# Solar proxy Beryllium-10 in late deglacial climate simulated by ECHAM5-HAM #----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # NOTE: Please cite original publication, online resource and date accessed when using these data, # If there is no publication information, please cite investigator, title, online resource and date accessed. # # Online_Resource: http://www.ncdc.noaa.gov/paleo/study/17193 # Online_Resource: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/gcmoutput/heikkila2014/heikkila2014.txt # # Archive: Climate Modelling #-------------------- # Contribution_Date # Date: 09-09-14 #-------------------- # Title # Study_Name: Solar proxy Beryllium-10 in late deglacial climate simulated by ECHAM5-HAM #-------------------- # Investigators # Investigators: Heikkilä, U.; Smith, A.M.; Phipps, S.J. #-------------------- # Description_and_Notes # Description: This model experiment consists of four 30-year time window simulations: # # 1) "ctrl" - a preindustrial control simulation: preindustrial aerosol load (AEROCOM: http://nansen.ipsl.jussieu.fr/AEROCOM) and greenhouse gas concentrations: # CH4: 760.0 ppb, CO2: 280.0 ppm, N2O: 270.0 ppb # 2) "10k" - 10'000 years before present (BP, 1950CE) # CH4: 702.9 ppb, CO2: 265.0 ppm, N2O: 269.9 ppb # 3) "11k" - 11'000 years BP # CH4: 701.3 ppb, CO2: 263.0 ppm, N2O: 267.8 ppb # 4) "12k" - 12'000 years BP # CH4: 479.3 ppb, CO2: 240.6 ppm, N2O: 242.3 ppb # For all further details we refer to Heikkilä et al., 2013, 2014 and references therein. # # Resolution: # Gaussian 128 x 64 grid (ca. 2.8 degrees or roughly 300km at Equator), 31 vertical levels up to 10hPa (ca. 30km). Monthly means over a pseudo 30-yr period. # #-------------------- # Publication # Authors: Heikkilä, U., S.J. Phipps, and A.M. Smith # Published_Date_or_Year: 2013 # Published_Title: 10Be in late deglacial climate simulated by ECHAM5-HAM – Part 1: Climatological influences on 10Be deposition # Journal_Name: Climate of the Past # Volume: 9 # Issue: # Pages: 2641-2649 # DOI: 10.5194/cp-9-2641-2013 # Abstract: Reconstruction of solar irradiance has only been possible for the Holocene so far. During the last deglaciation, two solar proxies (10Be and 14C) deviate strongly, both of them being influenced by climatic changes in a different way. This work addresses the climate influence on 10Be deposition by means of ECHAM5-HAM atmospheric aerosol–climate model simulations, forced by sea surface temperatures and sea ice extent created by the CSIRO Mk3L coupled climate system model. Three time slice simulations were performed during the last deglaciation: 10 000 BP ("10k"), 11 000 BP ("11k") and 12 000 BP ("12k"), each 30 yr long. The same, theoretical, 10Be production rate was used in each simulation to isolate the impact of climate on 10Be deposition. The changes are found to follow roughly the reduction in the greenhouse gas concentrations within the simulations. The 10k and 11k simulations produce a surface cooling which is symmetrically amplified in the 12k simulation. The precipitation rate is only slightly reduced at high latitudes, but there is a northward shift in the polar jet in the Northern Hemisphere, and the stratospheric westerly winds are significantly weakened. These changes occur where the sea ice change is largest in the deglaciation simulations. This leads to a longer residence time of 10Be in the stratosphere by 30 (10k and 11k) to 80 (12k) days, increasing the atmospheric concentrations (25–30% in 10k and 11k and 100% in 12k). Furthermore the shift of westerlies in the troposphere leads to an increase of tropospheric 10Be concentrations, especially at high latitudes. The contribution of dry deposition generally increases, but decreases where sea ice changes are largest. In total, the 10Be deposition rate changes by no more than 20% at mid- to high latitudes, but by up to 50% in the tropics. We conclude that on "long" time scales (a year to a few years), climatic influences on 10Be