Reply on RC2

Abstract

<strong class="journal-contentHeaderColor">Abstract.</strong> ¹⁰Be is produced by the interaction between galactic cosmic rays (GCR) and solar energetic particles (SEP) with the Earth&rsquo;s atmospheric constituents. The flux of GCR is modulated by the varying strength of the magnetic fields of the Earth and the Sun. Measurement of ¹⁰Be concentrations from polar ice cores is thus a valuable tool to reconstruct the variations of the geomagnetic field and solar activity levels. The interpretation of ¹⁰Be records is, however, complicated by non-production related effects on the ¹⁰Be deposition rate caused by climate/weather induced noise. Furthermore, volcanic eruptions have been proposed to lead to short-term ¹⁰Be deposition enhancements. In this study, we test the use of excess meltwater from continuous flow analysis (CFA) to measure ¹⁰Be, allowing less time-consuming and more cost-effective sample preparation. We compare two records obtained from CFA and discrete samples from the EGRIP S6 firn core, reaching back to 1900 CE. We find that the two records agree well and that the ¹⁰Be record from CFA samples agrees as well as the discrete samples with other records from Greenland. Furthermore, by subtracting the theoretically expected GCR-induced signal, we investigate the high-frequency variability of the ¹⁰Be records from Greenland and Antarctica after 1951 CE, with focus on SEP events and volcanic eruptions. Finally, we use the ¹⁰Be records from Greenland and Antarctica to study the 11-year solar cycles, allowing us to assess the suitability of the CFA samples for the reconstruction of solar activity. This result opens new opportunities for the collection of continuous ¹⁰Be records with less time-consuming sample preparation while saving an important portion of the ice cores for other measurements.