Abstracts
Abstract
Three ice cores recovered on or near Mount Logan, together with a nearby lake record (Jellybean Lake), cover variously 500 to 30 000 years. This suite of records offers a unique view of the lapse rate in stable isotopes from the lower to upper troposphere. The region is climatologically important, being beside the Cordilleran pinning-point of the Rossby Wave system and the Aleutian Low. Comparison of stable isotope series over the last 2000 years and model simulations suggest sudden and persistent shifts between modern (mixed) and zonal flow regimes of water vapour transport to the Pacific Northwest. The last such shift was in A.D. 1840. Model simulations for modern and “pure” zonal flow suggest that these shifts are consistent regime changes between these flow types, with predominantly zonal flow prior to ca. A.D. 1840 and modern thereafter. The 5.4 and 0.8 km asl records show a shift at A.D. 1840 and another at A.D. 800. It is speculated that the A.D. 1840 regime shift coincided with the end of the Little Ice Age and the A.D. 800 shift with the beginning of the European Medieval Warm Period. The shifts are very abrupt, taking only a few years at most.
Résumé
Trois carottes de glace prélevées à proximité du mont Logan, combinées à une coupe stratigraphique du lac Jellybean, couvrent une période comprise entre 500 et 30 000 ans. Elles renseignent sur les taux de changement de la composition isotopique de la troposphère. La région étudiée est importante au niveau climatologique puisqu’elle est au point de convergence des ondes de Rossby et de la dépression des Aléoutiennes. La comparaison entre la composition isotopique depuis 2000 ans et les résultats des simulations suggère des changements brusques et persistants entre les régimes de transport de vapeur d’eau modernes et zonaux dans le nord-est du Pacifique, où le dernier changement s’est produit en 1840 de notre ère. Les simulations indiquent que les changements de flux correspondent aux changements de régime, avec un flux zonal avant ca 1840 pour passer au type moderne ensuite. Les forages à 5,4 et 0,8 km d’altitude montrent un changement en A.D. 1840 et un autre en l’an 800. On présume que ces changements de régime coïncident respectivement avec la fin du Petit Âge Glaciaire et le début de la période médiévale chaude, ces changements s’étant produits en quelques années seulement.
Appendices
References
- Anderson, L., 2005. Holocene climate from lake level and isotope analyses of small carbonate lakes of the southwest Yukon Territory, Canada. Unpublished Ph.D. dissertation. University of Massachusetts at Amherst, 353 p.
- Anderson, L., Abbott, M.B., Finney, B.P. and Burns, S.J., 2004. Regional atmospheric circulation change in the North Pacific during the Holocene inferred from Lascustrine carbonate oxygen isotopes, Yukon Territory, Canada. EOS, Transactions of the American Geophysical Union, 85, Fall meeting Supplement, Abstract PP23C‑04.
- Anderson, L., Abbott, M.B., Finney, B.P. and Burns, S.J., 2005. Regional atmospheric circulation change in the North Pacific during the Holocene inferred from Lascustrine carbonate oxygen isotopes, Yukon Territory, Canada. Quaternary Research, 64 : 21‑35.
- Clague, J.J., Evans, S.G., Rampton, V.N., and Woodsworth, G.J., 1995. Improved age estimates for the White River and Bridge River tephras, western Canada. Canadian Journal of Earth Sciences, 32 : 1172‑1179.
- Clausen, H.B., Hammer, C.U., Christensen, J., Schøtt-Hvidberg, C.S., Dahl-Jensen, D., Legrand, M. and Steffensen, J.P., 1995. 1250 years of global volcanism as revealed by central Greenland ice cores. NATO ASI Series I, 30, p. 517‑552. In R.J. Delmas, ed., Ice Core Studies of Global Biogeochemical Cycles. Springer, New York, 402 p.
- Cropper, J.P., 1982. Climate reconstructions (1801 to 1938) inferred from tree-ring width chronologies of the North American Arctic. Arctic and Alpine Research, 14 : 223‑241.
- Dansgaard, W., Johnsen, S.J., Clausen, H.B. and Gundestrup, N., 1973. Stable isotope glaciology. Meddeleser om Grønland, 197, 53 p.
- Fisher, D.A., 1990. A zonally averaged stable-isotope model coupled to a regional variable-elevation stable isotope model. Annals of Glaciology, 14 : 65‑71.
