Solar proxy Beryllium-10 in late deglacial climate simulated by ECHAM5-HAM Heikkilä, U.; Smith, A.M.; Phipps, S.J. Heikkilä, U. Smith, A.M. Phipps, S.J. earth science/paleoclimate/paleoclimatic modeling (7Be,null,null,count per square meter per second,null,paleoclimatic modeling,null,null,N,integrated stratospheric content of 7Be) earth science/paleoclimate/paleoclimatic modeling (surface pressure,null,null,pascal,null,paleoclimatic modeling,null,null,N,null) earth science/paleoclimate/paleoclimatic modeling (10Be,null,null,count per square meter per second,null,paleoclimatic modeling,null,null,N,sedimentation rate of 10Be) earth science/paleoclimate/paleoclimatic modeling (10Be,null,null,count per square meter per second,null,paleoclimatic modeling,null,null,N,dry deposition rate of 10Be) earth science/paleoclimate/paleoclimatic modeling (10Be,null,null,count per square meter,null,paleoclimatic modeling,null,null,N,integrated stratospheric content of 10Be) earth science/paleoclimate/paleoclimatic modeling (7Be,null,null,count per square meter per second,null,paleoclimatic modeling,null,null,N,production rate of 7Be integrated over stratosphere) earth science/paleoclimate/paleoclimatic modeling (10Be,null,null,count per square meter per second,null,paleoclimatic modeling,null,null,N,wet deposition rate of 10Be) earth science/paleoclimate/paleoclimatic modeling (7Be,null,null,count per square meter per second,null,paleoclimatic modeling,null,null,N,radioactive decay of 7Be integrated over atmosphere) earth science/paleoclimate/paleoclimatic modeling (7Be,null,null,count per square meter per second,null,paleoclimatic modeling,null,null,N,integrated tropospheric content of 7Be) earth science/paleoclimate/paleoclimatic modeling (10Be,null,null,count per kilogram,null,paleoclimatic modeling,null,null,N,atmospheric concentration of 10Be) earth science/paleoclimate/paleoclimatic modeling (10Be,null,null,count per square meter,null,paleoclimatic modeling,null,null,N,integrated tropospheric content of 10Be) earth science/paleoclimate/paleoclimatic modeling (10Be,null,null,count per square meter per second,null,paleoclimatic modeling,null,null,N,production rate of 10Be integrated over atmosphere) earth science/paleoclimate/paleoclimatic modeling (7Be,null,null,count per square meter per second,null,paleoclimatic modeling,null,null,N,production rate of 7Be integrated over troposphere) earth science/paleoclimate/paleoclimatic modeling (7Be,null,null,count per square meter per second,null,paleoclimatic modeling,null,null,N,sedimentation rate of 7Be) earth science/paleoclimate/paleoclimatic modeling (7Be,null,null,count per square meter per second,null,paleoclimatic modeling,null,null,N,dry deposition rate of 7Be) earth science/paleoclimate/paleoclimatic modeling (7Be,null,null,count per kilogram,null,paleoclimatic modeling,null,null,N,atmospheric concentration of 7Be) earth science/paleoclimate/paleoclimatic modeling (10Be,null,null,count per square meter per second,null,paleoclimatic modeling,null,null,N,production rate of 10Be integrated over stratosphere) earth science/paleoclimate/paleoclimatic modeling (7Be,null,null,count per square meter per second,null,paleoclimatic modeling,null,null,N,production rate of 7Be integrated over atmosphere) earth science/paleoclimate/paleoclimatic modeling (7Be,null,null,count per square meter per second,null,paleoclimatic modeling,null,null,N,integrated atmospheric content of 7Be) earth science/paleoclimate/paleoclimatic modeling (precipitation,null,null,millimeter per day,null,paleoclimatic modeling,null,null,N,null) earth science/paleoclimate/paleoclimatic modeling (10Be,null,null,count per square meter,null,paleoclimatic modeling,null,null,N,integrated atmospheric content of 10Be) earth science/paleoclimate/paleoclimatic modeling (10Be,null,null,count per square meter per second,null,paleoclimatic modeling,null,null,N,production rate of 10Be integrated over troposphere) earth science/paleoclimate/paleoclimatic modeling (7Be,null,null,count per square meter per second,null,paleoclimatic modeling,null,null,N,wet deposition rate of 7Be) earth science/paleoclimate/reconstructions (Global>LATITUDE >LONGITUDE ) 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). STUDY NOTES: 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. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Heikkilä, U. Investigator : Smith, A.M. Investigator : Phipps, S.J. 2014-09-09 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/17193 https://www1.ncdc.noaa.gov/pub/data/paleo/gcmoutput/heikkila2014/heikkila2014.txt https://www1.ncdc.noaa.gov/pub/data/paleo/gcmoutput/heikkila2014/ https://www1.ncdc.noaa.gov/pub/data/paleo/gcmoutput/heikkila2014/heikkila2014.txt https://www1.ncdc.noaa.gov/pub/data/paleo/gcmoutput/heikkila2014/ English https://www.ncdc.noaa.gov/paleo/study/17193 https://www1.ncdc.noaa.gov/pub/data/paleo/gcmoutput/heikkila2014/heikkila2014.txt https://www1.ncdc.noaa.gov/pub/data/paleo/gcmoutput/heikkila2014/ Heikkilä, U., S.J. Phipps, and A.M. Smith201310Be in late deglacial climate simulated by ECHAM5-HAM – Part 1: Climatological influences on 10Be depositionClimate of the Past92641-264910.5194/cp-9-2641-2013 Heikkilä, U., X. Shi, S.J. Phipps, and A.M. Smith201410Be in late deglacial climate simulated by ECHAM5-HAM – Part 2: Isolating the solar signal from 10Be depositionClimate of the Past10687-69610.5194/cp-10-687-2014 -180 -90 180 90