Seasonal Transitions and the Westerly Jet in the Holocene East Asian Summer Monsoon

Wenwen Kong Department of Geography and Berkeley Atmospheric Sciences Center, University of California, Berkeley, Berkeley, California

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Leif M. Swenson Department of Geography and Berkeley Atmospheric Sciences Center, University of California, Berkeley, Berkeley, California

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John C. H. Chiang Department of Geography and Berkeley Atmospheric Sciences Center, University of California, Berkeley, Berkeley, California

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Abstract

The Holocene East Asian summer monsoon (EASM) was previously characterized as a trend toward weaker monsoon intensity paced by orbital insolation. It is demonstrated here that this evolution is more accurately characterized as changes in the transition timing and duration of the EASM seasonal stages (spring, pre-mei-yu, mei-yu, midsummer), and tied to the north–south displacement of the westerlies relative to Tibet. To this end, time-slice simulations across the Holocene are employed using an atmospheric general circulation model. Self-organizing maps are used to objectively identify the transition timing and duration of the EASM seasonal stages.

Compared to the late Holocene, an earlier onset of mei-yu and an earlier transition from mei-yu to midsummer in the early to mid-Holocene are found, resulting in a shortened mei-yu and prolonged midsummer stage. These changes are accompanied by an earlier northward positioning of the westerlies relative to Tibet. Invoking changes to seasonal transitions also provides a more satisfactory explanation for two key observations of Holocene East Asian climate: the “asynchronous Holocene optimum” and changes to dust emissions.

A mechanism is proposed to explain the altered EASM seasonality in the simulated early to mid-Holocene. The insolation increase over the boreal summer reduces the pole–equator temperature gradient, leading to northward-shifted and weakened westerlies. The meridional position of the westerlies relative to the Tibetan Plateau determines the onset of mei-yu and possibly the onset of the midsummer stage. The northward shift in the westerlies triggers earlier seasonal rainfall transitions and, in particular, a shorter mei-yu and longer midsummer stage.

© 2017 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Current affiliation: Department of Land, Air, and Water Resources, University of California, Davis, Davis, California.

Corresponding author e-mail: Wenwen Kong, wenwen.kong@berkeley.edu

Abstract

The Holocene East Asian summer monsoon (EASM) was previously characterized as a trend toward weaker monsoon intensity paced by orbital insolation. It is demonstrated here that this evolution is more accurately characterized as changes in the transition timing and duration of the EASM seasonal stages (spring, pre-mei-yu, mei-yu, midsummer), and tied to the north–south displacement of the westerlies relative to Tibet. To this end, time-slice simulations across the Holocene are employed using an atmospheric general circulation model. Self-organizing maps are used to objectively identify the transition timing and duration of the EASM seasonal stages.

Compared to the late Holocene, an earlier onset of mei-yu and an earlier transition from mei-yu to midsummer in the early to mid-Holocene are found, resulting in a shortened mei-yu and prolonged midsummer stage. These changes are accompanied by an earlier northward positioning of the westerlies relative to Tibet. Invoking changes to seasonal transitions also provides a more satisfactory explanation for two key observations of Holocene East Asian climate: the “asynchronous Holocene optimum” and changes to dust emissions.

A mechanism is proposed to explain the altered EASM seasonality in the simulated early to mid-Holocene. The insolation increase over the boreal summer reduces the pole–equator temperature gradient, leading to northward-shifted and weakened westerlies. The meridional position of the westerlies relative to the Tibetan Plateau determines the onset of mei-yu and possibly the onset of the midsummer stage. The northward shift in the westerlies triggers earlier seasonal rainfall transitions and, in particular, a shorter mei-yu and longer midsummer stage.

© 2017 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Current affiliation: Department of Land, Air, and Water Resources, University of California, Davis, Davis, California.

Corresponding author e-mail: Wenwen Kong, wenwen.kong@berkeley.edu
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  • An, Z., S. C. Porter, J. E. Kutzbach, X. Wu, S. Wang, X. Liu, X. Li, and W. Zhou, 2000: Asynchronous Holocene optimum of the East Asian monsoon. Quat. Sci. Rev., 19, 743762, doi:10.1016/S0277-3791(99)00031-1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • An, Z., and Coauthors, 2012: Interplay between the westerlies and Asian monsoon recorded in Lake Qinghai sediments since 32 ka. Sci. Rep., 2, 619, doi:10.1038/srep00619.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Bao, M., and J. M. Wallace, 2015: Cluster analysis of Northern Hemisphere wintertime 500-hPa flow regimes during 1920–2014. J. Atmos. Sci., 72, 35973608, doi:10.1175/JAS-D-15-0001.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Bao, Q., and Coauthors, 2013: The Flexible Global Ocean–Atmosphere–Land System Model, spectral version 2: FGOALS-s2. Adv. Atmos. Sci., 30, 561576, doi:10.1007/s00376-012-2113-9.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Berger, A., M.-F. Loutre, and C. Tricot, 1993: Insolation and Earth’s orbital periods. J. Geophys. Res., 98, 10 34110 362, doi:10.1029/93JD00222.