- Fisher, D.A., 1991. Remarks on the deuterium excess in precipitation in cold regions. Tellus, 43B : 401‑407.
- Fisher, D.A., 1992. Stable isotope simulations using a regional isotope model coupled to a zonally averaged global model. Cold Regions Science and Technology, 21 : 61‑77.
- Fisher, D.A., 2002. High-resolution multiproxy climatic records from ice cores, tree rings, corals and documentary sources using eigenvector techniques and maps: assessment of recovered signal and errors. The Holocene, 12 : 401‑418.
- Fisher, D.A., Bourgeois, J.B., Demuth, M., Koerner, R.M., Parnandi, M., Sekerka, J., Zdanowicz, C., Zheng, J., Wake, C., Yalcin, K., Mayewski, P., Kreutz, C., Osterberg, E., Dahl-Jensen, D., Goto-Azuma, K., Holdsworth, G., Steig, E., Rupper, S. and Wasckiewicz, M., 2004. Mount Logan ice cores: the water cycle of the North Pacific in the Holocene. EOS, Transactions of the American Geophysical Union, 85, Fall Meeting Supplement, Abstract PP23C‑07.
- Fisher, D.A., Koerner, R.M., Kuivinen, K., Clausen, H.B., Johnsen, S.J., Steffensen, J.P., Gundestrup, N. and Hammer, C.U., 1996. Intercomparison of ice core δ(18O) and precipitation records from sites in Canada and Greenland over the last 3500 years and over the last few centuries in detail using EOF techniques, p. 297‑328. In P.D. Jones, R.S. Bradley and J. Jouzel, eds., Climate Variations and Forcing Mechanisms of the Past 2000 Years. Springer Verlag, Berlin, 649 p.
- Fisher, D.A., Koerner, R.M., Paterson, W.S.B., Dansgaard, W., Gundestrup N. and Reeh, N., 1983. Effect of wind scour on climatic records from ice-core oxygen–isotope profiles. Nature, 301 : 205‑209.
- Goto-Azuma, K., Shiraiwa, T., Matoba, S., Segawa, T., Kanamori, S., Fujii, Y. and Yomasaki, T.Y., 2003. An overview of the Japanese glaciological studies on Mt. Logan, Yukon Territory, Canada, in 2002. Bulletin of Glaciological Research, 20 : 65‑72.
- Hammer, C.U., 1983. Initial direct current in the buildup of space charges and the acidity of ice cores. The Journal of Physical Chemistry, 87 : 4099‑4103.
- Hendy, E.J., Gagan, M.K., Alibert, C.A., McCulloch, M.T., Lough, J.M., and Isdale, P.J., 2002. Abrupt decrease in tropical Pacific sea surface salinity at the end of the Little Ice Age. Science, 295 : 1511‑1514.
- Holdsworth, G.H., 2001. Calibration changes in the isotopic thermometer for snow according to different climatic states. Geophysical Research Letters, 28 : 2625‑2628.
- Holdsworth, G.H. and Krouse, H.R., 2002. Altitudinal variation of the stable isotopes of snow in regions of high relief. Journal of Glaciology, 48 : 31‑41.
- Holdsworth, G.H., Krouse, H.R. and Nosal, M., 1992. Ice core climate signals from Mount Logan Yukon A.D. 1700‑1987, p. 483‑504. In R.S. Bradley and P.D. Jones, eds., Climate Since A.D. 1500, Routledge, London, 525 p.
- Jaeger, L., 1983. Monthly and areal patterns of mean global precipitation, p. 129‑140. In A. Street-Perrott, M. Beran and R. Ratcliffe, eds., Variations in The Global Water Budget, R. Reidel Publishing Co., 518 p.
- Johnsen, S.J., Clausen, H.B., Dansgaard, W., Gundestrup, N.S., Hammer, C.U.H., Andersen, U., Andersen, K.K., Hvidberg, S., Dahl-Jensen, D., Steffensen, J.P., Shoji, H., Sveinbjörnsdóttir, A.E., White, J., Jouzel, J. and Fisher, D., 1997. The δ(18O) record along the Greenland Ice Core Project deep ice and the problem of possible Eemian climatic instability. Greenland Summit Ice Cores. Journal of Geophysical Research, 102(C12) : 26397‑26410.
- Johnsen, S.J., Dansgaard, W. and White, J.W.C., 1989. The origin of Arctic precipitation under present and glacial conditions. Tellus, 41B : 452‑468.
