• Athanasiadis, P. J., J. M. Wallace, and J. J. Wettstein, 2010: Patterns of wintertime jet stream variability and their relation to the storm tracks. J. Atmos. Sci., 67, 13611381, https://doi.org/10.1175/2009JAS3270.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Barton, N. P., and A. W. Ellis, 2009: Variability in wintertime position and strength of the North Pacific jet stream as represented by re-analysis data. Int. J. Climatol., 29, 851–862, https://doi.org/10.1002/joc.1750.

    • Crossref
    • Export Citation
  • Baxter, S., and S. Nigam, 2015: Key role of the North Pacific Oscillation–west Pacific pattern in generating the extreme 2013/14 North American winter. J. Climate, 28, 81098117, https://doi.org/10.1175/JCLI-D-14-00726.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Bond, N., J. Overland, M. Spillane, and P. Stabeno, 2003: Recent shifts in the state of the North Pacific. Geophys. Res. Lett., 30, 2183, https://doi.org/10.1029/2003GL018597.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chan, D., Y. Zhang, Q. Wu, and X. Dai, 2020: Quantifying the dynamics of the interannual variabilities of the wintertime East Asian jet core. Climate Dyn., 54, 24472463, https://doi.org/10.1007/s00382-020-05127-3.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chowdary, J. S., K. Hu, G. Srinivas, Y. Kosaka, L. Wang, and K. K. Rao, 2019: The Eurasian jet streams as conduits for East Asian monsoon variability. Curr. Climate Change Rep., 5, 233244, https://doi.org/10.1007/s40641-019-00134-x.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Cohen, J., and et al. , 2014: Recent Arctic amplification and extreme mid-latitude weather. Nat. Geosci., 7, 627637, https://doi.org/10.1038/ngeo2234.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Cressman, G. P., 1984: Energy transformations in the East Asia–west Pacific jet stream. Mon. Wea. Rev., 112, 563571, https://doi.org/10.1175/1520-0493(1984)112<0563:ETITEA>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Delcambre, S. C., D. J. Lorenz, D. J. Vimont, and J. E. Martin, 2013: Diagnosing Northern Hemisphere jet portrayal in 17 CMIP3 global climate models: Twenty-first-century projections. J. Climate, 26, 49304946, https://doi.org/10.1175/JCLI-D-12-00359.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Di Lorenzo, E., and et al. , 2008: North Pacific Gyre Oscillation links ocean climate and ecosystem change. Geophys. Res. Lett., 35, L08607, https://doi.org/10.1029/2007GL032838.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Eady, E. T., 1949: Long waves and cyclone waves. Tellus, 1, 3352, https://doi.org/10.3402/tellusa.v1i3.8507.

  • Eichelberger, S. J., and D. L. Hartmann, 2007: Zonal jet structure and the leading mode of variability. J. Climate, 20, 51495163, https://doi.org/10.1175/JCLI4279.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Griffin, K. S., and J. E. Martin, 2017: Synoptic features associated with temporally coherent modes of variability of the North Pacific jet stream. J. Climate, 30, 3954, https://doi.org/10.1175/JCLI-D-15-0833.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Hall, R., R. Erdélyi, E. Hanna, J. M. Jones, and A. A. Scaife, 2015: Drivers of North Atlantic polar front jet stream variability. Int. J. Climatol., 35, 16971720, https://doi.org/10.1002/joc.4121.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Harnik, N., E. Galanti, O. Martius, and O. Adam, 2014: The anomalous merging of the African and North Atlantic jet streams during the Northern Hemisphere winter of 2010. J. Climate, 27, 73197334, https://doi.org/10.1175/JCLI-D-13-00531.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Hartmann, D. L., 2015: Pacific sea surface temperature and the winter of 2014. Geophys. Res. Lett., 42, 18941902, https://doi.org/10.1002/2015GL063083.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Held, I. M., 1975: Momentum transport by quasi-geostrophic eddies. J. Atmos. Sci., 32, 14941497, https://doi.org/10.1175/1520-0469(1975)032<1494:MTBQGE>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Held, I. M., and A. Y. Hou, 1980: Nonlinear axially symmetric circulations in a nearly inviscid atmosphere. J. Atmos. Sci., 37, 515533, https://doi.org/10.1175/1520-0469(1980)037<0515:NASCIA>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Hersbach, H., and D. Dee, 2016: ERA5 reanalysis is in production. ECMWF Newsletter, No. 147, ECMWF, Reading, United Kingdom, 7, http://www.ecmwf.int/sites/default/files/elibrary/2016/16299-newsletter-no147-spring-2016.pdf.

