Essential Ingredients to the Dynamics of Westerly Wind Bursts

Minmin Fu Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts

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Eli Tziperman Department of Earth and Planetary Sciences, and School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts

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Abstract

Westerly wind bursts (WWBs) are brief, anomalously westerly winds in the tropical Pacific that play a role in the dynamics of ENSO through their forcing of ocean Kelvin waves. They have been associated with atmospheric phenomena such as tropical cyclones, the MJO, and convectively coupled Rossby waves, yet their basic mechanism is not yet well understood. We study WWBs using an aquaplanet general circulation model, and find that eastward-propagating convective heating plays a key role in the generation of model WWBs, consistent with previous studies. Furthermore, wind-induced surface heat exchange (WISHE) acts on a short time scale of about two days to dramatically amplify the model WWB winds near the peak of the event. On the other hand, it is found that radiation feedbacks (i.e., changes in the net radiative anomalies accompanying westerly wind bursts) are not essential for the development of WWBs, and act as a weak negative feedback on WWBs and their associated convection. Similarly, sensible surface heat flux anomalies are not found to have an effect on the development of model WWBs.

© 2019 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: Minmin Fu, mjfu@g.harvard.edu

Abstract

Westerly wind bursts (WWBs) are brief, anomalously westerly winds in the tropical Pacific that play a role in the dynamics of ENSO through their forcing of ocean Kelvin waves. They have been associated with atmospheric phenomena such as tropical cyclones, the MJO, and convectively coupled Rossby waves, yet their basic mechanism is not yet well understood. We study WWBs using an aquaplanet general circulation model, and find that eastward-propagating convective heating plays a key role in the generation of model WWBs, consistent with previous studies. Furthermore, wind-induced surface heat exchange (WISHE) acts on a short time scale of about two days to dramatically amplify the model WWB winds near the peak of the event. On the other hand, it is found that radiation feedbacks (i.e., changes in the net radiative anomalies accompanying westerly wind bursts) are not essential for the development of WWBs, and act as a weak negative feedback on WWBs and their associated convection. Similarly, sensible surface heat flux anomalies are not found to have an effect on the development of model WWBs.