  • Braconnot, P., S. P. Harrison, M. Kageyama, P. J. Bartlein, V. Masson-Delmotte, A. Abe-Ouchi, B. Otto-Bliesner, and Y. Zhao, 2012: Evaluation of climate models using palaeoclimatic data. Nat. Climate Change, 2, 417424, doi:10.1038/nclimate1456.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chang, C.-H., and N. C. Johnson, 2015: The continuum of wintertime Southern Hemisphere atmospheric teleconnection patterns. J. Climate, 28, 95079529, doi:10.1175/JCLI-D-14-00739.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chattopadhyay, R., A. K. Sahai, and B. N. Goswami, 2008: Objective identification of nonlinear convectively coupled phases of monsoon intraseasonal oscillation: Implications for prediction. J. Atmos. Sci., 65, 15491569, doi:10.1175/2007JAS2474.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chen, J., and S. Bordoni, 2014: Orographic effects of the Tibetan Plateau on the East Asian summer monsoon: An energetic perspective. J. Climate, 27, 30523072, doi:10.1175/JCLI-D-13-00479.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chen, S.-J., Y.-H. Kuo, W. Wang, Z.-Y. Tao, and B. Cui, 1998: A modeling case study of heavy rainstorms along the mei-yu front. Mon. Wea. Rev., 126, 23302351, doi:10.1175/1520-0493(1998)126<2330:AMCSOH>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chiang, J. C. H., and Coauthors, 2015: Role of seasonal transitions and westerly jets in East Asian paleoclimate. Quat. Sci. Rev., 108, 111129, doi:10.1016/j.quascirev.2014.11.009.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chu, J.-E., S. N. Hameed, and K.-J. Ha, 2012: Nonlinear, intraseasonal phases of the East Asian summer monsoon: Extraction and analysis using self-organizing maps. J. Climate, 25, 69756988, doi:10.1175/JCLI-D-11-00512.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Dansgaard, W., 1964: Stable isotopes in precipitation. Tellus, 16, 436468, doi:10.3402/tellusa.v16i4.8993.

  • Ding, R., J. Li, S. Wang, and F. Ren, 2005: Decadal change of the spring dust storm in northwest China and the associated atmospheric circulation. Geophys. Res. Lett., 32, L02808, doi:10.1029/2004GL021561.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Ding, Y., and J. C. L. Chan, 2005: The East Asian summer monsoon: An overview. Meteor. Atmos. Phys., 89, 117142, doi:10.1007/s00703-005-0125-z.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Gent, P. R., and Coauthors, 2011: The Community Climate System Model version 4. J. Climate, 24, 49734991, doi:10.1175/2011JCLI4083.1.

  • Han, Z., and T. Zhou, 2012: Assessing the quality of APHRODITE high-resolution daily precipitation dataset over contiguous China. Chin. J. Atmos. Sci., 36, 361373.

    • Search Google Scholar
    • Export Citation
  • Hurrell, J. W., and Coauthors, 2013: The Community Earth System Model: A framework for collaborative research. Bull. Amer. Meteor. Soc., 94, 13391360, doi:10.1175/BAMS-D-12-00121.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Iskandar, I., 2009: Variability of satellite-observed sea surface height in the tropical Indian Ocean: Comparison of EOF and SOM analysis. Makara J. Sci., 13, 173179, doi:10.7454/mss.v13i2.421.

    • Search Google Scholar
    • Export Citation
  • Jin, L., B. Schneider, W. Park, M. Latif, V. Khon, and X. Zhang, 2014: The spatial–temporal patterns of Asian summer monsoon precipitation in response to Holocene insolation change: A model-data synthesis. Quat. Sci. Rev., 85, 4762, doi:10.1016/j.quascirev.2013.11.004.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Johnson, N. C., 2013: How many ENSO flavors can we distinguish? J. Climate, 26, 48164827, doi:10.1175/JCLI-D-12-00649.1.