  • Holton, J. R., 1973: An introduction to dynamic meteorology. Amer. J. Phys., 41, 752754, https://doi.org/10.1119/1.1987371.

  • Horel, J. D., and J. M. Wallace, 1981: Planetary-scale atmospheric phenomena associated with the Southern Oscillation. Mon. Wea. Rev., 109, 813829, https://doi.org/10.1175/1520-0493(1981)109<0813:PSAPAW>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Hoskins, B. J., and P. J. Valdes, 1990: On the existence of storm-tracks. J. Atmos. Sci., 47, 18541864, https://doi.org/10.1175/1520-0469(1990)047<1854:OTEOST>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Huang, D., A. Dai, J. Zhu, Y. Zhang, and X. Kuang, 2017: Recent winter precipitation changes over Eastern China in different warming periods and the associated East Asian jets and oceanic conditions. J. Climate, 30, 44434462, https://doi.org/10.1175/JCLI-D-16-0517.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Huang, D., A. Dai, B. Yang, P. Yan, J. Zhu, and Y. Zhang, 2019: Contributions of different combinations of the IPO and AMO to recent changes in winter East Asian jets. J. Climate, 32, 16071626, https://doi.org/10.1175/JCLI-D-18-0218.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Huang, J., Y. Zhang, X.-Q. Yang, X. Ren, and H. Hu, 2020: Impacts of North Pacific subtropical and subarctic oceanic frontal zones on the wintertime atmospheric large-scale circulations. J. Climate, 33, 18971914, https://doi.org/10.1175/JCLI-D-19-0308.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Jaffe, S. C., J. E. Martin, D. J. Vimont, and D. J. Lorenz, 2011: A synoptic climatology of episodic, subseasonal retractions of the Pacific jet. J. Climate, 24, 28462860, https://doi.org/10.1175/2010JCLI3995.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Jhun, J.-G., and E.-J. Lee, 2004: A new East Asian winter monsoon index and associated characteristics of the winter monsoon. J. Climate, 17, 711726, https://doi.org/10.1175/1520-0442(2004)017<0711:ANEAWM>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Jo, H. S., S. W. Yeh, and C. H. Kim, 2013: A possible mechanism for the North Pacific regime shift in winter of 1998/1999. Geophys. Res. Lett., 40, 43804385, https://doi.org/10.1002/grl.50798.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kalnay, E., and et al. , 1996: The NCEP/NCAR 40-Year Reanalysis Project. Bull. Amer. Meteor. Soc., 77, 437472, https://doi.org/10.1175/1520-0477(1996)077<0437:TNYRP>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kim, B.-M., and et al. , 2014: Weakening of the stratospheric polar vortex by Arctic sea-ice loss. Nat. Commun., 5, 4646, https://doi.org/10.1038/ncomms5646.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Krishnamurti, T. N., 1961: The subtropical jet stream of winter. J. Meteor., 18, 172191, https://doi.org/10.1175/1520-0469(1961)018<0172:TSJSOW>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lachmy, O., and N. Harnik, 2014: The transition to a subtropical jet regime and its maintenance. J. Atmos. Sci., 71, 13891409, https://doi.org/10.1175/JAS-D-13-0125.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lachmy, O., and N. Harnik, 2016: Wave and jet maintenance in different flow regimes. J. Atmos. Sci., 73, 24652484, https://doi.org/10.1175/JAS-D-15-0321.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lee, M. Y., C. C. Hong, and H. H. Hsu, 2015: Compounding effects of warm sea surface temperature and reduced sea ice on the extreme circulation over the extratropical North Pacific and North America during the 2013–2014 boreal winter. Geophys. Res. Lett., 42, 16121618, https://doi.org/10.1002/2014GL062956.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lee, S., and H. Kim, 2003: The dynamical relationship between subtropical and eddy-driven jets. J. Atmos. Sci., 60, 14901503, https://doi.org/10.1175/1520-0469(2003)060<1490:TDRBSA>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Li, C., and J. J. Wettstein, 2012: Thermally driven and eddy-driven jet variability in reanalysis. J. Climate, 25, 15871596, https://doi.org/10.1175/JCLI-D-11-00145.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Li, X.-F., J. Li, and Y. Li, 2015: Recent winter precipitation increase in the middle–lower Yangtze River Valley since the late 1970s: A response to warming in the tropical Indian Ocean. J. Climate, 28, 38573879, https://doi.org/10.1175/JCLI-D-14-00701.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Li, Y., and S. Yang, 2010: A dynamical index for the East Asian winter monsoon. J. Climate, 23, 42554262, https://doi.org/10.1175/2010JCLI3375.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Linkin, M. E., and S. Nigam, 2008: The North Pacific Oscillation–west Pacific teleconnection pattern: Mature-phase structure and winter impacts. J. Climate, 21, 19791997, https://doi.org/10.1175/2007JCLI2048.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lopez, H., S. K. Lee, S. Dong, G. Goni, B. Kirtman, R. Atlas, and A. Kumar, 2019: East Asian monsoon as a modulator of U.S. Great Plains heat waves. J. Geophys. Res., 124, 63426358, https://doi.org/10.1029/2018JD030151.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Madonna, E., C. Li, and J. J. Wettstein, 2019: Suppressed eddy driving during southward excursions of the North Atlantic jet on synoptic to seasonal time scales. Atmos. Sci. Lett., 20, e937, https://doi.org/10.1002/asl.937.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Mantua, N. J., S. R. Hare, Y. Zhang, J. M. Wallace, and R. C. Francis, 1997: A Pacific interdecadal climate oscillation with impacts on salmon production. Bull. Amer. Meteor. Soc., 78, 10691080, https://doi.org/10.1175/1520-0477(1997)078<1069:APICOW>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Nakamura, H., T. Sampe, A. Goto, W. Ohfuchi, and S. P. Xie, 2008: On the importance of midlatitude oceanic frontal zones for the mean state and dominant variability in the tropospheric circulation. Geophys. Res. Lett., 35, L15709, https://doi.org/10.1029/2008GL034010.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Neale, R. B., and et al. , 2012: Description of the NCAR Community Atmosphere Model (CAM 5.0). NCAR Tech. Note NCAR/TN-486+STR, 274 pp., www.cesm.ucar.edu/models/cesm1.0/cam/docs/description/cam5_desc.pdf.

