Cosmogenic production and climate contributions to nitrate record in the TALDICE Antarctic ice core
Abstract
This paper presents the results of a comparative wavelet coherence analysis of a multimillennial nitrate record with a number of climatic and solar activity proxies. Distinguishing between these factors is important in the view of a possibility of nitrate deposited in a polar region to represent galactic cosmic ray flux and, consequently, solar activity. We used the data from the TALDICE drilling project (Talos Dome, Antarctica), which covers the age range 12,000-700 BP (years before present, i.e. before 1950) and includes records of nitrate as well as climatic proxies, such as Na+, Ca2+, MSA (methanesulphonic acid), δ18O, SO42-. The solar activity series is represented by reconstructions of the heliospheric modulation parameter from the 14C and 10Be data. We found (1) a confirmation of multimillennial relation between nitrate and galactic cosmic ray flux; (2) no clear signature of long-term variations of nitrate transport from lower latitudes. We suggest that variations in the nitrate record in the time scale of hundreds-thousands years are most likely caused by local production, deposition and post-deposition processes.
- Publication:
-
Journal of Atmospheric and Solar-Terrestrial Physics
- Pub Date:
- December 2014
- DOI:
- 10.1016/j.jastp.2014.09.011
- Bibcode:
- 2014JASTP.121...50P
- Keywords:
-
- Solar activity;
- Nitrate;
- Holocene;
- TALDICE