Seasonal variability in a 1600 year-long ice core chemical record, Pamir Mountains, Central Asia

• Main Authors: Rodda, Charles, Mayewski, Paul, Kurbatov, Andrei, Aizen, Elena, Aizen, Vladimir, Korotkikh, Elena, Takeuchi, Nozomu, Fujita, Koji, Kawamura, Kenji, Tsushima, Akane
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: arXiv 2019
• Subjects: Atmospheric and Oceanic Physics physics.ao-ph; FOS Physical sciences; Arctic; ice core
• Online Access: https://dx.doi.org/10.48550/arxiv.1910.10339; https://arxiv.org/abs/1910.10339

Targeted ultra-high resolution Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) analysis of an ice core drilled in the Pamir Mountains of Central Asia (CA) records changes in seasonal patterns of atmospheric circulation and moisture delivery to CA over the past 1600 years. Fe, Ca, and Mg signals in the LNC3 Pamir ice core reflect variable delivery of these elements during the pre-Medieval Warm Period (pre-MWP), Medieval Warm Period (MWP), and during the onset of the Little Ice Age (LIA) in CA. During the pre-MWP, hiatuses between dust seasons are observed due to a lengthened accumulation season, and dust delivery limited to a short period at the end of the accumulation season when modern summer-style northerly airflow occurred. During the MWP, dust delivery to CA decreased, though Fe-intensity in the core indicates episodic northerly air incursion. By the onset of the LIA, dust availability increased due to regional drying and strengthening winds, and strong westerlies blocked meridional flow reducing Fe-rich dust input from the north. CA has experienced recent warming, desiccation, weakening winds, and glacier loss. Major climate circulation drivers (Westerlies, Icelandic Low, Siberian High) continue to display LIA-style patterns, and annual temperatures are approaching those of the MWP. While none of the preceding climate periods in CA history can serve as an absolute wholesale proxy for conditions that are likely to prevail in the near future continued Northern Hemisphere westerlies weakening in a changing climate may enhance meridional flow and bring more moisture into the Aral Sea catchment from the Arctic. : 19 pages, 6297 words (including references)