CPD Climate of the Past Discussions CPD 1814-9359 Copernicus GmbH Göttingen, Germany 10.5194/cpd-8-63-2012 The impact of different glacial boundary conditions on atmospheric dynamics and precipitation in the North Atlantic region Hofer D. 1 2 Raible C. C. 1 2 Dehnert A. 3 Kuhlemann J. 3 Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland Swiss Federal Nuclear Safety Inspectorate, Switzerland 04 01 2012 8 1 63 101 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.clim-past-discuss.net/8/63/2012/cpd-8-63-2012.html The full text article is available as a PDF file from http://www.clim-past-discuss.net/8/63/2012/cpd-8-63-2012.pdf

Using a highly resolved atmospheric general circulation model the impact of different glacial boundary conditions on precipitation and atmospheric dynamics in the North Atlantic region is investigated. Seven 30-yr time slice experiments of the Last Glacial Maximum (21 ka ago) and of a less pronounced glacial state – the Middle Weichselian (65 ka ago) – are compared to analyse the sensitivity to changes in the ice sheet distribution, in the radiative forcing, and in the prescribed time-varying lower boundary conditions, which are taken from a lower-resolved but fully-coupled atmosphere-ocean general circulation model. <br><br> The strongest differences are found for simulations with different heights of the Laurentide ice sheet. A large altitude of this ice sheet leads to a southward displacement of the jet stream and the storm track in the North Atlantic region. These changes in the atmospheric dynamics generate a band of increased precipitation in the mid-latitudes across the Atlantic to southern Europe in winter, while the precipitation pattern in summer is only marginally affected. The impact of the radiative forcing differences between the two glacial periods and of the prescribed time-varying lower boundary conditions – evaluated using two simulations of the Last Glacial Maximum with a global mean temperature difference of 1.1 &deg;C – are of second order compared to the one of the Laurentide ice sheet. They affect the atmospheric dynamics and precipitation in a similar but less pronounced manner as the topographic changes.

 References Allen, R., Siegert, M. J., and Payne, A. J.: Reconstructing glacier-based climates of LGM Europe and Russia – Part 2: A dataset of LGM precipitation/temperature relations derived from degree-day modelling of palaeo glaciers, Clim. Past, 4, 249–263, http://dx.doi.org/10.5194/cp-4-249-2008doi:10.5194/cp-4-249-2008, 2008. Berger, A L.: Long-term variations of daily insolation and quarternary climatic changes, J. Atmos. Sci., 35, 2362–2367, 1978. Blackmon, M L.: Climatological Spectral Study of 500 Mb Geopotential Height of Northern Hemisphere, J. Atmos. Sci., 33, 1607–1623, 1976. Blender, R., Fraedrich, K., and Lunkeit, F.: Identification of cyclone-track regimes in the North Atlantic, Q. J. Roy. Meteorol. Soc., 123, 727–741, http://dx.doi.org/10.1002/qj.49712353910doi:10.1002/qj.49712353910, 1997. 