© 2019 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: Minmin Fu, mjfu@g.harvard.edu
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  • Barlow, M., A. Hoell, and F. Colby, 2007: Examining the wintertime response to tropical convection over the Indian Ocean by modifying convective heating in a full atmospheric model. Geophys. Res. Lett., 34, L19702, https://doi.org/10.1029/2007GL030043.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Bony, S., and K. A. Emanuel, 2005: On the role of moist processes in tropical intraseasonal variability: Cloud–radiation and moisture–convection feedbacks. J. Atmos. Sci., 62, 27702789, https://doi.org/10.1175/JAS3506.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chao, W. C., and L. Deng, 1998: Tropical intraseasonal oscillation, super cloud clusters, and cumulus convection schemes. Part II: 3D aquaplanet simulations. J. Atmos. Sci., 55, 690709, https://doi.org/10.1175/1520-0469(1998)055<0690:TIOSCC>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chen, S., R. Houze, and B. Mapes, 1996: Multiscale variability of deep convection in relation to large-scale circulation in TOGA COARE. J. Atmos. Sci., 53, 13801409, https://doi.org/10.1175/1520-0469(1996)053<1380:MVODCI>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chiodi, A. M., D. E. Harrison, and G. A. Vecchi, 2014: Subseasonal atmospheric variability and El Niño waveguide warming: Observed effects of the Madden–Julian oscillation and westerly wind events. J. Climate, 27, 36193642, https://doi.org/10.1175/JCLI-D-13-00547.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chu, P.-S., 1988: Extratropical forcing and the burst of equatorial westerlies in the western Pacific: A synoptic study. J. Meteor. Soc. Japan, 66, 549564, https://doi.org/10.2151/jmsj1965.66.4_549.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Eisenman, I., L. S. Yu, and E. Tziperman, 2005: Westerly wind bursts: ENSO’s tail rather than the dog? J. Climate, 18, 52245238, https://doi.org/10.1175/JCLI3588.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Emanuel, K. A., 1986: An air–sea interaction theory for tropical cyclones. Part I: Steady-state maintenance. J. Atmos. Sci., 43, 585605, https://doi.org/10.1175/1520-0469(1986)043<0585:AASITF>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Emanuel, K. A., 1987: An air–sea interaction model of intraseasonal oscillations in the tropics. J. Atmos. Sci., 44, 23242340, https://doi.org/10.1175/1520-0469(1987)044<2324:AASIMO>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Fasullo, J., and P. J. Webster, 2000: Atmospheric and surface variations during westerly wind bursts in the tropical western Pacific. Quart. J. Roy. Meteor. Soc., 126, 899924, https://doi.org/10.1002/qj.49712656407.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Gebbie, G., and E. Tziperman, 2009a: Incorporating a semi-stochastic model of ocean-modulated westerly wind bursts into an ENSO prediction model. Theor. Appl. Climatol., 97, 6573, https://doi.org/10.1007/s00704-008-0069-6.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Gebbie, G., and E. Tziperman, 2009b: Predictability of SST-modulated westerly wind bursts. J. Climate, 22, 38943909, https://doi.org/10.1175/2009JCLI2516.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Gebbie, G., I. Eisenman, A. T. Wittenberg, and E. Tziperman, 2007: Modulation of westerly wind bursts by sea surface temperature: A semi-stochastic feedback for ENSO. J. Atmos. Sci., 64, 32813295, https://doi.org/10.1175/JAS4029.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Giese, B., and D. Harrison, 1991: Eastern equatorial Pacific response to three composite westerly wind types. J. Geophys. Res., 96, 32393248, https://doi.org/10.1029/90JC01861.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Gill, A. E., 1980: Some simple solutions for heat-induced tropical circulation. Quart. J. Roy. Meteor. Soc., 106, 447462, https://doi.org/10.1002/qj.49710644905.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Grabowski, W. W., 2001: Coupling cloud processes with the large-scale dynamics using the cloud-resolving convection parameterization (CRCP). J. Atmos. Sci., 58, 978997, https://doi.org/10.1175/1520-0469(2001)058<0978:CCPWTL>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Harrison, D. E., and B. S. Giese, 1991: Episodes of surface westerly winds as observed from islands in the western tropical Pacific. J. Geophys. Res., 96, 32213237, https://doi.org/10.1029/90JC01775.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Harrison, D. E., and G. A. Vecchi, 1997: Westerly wind events in the tropical Pacific, 1986–95. J. Climate, 10, 31313156, https://doi.org/10.1175/1520-0442(1997)010<3131:WWEITT>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Hartten, L. M., 1996: Synoptic settings of westerly wind bursts. J. Geophys. Res., 101, 16 99717 019, https://doi.org/10.1029/96JD00030.

  • Hayashi, M., and H. Itoh, 2017: A new mechanism of the slow eastward propagation of unstable disturbances with convection in the tropics: Implications for the MJO. J. Atmos. Sci., 74, 37493769, https://doi.org/10.1175/JAS-D-16-0300.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Hayashi, Y.-Y., and A. Sumi, 1986: The 30–40 day oscillations simulated in an “aqua planet” model. J. Meteor. Soc. Japan, 64, 451467, https://doi.org/10.2151/jmsj1965.64.4_451.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Held, I. M., and M. J. Suarez, 1994: A proposal for the intercomparison of the dynamical cores of atmospheric general circulation models. Bull. Amer. Meteor. Soc., 75, 18251830, https://doi.org/10.1175/1520-0477(1994)075<1825:APFTIO>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Hendon, H. H., M. C. Wheeler, and C. Zhang, 2007: Seasonal dependence of the MJO–ENSO relationship. J. Climate, 20, 531543, https://doi.org/10.1175/JCLI4003.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Jin, F.-F., L. Lin, A. Timmermann, and J. Zhao, 2007: Ensemble-mean dynamics of the ENSO recharge oscillator under state-dependent stochastic forcing. Geophys. Res. Lett., 34, L03807, https://doi.org/10.1029/2006GL027372.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Keen, R. A., 1982: The role of cross-equatorial tropical cyclone pairs in the Southern Oscillation. Mon. Wea. Rev., 110, 14051416, https://doi.org/10.1175/1520-0493(1982)110<1405:TROCET>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Keen, R. A., 1987: Equatorial westerlies and the southern oscillation. Proceedings of the US TOGA western Pacific air–sea interaction workshop. Honolulu, HI, UCAR, 121–140.

