Climate of the Past Discussions www.clim-past-discuss.net 1814-9340 1814-9359 4 3 2008 10.5194/cpd-4-585-2008 http://www.clim-past-discuss.net/4/585/2008/ http://www.clim-past-discuss.net/4/585/2008/cpd-4-585-2008.html http://www.clim-past-discuss.net/4/585/2008/cpd-4-585-2008.pdf 585 610 2008-05-16 Anticyclonic atmospheric circulation as an analogue for the warm and dry mid-Holocene summer climate in central Scandinavia K. Antonsson D. Chen H. Seppä heikki.seppa@helsinki.fi Department of Earth Sciences, Uppsala University, Villavägen 16, 752 36 Uppsala, Sweden Earth Sciences Centre, University of Gothenburg, P.O. Box 460, 405 30, Göteborg, Sweden Department of Geology, P.O. Box 64, 00014, University of Helsinki, Helsinki, Finland Climate reconstructions from central Scandinavia suggest that annual and summer temperatures were rising during the early Holocene and reached their maximum after 8000 cal yr BP. The period with highest temperatures was characterized by increasingly low lake-levels and dry climate, with driest and warmest conditions at about 7000 to 5000 cal yr BP. We compare the reconstructed climate pattern with simulations of a climate model for the last 9000 yr and show that the model, which is predominantly driven by solar insolation patterns, fails to produce the reconstructed mid-Holocene dry and warm period in Scandinavia. As an alternative explanation for the reconstructed climate, we hypothesize that the trend from the moist early Holocene towards dry and warm mid-Holocene was caused by a changing atmospheric circulation pattern with a mid-Holocene dominance of summer-time anticyclonic circulation. An extreme case of the anticyclonic conditions is the persistent blocking high, an atmospheric pressure pattern that at present often causes long spells of particularly dry and warm summer weather, or "Indian summers". The hypothesis is tested with daily instrumental temperature and precipitation records in central Sweden and an objective circulation classification based on surface air pressure over the period 1900–2002. It is concluded that the differences between the precipitation and temperature climates under anticyclonic and non-anticyclonic conditions are significant. Further, warm and dry combination, as indicated by mid-Holocene reconstructions, is a typical pattern under anticyclonic conditions. These results indicate that the presented hypothesis for the mid-Holocene climate is likely valid. Achberger, C., Box, J. E., and Chen, D.: Nordic Region, in State of the Climate in 2006, edited by: Arguez, A., B. Am. Meteorol. Soc., 88, S104–S106, 2007. Almquist-Jacobson, H.: Lake-level fluctuations at Ljustjärnen, central Sweden and their implications for the Holocene climate of Scandinavia, Palaeogeogr. Palaeocl., 118, 269–290, 1995. Ansell, T. J. Jones, P. D., Allan, R. J., et al.:Daily mean sea level pressure reconstructions for the European - North Atlantic region for the period 1850-2003, J. Climate, 19, 12, 2717–2742, doi:10.1175/JCLI3775.1, 2006. Antonsson, K. and Seppä, H.: Holocene temperatures in Bohuslän, Southwestern Sweden: a quantitative reconstruction from fossil pollen data, Boreas, 36, 400–410, 2007. Antonsson, K., Brooks, S. J., Seppä, H., Telford, R. J., and Birks, H. J. B.: Quantitative palaeotemperature records inferred from fossil chironomid and pollen assemblages from Lake Gilltjärnen, northern central Sweden, J. Quaternary Sci., 21, 831–841, 2006. Bakke, J., Lie, Ø., Dahl, S. O., Nesje, A, and Bjune, A. E.: Strength and spatial patterns of the Holocene wintertime westerlies in the NE Atlantic region, Global Planet Change, 60, 28–41, 2008. Berger, A.: Long-term variations of caloric insolation resulting from the Earth's orbital elements, Quaternary Res., 9, 139–167, 1978. Birks, H. J. B.:Numerical tools in quantitative palaeolimnology – progress, potentialities, and problems, J. Paleolimnol., 20, 301–332, 1998. Birks, H. J. B.:Quantitative palaeoenvironmental reconstructions from Holocene biological data, in: Global Change in the Holocene, edited by: Mackay, A., Battarbee, R. W., Birks, H. J. B., and Oldfield, F., Arnold, London, 107–123, 2003. Birks, H. J. B. and Seppä, H.: Pollen-based reconstructions of late-Quaternary climate in Europe – progress, problems, and pitfalls, Acta Palaeobotanica, 44, 317–334, 2004. ter Braak, C. J. F. and Juggins, S.: Weighted averaging partial least squares regression (WA-PLS): an improved method for reconstructing environmental variables from species assemblages, Hydrobiologia, 