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, http://dx.doi.org/10.5194/cp-3-261-2007doi:10.5194/cp-3-261-2007, 2007. Brandefelt, J. and Otto-Bliesner, B L.: Equilibration and variability in a Last Glacial Maximum climate simulation with CCSM3, Geophys. Res. Lett., 36, L19712, http://dx.doi.org/10.1029/2009GL040364doi:10.1029/2009GL040364, 2009. Collins, W D., Bitz, C M., Blackmon, M L., Bonan, G B., Bretherton, C S., Carton, J A., Chang, P., Doney, S C., Hack, J J., Henderson, T B., Kiehl, J T., Large, W G., McKenna, D S., Santer, B D., and Smith, R D.: The Community Climate System Model version 3 (CCSM3), J. Climate, 19, 2122–2143, 2006. de~Vernal, A., Rosell-Mele, A., Kucera, M., Hillaire-Marcel, C., Eynaud, F., Weinelt, M., Dokken, T., and Kageyama, M.: Comparing proxies for the reconstruction of LGM sea-surface conditions in the northern North Atlantic, Quater. Sci. Rev., 25, 2820–2834, http://dx.doi.org/10.1016/j.quascirev.2006.06.006doi:10.1016/j.quascirev.2006.06.006, 2006. Gent, P R., Danabasoglu, G., Donner, L J., Holland, M M., Hunke, E C., Jayne, S R., Lawrence, D M., Neale, R B., Rasch, P J., Vertenstein, M., Worley, P H., Yang, Z L., and M., Z.: The Community Climate System Model version 4, J. Climate, 24, 19, 4973–4991, http://dx.doi.org/10.1175/2011JCLI4083.1doi:10.1175/2011JCLI4083.1, 2011. Hunke, E C. and Lipscomb, W H.: CICE: The Los Alamos sea ice model user’s manual, version 4, Los Alamos National Laboratory Tech. Rep. LA-CC-06-012, 76 pp., 2008. Hurrell, J W., Hack, J J., Shea, D., Caron, J M., and Rosinski, J.: A new sea surface temperature and sea ice boundary dataset for the Community Atmosphere Model, J. Climate, 21, 5145–5153, http://dx.doi.org/10.1175/2008JCLI2292.1doi:10.1175/2008JCLI2292.1, 2008. IPCC: Climate Change 2001: The Scientific Basis. Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 2001. Jahn, A., Claussen, M., Ganopolski, A., and Brovkin, V.: Quantifying the effect of vegetation dynamics on the climate of the Last Glacial Maximum, Clim. Past, 1, 1–7, http://dx.doi.org/10.5194/cp-1-1-2005doi:10.5194/cp-1-1-2005, 2005. Jost, A., Lunt, D., Kageyama, M., Abe-Ouchi, A., Peyron, O., Valdes, P J., and Ramstein, G.: High-resolution simulations of the last glacial maximum climate over Europe: a solution to discrepancies with continental palaeoclimatic reconstructions?, Clim. Dynam., 24, 577–590, http://dx.doi.org/10.1007/s00382-005-0009-4doi:10.1007/s00382-005-0009-4, 2005. Joussaume, S. and Taylor, K E.: Status of the paleoclimate modeling intercomparison project (PMIP), in: Proceedings of the first international AMIP sciencific conference, 425–430, WCRP-92, Monterey, USA, 1995. Kageyama, M., Valdes, P J., Ramstein, G., Hewitt, C., and Wyputta, U.: Northern hemisphere storm tracks in present day and last glacial maximum climate simulations: A comparison of the European PMIP models, J. Climate, 12, 742–760, 1999. Kageyama, M., Laine, A., Abe-Ouchi, A., Braconnot, P., Cortijo, E., Crucifix, M., de~Vernal, A., Guiot, J., Hewitt, C D., Kitoh, A., Kucera, M., Marti, O., Ohgaito, R., Otto-Bliesner, B., Peltier, W R., Rosell-Mele, A., Vettoretti, G., Weber, S L., and Yu, Y.: Last Glacial Maximum temperatures over the North Atlantic, Europe and western Siberia: a comparison between PMIP models, MARGO sea-surface temperatures and pollen-based reconstructions, Quatern. Sci. Rev., 25, 2082–2102, http://dx.doi.org/10.1016/j.quascirev.2006.02.010doi:10.1016/j.quascirev.2006.02.010, 2006. Kim, S J., Crowley, T J., Erickson, D J., Govindasamy, B., Duffy, P B., and Lee, B Y.: High-resolution climate simulation of the last glacial maximum, Clim. Dynam., 31, 1–16, http://dx.doi.org/10.1007/s00382-007-0332-zdoi:10.1007/s00382-007-0332-z, 2008. Laine, A., Kageyama, M., Salas-Melia, D., Voldoire, A., Riviere, G., Ramstein, G., Planton, S., Tyteca, S., and Peterschmitt, J Y.: Northern hemisphere storm tracks during the last glacial maximum in the PMIP2 ocean-atmosphere coupled models: energetic study, seasonal