Bat Cave, Northern Hemisphere Past Millennium Stalagmite Data Asmerom, Y.; Polyak, V.J.; Rasmussen, J.B.T.; Burns, S.J.; Lachniet, M.S. Asmerom, Y. Polyak, V.J. Rasmussen, J.B.T. Burns, S.J. Lachniet, M.S. earth science/paleoclimate/speleothems (delta 13C,calcite,null,per mil VPDB,null,speleothems,raw,isotope ratio mass spectrometry,N,null) earth science/paleoclimate/speleothems (age,null,null,calendar year before present,null,speleothems,null,null,N,null) earth science/paleoclimate/speleothems (age,null,null,year Common Era,null,speleothems,null,null,N,null) earth science/paleoclimate/speleothems (delta 18O,calcite,null,per mil VPDB,null,speleothems,raw,isotope ratio mass spectrometry,N,null) earth science/paleoclimate/speleothems (Bat Cave>LATITUDE 32.2>LONGITUDE -104.4) Late Holocene climate in western North America was punctuated by periods of extended aridity called megadroughts. These droughts have been linked to cool eastern tropical Pacific sea surface temperatures (SSTs). Here, we show both short-term and long-term climate variability over the last 1,500 y from annual band thickness and stable isotope speleothem data. Several megadroughts are evident, including a multicentury one, AD 1350–1650, herein referred to as Super Drought, which corresponds to the coldest period of the Little Ice Age. Synchronicity between southwestern North American, Chinese, and West African monsoon precipitation suggests the megadroughts were hemispheric in scale. Northern Hemisphere monsoon strength over the last millennium is positively correlated with Northern Hemisphere temperature and North Atlantic SST. The megadroughts are associated with cooler than average SST and Northern Hemisphere temperatures. Furthermore, the megadroughts, including the Super Drought, coincide with solar insolation minima, suggesting that solar forcing of sea surface and atmospheric temperatures may generate variations in the strength of Northern Hemisphere monsoons. Our findings seem to suggest stronger (wetter) Northern Hemisphere monsoons with increased warming. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Asmerom, Y. Investigator : Polyak, V.J. Investigator : Rasmussen, J.B.T. Investigator : Burns, S.J. Investigator : Lachniet, M.S. 2017-11-13 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/23085 https://www1.ncdc.noaa.gov/pub/data/paleo/pages2k/NAm2kHydro-2017/noaa-templates/data-version-1.0.0/Bat.Asmerom.2013.txt https://www1.ncdc.noaa.gov/pub/data/paleo/pages2k/NAm2kHydro-2017/data-version-1.0.0/Bat.Asmerom.2013.lpd https://www1.ncdc.noaa.gov/pub/data/paleo/pages2k/NAm2kHydro-2017/noaa-templates/data-version-1.0.0/Bat.Asmerom.2013.txt https://www1.ncdc.noaa.gov/pub/data/paleo/pages2k/NAm2kHydro-2017/data-version-1.0.0/Bat.Asmerom.2013.lpd English https://www.ncdc.noaa.gov/paleo/study/23085 https://www1.ncdc.noaa.gov/pub/data/paleo/pages2k/NAm2kHydro-2017/noaa-templates/data-version-1.0.0/Bat.Asmerom.2013.txt https://www1.ncdc.noaa.gov/pub/data/paleo/pages2k/NAm2kHydro-2017/data-version-1.0.0/Bat.Asmerom.2013.lpd Asmerom, Y.; Polyak, V. J.; Rasmussen, J. B. T.; Burns, S. J.; Lachniet, M.2013Multidecadal to multicentury scale collapses of Northern Hemisphere monsoons over the past millenniumProceedings of the National Academy of Sciences110249651-965610.1073/pnas.1214870110 START YEAR: 1408 cal yr BP * END YEAR: -54 cal yr BP -104.4 32.2 -104.4 32.2