Climate of the Past Discussions www.clim-past-discuss.net 1814-9340 1814-9359 5 5 2009 10.5194/cpd-5-2311-2009 http://www.clim-past-discuss.net/5/2311/2009/ http://www.clim-past-discuss.net/5/2311/2009/cpd-5-2311-2009.html http://www.clim-past-discuss.net/5/2311/2009/cpd-5-2311-2009.pdf 2311 2341 2009-10-13 Effects of orbital forcing on atmosphere and ocean heat transports in Holocene and Eemian climate simulations with a comprehensive Earth system model N. Fischer nils.fischer@zmaw.de J. Jungclaus Max Planck Institute for Meteorology, Hamburg, Germany International Max Planck Research School for Earth System Modelling, Germany Orbital forcing does not only exert direct insolation effects but also alters climate indirectly through feedback mechanisms that modify atmosphere and ocean dynamics and meridional heat and moisture transfers. We investigate the regional effects of these changes by detailed analysis of atmosphere and ocean circulation and heat transports in a coupled atmosphere-ocean-sea ice-biosphere general circulation model (ECHAM5/JSBACH/MPI-OM). We perform long term quasi equilibrium simulations under pre-industrial, mid-Holocene (6000 years before present – yBP), and Eemian (125 000 yBP) orbital boundary conditions. Compared to pre-industrial climate, Eemian and Holocene temperatures show generally warmer conditions at higher and cooler conditions at lower latitudes. Changes in sea-ice cover, ocean heat transports, and atmospheric circulation patterns lead to pronounced regional heterogeneity. Over Europe, the warming is most pronounced over the north-eastern part in accordance with recent reconstructions for the Holocene. We attribute this warming to enhanced ocean circulation in the Nordic Seas and enhanced ocean-atmosphere heat flux over the Barents Shelf in conduction with retreat of sea ice and intensified winter storm tracks over northern Europe. Antonsson,~K., Chen,~D., and Seppä,~H.: Anticyclonic atmospheric circulation as an analogue for the warm and dry mid-Holocene summer climate in central Scandinavia, Clim. Past, 4, 215–224, 2008. Barnekow,~L.: Holocene regional and local vegetation history and lake-level changes in the Tornetrsk area, northern Sweden, J Paleolimnol., 23, 343–456, 2000. Bauch,~H A. and Erlenkeuser,~H.: A~critical climatic evaluation of last interglacial (MIS 5e) records from the Norwegian Sea, Polar Res., 27, 135–151, 2008. Blackmon,~M.: Climatological spectral study of 500 \unitmb geopotential height of Northern Hemisphere, J Atmos. Sci., 33, 1607–1623, 1976. Braconnot,~P., Otto-Bliesner,~B., Harrison,~S., Joussaume,~S., Peterchmitt,~J.-Y., Abe-Ouchi,~A., Crucifix,~M., Driesschaert,~E., Fichefet, Th., Hewitt,~C D., Kageyama,~M., Kitoh,~A., Laîné,~A., Loutre,~M.-F., Marti,~O., Merkel,~U., Ramstein,~G., Valdes,~P., Weber,~S L., Yu,~Y., and Zhao,~Y.: Results of PMIP2 coupled simulations of the Mid-Holocene and Last Glacial Maximum – Part~1: experiments and large-scale features, Clim. Past, 3, 261–277, 2007a. Braconnot,~P., Otto-Bliesner,~B., Harrison,~S., Joussaume,~S., Peterchmitt,~J.-Y., Abe-Ouchi,~A., Crucifix,~M., Driesschaert,~E., Fichefet, Th., Hewitt,~C D., Kageyama,~M., Kitoh,~A., Loutre,~M.