  • Johnson, N. C., S. B. Feldstein, and B. Tremblay, 2008: The continuum of Northern Hemisphere teleconnection patterns and a description of the NAO shift with the use of self-organizing maps. J. Climate, 21, 63546371, doi:10.1175/2008JCLI2380.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kohonen, T., 2001: Self-Organizing Maps. Springer, 502 pp.

  • Kohonen, T., J. Hynninen, J. Kangas, and J. Laaksonen, 1996: SOM_PAK: The self-organizing maps program package. Tech. Rep. A31, Helsinki University of Technology, Laboratory of Computer and Information Science, 25 pp.

  • Kurosaki, Y., and M. Mikami, 2003: Recent frequent dust events and their relation to surface wind in East Asia. Geophys. Res. Lett., 30, 1736, doi:10.1029/2003GL017261.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lau, K.-M., G. J. Yang, and S. H. Shen, 1988: Seasonal and intraseasonal climatology of summer monsoon rainfall over East Asia. Mon. Wea. Rev., 116, 1837, doi:10.1175/1520-0493(1988)116<0018:SAICOS>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Li, C., and M. Yanai, 1996: The onset and interannual variability of the Asian summer monsoon in relation to land–sea thermal contrast. J. Climate, 9, 358375, doi:10.1175/1520-0442(1996)009<0358:TOAIVO>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Li, L., and Coauthors, 2013: The Flexible Global Ocean–Atmosphere–Land System Model, grid-point version 2: FGOALS-g2. Adv. Atmos. Sci., 30, 543560, doi:10.1007/s00376-012-2140-6.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Liang, X.-Z., and W.-C. Wang, 1998: Associations between China monsoon rainfall and tropospheric jets. Quart. J. Roy. Meteor. Soc., 124, 25972623, doi:10.1002/qj.49712455204.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lin, G.-F., and L.-H. Chen, 2006: Identification of homogeneous regions for regional frequency analysis using the self-organizing map. J. Hydrol., 324, 19, doi:10.1016/j.jhydrol.2005.09.009.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Liu, Y., R. H. Weisberg, and C. N. K. Mooers, 2006: Performance evaluation of the self-organizing map for feature extraction. J. Geophys. Res., 111, C05018, doi:10.1029/2005JC003117 .

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Molnar, P., W. R. Boos, and D. S. Battisti, 2010: Orographic controls on climate and paleoclimate of Asia: Thermal and mechanical roles for the Tibetan Plateau. Annu. Rev. Earth Planet. Sci., 38, 77102, doi:10.1146/annurev-earth-040809-152456.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Nagashima, K., R. Tada, A. Tani, Y. Sun, Y. Isozaki, S. Toyoda, and H. Hasegawa, 2011: Millennial-scale oscillations of the westerly jet path during the last glacial period. J. Asian Earth Sci., 40, 12141220, doi:10.1016/j.jseaes.2010.08.010.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Nagashima, K., R. Tada, and S. Toyoda, 2013: Westerly jet–East Asian summer monsoon connection during the Holocene. Geochem. Geophys. Geosyst., 14, 50415053, doi:10.1002/2013GC004931.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Ninomiya, K., 1984: Characteristics of Baiu front as a predominant subtropical front in the summer northern hemisphere. J. Meteor. Soc. Japan, 62, 880894.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Roe, G., 2009: On the interpretation of Chinese loess as a paleoclimate indicator. Quat. Res., 71, 150161, doi:10.1016/j.yqres.2008.09.004.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Sampe, T., and S.-P. Xie, 2010: Large-scale dynamics of the meiyu–baiu rainband: Environmental forcing by the westerly jet. J. Climate, 23, 113134, doi:10.1175/2009JCLI3128.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Schiemann, R., D. Lüthi, and C. Schär, 2009: Seasonality and interannual variability of the westerly jet in the Tibetan Plateau region. J. Climate, 22, 29402957, doi:10.1175/2008JCLI2625.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Shi, Z., 2016: Response of Asian summer monsoon duration to orbital forcing under glacial and interglacial conditions: Implication for precipitation variability in geological records. Quat. Sci. Rev., 139, 3042, doi:10.1016/j.quascirev.2016.03.008.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Solidoro, C., V. Bandelj, P. Barbieri, G. Cossarini, and S. Fonda Umani, 2007: Understanding dynamic of biogeochemical properties in the northern Adriatic Sea by using self-organizing maps and k-means clustering. J. Geophys. Res., 112, C07S90, doi:10.1029/2006JC003553.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Staff, 1957: On the general circulation over eastern Asia (I). Tellus, 9, 432446. [The complete “author” as given in print for Staff (1957) and Staff (1958a,b) is “Staff Members of the Section of Synoptic and Dynamic Meteorology, Institute of Geophysics and Meteorology, Academia Sinica, Peking”; no individual authors were listed.]