deposition remain small (less than 50%) even though atmospheric concentrations can vary significantly. Averaged over a longer period, all 10Be produced has to be deposited by mass conservation. This dominates over any climatic influences on 10Be deposition. Snow concentrations, however, do not follow mass conservation and can potentially be impacted more by climate due to precipitation changes. Quantifying the impact of deglacial climate modulation on 10Be in terms of preserving the solar signal locally is analysed in an accompanying paper (Heikkilä et al., 10Be in late deglacial climate simulated by ECHAM5-HAM – Part 2: Isolating the solar signal from 10Be deposition). # #-------------------- # Publication # Authors: Heikkilä, U., Shi, X., Phipps, S.J., and Smith, A.M. # Published_Date_or_Year: 2014 # Published_Title: 10Be in late deglacial climate simulated by ECHAM5-HAM – Part 2: Isolating the solar signal from 10Be deposition # Journal_Name: Climate of the Past # Volume: 10 # Issue: # Pages: 687-696 # DOI: 10.5194/cp-10-687-2014 # Abstract: This study investigates the effect of deglacial climate on the deposition of the solar proxy 10Be globally, and at two specific locations, the GRIP site at Summit, Central Greenland, and the Law Dome site in coastal Antarctica. The deglacial climate is represented by three 30 year time slice simulations of 10 000 BP (years before present = 1950 CE), 11 000 and 12 000 BP, compared with a preindustrial control simulation. The model used is the ECHAM5-HAM atmospheric aerosol–climate model, driven with sea-surface temperatures and sea ice cover simulated using the CSIRO Mk3L coupled climate system model. The focus is on isolating the 10Be production signal, driven by solar variability, from the weather- or climate-driven noise in the 10Be deposition flux during different stages of climate. The production signal varies at lower frequencies, dominated by the 11 year solar cycle within the 30 year timescale of these experiments. The climatic noise is of higher frequencies than 11 years during the 30 year period studied. We first apply empirical orthogonal function (EOF) analysis to global 10Be deposition on the annual scale and find that the first principal component, consisting of the spatial pattern of mean 10Be deposition and the temporally varying solar signal, explains 64% of the variability. The following principal components are closely related to those of precipitation. Then, we apply ensemble empirical decomposition (EEMD) analysis to the time series of 10Be deposition at GRIP and at Law Dome, which is an effective method for adaptively decomposing the time series into different frequency components. The low-frequency components and the long-term trend represent production and have reduced noise compared to the entire frequency spectrum of the deposition. The high-frequency components represent climate-driven noise related to the seasonal cycle of e.g. precipitation and are closely connected to high frequencies of precipitation. These results firstly show that the 10Be atmospheric production signal is preserved in the deposition flux to surface even during climates very different from today's both in global data and at two specific locations. Secondly, noise can be effectively reduced from 10Be deposition data by simply applying the EOF analysis in the case of a reasonably large number of available data sets, or by decomposing the individual data sets to filter out high-frequency fluctuations. #--------------------- # Funding_Agency # Funding_Agency_Name: Merit Allocation Scheme of the NCI National Facility at the Australian National University (ANU), Canberra, Australia # Grant: #--------------------- # Site_Information # Site_Name: Global # Location: # Country: # Northernmost_Latitude: 90 # Southernmost_Latitude: -90 # Easternmost_Longitude: 180 # Westernmost_Longitude: -180 # Elevation: #------------------ # Data_Collection # Collection_Name: ECHAM5-HAM 10Be H14 # Earliest_Year: # Most_Recent_Year: # Time_Unit: # Core_Length: # Notes: The deglacial climate is represented by three 30 year time slice simulations of 10 000 BP (years before present = 1950 CE), 11 000 and 12 000 BP, compared with a preindustrial control simulation. #------------------ # Chronology: # # #------------------ # Variables # # Data line variables format: one variable per line, shortname- 9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) # Data line format: tab-delimited text, variable short name as header ## be10_prod_acc - Production rate of 10Be, integrated over the atmosphere (atoms/m2/s) ## be10_wdep_acc - Wet deposition rate of 10Be (atoms/m2/s) ## be10_sed_acc - Sedimentation rate of 10Be (atoms/m2/s) ## be10_ddep_acc - Dry deposition rate of 10Be (atoms/m2/s) ## be10_burden - Integrated atmospheric content of 10Be (atoms/m2) ## burden_be10_str - Integrated stratospheric content of 10Be (atoms/m2) ## burden_be10_tr - Integrated tropospheric content of 10Be (atoms/m2) ## be10pro_str - Production rate of 10Be, integrated over the stratosphere (atoms/m2/s) ## be10pro_tr - Production rate of 10Be, integrated over the troposphere (atoms/m2/s) ## be7pro_str - Production rate of 7Be, integrated over the stratosphere (atoms/m2/s) ## be7pro_tr - Production rate of 7Be, integrated over the troposphere (atoms/m2/s) ## be7_prod_acc - Production rate of 7Be, integrated over the atmosphere (atoms/m2/s) ## be7_dec_acc - Radioactive decay of 7Be, integrated over the atmosphere (atoms/m2/s) ## be7_wdep_acc - Wet deposition rate of 7Be (atoms/m2/s) ## be7_sed_acc - Sedimentation rate of 7Be (atoms/m2/s) ## be7_ddep_acc - Dry deposition rate of 7Be (atoms/m2/s) ## be7_burden - Integrated atmospheric content of 7Be (atoms/m2) ## burden_be7_str - Integrated stratospheric content of 7Be (atoms/m2) ## burden_be7_tr - Integrated tropospheric content of 7Be (atoms/m2) ## be10 - Atmospheric concentrations of 10Be (atoms/kg) ## be7 - Atmospheric concentrations of 7Be (atoms/kg) ## aps - Surface pressure (Pa) ## hyam (Pa), hybm (-) - vertical coefficients. Vertical pressure: hyam+hybm*aps ## precip - Precipitation rate (mm/day) #----------------- # Data: # Missing Value: netCDF Data files are all located at: http://www1.ncdc.noaa.gov/pub/data/paleo/gcmoutput/heikkila2014/ Files and the variables they contain: Be10_fluxes_ctrl/10k/11k/12k.nc: be10_prod_acc - Production rate of 10Be, integrated over the atmosphere (atoms/m2/s) be10_wdep_acc - Wet deposition rate of 10Be (atoms/m2/s) be10_sed_acc - Sedimentation rate of 10Be (atoms/m2/s) be10_ddep_acc - Dry deposition rate of 10Be (atoms/m2/s) be10_burden - Integrated atmospheric content of 10Be (atoms/m2) burden_be10_str - Integrated stratospheric content of 10Be (atoms/m2) burden_be10_tr - Integrated tropospheric content of 10Be (atoms/m2) be10pro_str - Production rate of 10Be, integrated over the stratosphere (atoms/m2/s) be10pro_tr - Production rate of 10Be, integrated over the troposphere (atoms/m2/s) be7pro_str - Production rate of 7Be, integrated over the stratosphere (atoms/m2/s) be7pro_tr - Production rate of 7Be, integrated over the troposphere (atoms/m2/s) be7_prod_acc - Production rate of 7Be, integrated over the atmosphere (atoms/m2/s) be7_dec_acc - Radioactive decay of 7Be, integrated over the atmosphere (atoms/m2/s) be7_wdep_acc - Wet deposition rate of 7Be (atoms/m2/s) be7_sed_acc - Sedimentation rate of 7Be (atoms/m2/s) be7_ddep_acc - Dry deposition rate of 7Be (atoms/m2/s) be7_burden - Integrated atmospheric content of 7Be (atoms/m2) burden_be7_str - Integrated stratospheric content of 7Be (atoms/m2) burden_be7_tr - Integrated tropospheric content of 7Be (atoms/m2) Be10_3d_ctrl/10k/11k/12k.nc: be10 - Atmospheric concentrations of 10Be (atoms/kg) be7 - Atmospheric concentrations of 7Be (atoms/kg) aps - Surface pressure (Pa) hyam (Pa), hybm (-) - vertical coefficients. Vertical pressure: hyam+hybm*aps Precip_ctrl/10k/11k/12k.nc: precip - Precipitation rate (mm/day)