-F., Marti,~O., Merkel,~U., Ramstein,~G., Valdes,~P., Weber,~L., Yu,~Y., and Zhao,~Y.: Results of PMIP2 coupled simulations of the Mid-Holocene and Last Glacial Maximum – Part~2: feedbacks with emphasis on the location of the ITCZ and mid- and high latitudes heat budget, Clim. Past, 3, 279–296, 2007. Braconnot,~P., Marzin,~C., Grégoire,~L., Mosquet,~E., and Marti,~O.: Monsoon response to changes in Earth's orbital parameters: comparisons between simulations of the Eemian and of the Holocene, Clim. Past, 4, 281–294, 2008. Brovkin,~V., Raddatz,~T., Reick,~C H., Claussen,~M., and Gayler,~V.: Global biogeophysical interactions between forest and climate, Geophys. Res. Lett., 36, L07405, doi:10.1029/2009GL037543, 2009. Cheddadi,~R., Yu,~G., Guiot,~J., Harrison,~S., and Prentice,~I.: The climate of Europe 6000 years ago, Clim. Dynam., 13(1), 1–9, 1996. Davis,~B A S., Brewer,~S., Stevenson,~A C., Guiot,~J., and Contributors,~D.: The temperature of Europe during the Holocene reconstructed from pollen data, Quaternary Sci. Rev., 22, 1701–1716, 2003. Duplessy,~J.-C., Ivanova,~E., Murdmaa,~I., Paterne,~M., and Labeyrie,~L.: Holocene paleoceanography of the northern Barents Sea and variations of the northward heat transport by the Atlantic Ocean, Boreas, 30, 2–16, 2001. Groll,~N., Widmann,~M., Jones,~J., Kaspar,~F., and Lorenz,~S.: Simulated relationships between regional temperatures and large-scale circulation: 125 \unitkyr BP (Eemian) and the preindustrial period, J Climate, 18, 4032–4045, 2005. Hagemann,~S. and Dumenil,~L.: A~parametrization of the lateral waterflow for the global scale, Clim. Dynam., 14, 17–31, 1998. Hagemann,~S. and Gates,~L.: Improving a~subgrid runoff parameterization scheme for climate models by the use of high resolution data derived from satellite observations, Clim. Dynam., 21, 349–359, doi:10.1007/s00382-003-0349-x, 2003. Hald,~M., Andersson,~C., Ebbesen,~H., Jansen,~E., Klitgaard-Kristensen,~D., Risebrobakken,~B., Salomonsen,G., Sarnthein,~M., Sejrup, H P., and Telford,~R.: Variations in temperature and extent of Atlantic Water in the northern North Atlantic during the Holocene, Quaternary Sci. Rev., 26, 3423–3444, 2007. Harvey,~L D D.: On the role of high-latitude ice, snow, and vegetation feedbacks in the climatic response to external forcing changes, Climatic Change, 13, 191–224, 1988. Hays,~J., Imbrie,~J., and Shackleton,~N J.: Variations in the Earth's orbit: pacemaker of the ice ages, Science, 194, 1121–1132, 1976. Hibler,~W.: Dynamic thermodynamic sea ice model, J Phys. Oceanogr., 9, 815–846, 1979. Hurrell,~J W.: Decadal trends in the North Atlantic oscillation: regional temperatures and precipitation, Science, 269, 676–679, 1995. Imbrie,~J., Boyle,~E., Clemens,~S., Duffy,~A., Howard,~W., Kukla,~G., Kutzbach,~J., Martinson,~D., Mcintyre,~A., Mix,~A., Molfino,~B., Morley,~J., Peterson,~L., Pisias,~N., Prell,~W., Raytoo,~M., Shackletons,~N., and Toggweiler,~J.: On the structure and origin of major glaciation cycles 1. Linear responses to Milankovich forcing, Paleoceanography, 7(6), 701–738, 1992. Joussaume,~S. and Taylor,~K E.: Status of the Paleoclimate Modeling Intercomparison Project (PMIP), WCRP