  • Overland, J. E., J. A. Francis, E. Hanna, and M. Wang, 2012: The recent shift in early summer Arctic atmospheric circulation. Geophys. Res. Lett., 39, L19804, https://doi.org/10.1029/2012GL053268.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Overland, J. E., J. A. Francis, R. Hall, E. Hanna, S.-J. Kim, and T. Vihma, 2015: The melting Arctic and midlatitude weather patterns: Are they connected? J. Climate, 28, 79177932, https://doi.org/10.1175/JCLI-D-14-00822.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Panetta, R. L., 1993: Zonal jets in wide baroclinically unstable regions: Persistence and scale selection. J. Atmos. Sci., 50, 20732106, https://doi.org/10.1175/1520-0469(1993)050<2073:ZJIWBU>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Plumb, R., 1979: Eddy fluxes of conserved quantities by small-amplitude waves. J. Atmos. Sci., 36, 16991704, https://doi.org/10.1175/1520-0469(1979)036<1699:EFOCQB>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Rayner, N., D. E. Parker, E. B. Horton, C. K. Folland, L. V. Alexander, D. P. Rowell, E. C. Kent, and A. Kaplan, 2003: Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century. J. Geophys. Res., 108, 4407, https://doi.org/10.1029/2002JD002670.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Ren, X., Y. Zhang, and Y. Xiang, 2008: Connections between wintertime jet stream variability, oceanic surface heating, and transient eddy activity in the North Pacific. J. Geophys. Res., 113, D21119, https://doi.org/10.1029/2007JD009464.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Rhines, P. B., 1975: Waves and turbulence on a beta-plane. J. Fluid Mech., 69, 417443, https://doi.org/10.1017/S0022112075001504.

  • Rogers, J. C., 1981: The North Pacific Oscillation. J. Climatol., 1, 3957, https://doi.org/10.1002/joc.3370010106.

