Volcanic forcing of climate over the past 1500 years: An improved ice core-based index for climate models
Volcanic forcing of climate over the past 1500 years: An improved ice core-based index for climate models
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DOI：
10.1029/2009jd012133
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发表时间：
2008-12-13
影响因子：
4.4
通讯作者：
Ammann, Caspar
中科院分区：
文献类型：
--
作者：
Gao, Chaochao;Robock, Alan;Ammann, Caspar
了解气候变化的自然原因对于评估人类污染和地表改变对气候的相对影响至关重要。我们通过使用来自北极和南极的54个冰芯记录，调查了气候变化最重要的自然原因之一，火山爆发。我们最近收集的冰芯数据套件，是以前使用的冰芯数量的两倍多，减少了基于单个或少量冰芯的重建中固有的错误，这使我们能够在事件检测和辐射效应量化方面获得更高的准确性。我们从每个冰芯记录中提取火山沉积信号，通过对时间序列应用高通黄土滤波器，并检查超过31年运行中位数绝对偏差两倍的峰值。然后，我们研究了格陵兰岛和南极洲的火山硫酸盐沉积的空间格局，并结合这一知识与火山气溶胶平流层传输的新认识，以产生一个强迫数据集作为一个函数的月，纬度和海拔在过去的1500年。我们估计了与火山信号提取标准的选择，冰芯硫酸盐沉积平流层负载校准因子，以及没有记录的月份的爆发季节相关的不确定性。我们用这个新的火山强迫数据集强迫一个能量平衡气候模型，再加上太阳和人为强迫，来模拟大尺度的温度响应。结果与过去150年的仪器观测和整个时期的代理记录吻合良好。通过更好地描述气候变化的自然原因，这一新的数据集将有助于更好地预测人类活动对气候的影响。过去1500年来火山爆发平流层硫酸盐注入的新数据集，作为纬度，海拔和月份的函数，可以下载适合于气候系统强迫环流模型的格式。
Understanding natural causes of climate change is vital to evaluate the relative impacts of human pollution and land surface modification on climate. We have investigated one of the most important natural causes of climate change, volcanic eruptions, by using 54 ice core records from both the Arctic and Antarctica. Our recently collected suite of ice core data, more than double the number of cores ever used before, reduces errors inherent in reconstructions based on a single or small number of cores, which enables us to obtain much higher accuracy in both detection of events and quantification of the radiative effects. We extracted volcanic deposition signals from each ice core record by applying a high-pass loess filter to the time series and examining peaks that exceed twice the 31-year running median absolute deviation. We then studied the spatial pattern of volcanic sulfate deposition on Greenland and Antarctica and combined this knowledge with a new understanding of stratospheric transport of volcanic aerosols to produce a forcing data set as a function of month, latitude, and altitude for the past 1500 years. We estimated the uncertainties associated with the choice of volcanic signal extraction criteria, ice core sulfate deposition to stratospheric loading calibration factor, and the season for the eruptions without a recorded month. We forced an energy balance climate model with this new volcanic forcing data set, together with solar and anthropogenic forcing, to simulate the large-scale temperature response. The results agree well with instrumental observations for the past 150 years and with proxy records for the entire period. Through better characterization of the natural causes of climate change, this new data set will lead to improved prediction of anthropogenic impacts on climate. The new data set of stratospheric sulfate injections from volcanic eruptions for the past 1500 years, as a function of latitude, altitude, and month, is available for download in a format suitable for forcing general circulation models of the climate system.