6533b823fe1ef96bd127eb85

RESEARCH PRODUCT

Winter climate signal in boreal clastic-biogenic varves : a comprehensive analysis of three varved records from 1890 to 1990 AD with meteorological and hydrological data from Eastern Finland

Anssi LensuMira TammelinSaija SaarniTimo SaarinenEeva Haltia

subject

010506 paleontology010504 meteorology & atmospheric sciencesta1172ta1171Drainage basinlake sedimentsNorthern Europecatchment dynamics01 natural sciencesProxy (climate)clastic-biogenic varvesta2180105 earth and related environmental sciencesgeographyVarvegeography.geographical_feature_categoryPaleontologyGeology15. Life on landRadiative forcingSubarctic climateclimate forcingBoreal13. Climate actionClastic rockClimatologyfine-grained tillsClimate sensitivityGeologyboreal climate

description

Clastic-biogenic varves are widely used for reconstructing past climate: in boreal environments, the accumulation of minerogenic clasts on the lake floor is generally considered a proxy for past variations in spring floods reflecting previous winter conditions. However, the physical mechanisms behind this winter climate sensitivity and the influence of catchment type on the varve formation are not fully investigated. Here, we present a winter climate record inferred from the clastic laminae of three lakes located on the region of fine-grained tills in Eastern Finland spanning from AD 1890 to 1990. The minerogenic varve data are compared with instrumental meteorological and hydrological time series in order to investigate the physical link between winter and spring climate and minerogenic matter accumulation. Our analyses reveal that the climate-catchment mechanisms operating in the region of fine-grained tills differ crucially from previously described climate catchment interactions on sand morain...

10.1080/11035897.2017.1389984http://juuli.fi/Record/0285033017