cycle, precipitation, Clim. Dynam., 32, 593–614, http://dx.doi.org/10.1007/s00382-008-0391-9doi:10.1007/s00382-008-0391-9, 2009. Large, W G. and Danabasoglu, G.: Attribution and impacts of upper-ocean biases in CCSM3, J. Climate, 19, 2325–2346, 2006. Mahowald, N M., Yoshioka, M., Collins, W D., Conley, A J., Fillmore, D W., and Coleman, D B.: Climate response and radiative forcing from mineral aerosols during the last glacial maximum, pre-industrial, current and doubled-carbon dioxide climates, Geophys. Res. Lett., 33, L20705, http://dx.doi.org/10.1029/2006GL026126doi:10.1029/2006GL026126, 2006. Neale, R B., Richter, J H., Conley, A J., Park, S., Lauritzen, P H., Gettelman, A., a. W. D L., Rasch, P J., Vavrus, S J., Taylor, M A., Collins, W D., Zhang, M., and Lin, S.: Description of the NCAR Community Atmosphere Model (CAM4), National Center for Atmospheric Research Tech. Rep. NCAR/TN+STR, 194 pp., 2010. Oleson, K., Lawrence, D., Bonan, G., Flanner, M., Kluzek, E., Lawrence, P., Levis, S., Swenson, S., Thornton, P., Dai, A., Decker, M., Dickinson, R., Feddema, J., Heald, C., F Hoffman, a. J.-F L., Mahowald, N., Niu, G.-Y., Qian, T., Randerson, J., Running, S., Sakaguchi, K., Slater, A., Stockli, R., Wang, A., Yang, Z.-L., Zeng, X., and Zeng, X.: Technical Description of version 4.0 of the Community Land Model (CLM), NCAR Technical Note NCAR/TN-478+STR, National Center for Atmospheric Research, Boulder, CO, 257 pp., 2010. Otto-Bliesner, B L., Brady, E C., Clauzet, G., Tomas, R., Levis, S., and Kothavala, Z.: Last Glacial Maximum and Holocene climate in CCSM3, J. Climate, 19, 2526–2544, http://dx.doi.org/10.1175/JCLI3748.1doi:10.1175/JCLI3748.1, 2006a. Otto-Bliesner, B L., Tomas, R., Brady, E C., Ammann, C., Kothavala, Z., and Clauzet, G.: Climate sensitivity of moderate- and low-resolution versions of CCSM3 to preindustrial forcings, J. Climate, 19, 2567–2583, http://dx.doi.org/10.1175/JCLI3754.1doi:10.1175/JCLI3754.1, 2006b. Otto-Bliesner, B L., Schneider, R., Brady, E C., Kucera, M., Abe-Ouchi, A., Bard, E., Braconnot, P., Crucifix, M., Hewitt, C D., Kageyama, M., Marti, O., Paul, A., Rosell-Mele, A., Waelbroeck, C., Weber, S L., Weinelt, M., and Yu, Y.: A comparison of PMIP2 model simulations and the MARGO proxy reconstruction for tropical sea surface temperatures at last glacial maximum, Clim. Dynam., 32, 799–815, http://dx.doi.org/10.1007/s00382-008-0509-0doi:10.1007/s00382-008-0509-0, 2009. Peltier, W R.: Global glacial isostasy and the surface of the ice-age earth: The ice-5G (VM2) model and grace, Annu. Rev. Earth Pl. Sc., 32, 111–149, 2004. Peyron, O., Guiot, J., Cheddadi, R., Tarasov, P., Reille, M., de~Beaulieu, J L., Bottema, S., and Andrieu, V.: Climatic reconstruction in Europe for 18 000 yr B.P. from pollen data, Quatern. Res., 49, 183–196, 1998. Raible, C C., Yoshimori, M., Stocker, T F., and Casty, C.: Extreme midlatitude cyclones and their implications for precipitation and wind speed extremes in simulations of the Maunder Minimum versus present day conditions, Clim. Dynam., 28, 409–423, http://dx.doi.org/10.1007/s00382-006-0188-7doi:10.1007/s00382-006-0188-7, 2007. Raible, C C., Della-Marta, P M., Schwierz, C., Wernli, H., and Blender, R.: Northern hemisphere extratropical cyclones: A comparison of detection and tracking methods and different reanalyses, Month. Weather Rev., 136, 880–897, http://dx.doi.org/10.1175/2007MWR2143.1doi:10.1175/2007MWR2143.1, 2008. Ramstein, G., Kageyama, M., Guiot, J., Wu, H., Hély, C., Krinner, G., and