  • Kessler, W. S., and R. Kleeman, 2000: Rectification of the Madden–Julian oscillation into the ENSO cycle. J. Climate, 13, 35603575, https://doi.org/10.1175/1520-0442(2000)013<3560:ROTMJO>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kessler, W. S., M. J. McPhaden, and K. M. Weickmann, 1995: Forcing of intraseasonal Kelvin waves in the equatorial Pacific. J. Geophys. Res., 100, 10 61310 631, https://doi.org/10.1029/95JC00382.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kiladis, G. N., and M. Wheeler, 1995: Horizontal and vertical structure of observed tropospheric equatorial Rossby waves. J. Geophys. Res., 100, 22 98122 997, https://doi.org/10.1029/95JD02415.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kiladis, G. N., G. A. Meehl, and K. M. Weickmann, 1994: Large-scale circulation associated with westerly wind bursts and deep convection over the western equatorial Pacific. J. Geophys. Res., 99, 18 52718 544, https://doi.org/10.1029/94JD01486.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kiranmayi, L., and E. Maloney, 2011: The intraseasonal moist static energy budget in reanalysis data. J. Geophys. Res., 116, D21117, https://doi.org/10.1029/2011JD016031.

    • Search Google Scholar
    • Export Citation
  • Kleeman, R., 1991: A simple model of the atmospheric response to ENSO sea surface temperature anomalies. J. Atmos. Sci., 48, 319, https://doi.org/10.1175/1520-0469(1991)048<0003:ASMOTA>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Latif, M., J. Biercamp, and H. von Storch, 1988: The response of a coupled ocean–atmosphere general circulation model to wind bursts. J. Atmos. Sci., 45, 964979, https://doi.org/10.1175/1520-0469(1988)045<0964:TROACO>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lengaigne, M., J. P. Boulanger, C. Menkes, G. Madec, P. Delecluse, E. Guilyardi, and J. Slingo, 2003: The March 1997 westerly wind event and the onset of the 1997/98 El Niño: Understanding the role of the atmospheric response. J. Climate, 16, 33303343, https://doi.org/10.1175/1520-0442(2003)016<3330:TMWWEA>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lengaigne, M., J.-P. Boulanger, C. Menkes, P. Delecluse, and J. Slingo, 2004a: Westerly wind events in the tropical Pacific and their influence on the coupled ocean–atmosphere system: A review. Earth’s Climate: The Ocean–Atmosphere Interaction, Geophys. Monogr., Vol. 147, Amer. Geophys. Union, 49–69, https://doi.org/10.1029/147GM03.