Report, 425–430, http://pmip.lsce.ipsl.fr/, 1995. Jungclaus,~J H., Keenlyside,~N., Botzet,~M., Haak,~H., Luo,~J J., Latif,~M., Marotzke,~J., Mikolajewicz,~U., and Roeckner,~E.: Ocean circulation and tropical variability in the coupled model ECHAM5/MPI-OM, J Climate, 19, 3952–3972, 2006. Kaspar,~F., Kuhl,~N., Cubasch,~U., and Litt, T: A~model-data comparison of European temperatures in the Eemian interglacial, Geophys. Res. Lett., 32, L11703, doi:10.1029/2005GL022456, 2005. Kaspar,~F., Spangehl,~T., and Cubasch,~U.: Northern hemisphere winter storm tracks of the Eemian interglacial and the last glacial inception, Clim. Past, 3, 181–192, 2007. Keith,~D.: Meridional energy transport: uncertainty in zonal means, Tellus, 47, 30–44, 1995. Levitus,~S. and Isayev,~G.: Polynomial-approximation to the international equation of state for seawater, J Atmos Ocean. Tech., 9, 705–708, 1992. Marsland,~S J., Haak,~H., Jungclaus,~J H., Latif,~M., and Roske,~F.: The Max-Planck-Institute global ocean/sea ice model with orthogonal curvilinear coordinates, Ocean Model., 5, 91–127, 2003. Milankovic,~M.: Kanon der Erdbestrahlung und sieine Anwendung auf das Eiszeitenproblem, Special Publication, R Serb. Acad. Belgrade, 132, 633~pp., 1941. Otto,~J., Raddatz,~T., Claussen,~M., Brovkin,~V., and Gayler,~V.: Separation of atmosphere-ocean-vegetation feedbacks and synergies for mid-Holocene climate, Geophys. Res. Lett., 36, L09701, doi:10.1029/2009GL037482, 2009. Raddatz,~T J., Reick,~C H., Knorr,~W., Kattge,~J., Roeckner,~E., Schnur,~R., Schnitzler,~K G., Wetzel,~P., and Jungclaus,~J.: Will the tropical land biosphere dominate the climate-carbon cycle feedback during the twenty-first century?, Clim. Dynam., 29, 565–574, 2007. Renssen,~H., Goosse,~H., and Muscheler,~R.: Coupled climate model simulation of Holocene cooling events: oceanic feedback amplifies solar forcing, Clim. Past, 2, 79–90, 2006. Rimbu,~N., Lohmann,~G., Kim,~J.-H., Arz,~H W., and Schneider,~R.: Arctic/North Atlantic Oscillation signature in Holocene sea surface temperature trends as obtained from alkenone data, Geophys. Res. Lett., 30, 1280, 2003. Roeckner,~E., Bäuml,~G., Bonaventura,~L., Brokopf,~R., Esch,~M M G., Hagemann,~S., Kirchner,~I., Kornblueh,~L., Manzini,~E., Rhodin,~A., Schlese,~U., Schulzweida,~U., and Tompkins,~A.: The atmospheric general circulation model ECHAM5. Part~I: Model description, Tech. Rep 349, 127~pp., Max Planck Institute for Meteorology, Available from MPI for Meteorology, Bundesstr 53, 20146 Hamburg, Germany, 2003. Schurgers,~G., Mikolajewicz,~U., Groeger,~M., Maier-Reimer,~E., Vizcaino,~M., and Winguth,~A.: The effect of land surface changes on Eemian climate, Clim. Dynam., 29, 357–373, doi:10.1007/s00382-007-0237-x, 2007. Valcke,~S., Caubel,~A., Declat,~D., and Terray,~L.: OASIS Ocean Atmosphere Sea Ice Soil users guide, Tech. rep., CERFACS, 2003. Wanner,~H., Beer,~J. Bütikofer,~J., Crowley,~T., Cubasch,~U., Flckiger, J., Goosse,~H., Grosjean,~M., Joos,~F., Kaplan,~J., Küttel,~M., Müller,~S., Prentice,~I., Solomina,~O., Stocker,~T., Tarasov,~P., Wagner,~M., and Widmann, M., Mid- to late Holocene climate change: an overview, Quaternary Sci. Rev., 27, 1791–1828, 2008.