  • Schneider, E. K., 1977: Axially symmetric steady-state models of the basic state for instability and climate studies. Part II. Nonlinear calculations. J. Atmos. Sci., 34, 280296, https://doi.org/10.1175/1520-0469(1977)034<0280:ASSSMO>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Screen, J. A., and I. Simmonds, 2010: The central role of diminishing sea ice in recent Arctic temperature amplification. Nature, 464, 13341337, https://doi.org/10.1038/nature09051.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Screen, J. A., and I. Simmonds, 2013: Exploring links between Arctic amplification and mid-latitude weather. Geophys. Res. Lett., 40, 959964, https://doi.org/10.1002/grl.50174.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Simpson, I. R., C. Deser, K. A. McKinnon, and E. A. Barnes, 2018: Modeled and observed multidecadal variability in the North Atlantic jet stream and its connection to sea surface temperatures. J. Climate, 31, 83138338, https://doi.org/10.1175/JCLI-D-18-0168.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Son, S.-W., and S. Lee, 2005: The response of westerly jets to thermal driving in a primitive equation model. J. Atmos. Sci., 62, 37413757, https://doi.org/10.1175/JAS3571.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Song, S.-Y., S.-W. Yeh, and J.-H. Park, 2019: Change in relationship between the East Asian winter monsoon and the East Asian jet stream during the 1998–99 regime shift. J. Climate, 32, 61636175, https://doi.org/10.1175/JCLI-D-18-0844.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Song, S.-Y., S.-W. Yeh, and J.-H. Park, 2020: Dissimilar characteristics associated with the 1976/1977 and 1998/1999 climate regime shifts in the North Pacific. Theor. Appl. Climatol., 142, 14631470, https://doi.org/10.1007/s00704-020-03378-y.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Sun, J., S. Wu, and J. Ao, 2016: Role of the North Pacific sea surface temperature in the East Asian winter monsoon decadal variability. Climate Dyn., 46, 37933805, https://doi.org/10.1007/s00382-015-2805-9.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Sung, M.-K., H.-Y. Jang, B.-M. Kim, S.-W. Yeh, Y.-S. Choi, and C. Yoo, 2019: Tropical influence on the North Pacific Oscillation drives winter extremes in North America. Nat. Climate Change, 9, 413418, https://doi.org/10.1038/s41558-019-0461-5.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Takaya, K., and H. Nakamura, 1997: A formulation of a wave-activity flux for stationary Rossby waves on a zonally varying basic flow. Geophys. Res. Lett., 24, 29852988, https://doi.org/10.1029/97GL03094.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Takaya, K., and H. Nakamura, 2001: A formulation of a phase-independent wave-activity flux for stationary and migratory quasigeostrophic eddies on a zonally varying basic flow. J. Atmos. Sci., 58, 608627, https://doi.org/10.1175/1520-0469(2001)058<0608:AFOAPI>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Trouet, V., F. Babst, and M. Meko, 2018: Recent enhanced high-summer North Atlantic jet variability emerges from three-century context. Nat. Commun., 9, 180, https://doi.org/10.1038/s41467-017-02699-3.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wahl, E. R., E. Zorita, V. Trouet, and A. H. Taylor, 2019: Jet stream dynamics, hydroclimate, and fire in California from 1600 CE to present. Proc. Natl. Acad. Sci. USA, 116, 53935398, https://doi.org/10.1073/pnas.1815292116.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wang, B., 2006: The Asian Monsoon. Springer, 787 pp.

  • Wang, L., X. Q. Yang, D. Yang, Q. Xie, J. Fang, and X. Sun, 2017: Two typical modes in the variabilities of wintertime North Pacific basin-scale oceanic fronts and associated atmospheric eddy-driven jet. Atmos. Sci. Lett., 18, 373380, https://doi.org/10.1002/asl.766.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wang, S.-Y. S., W.-R. Huang, and J.-H. Yoon, 2015: The North American winter ‘dipole’ and extremes activity: A CMIP5 assessment. Atmos. Sci. Lett., 16, 338345, https://doi.org/10.1002/asl2.565.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wettstein, J. J., and J. M. Wallace, 2010: Observed patterns of month-to-month storm-track variability and their relationship to the background flow. J. Atmos. Sci., 67, 14201437, https://doi.org/10.1175/2009JAS3194.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Winters, A. C., D. Keyser, and L. F. Bosart, 2019: The development of the North Pacific jet phase diagram as an objective tool to monitor the state and forecast skill of the upper-tropospheric flow pattern. Wea. Forecasting, 34, 199219, https://doi.org/10.1175/WAF-D-18-0106.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Xie, Z., Y. Du, and S. Yang, 2015: Zonal extension and retraction of the subtropical westerly jet stream and evolution of precipitation over East Asia and the western Pacific. J. Climate, 28, 67836798, https://doi.org/10.1175/JCLI-D-14-00649.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Yang, S., K. Lau, and K. Kim, 2002: Variations of the East Asian jet stream and Asian–Pacific–American winter climate anomalies. J. Climate, 15, 306325, https://doi.org/10.1175/1520-0442(2002)015<0306:VOTEAJ>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Yeh, S.-W., R.-J. Park, M.-J. Kim, and C.-K. Song, 2015: Effect of anthropogenic sulphate aerosol in China on the drought in the western-to-central US. Sci. Rep., 5, 14 305, https://doi.org/10.1038/srep14305.

