A snapshot of Antarctic climate variability over the last 2000 years
Climate trends in the Antarctic region remain poorly characterized, due to the brevity and scarcity of direct climate observations and the large magnitude of interannual to decadal-scale climate variability. As a result, the knowledge of past Antarctic temperature and climate variability is predominantly dependent on proxy records from natural archives.
Paleotemperature reconstructions from Antarctica mainly rely on water stable isotope records from ice cores with the key factor controlling this proxy mainly related to temperature variations. Early efforts to reconstruct the continental-scale temperature history of Antarctica over the past 2000 years indicated that at the continent-scale Antarctica is the only land region where the long-term cooling trend of the last 2000 years has not yet been reversed by recent significant warming. However, this Antarctic temperature reconstruction has large uncertainties and masks important regional-scale features of Antarctica’s climate evolution over the last 2000 years.
On June 26, 2018, Barbara Stenni (Associate professor of Geochemistry, Department of Environmental Sciences, Informatics and Statistics, Ca’ Foscari University of Venice) presented an expanded paleoclimate database including ice core isotope records over 7 distinct climatic regions (the Antarctic Peninsula, the West Antarctic Ice Sheet, the East Antarctic Plateau, and four coastal domains of East Antarctica) during the CMCC-SISC webinar “Antarctic climate variability over the last 2000 years”.
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A significant cooling trend from 0 to 1900 CE has been observed across all Antarctic regions where records extend back into the 1st millennium. Since 1900 CE, significant warming trends have been identified for the West Antarctic Ice Sheet, the Dronning Maud Land coast and the Antarctic Peninsula regions, but only for the Antarctic Peninsula is currently this most recent century-scale trend unusual in the context of natural variability over the last 2000-years.
The work is the first long-term quantification of regional climate in Antarctica and will be a basis for data-model comparison and assessments of past, present and future driving factors of Antarctic climate.