Project ARRCC: Analysis of Rapid and Recent Climatic Change

气候变化在年到世纪的时间尺度上对社会和人类产生最直接的影响。然而，这些时间尺度上的变化很难预测，因为我们还没有在这个频率范围内分离出气候强迫因子。ARRCC项目旨在从年到世纪的时间尺度上评估过去的气候变化，以便更好地了解观测到的变化的类型和幅度，并评估两个潜在的原因：太阳活动的变化和火山气溶胶输入大气的影响。ARRCC项目将生成过去500年气候变化的详细时间序列，其中包括小冰期。在此期间，太阳黑子的数量也显著减少（蒙德极小期），导致许多研究人员提出一些因果关系。ARRCC项目中的pi将综合这一时间段的定量古气候数据，并将结果与模式模拟结果进行比较，模式模拟结果由于火山气溶胶浓度的变化而改变了入射太阳辐射强度和大气反射率。本研究的重要意义在于：1)首次对这一重要的古气候事件进行综合研究；2)它将产生一个严谨的全球过去气候数据库，供其他研究人员使用；3)这将是量化太阳辐射和火山活动对气候变化影响的首次严谨尝试。这项研究是美国全球变化研究计划的重点项目。

Project ARRCC: Analysis of Rapid and Recent Climate Change Climatic changes on time scales of years to centuries have the most direct impact on society and humanity. Yet changes on these time scales are hard to predict because we have yet to isolate climate forcing factors in this frequency range. Project ARRCC aims to evaluate past variations in climate on annual to century time scales in order to develop a better understanding of the types and magnitude of the changes observed as well as to evaluate two potential causes: changes in solar activity and the effects of volcanic aerosol input into the atmosphere. Project ARRCC will produce detailed time series of climate variations for the last 500 years, an interval which includes the Little Ice Age. During this interval there was also a significant reduction in the number of sunspots (the Maunder Minimum) leading many researchers to suggest some causal relationship. The PIs in Project ARRCC will synthesize the quantitative paleoclimate data for this time interval and compare the results to model simulations which vary the intensity of incoming solar radiation and the reflectivity of the atmosphere because of changes in volcanic aerosol concentration. This research is important for three reasons: 1) it will be the first synthesis of this important paleoclimate event; 2) it will produce a rigorous, global data base of past climate for use by other researchers; and 3) it will be the first rigorous attempt to quantify the effects of solar radiation and volcanic activity on climate change. This research is a high-priorty for the US Global Change Research Program.