    • 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.

  • Yuval, J., and Y. Kaspi, 2018: Eddy sensitivity to jet characteristics. J. Atmos. Sci., 75, 13711383, https://doi.org/10.1175/JAS-D-17-0139.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Yuval, J., H. Afargan, and Y. Kaspi, 2018: The relation between the seasonal changes in jet characteristics and the Pacific midwinter minimum in eddy activity. Geophys. Res. Lett., 45, 999510 002, https://doi.org/10.1029/2018GL078678.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Zhang, W., and G. Villarini, 2018: Uncovering the role of the East Asian jet stream and heterogeneities in atmospheric rivers affecting the western United States. Proc. Natl. Acad. Sci. USA, 115, 891896, https://doi.org/10.1073/pnas.1717883115.

    • Crossref
    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 201 201 40
Full Text Views 41 41 10
PDF Downloads 58 58 16

Changes in the Characteristics of the North Pacific Jet as a Conduit for U.S. Surface Air Temperature in Boreal Winter across the Late 1990s

View More View Less
  • 1 a Department of Marine Sciences and Convergence Technology, Hanyang University, Ansan, South Korea
  • | 2 b Department of Oceanography, Chonnam National University, Gwangju, South Korea
© Get Permissions Rent on DeepDyve
Restricted access

Abstract

The leading modes of the North Pacific jet (NPJ) variability include intensity changes and meridional shifts in jet position on low-frequency time scales. These leading modes of NPJ variability are closely associated with weather and climate conditions spanning from Asia to the United States. In this study, we investigated changes in the NPJ’s role as a conduit for U.S. surface air temperature (SAT) anomalies during the boreal winter across the late 1990s. We found that the leading mode of NPJ variability changed from the NPJ intensity changes to meridional shifts in NPJ position across the late 1990s. It leads to the change in the role of the NPJ as a conduit for U.S. SAT anomalies. Before the late 1990s, the variability of NPJ intensity significantly impacted western U.S. SAT anomalies related to the anomalous surface cyclonic circulation over the North Pacific. After the late 1990s, however, the variability of the NPJ’s meridional shift significantly influenced the eastern U.S. SAT anomalies in association with the anomalous surface cyclonic circulation over the northern North Pacific. Further analysis and model experiments revealed that the western to central North Pacific Ocean has been warming since the late 1990s and modulates atmospheric baroclinicity. This phenomenon mainly leads to a northward NPJ shift and implies that the eddy-driven mechanism on the NPJ’s formation, which acts to enhance the meridional variability of NPJ position, becomes dominant. We conclude that this northward shift of NPJ could have contributed to enhancing the NPJ’s meridional shift variability, significantly influencing the eastern U.S. SAT anomalies since the late 1990s.

© 2021 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Sang-Wook Yeh, swyeh@hanyang.ac.kr

Abstract

The leading modes of the North Pacific jet (NPJ) variability include intensity changes and meridional shifts in jet position on low-frequency time scales. These leading modes of NPJ variability are closely associated with weather and climate conditions spanning from Asia to the United States. In this study, we investigated changes in the NPJ’s role as a conduit for U.S. surface air temperature (SAT) anomalies during the boreal winter across the late 1990s. We found that the leading mode of NPJ variability changed from the NPJ intensity changes to meridional shifts in NPJ position across the late 1990s. It leads to the change in the role of the NPJ as a conduit for U.S. SAT anomalies. Before the late 1990s, the variability of NPJ intensity significantly impacted western U.S. SAT anomalies related to the anomalous surface cyclonic circulation over the North Pacific. After the late 1990s, however, the variability of the NPJ’s meridional shift significantly influenced the eastern U.S. SAT anomalies in association with the anomalous surface cyclonic circulation over the northern North Pacific. Further analysis and model experiments revealed that the western to central North Pacific Ocean has been warming since the late 1990s and modulates atmospheric baroclinicity. This phenomenon mainly leads to a northward NPJ shift and implies that the eddy-driven mechanism on the NPJ’s formation, which acts to enhance the meridional variability of NPJ position, becomes dominant. We conclude that this northward shift of NPJ could have contributed to enhancing the NPJ’s meridional shift variability, significantly influencing the eastern U.S. SAT anomalies since the late 1990s.

© 2021 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Sang-Wook Yeh, swyeh@hanyang.ac.kr

Supplementary Materials

    • Supplemental Materials (PDF 1.22 MB)
Save