The role of Southern Hemispheric Westerlies for Holocene hydroclimatic changes in the steppe of Tierra del Fuego (Argentina)

The steppe of northern Tierra del Fuego is an important region for studying climate variability in the Southern Hemisphere, due to its position at southern margin Hemisphere Westerly Wind belt. Here we present a multiproxy analysis sedimentary sequence from Laguna Carmen (53°S, 68°W) which provides evidence progressive aridity and strengthening low-level Westerlies during Late Holocene. We identified three prominent phases climatic record Carmen: cold wet period between ~4000 cal. BP ~2200 BP, evidenced by relative high lake level, periodic runoff into lake, oligohaline (mean: 2554 ?S/cm) salinities; step-change towards warmer drier conditions after reflected limited oligo-mesohaline salinities 4799 ?S/cm); finally, establishment modern semi-arid some time ~1000 when became shallow that sometimes dried out summer. Our results coincide with paleoclimatic numerical models suggest aridification Patagonian since 6000 stronger higher temperatures associated changes solar irradiance.