Brewer, S.: How cold was Europe at the Last Glacial Maximum? A synthesis of the progress achieved since the first PMIP model-data comparison, Clim. Past, 3, 331–339, http://dx.doi.org/10.5194/cp-3-331-2007doi:10.5194/cp-3-331-2007, 2007. Schilt, A., Baumgartner, M., Schwander, J., Buiron, D., Capron, E., Chappellaz, J., Loulergue, L., Schupbach, S., Spahni, R., Fischer, H., and Stocker, T F.: Atmospheric nitrous oxide during the last 140 000 years, Earth Planet. Sci. Lett., 300, 33–43, http://dx.doi.org/10.1016/j.epsl.2010.09.027doi:10.1016/j.epsl.2010.09.027, 2010. Shin, S I., Liu, Z., Otto-Bliesner, B., Brady, E C., Kutzbach, J E., and Harrison, S P.: A simulation of the last glacial maximum climate using the NCAR-CCSM, Clim. Dynam., 20, 127–151, http://dx.doi.org/10.1007/s00382-002-0260-xdoi:10.1007/s00382-002-0260-x, 2003. Siddall, M., Rohling, E J., Thompson, W G., and Waelbroeck, C.: Marine Isotope Stage 3 Sea Level Fluctuations: Data Synthesis and New Outlook, Rev. Geophys., 46, RG4003, http://dx.doi.org/10.1029/2007RG000226doi:10.1029/2007RG000226, 2008. Strandberg, G., Brandefelt, J., Kjellstrom, E., and Smith, B.: High-resolution regional simulation of last glacial maximum climate in Europe, Tellus Series A-dynamic Meteorology and Oceanography, 63, 107–125, http://dx.doi.org/10.1111/j.1600-0870.2010.00485.xdoi:10.1111/j.1600-0870.2010.00485.x, 2011. Toracinta, E R., Oglesby, R J., and Bromwich, D H.: Atmospheric response to modified CLIMAP ocean boundary conditions during the Last Glacial Maximum, J. Climate, 17, 504–522, 2004. Uppala, S M., Kallberg, P W., Simmons, A J., Andrae, U., Bechtold, V D., Fiorino, M., Gibson, J K., Haseler, J., Hernandez, A., Kelly, G A., Li, X., Onogi, K., Saarinen, S., Sokka, N., Allan, R P., Andersson, E., Arpe, K., Balmaseda, M A., Beljaars, A. C M., Van De~Berg, L., Bidlot, J., Bormann, N., Caires, S., Chevallier, F., Dethof, A., Dragosavac, M., Fisher, M., Fuentes, M., Hagemann, S., Holm, E., Hoskins, B J., Isaksen, L., Janssen, P. A. E M., Jenne, R., McNally, A P., Mahfouf, J F., Morcrette, J J., Rayner, N A., Saunders, R W., Simon, P., Sterl, A., Trenberth, K E., Untch, A., Vasiljevic, D., Viterbo, P., and Woollen, J.: The ERA-40 re-analysis, Q. J. Roy. Meteorol. Soc., 131, 2961–3012, http://dx.doi.org/10.1256/qj.04.176doi:10.1256/qj.04.176, 2005. Waelbroeck, C., Paul, A., Kucera, M., Rosell-Melee, A., Weinelt, M., Schneider, R., Mix, A C., Abelmann, A., Armand, L., Bard, E., Barker, S., Barrows, T T., Benway, H., Cacho, I., Chen, M T., Cortijo, E., Crosta, X., de~Vernal, A., Dokken, T., Duprat, J., Elderfield, H., Eynaud, F., Gersonde, R., Hayes, A., Henry, M., Hillaire-Marcel, C., Huang, C C., Jansen, E., Juggins, S., Kallel, N., Kiefer, T., Kienast, M., Labeyrie, L., Leclaire, H., Londeix, L., Mangin, S., Matthiessen, J., Marret, F., Meland, M., Morey, A E., Mulitza, S., Pflaumann, U., Pisias, N G., Radi, T., Rochon, A., Rohling, E J., Sbaffi, L., Schafer-Neth, C., Solignac, S., Spero, H., Tachikawa, K., and Turon, J L.: Constraints on the magnitude and patterns of ocean cooling at the Last Glacial Maximum, Nature Geosci., 2, 127–132, http://dx.doi.org/10.1038/NGEO411doi:10.1038/NGEO411, 2009. Wu, H B., Guiot, J L., Brewer, S., and Guo, Z T.: Climatic changes in Eurasia and Africa at the last glacial maximum and mid-Holocene: reconstruction from pollen data using inverse vegetation modelling, Clim. Dynam., 29, 211–229, http://dx.doi.org/10.1007/s00382-007-0231-3doi:10.1007/s00382-007-0231-3, 2007.