# Paleoclimate Data-Model Comparison and the Role of Climate Forcings over the Past 1500 Years #----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # NOTE: Please cite Publication, and Online_Resource and date accessed when using these data. # # Online_Resource: http://hurricane.ncdc.noaa.gov/pls/paleox/f?p=519:1:::::P1_STUDY_ID:16337 # # Original_Source_URL: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/gcmoutput/gcmoutput/phipps2014/phipps2014-readme.txt # # Description/Documentation lines begin with # # Data lines have no # # # Archive: Paleoclimatic Modeling #-------------------- # Contribution_Date # Date: 2014-03-18 #-------------------- # Title # Study_Name: Paleoclimate Data-Model Comparison and the Role of Climate Forcings over the Past 1500 Years #-------------------- # Investigators # Investigators: 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. #-------------------- # Description_and_Notes # Description: Simulations of the climate of the past 2000 years, conducted using the CSIRO Mk3L climate system model version 1.2. #-------------------- # Publication # Authors: 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 Ommen # Published_Date_or_Year: 2013-09-15 # Published_Title: Paleoclimate Data-Model Comparison and the Role of Climate Forcings over the Past 1500 Years # Journal_Name: Journal of Climate # Volume: 26 # Issue: 18 # Pages: 6915-6936 # DOI: 10.1175/JCLI-D-12-00108.1 # Online_Resource: http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00108.1 # Abstract: 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. #------------------ # Funding_Agency # Funding_Agency_Name: Australian Research Council # Grant: Discovery Project DP1092945, Linkage Project LP0990151 #------------------ # Funding_Agency_Name: Australian Government Department of Climate Change and Energy Efficiency #------------------ # Funding_Agency_Name: National Computational Merit Allocation Scheme #------------------ # Site_Information # Site_Name: Global # Location: Global # Northernmost_Latitude: 90.0 # Southernmost_Latitude: -90.0 # Easternmost_Longitude: 180.0 # Westernmost_Longitude: -180.0 #------------------ # Data_Collection # Collection_Name: Control simulation # Earliest_Year: 201 # Most_Recent_Year: 1200 # Time_Unit: Model years # Notes: Pre-industrial control simulation; this is also the CMIP5/PMIP3 piControl simulation for model CSIRO-Mk3L-1-2. The calendar is arbitrary, and does not correspond to specific calendar years. #------------------ # Data_Collection # Collection_Name: Ensemble O # Earliest_Year: 1 # Most_Recent_Year: 2000 # Time_Unit: AD # Notes: Three-member ensemble of climate model simulations, driven with orbital forcing only. Individual ensemble members are named O1, O2 and O3. #------------------ # Data_Collection # Collection_Name: Ensemble OG # Earliest_Year: 1 # Most_Recent_Year: 2000 # Time_Unit: AD # Notes: Three-member ensemble of climate model simulations, driven with orbital and greenhouse gas forcing. Individual ensemble members are named OG1, OG2 and OG3. #------------------ # Data_Collection # Collection_Name: Ensemble OGS # Earliest_Year: 1 # Most_Recent_Year: 2000 # Time_Unit: AD # Notes: Three-member ensemble of climate model simulations, driven with orbital, greenhouse gas and solar forcing. Individual ensemble members are named OGS1, OGS2 and OGS3. #------------------ # Data_Collection # Collection_Name: Ensemble OGSV # Earliest_Year: 501 # Most_Recent_Year: 2000 # Time_Unit: AD # Notes: Three-member ensemble of climate model simulations, driven with orbital, greenhouse gas, solar and volcanic forcing. Individual ensemble members are named OGSV1, OGSV2 and OGSV3. #------------------ # Data_Collection # Collection_Name: Forcing data # Earliest_Year: 1 # Most_Recent_Year: 2000 # Time_Unit: AD # Notes: Forcing data used to drive the model. #------------------ # Variables # Data variables follow (have two '##') # Variables in netCDF output files: ## evp Evaporation (mm/day) ## psl Mean sea level pressure (hPa) ## rnd Precipitation (mm/day) ## sss Sea surface salinity (psu) ## sst Sea surface temperature (degrees Celsius) ## tsc Surface air temperature (Kelvin) # Data: netCDF model output files are available in this directory: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/gcmoutput/phipps2014/ Forcings used to drive the model are in this file: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/gcmoutput/phipps2014/phipps2014-forcing.txt