站（g30厘米yr-1），但接近平衡值在东南极高原，那里是干燥的（l11厘米yr-1）。它还估计每年大气H2 O2循环的加权平均值为1-3 pptv，约为冬季和早春在南极洲沿海观察到的H2 O2范围底部水平的10%。从模型拟合的敏感性表明，最近在南极洲观测到的年平均温度的变化有没有显着的影响，在南极洲西部的内部和年际变化的H2 O2的记录是占主导地位的区域尺度积累的变化，在目前的WAIS气候。在扩展的厄尔尼诺-拉尼娜事件期间，积累率和H2 O2浓度异常的第一个PC时间序列与20世纪的年化SOI之间的间歇性相关性具有统计学意义（r g 0.6，p l 0.05），并解释了H2 O2记录中ENSO样周期（2-7年）的显著谱峰的发生。核心记录的H2 O2在高积累的网站（g30厘米yr-1）是最适合检测大气浓度的时间变化，虽然长期的H2 O2记录将保存完好，在目前的环境下，在WAIS分水岭核心网站。版权所有2006年由美国地球物理联盟。
Author(s): Frey, MM; Bales, RC; McConnell, JR | Abstract: We report new century-scale ice core records of hydrogen peroxide (H2O2), a major atmospheric oxidant, from 23 locations across the West Antarctic Ice Sheet (WAIS) and use the spatial variability of (multi-) annual mean H2O2 concentrations in snow and firn to investigate the sensitivity of ice core H2O2 preservation to mean annual temperature and accumulation rate. In agreement with the ice-air equilibrium partitioning, H2O2 uptake in near-surface firn was found to be greatest at low temperatures, while postdepositional losses from degassing increase as accumulation rates decrease. This resulted in almost complete loss of H2O2 at warm (g-25°C), low-accumulation sites (l13 cm yr-1), but excellent preservation of records at cold, high-accumulation sites. A two-parameter semiempirical model fitted to the 1911-1960 H2O2 means across all sites predicts g94% deviations from the ice-air equilibrium at high-accumulation sites (g30 cm yr-1), but close-to-equilibrium values on the East Antarctic Plateau, where it is dry (l11 cm yr-1). It also estimates a weighted average of the annual atmospheric H2O2 cycle of 1-3 pptv, about 10% of the levels at the bottom of the H2O2 range observed in winter and early spring in coastal Antarctica. Sensitivities from the model fit suggest that recent changes of annual mean temperature observed in Antarctica have no noticeable effect on the H2O2 record in the interior of West Antarctica and that interannual variability of annual H2O2 is dominated by variations in regional-scale accumulation under the current WAIS climate. Intermittent correlations between the first PC time series of accumulation rate and H2O2 concentration anomalies and the annualized SOI during the 20th century are statistically significant (r g 0.6, p l 0.05) during extended El Nino-La Nina events and explain the occurrence of significant spectral peaks at ENSO-like periodicities (2-7 years) in the H2O2 record. Core records of H2O2 at high-accumulation sites (g30 cm yr-1) are most suitable for detection of temporal changes in atmospheric concentration, although a long-term H2O2 record will be well preserved under the current environment at the WAIS Divide core site. Copyright 2006 by the American Geophysical Union.