    • Search Google Scholar
    • Export Citation
  • Staff, 1958a: On the general circulation over eastern Asia (II). Tellus, 10, 5875.

  • Staff, 1958b: On the general circulation over eastern Asia (III). Tellus, 10, 299312.

  • Tao, S., and L. Chen, 1987: A review of recent research on the East Asian summer monsoon in China. Monsoon Meteorology, C.-P. Chang and T. N. Krishnamurti, Eds., Oxford University Press, 60–92.

  • Thompson, D. W. J., and T. Birner, 2012: On the linkages between the tropospheric isentropic slope and eddy fluxes of heat during Northern Hemisphere winter. J. Atmos. Sci., 69, 18111823, doi:10.1175/JAS-D-11-0187.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Tomita, T., T. Yamaura, and T. Hashimoto, 2011: Interannual variability of the baiu season near Japan evaluated from the equivalent potential temperature. J. Meteor. Soc. Japan, 89, 517537, doi:10.2151/jmsj.2011-507.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wang, B., and LinHo, 2002: Rainy season of the Asian–Pacific summer monsoon. J. Climate, 15, 386398, doi:10.1175/1520-0442(2002)015<0386:RSOTAP>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wang, Y., H. Cheng, R. L. Edwards, Z. An, J. Wu, C.-C. Shen, and J. Dorale, 2001: A high-resolution absolute-dated late Pleistocene monsoon record from Hulu Cave, China. Science, 294, 23452348, doi:10.1126/science.1064618.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wang, Y., and Coauthors, 2005: The Holocene Asian monsoon: Links to solar changes and North Atlantic climate. Science, 308, 854857, doi:10.1126/science.1106296.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wang, Y., and Coauthors, 2008: Millennial- and orbital-scale changes in the East Asian monsoon over the past 224,000 years. Nature, 451, 10901093, doi:10.1038/nature06692.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wu, G., and Coauthors, 2007: The influence of mechanical and thermal forcing by the Tibetan Plateau on Asian climate. J. Hydrometeor., 8, 770789, doi:10.1175/JHM609.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wu, T., and Coauthors, 2013: Global carbon budgets simulated by the Beijing Climate Center Climate System Model for the last century. J. Geophys. Res. Atmos., 118, 43264347, doi:10.1002/jgrd.50320.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Xu, W., and E. J. Zipser, 2011: Diurnal variations of precipitation, deep convection, and lightning over and east of the eastern Tibetan Plateau. J. Climate, 24, 448465, doi:10.1175/2010JCLI3719.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Yanai, M., and G.-X. Wu, 2006: Effects of the Tibetan Plateau. The Asian Monsoon, B. Wang, Ed., Springer, 513–549.

    • Crossref
    • Export Citation
  • Yatagai, A., O. Arakawa, K. Kamiguchi, H. Kawamoto, M. I. Nodzu, and A. Hamada, 2009: A 44-year daily gridded precipitation dataset for Asia based on a dense network of rain gauges. SOLA, 5, 137140, doi:10.2151/sola.2009-035.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Yatagai, A., K. Kamiguchi, O. Arakawa, A. Hamada, N. Yasutomi, and A. Kitoh, 2012: APHRODITE: Constructing a long-term daily gridded precipitation dataset for Asia based on a dense network of rain gauges. Bull. Amer. Meteor. Soc., 93, 14011415, doi:10.1175/BAMS-D-11-00122.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Yeh, T.-C., S.-Y. Dao, and M.-T. Li, 1959: The abrupt change of circulation over the Northern Hemisphere during June and October. The Atmosphere and the Sea in Motion, B. Bolin, Ed., Rockefeller Institute Press, 249–267.

  • Zheng, W., B. Wu, J. He, and Y. Yu, 2013: The East Asian summer monsoon at mid-Holocene: Results from PMIP3 simulations. Climate Past, 9, 453466, doi:10.5194/cp-9-453-2013.

    • Crossref
    • Search Google Scholar
    • Export Citation
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