Frisia et al. 2003 Grotta di Ernesto, Italy Speleothem Layer Thickness Data Frisia, S.; Borsato, A.; Preto, N.; McDermott, F. Frisia, S. Borsato, A. Preto, N. McDermott, F. earth science/paleoclimate/speleothems (age,null,null,year Common Era,null,speleothems,null,null,N,null) earth science/paleoclimate/speleothems (growth rate,calcium carbonate,null,micrometer per year,null,speleothems,raw,optical microscopy|ultraviolet microscopy,N,null) earth science/paleoclimate/speleothems (Grotta di Ernesto>LATITUDE 45.98>LONGITUDE 11.66) Annual growth rates and the ratio of dark to light-colored calcite within single annual laminae in three contemporaneously deposited Holocene speleothems from Grotta di Ernesto, an Alpine cave in northern Italy, respond to changes in surface temperature rather than precipitation. Based on monitoring of present-day calcite growth, and correlation with instrumental data for surface climatic conditions, we interpret a higher ratio of dark to light-colored calcite and the simultaneous thinning of annual laminae as indicative of colder-than-present winters. Such dark and thin laminae occur in those parts of the three stalagmites deposited from AD 1650 to 1713 and from AD 1798 to 1840, as reconstructed through lamina counting. These periods correspond to the well-known Maunder and Dalton Minima of solar activity. An 11-yr cyclicity in growth rate, coupled with reduced calcite deposition during the historic minima of solar activity, is indicative of a solar influence on lamina thickness. Spectral analysis of the lamina thickness data also suggests that the North Atlantic Oscillation variability influenced winter temperatures. Based on the present-day controls on cave calcite formation, we infer that high-frequency changes in solar activity modulated the seasonal duration of soil CO2 production. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Frisia, S. Investigator : Borsato, A. Investigator : Preto, N. Investigator : McDermott, F. 2003-07-01 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/5438 https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/europe/italy/ernesto2003.txt https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/europe/italy/ernesto2003.txt English https://www.ncdc.noaa.gov/paleo/study/5438 https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/europe/italy/ernesto2003.txt Frisia, S.;Borsato, A.;Preto, N.;McDermott, F. 2003. Late Holocene annual growth in three Alpine stalagmites records the influence of solar activity and the North Atlantic Oscillation on winter climate. Earth and Planetary Science Letters, 216 (3), 411-424. START YEAR: 1387 AD * END YEAR: 2000 AD 11.66 45.98 11.66 45.98