- Jouzel, J., Alley, R.B., Cuffey, K.M., Dansgaard, W., Grootes, P., Hoffmann, G., Johnsen, S.J., Koster, R.D., Peel, D., Shuman, C.A., Stievenard, M. and White, J., 1997. Validity of the temperature reconstruction from water isotopes in ice cores. Journal of Geophysical Research, 102(C12) : 26471‑26488.
- Jouzel, J., Merlivat, L. and Lorious, C., 1984. Deuterium and Oxygen 18 in precipitation: modeling of the isotopic effects during snow formation. Journal of Geophysical Research, 89(D7) : 11749‑11757.
- Kavanaugh, J.L. and Cuffey, K.M., 2003. Space and time variations of d(18O) and d(D) in Antarctic precipitation revisited, Global Biogeochemical Cycles, 17, 1017, doi: 10.1019/2002GB001910, 2003.
- Keigwin, L.D., Sachs, J.P. and Rosenthal, Y., 2003. A 1600‑year history of the Labrador Current of Nova Scotia. Climate Dynamics, 21 : 53‑62.
- Koerner, R.M. and Russell, R.D., 1979. δ(18O) variations in snow on the Devon Island Ice Cap, Northwest Territories, Canada. Canadian Journal of Earth Sciences, 16 : 1419‑1427.
- Mann, M.E., Bradley, R.S. and Hughes, M.K., 2000. Long-term variability in El Niño-Southern Oscillation and associated teleconnections, p. 357‑412. In H.F. Diaz and V. Markgraf, eds., El Niño and the Southern Oscillation, Cambridge University Press, 496 p.
- Marcus, M.G. and Ragle, R.H., 1972. Snow accumulation in the Icefield Ranges, St. Elias Mountains, p. 130‑142. In V.C. Bushnell and R.H. Ragle, eds., Icefield Ranges Research Project Scientific Results, Vol. 3. American Geographical Society, New York and Arctic Institute of North America, Montréal, 261 p.
- Mashiotta, T.A., Thompson, L.G. and Davis, M.E., 2004. The White River ash: new evidence from the Bona-Churchill ice core record. EOS, Transactions of the American Geophysical Union, 85, Fall Meeting Supplement, Abstract PP21A‑1369.
- Mayewski, P.A. et al., 1994. Changes in atmospheric circulation and ocean ice cover over the North Atlantic during the last 41 000 years. Science, 263 : 1747‑1751.
- Mayewski, P.A., Holdsworth, G., Spencer, M.J., Whitlow, S., Twickler, M., Morrison, M.C., Ferland, K.K. and Meeker, L.D., 1993. Ice core sulfate from three Northern Hemisphere sites: Source and temperature forcing implications. Atmospheric Environment, Part A, 27 : 2915‑2919.
- Mayewski, P.A., Maasch, K.A., White, J.W.C., Steig, E.J., Meyerson, E., Goodwin, I., Morgan, V.I., van Ommen, T., Curran, M.A.J., Souney, J. and Kreutz, K., 2004. A 700‑year record of Southern Hemisphere extratropical climate variability. Annals of Glaciology, 39 : 127‑132.
- Mayewski, P.A., Meeker, L.D., Twickler, M.S., Whitlow, S., Yang, Q., Lyons, W.B. and Prentice, M., 1997. Major features and forcing of high-latitude northern hemisphere atmospheric circulation using a 110 000‑year-long glaciochemical series. Journal of Geophysical Research, 102(C12) : 26345‑26366.
- Meeker, L.D. and Mayewski, P.A., 2002. A 1400‑year high-resolution record of atmospheric circulation over the North Atlantic and Asia. The Holocene, 12 : 257‑266.
- Merlivat, L. and Jouzel, J., 1979. Global climatic interpretation of the deuterium-oxygen 18 relationship for precipitation. Journal of Geophysical Research, 84(C8) : 5029‑5033.
- Moore, G.W.K., Alverson, K. and Holdsworth, G., In press. Mount Logan ice core evidence for changes in the Hadley and Walker circulations following the end of the Little Ice Age. In R. Bradley and H.F. Diaz, eds., The Hadley Circulation: Past, Present and Future.
- Moore, G.W.K., Holdsworth, G. and Alverson, K., 2001. Extra-tropical response to ENSO as expressed in an ice core from the Saint Elias Mountain range. Geophysical Research Letters, 28 : 3457‑3460.
