LOSCAR Model Paleocene-Eocene Thermal Maximum pCO2 Output Zeebe, R.E. Zeebe, R.E. carbon cycle earth science/paleoclimate/climate forcing|paleoclimatic modeling (age,null,null,calendar year,null,climate forcing|paleoclimatic modeling,null,null,N,years from start of model simulation) earth science/paleoclimate/climate forcing|paleoclimatic modeling (carbon dioxide,null,null,parts per million,null,climate forcing|paleoclimatic modeling,null,null,N,null) earth science/paleoclimate/climate forcing (Global>LATITUDE >LONGITUDE ) The LOSCAR model is designed to efficiently compute the partitioning of carbon between ocean, atmosphere, and sediments on time scales ranging from centuries to millions of years. While a variety of computationally inexpensive carbon cycle models are already available, many are missing a critical sediment component, which is indispensable for long-term integrations. One of LOSCAR's strengths is the coupling of ocean-atmosphere routines to a computationally efficient sediment module. This allows, for instance, adequate computation of CaCO3 dissolution, calcite compensation, and long-term carbon cycle fluxes, including weathering of carbonate and silicate rocks. The ocean component includes various biogeochemical tracers such as total carbon, alkalinity, phosphate, oxygen, and stable carbon isotopes. LOSCAR's configuration of ocean geometry is flexible and allows for easy switching between modern and paleo-versions. We have previously published applications of the model tackling future projections of ocean chemistry and weathering, pCO2 sensitivity to carbon cycle perturbations throughout the Cenozoic, and carbon/calcium cycling during the Paleocene-Eocene Thermal Maximum. The focus of the present contribution is the detailed description of the model including numerical architecture, processes and parameterizations, tuning, and examples of input and output. Typical CPU integration times of LOSCAR are of order seconds for several thousand model years on current standard desktop machines. The LOSCAR source code in C can be obtained from the author by sending a request to loscar.model@gmail.com. STUDY NOTES: pCO2 output for the Palaeocene-Eocene Thermal Maximum from LOSCAR model (Long-term Ocean-atmosphere-Sediment CArbon cycle Reservoir Model) Model run is for 200,000 y after Paleocene-Eocene boundary (~56 Ma) NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Zeebe, R.E. 2012-07-11 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/13136 https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/loscar-petm-co2.txt https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/loscar-petm-co2.xls https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/loscar-petm-co2.txt https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/loscar-petm-co2.xls English https://www.ncdc.noaa.gov/paleo/study/13136 https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/loscar-petm-co2.txt https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/loscar-petm-co2.xls Zeebe, R.E. 2012. LOSCAR: Long-term Ocean-atmosphere-Sediment CArbon cycle Reservoir Model v2.0.4. Geosci. Model Dev., 5, 149-166 www.geosci-model-dev.net/5/149/2012/ doi:10.5194/gmd-5-149-2012 START YEAR: 56000000 cal yr BP * END YEAR: 55800000 cal yr BP -180 -90 180 90