Isotopic evidence for Holocene January air temperature variability on the East Chukotka Peninsula

Abstract

AbstractIce‐wedge ice can provide a valuable record of past winter climate variability at high latitudes yet to date this proxy has been applied only sparsely across the Chukotka region of Siberia. Here we present data from eight ice‐wedges at four sites across a 600‐km transect in Eastern Chukotka which we use to reconstruct regional Holocene winter paleotemperature. The Holocene age of ice‐wedges was established by radiocarbon dating of peat surrounding individual ice‐wedges. Our suite of radiocarbon ages suggests that the studied ice‐wedges formed between 12.9–11.8 and 3–2.5 cal ka BP. δ18O and δ2H values from ice‐wedge ice indicate that in coastal areas of Eastern Chukotka mean January air temperatures in the first half of the Holocene were on average 2–3°С lower than modern values, a finding that corresponds well with winter climate reconstructions for the other areas of Beringia. The variability of reconstructed mean January air temperatures in the study area did not exceed 2–4°C during the early to mid‐Holocene.