- Moore, G.W.K., Holdsworth, G. and Alverson, K., 2002. Climate change in the North Pacific region over the past three centuries. Nature, 429 : 401‑403.
- Neumann, T.A. and Waddington, E.D., 2004. Effects of firn ventilation on isotopic exchange. Journal of Glaciology, 50 : 183‑194.
- Peixóto, J.P. and Oort, A.H., 1983. The atmospheric branch of the hydrological cycle and climate, p. 5‑66. In A. Street-Perrott, M. Beran and R. Ratcliffe, eds., Variations in The Global Water Budget, R. Reidel Publishing Co., 518 p.
- Petit, J.R., White, J.W.C., Young, N.W., Jouzel, J. and Korotkevich, Y.S., 1991. Deuterium excess in recent Antarctic snow. Journal of Geophysical Research, 96(D3) : 5113‑5122.
- Rein, B., Lückge, A. and Sirocka, F., 2004. A major Holocene ENSO anomaly during the Medieval period. Geophysical Research Letters, 31 : L17211.
- Rupper, S., Steig, E.J. and Roe, G., 2004. The relationship between snow accumulation at Mt. Logan, Yukon and climate variability in the North Pacific. Journal of Climate, 17 : 4724‑4739.
- Thompson, L.G., Mosley-Thompson, E., Dansgaard, W. and Grootes, P.M., 1986. The Little Ice Age as recorded in the stratigraphy of the tropical Quelccaya Ice Cap. Science, 234 : 361‑364.
- Thompson, L.G., Mosley-Thompson, E.S., Zagorodnov, V., Davis, M.E., Mashiotta, T.A. and Lin, P., 2004. 1500 years of annual climate and environmental variability as recorded in Bona-Churchill (Alaska) ice cores. EOS, Transactions of the American Geophysical Union, 85, Fall Meeting Supplement, Abstract PP23C‑05.
- Trenberth, K.E. and Hoar, T.J., 1997. El Niño and climate change. Geophysical Research Letters, 24 : 3057‑3060.
- Wake, C.P., Yalcin, K. and Gundestrup, N.S., 2003. The climate signal recorded in the oxygen isotope accumulation and major-ion time series from the Eclipse ice core, Yukon Territory, Canada. Annals of Glaciology, 35 : 416‑422.
- West, K.E. and Krouse, H.R., 1972. Abundances of Isotopic Species of water in the St. Elias Mountains, p. 117‑130. In V.C. Bushnell and R.H. Ragle, eds., Icefield Ranges Research Project Scientific Results, Vol. 3. American Geographical Society, New York and Arctic Institute of North America, Montréal, 261 p.
- Whitlow, S., Mayewski, P.A. and Dibb, J.E., 1992. A comparison of major chemical species seasonal concentration and accumulation at the South Pole and Summit, Greenland. Atmospheric Environment, 26A : 2045‑2054.
- Wolfe, E., Moore, J.C., Clausen, H.B. and Hammer, C.U., 1997. Climate implications of background acidity and other chemistry derived from electrical studies of the Greenland Ice Core Project ice core. Journal of Geophysical Research, 102(C12) : 26325‑26332.
- Yalcin, K. and Wake, C.P., 2001. Anthropogenic signals recorded in an ice core from Eclipse Icefield, Yukon Territory, Canada. Geophysical Research Letters, 28 : 4487‑4490.
- Yalcin, K. and Wake, C.P., 2003. A 100‑year record of North Pacific volcanism in an ice core from Eclipse Icefield, Yukon Territory, Canada. Journal of Geophysical Research, 108(D1) : 4012.
- Yalcin, K., Wake, C.P., Whitlow, S.I., and Kreutz, K.J., 2004. Forest fire signals recorded in ice cores from Eclipse Icefield, Yukon Territory, Canada. EOS, Transactions of the American Geophysical Union, 85, Fall Meeting Supplement, Abstract PP23C‑06.
- Zheng, J., Kudo, A., Fisher, D.A., Blake, E.W. and Gerasimoff, M., 1998. Solid electrical conductivity (ECM) from four Agassiz ice cores, Ellesmere Island, NWT, Canada: High-resolution signal and noise over the last millenium and low resolution over the Holocene. The Holocene, 8 : 413‑421.