SGER: Solar Influence on High-frequency Climate Variability--Possible Links to the Atlantic Multidecadal Oscillation and Hurricane Activity

该奖项资助了由探索研究小额赠款(SGER)计划赞助的研究，以检验大西洋数十年振荡(AMO)与太阳能量输出的80年周期(即Gleissberg周期)有关的假设。AMO的特点是北大西洋海面温度在统计上具有显著的变异性。正如几位研究人员所报告的那样，对全球仪器记录、过去400年的代理气候记录和模式输出的分析发现，气候信号存在60至80年的振荡。虽然AMO在北大西洋海盆表达最强烈，但AMO的影响延伸到北大西洋附近地区。AMO与密西西比河流域的降雨量变化、非洲干旱频率和欧洲冬季温度相关。AMO似乎也影响了北大西洋盆地的飓风频率。AMO的强迫机制目前尚不清楚，但大多数研究人员推断，AMO代表了大气-海洋系统的内部振荡。具体地说，研究人员将分析北大西洋盆地附近现有高分辨率气候代理记录的频率，以确定在全新世晚期(~最近2000年)是否发生了类似AMO的变化。确定过去几千年来类似AMO的振荡的存在，将有助于评估这些振荡是否是晚全新世气候的持久特征。此外，研究人员将分析北大西洋盆地远端地区现有的高度分辨率的晚全新世气候代理记录，以确定是否存在类似AMO的振荡。研究人员的动机是这样一个假设：如果AMO是集中在北大西洋盆地的大气-海洋系统的内部振荡，那么远离北大西洋盆地的记录中类似AMO的振荡应该被抑制或不出现。相比之下，如果AMO是由太阳输出的变化迫使的，研究人员推测，类似AMO的振荡应该是一个持久的全球信号，并出现在广泛地理区域的气候代理记录中。拟议的研究似乎很好地符合SGER计划的高风险和探索性。拟议的研究是非常独特和及时的。正如书面记录所证明的那样，2005年飓风季节异常活跃，出现了一些关键的研究问题，涉及探索古气候档案以寻找大规模气候振荡的证据，并确定可能的物理强迫机制。这种研究可能会在更全面地了解地球气候方面产生重大的科学回报。

This award funds research, under the auspices of the Small Grants for Exploratory Research (SGER) program, to test the hypothesis that the Atlantic Multidecadal Oscillation (AMO) is related to an 80-year cycle in energy output from the sun (i.e. the Gleissberg cycle). The AMO is characterized by statistically significant variability in North Atlantic Ocean sea-surface temperature.As reported by several researchers, analyses of global instrumental records, proxy climate records of the last 400 years, and model output have identified a 60 year to 80 year oscillation in climate signals. Although the AMO is most strongly expressed in the North Atlantic Basin, the influence of the AMO extends to areas adjacent to the North Atlantic. The AMO correlates with rainfall variations in the Mississippi River Basin, African drought frequency, and winter temperatures in Europe. The AMO also appears to influence the frequency of hurricanes in the North Atlantic Basin. The mechanism behind how the AMO is forced is currently unknown, but most researchers infer that the AMO represents an internal oscillation of the atmosphere-ocean system.Specifically, the researchers will analyze the frequency of existing highly resolved climate proxy records adjacent to the North Atlantic Basin to determine if AMO-like variability occurs over the late Holocene (~last 2,000 years). Identifying the presence of AMO-like oscillations for the last few thousand years will help evaluate whether these oscillations are a persistent feature of late Holocene climate. In addition, the researchers will analyze existing highly resolved late Holocene climate proxy records from area distal to the North Atlantic Basin for the presence of AMO-like oscillations. The researchers are motivated by the hypothesis that if the AMO is an internal oscillation of the atmosphere-ocean system focused in the North Atlantic Basin, then the occurrence of AMO-like oscillations in records far from the North Atlantic Basin should be subdued or absent. In contrast, if the AMO is forced by variations in solar output, the researchers speculate that AMO-like oscillations should be a persistent global signal and be present in climate proxy records from a wide geographic area. The proposed research seems to fit well into the high risk and exploratory nature of the SGER program. The proposed research is quite unique and timely. The 2005 hurricane season was unusually active, as evidenced by written records, and some key research questions have emerged that involve exploring paleoclimate archives for evidence of large-scale climate oscillations and identifying possible physical forcing mechanisms. Such research may yield a significant scientific payoff in terms of a more complete understanding of Earths climate.