Abstract
Polar ice sheets conserve atmospheric aerosols at the time of snowfall, which can be used to reconstruct past climate and environmental conditions. We investigated mineral dust and major ion records in snowpit samples obtained from the northwestern Greenland ice sheet near the North Greenland Eemian Ice Drilling (NEEM) camp in June 2009. We analyzed the samples for mineral dust concentrations as well as stable water isotopes (δ18O, δD, and deuterium excess) and major ions (Cl-, SO42-, methanesulfonic acid (MSA), Na+, and Ca2+). Seasonal δ18O and δD cycles indicate that the snowpit samples covered a six-year period from spring 2003 to early summer 2009. Concentrations of mineral dust, nss-Ca2+, and nss-SO42- showed seasonal deposition events with maxima in the winter-spring layers. On the other hand, the Cl-/Na+ ratio and the concentrations of MSA exhibited maxima in the summer layers, making them useful indicators for the summer season. Moreover, an anomalous atmospheric mineral dust event was recorded at a depth of 165-170 cm corresponding to late winter 2005 to spring 2006. A back trajectory analysis suggests that a major contributor to the Greenland aerosol was an air mass passing over the Canadian Arctic and North America. Several trajectories point to Asian regions as a dust source. The mineral dust deposited at NEEM was strongly influenced by long-range atmospheric transport and dust input from arid source areas in northern China and Mongolia.
Original language | English |
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Pages (from-to) | 137-143 |
Number of pages | 7 |
Journal | Atmospheric Environment |
Volume | 120 |
DOIs | |
State | Published - 1 Nov 2015 |
Bibliographical note
Funding Information:This work was supported by a research grant ( PE15010 ) from the Korea Polar Research Institute (KOPRI) . We are thankful for the efforts of all field personnel involved in sampling during the NEEM deep ice core drilling project. The NEEM project was directed and organized by the Center for Ice and Climate at the Niels Bohr Institute and the Polar Programs office of the US national Science Foundation. The project was supported by funding agencies and institutions in Belgium (FNRS-CFB and FWO), Canada (NRCan/GSC), China (CAS), Denmark (FIST), France (IPEV, CNRS/INSU, CEA and ANR), Germany (AWI), Iceland (Rannls), Japan (NIPR), Korea (KOPRI), Netherlands (NOW/ALW), Sweden (VR), Switzerland (SNF), the UK (NERC), and the USA (US NSF OPP). The authors wish to thank the anonymous reviewers for providing helpful comments which improved the manuscript.
Publisher Copyright:
© 2015 Elsevier Ltd.
Keywords
- Atmospheric mineral dust
- Greenland
- Major ions
- Seasonal variation