Collaborative Research: A High-sensitivity Beryllium-10 Record from an Ice Core at South Pole

该项目将从南极洲南极的冰芯中获取铍-10（10 Be）浓度的测量值。 铍的同位素10 Be是由从太空进入地球大气层的高能质子（宇宙射线）在大气中产生的。 它通过沉降或被雨或雪清除而从大气中去除。 因此，南极雪中10 Be的浓度反映了大气中10 Be的生产率。 由于10 Be在南极上空的产生率主要取决于太阳磁场的强度，因此南极冰芯中10 Be的测量将提供太阳活动变化的记录。 南极冰芯底部的年龄将达到4万年。 该项目将对过去100年和更遥远的过去的选定时期，如蒙德极小期（17世纪末没有观测到太阳黑子的时期）或约20，000年前的末次冰期进行年度分辨率的10 Be测量。 一个气候模型，可以模拟生产的10 Be在大气中，它的运输通过大气，其沉积在南极洲的雪表面将被用来帮助使用10 Be的数据，以确定过去的变化太阳活动从十年到千年的规模，并反过来评估太阳在地球上的作用？地球大气中10 Be的产生是由于宇宙射线对大气中氧和氮的散射。 高纬度地区的宇宙线变化主要受太阳变化的调制。因此，冰芯中10 Be的时间序列记录对于推导太阳活动随时间的变化非常重要，这对于了解气候变化至关重要。10 Be在冰面上的沉积也受到大气环流和沉积过程变化的影响，南极是最大限度地减少大气环流变化对10 Be沉积影响的最佳地点。到目前为止，只有一个10 Be的记录存在于南极;该记录被广泛用于气候模型中使用的太阳强迫估计，但仅涵盖上个千年，并于CE 1982结束。 我们将获得10 Be浓度测量在1500米，40000年长的冰芯从南极。 这将使现有的记录在时间上更早地向前延伸到现在，与现代仪器记录的太阳和气候变化重叠。高分辨率（每年到半年）测量将在目标地区的利益，包括过去100年，蒙德极小期（CE 1650-1715），和末次冰期最大。新的数据将与气候模型实验结合使用，这些实验将10 Be生产，运输和沉积物理学结合起来。数据和建模将共同创建大气10 Be生产的最新记录，从而创建太阳活动的最新记录。

This project will acquire measurements of the concentration of beryllium-10 (10Be) from an ice core from the South Pole, Antarctica. An isotope of the element beryllium, 10Be, is produced in the atmosphere by high-energy protons (cosmic rays) that enter Earth's atmosphere from space. It is removed from the atmosphere by settling or by scavenging by rain or snowfall. Hence, concentrations of 10Be in snow at the South Pole reflect the production rate of 10Be in the atmosphere. Because the rate of production of 10Be over Antarctica depends primarily on the strength of the Sun's magnetic field, measurements of 10Be in the South Pole ice core will provide a record of changes in solar activity. The South Pole ice core will reach an age of 40,000 years at the bottom. The project will result in measurements of 10Be at annual resolution for the last 100 years and selected periods in the more distant past, such as the Maunder Minimum, a period during the late 17th century during which no sunspots were observed, or the last glacial cold period, about 20,000 years ago. A climate model that can simulate the production of 10Be in the atmosphere, it's transport through the atmosphere, and its deposition at the snow surface in Antarctica will be used to aid in using the 10Be data to determine past changes in solar activity from decadal to millennial scale, and in turn to evaluate the role of the Sun in Earth?s climate from a new perspective.The production of 10Be in Earth's atmosphere results from the spallation of oxygen and nitrogen in the atmosphere by cosmic rays. Cosmic ray variations in the high latitudes are primarily modulated by solar variability. Time-series records of 10Be from ice cores are therefore important for deriving variations in solar activity through time, which is fundamental to understanding climate variability. Deposition of 10Be to the ice surface is also influenced by variability in atmospheric circulation and deposition processes, and South Pole is the best available location for minimizing the influence of variable atmospheric circulation on 10Be deposition. To date, only one record of 10Be exists from South Pole; that record is widely used in solar forcing estimates used in climate models, but covers only the last millennium and ends in CE 1982. We will obtain 10Be concentration measurements in a 1500-m, 40000-year long ice core from the South Pole. This will extend the existing record both further back in time and forward to the present, providing overlap with the modern instrumental record of solar and climate variability. High resolution (annual to biannual) measurements will be made in targeted areas of interest, including the last 100 years, the Maunder Minimum (CE 1650-1715), and the last glacial maximum. The novel data will be used in conjunction with climate model experiments that incorporate 10Be production, transport, and deposition physics. Together, data and modeling will create an updated record of atmospheric 10Be production and hence of solar activity.