269/270, 485–502, 1993. Brooks, S. J.: Fossil midges (Diptera: Chironomidae) as palaeoclimatic indicators for the Eurasian region, Quaternary Sci. Rev., 25, 1894–1910, 2006. Busuioc, A., Chen, D., and Hellström, C.: Temporal and spatial variability of precipitation in Sweden and its link with the large scale atmospheric circulation, Tellus, 53A, 348–367, 2001. Carril, A. F., Gualdi, S., Cherchi, A., and Navarra, A.:Heatwaves in Europe: areas of homogenous variability and link with the regional to large-scale atmospheric and SSTs anomalies, Clim. Dynam., 30, 77–98, 2008. Chen, D.: A monthly circulation climatology for Sweden and its application to a winter temperature case study, Int. J. Climatol., 20, 1067–1076, 2000. Chen, D. and Hellström, C.: The influence of the North Atlantic Oscillation on the regional temperature variability in Sweden: spatial and temporal variations, Tellus, 51A, 505–516, 1999. Chen, D. and Li, X.: Scale dependent relationship between maximum ice extent in the Baltic Sea and atmospheric circulation, Global Planet Change, 41, 275–283, 2004. Crucifix, M., Loutre, M.-F., Tulkens, P., Fichefet, T., and Berger, A.: Climate evolution during the Holocene: a study with an Earth system model of intermediate complexity, Clim. Dynam., 19, 43–60, 2002. Diekman, M.: Ecological behavior of deciduous hardwood trees in Boreo-nemoral Sweden in relation to light and soil conditions, Forest Ecol. Manag., 86, 1–14, 1996. Digerfeldt, G.: Reconstruction and regional correlation of Holocene lake-level fluctuations in Lake Bysjön, South Sweden, Boreas, 17, 165–182, 1988. Edwards, M. E., Mock, C. J., Finney, B. P., Barber, V. A., and Bartlein, P. J.: Potential analogues for palaeoclimatic variations in eastern interior Alaska during the past 14 000 yr: atmospheric-circulation controls of regional temperature and moisture responses, Quaternary Sci. Rev., 20, 189–202, 2001 FMI: Finnish Meteorological Institute, Monthly hydrological report in August 2002, available on line at http://www.environment.fi, 2002. Giesecke, T.: Holocene dynamics of the southern boreal forest in Sweden, The Holocene, 15, 858–872, 2005. Hammarlund, D., Björck, S., Buchardt, B., Israelson, C., and Thomsen, C. T.: Rapid hydrological changes during the Holocene revealed by stable isotope records of lacustrine carbonates from Lake Igelsjön, southern Sweden, Quaternary Sci. Rev., 22, 353–370, 2003. Hintikka, V.: Über das Grossklima einiger Pflanzenareale in zwei Klimakoordinatensystemen dargestellt, Annales Botanici Societatis Zoologicǽ Botanicǽ Fennicǽ ,,Vanamo", 34, 1–63, 1963. Hyvärinen, H. and Alhonen, P.: Holocene lake-level changes in the Fennoscandian tree-line region, western Finnish Lapland: diatom and cladoceran evidence, The Holocene, 4, 251–258, 1994. Jenkinson, A. F. and Collison, F. P.: An initial climatology of gales over the North Sea, Synoptic Climatology Branch Memorandum, 62, Meteorological Office, Bracknell, 1977. Johannessen, R. W.: The Climate of Scandinavia, in: Climates of Northern and Western Europe, World Survey of Climatology, edited by: Landsberg, H.E., Elsevier Publishing Company, Amsterdam, 5, 23–80, 1970. Jongma, J. I., Prange, M., Renssen, H., and Schultz, M.: Amplification of Holocene multicentennial climate forcing by mode transitions in North Atlantic overturning circulation, Geophys. Res. Lett., 34, L15706, doi:10.1029/2007GL030642, 2007. Korhola, A. and Rautio, M.: Cladocera and other brachiopod crustacean, in: Tracking Environmental Change Using Lake Sediments, 4, Zoological Indicators, edited by: Smol, J. P., Birks, H. J. B., and Last, W. M., Kluwer Academic Publishers, Dordrecht, 2002. Korhola, A., Tikkanen, M., and Weckström, J.: Quantification of Holocene lake-level changes in Finnish Lapland using a cladocera – lake depth transfer function, J. Paleolimnol., 34, 175–190, 2005. Lamb, H. H.: Types and spells of weather around the year in the British Isles, Q. J. Roy. Meteor. Soc., 76, 393–438, 1950. Linderholm, H. W., Jansson, P., and Chen, D.: A high-resolution reconstruction of Storglaciären mass balance back to 1781 using tree-ring data and circulation indices, Quaternary Res., 67, 12–20, doi:10.1016/j.yqres.2006.08.005, 2007. Lupo, A. R., Oglesby, R. J., and Mokhov, I. I.: Climatological features of blocking anticyclones: a study of Northern Hemisphere CCM1 model blocking events in present-day and double CO₂ concentration atmospheres, Clim. Dynam., 13, 181–195, 1997. Miller, P. A., Giesecke, T., Hickler, T., Bradshaw, R. H. W., Smith, B., Seppä, H., Valdes, P. J., and