Paleoclimate Data-Model Comparison and the Role of Climate Forcings over the Past 1500 Years Phipps, S.J.; McGregor, H.V.; Gergis, J.; Gallant, A.J.E.; Neukom, R.; Stevenson, S.; Ackerley, D.; Brown, J.R.; Fischer, M.J.; van Ommen, T.D. Phipps, S.J. McGregor, H.V. Gergis, J. Gallant, A.J.E. Neukom, R. Stevenson, S. Ackerley, D. Brown, J.R. Fischer, M.J. van Ommen, T.D. earth science/paleoclimate/climate forcing (carbon dioxide,null,null,parts per million,null,climate forcing,null,null,N,Equivalent CO2 concentration) earth science/paleoclimate/climate forcing (volcanic forcing,null,null,watt per square meter,null,climate forcing,null,null,N,null) earth science/paleoclimate/paleoclimatic modeling (latitude,null,null,degree north,null,paleoclimatic modeling,null,null,N,null) earth science/paleoclimate/paleoclimatic modeling (age,null,null,year Common Era,null,paleoclimatic modeling,null,null,N,null) earth science/paleoclimate/climate forcing (greenhouse gas forcing,null,null,watt per square meter,null,climate forcing,null,null,N,null) earth science/paleoclimate/paleoclimatic modeling (surface air temperature,null,null,kelvin,null,paleoclimatic modeling,null,null,N,null) earth science/paleoclimate/paleoclimatic modeling (evaporation,null,null,millimeter per day,null,paleoclimatic modeling,null,null,N,null) earth science/paleoclimate/climate forcing (solar irradiance,null,null,watt per square meter,null,climate forcing,null,null,N,null) earth science/paleoclimate/paleoclimatic modeling (precipitation,null,null,millimeter per day,null,paleoclimatic modeling,null,null,N,null) earth science/paleoclimate/paleoclimatic modeling (longitude,null,null,degree east,null,paleoclimatic modeling,null,null,N,null) earth science/paleoclimate/paleoclimatic modeling (sea level pressure,null,null,hectopascal,null,paleoclimatic modeling,null,null,N,null) earth science/paleoclimate/paleoclimatic modeling (salinity,sea surface,null,practical salinity unit,null,paleoclimatic modeling,null,null,N,null) earth science/paleoclimate/paleoclimatic modeling (sea surface temperature,null,null,degree Celsius,null,paleoclimatic modeling,null,null,N,null) earth science/paleoclimate/model earth science/paleoclimate/model (Global>LATITUDE >LONGITUDE ) The past 1500 years provide a valuable opportunity to study the response of the climate system to external forcings. However, the integration of paleoclimate proxies with climate modeling is critical to improving the understanding of climate dynamics. In this paper, a climate system model and proxy records are therefore used to study the role of natural and anthropogenic forcings in driving the global climate. The inverse and forward approaches to paleoclimate data-model comparison are applied, and sources of uncertainty are identified and discussed. In the first of two case studies, the climate model simulations are compared with multiproxy temperature reconstructions. Robust solar and volcanic signals are detected in Southern Hemisphere temperatures, with a possible volcanic signal detected in the Northern Hemisphere. The anthropogenic signal dominates during the industrial period. It is also found that seasonal and geographical biases may cause multiproxy reconstructions to overestimate the magnitude of the long-term preindustrial cooling trend. In the second case study, the model simulations are compared with a coral δ18O record from the central Pacific Ocean. It is found that greenhouse gases, solar irradiance, and volcanic eruptions all influence the mean state of the central Pacific, but there is no evidence that natural or anthropogenic forcings have any systematic impact on El Niño-Southern Oscillation. The proxy climate relationship is found to change over time, challenging the assumption of stationarity that underlies the interpretation of paleoclimate proxies. These case studies demonstrate the value of paleoclimate data-model comparison but also highlight the limitations of current techniques and demonstrate the need to develop alternative approaches. STUDY NOTES: Simulations of the climate of the past 2000 years, conducted using the CSIRO Mk3L climate system model version 1.2. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Phipps, S.J. Investigator : McGregor, H.V. Investigator : Gergis, J. Investigator : Gallant, A.J.E. Investigator : Neukom, R. Investigator : Stevenson, S. Investigator : Ackerley, D. Investigator : Brown, J.R. Investigator : Fischer, M.J. Investigator : van Ommen, T.D. 2014-03-18 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/16337 https://www1.ncdc.noaa.gov/pub/data/paleo/gcmoutput/phipps2014/phipps2014-readme.txt https://www1.ncdc.noaa.gov/pub/data/paleo/gcmoutput/phipps2014/phipps2014-forcing.txt https://www1.ncdc.noaa.gov/pub/data/paleo/gcmoutput/phipps2014/ https://www1.ncdc.noaa.gov/pub/data/paleo/gcmoutput/phipps2014/phipps2014-readme.txt https://www1.ncdc.noaa.gov/pub/data/paleo/gcmoutput/phipps2014/phipps2014-forcing.txt https://www1.ncdc.noaa.gov/pub/data/paleo/gcmoutput/phipps2014/ English https://www.ncdc.noaa.gov/paleo/study/16337 https://www1.ncdc.noaa.gov/pub/data/paleo/gcmoutput/phipps2014/phipps2014-readme.txt https://www1.ncdc.noaa.gov/pub/data/paleo/gcmoutput/phipps2014/phipps2014-forcing.txt https://www1.ncdc.noaa.gov/pub/data/paleo/gcmoutput/phipps2014/ Steven J. Phipps, Helen V. McGregor, Joëlle Gergis, Ailie J.E. Gallant, Raphael Neukom, Samantha Stevenson, Duncan Ackerley, Josephine R. Brown, Matt J. Fischer, and Tas D. van Ommen2013Paleoclimate Data-Model Comparison and the Role of Climate Forcings over the Past 1500 YearsJournal of Climate26186915-693610.1175/JCLI-D-12-00108.1http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00108.1 START YEAR: 1 AD * END YEAR: 2000 AD -180 -90 180 90