Sykes, M. T.:Exploring climatic and biotic controls on Holocene vegetation change in Fennoscandia, J. Ecol., 96, 247–259, 2008. Moberg, A. and Jones, P. D.: Trends in indices for extremes in daily temperature and precipitation in central and Europe, 1901-99, Int. J. Climatol., 25, 1149–1171, 2005. Mock, G. and Brunelle-Daines, A. R.: A modern analogue of western United States summer palaeoclimate at 6000 years before present, The Holocene, 9, 541–545, 1999. Nesje, A., Jansen, E., Birks, H. J. B., Bjune, A. E., Bakke, J., Andersson, C., Dahl, S. O., Klitgaard Kristensen, D., Lauritzen, S. E., Lie, Ø., Risebrobakken, B., and Svendsen, J.-I.: Holocene Climate Variability in the Northern North Atlantic Region: A Review of Terrestrial and Marine Evidence, in: The Nordic Seas, An Intergrated Perspective, edited by: Drange, H., Dokken, T., Furevik, T, Gerden, R., and Berger, R., AGU, Washington, 289–322, 2005. Pigott, C. D.: Nature of seed sterility and natural regeneration of Tilia cordata near its northern limit in Finland, Ann. Bot. Fenn., 18, 255–263, 1981. Prentice, I. C. and Helmisaari, H.: Silvics of north European trees: Compilation, comparisons and implication for forest succession modeling, Forest Ecol. Manag., 42, 79–93, 1991. Renssen, H., Goosse, H., Fichefet, T., Brovkin, V., Driesschaert, E., and Wolk, F.: Simulating the Holocene climate evolution at northern high latitudes using a coupled atmosphere-sea ice-ocean-vegetation model, Clim. Dynam., 24, 23–43, 2005. Rimbu, N., Lohmann, G., and Grosfeld, K.: Northern Hemisphere atmospheric blocking in ice core records from northern Greenland, Geophys. Res. Lett., 34, L09704, doi:10.1029/2006GL029175, 2007. Seppä, H. and Birks, H. J. B.: July mean temperature and annual precipitation trends during the Holocene in the Fennoscandian tree-line area: pollen-based climate reconstructions, The Holocene, 11, 527–539, 2001. Seppä, H. and Bennett, K. D.: Quaternary pollen analysis: recent progress in palaeoecology and palaeoclimatology, Prog. Phys. Geog., 27, 580–611, 2003. Seppä, H. and Poska, A.: Holocene annual mean temperature changes in Estonia and their relationship to solar insolation and atmospheric circulation patterns, Quaternary Res., 61, 22–31, 2004. Seppä, H., Birks, H.J.B., Odland, A., Poska, A., and Veski, S.: Modern pollen surface sample set from northern Europe: developing and testing a tool for palaeoclimatological reconstructions, J. Biogeogr., 31, 251–267, 2004. Seppä, H., Hammarlund, D., and Antonsson, K.: Low- and high-frequency changes in temperature and effective humidity during the Holocene in South central Sweden: Implications for atmospheric and oceanic forcings of climate, Clim. Dynam., 25, 285–297, 2005. Shrinker, J. J., Bartlein, P. J., and Shuman, B.:Synoptic and dynamic controls of North American mid-continental aridity, Quaternary Sci. Rev., 25, 1401–1417, 2006. Skre, O.: The regional distribution of vascular plants in Scandinavia with requirements for high summer temperatures, Norw. J. Bot., 26, 295–318, 1979. Slonosky, V. C., Jones, P. D., and Davies, T. D.: Variability of the surface atmospheric circulation over Europe, 1774–1995, Int. J. Climatol., 20, 1875–1897, 2000. Slonosky, V. C., Jones, P. D., and Davies, T. D.:Atmospheric circulation and surface temperature in Europe from the 18th century to 1995, Int. J. Climatol., 21, 63–75, 2001. SMHI: Väder och Vatten, Direkt Offset AB, Norrköping, 8, 2002. Sutton, R. T. and Hodson, D. L. R.: Atlantic Ocean forcing of North American and European summer climate, Science, 309, 115–118, 2005. Vassiljev, J. and Harrison, S. P.: Simulating the Holocene Lake-Level Record of Lake Bysjön, Southern Sweden, Quaternary Res., 49, 62–71, 1998. Velle, G., Brooks, S. J., Birks, H. J. B., and Willassen, E.: Chironomids as a tool for inferring Holocene climate: an assessment based on six sites in south Scandinavia, Quaternary Sci. Rev., 24, 1429–1462, 2005. Vonmoos, M., Beer, J., and Muscheler, R.: Large variations in Holocene solar activity: constraints from Be-10 in the Greenland Ice Core Project ice core, J. Geophys. Res., 111, A10105, doi:10.1029/2005JA011500, 2006. Weber, S. L., Crowley, T. J., and van der Schrier, G.: Solar irradiance forcing of centennial climate variability during the Holocene, Clim. Dynam., 22, 539–553, 2004. Yu, G. and Harrison, S. P.: Holocene changes in atmospheric circulation patterns as shown by lake status in northern Europe, Boreas, 24, 260–268, 1995.