    • Crossref
    • Export Citation
  • Lengaigne, M., E. Guilyardi, J. P. Boulanger, C. Menkes, P. Delecluse, P. Inness, J. Cole, and J. Slingo, 2004b: Triggering of El Niño by westerly wind events in a coupled general circulation model. Climate Dyn., 23, 601620, https://doi.org/10.1007/s00382-004-0457-2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lian, T., Y. Tang, L. Zhou, S. Ul Islam, C. Zhang, X. Li, and Z. Ling, 2018: Westerly wind bursts simulated in CAM4 and CCSM4. Climate Dyn., 50, 13531371, https://doi.org/10.1007/s00382-017-3689-7.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Luther, D. S., D. E. Harrison, and R. A. Knox, 1983: Zonal winds in the central equatorial Pacific and El Niño. Science, 222, 327330, https://doi.org/10.1126/science.222.4621.327.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Ma, D., and Z. Kuang, 2016: A mechanism-denial study on the Madden–Julian oscillation with reduced interference from mean state changes. Geophys. Res. Lett., 43, 29892997, https://doi.org/10.1002/2016GL067702.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Madden, R. A., and P. R. Julian, 1971: Detection of a 40–50 day oscillation in zonal wind in tropical Pacific. J. Atmos. Sci., 28, 702708, https://doi.org/10.1175/1520-0469(1971)028<0702:DOADOI>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Matsuno, T., 1966: Quasi-geostrophic motions in the equatorial area. J. Meteor. Soc. Japan, 44, 2543, https://doi.org/10.2151/jmsj1965.44.1_25.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • McPhaden, M. J., F. Bahr, Y. Du Penhoat, E. Firing, S. Hayes, P. Niiler, P. Richardson, and J. Toole, 1992: The response of the western equatorial Pacific Ocean to westerly wind bursts during November 1989 to January 1990. J. Geophys. Res. Oceans, 97, 14 28914 303, https://doi.org/10.1029/92JC01197.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Medeiros, B., D. L. Williamson, and J. G. Olson, 2016: Reference aquaplanet climate in the Community Atmosphere Model, version 5. J. Adv. Model. Earth Syst., 8, 406424, https://doi.org/10.1002/2015MS000593.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Moore, A. M., and R. Kleeman, 1999: Stochastic forcing of ENSO by the intraseasonal oscillation. J. Climate, 12, 11991220, https://doi.org/10.1175/1520-0442(1999)012<1199:SFOEBT>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Moustaoui, M., H. Teitelbaum, C. Basdevant, and Y. Boughaleb, 2002: Linked behavior of twin tropical cyclones. J. Geophys. Res., 107, 4378, https://doi.org/10.1029/2000JD000066.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Neale, R., and B. J. Hoskins, 2000: A standard test for AGCMs including their physical parametrizations. II: Results for the Met Office model. Atmos. Sci. Lett., 1, 108114.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Neale, R., and Coauthors, 2010: Description of the NCAR Community Atmosphere Model (CAM 4.0). NCAR Tech. Note NCAR/TN-485+STR, 212 pp., www.cesm.ucar.edu/models/ccsm4.0/cam/docs/description/cam4_desc.pdf.

  • Neelin, J. D., I. M. Held, and K. H. Cook, 1987: Evaporation–wind feedback and low-frequency variability in the tropical atmosphere. J. Atmos. Sci., 44, 23412348, https://doi.org/10.1175/1520-0469(1987)044<2341:EWFALF>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Nitta, T., 1989: Development of a twin cyclone and westerly bursts during the initial phase of the 1986-87 El Niño. J. Meteor. Soc. Japan, 67, 677681, https://doi.org/10.2151/jmsj1965.67.4_677.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Nitta, T., and T. Motoki, 1987: Abrupt enhancement of convective activity and low-level westerly burst during the onset phase of the 1986-87 El Niño. J. Meteor. Soc. Japan, 65, 497506, https://doi.org/10.2151/jmsj1965.65.3_497.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Penland, C., and P. D. Sardeshmukh, 1995: The optimal-growth of tropical sea-surface temperature anomalies. J. Climate, 8, 19992024, https://doi.org/10.1175/1520-0442(1995)008<1999:TOGOTS>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Perez, C. L., A. M. Moore, J. Zavala-Garay, and R. Kleeman, 2005: A comparison of the influence of additive and multiplicative stochastic forcing on a coupled model of ENSO. J. Climate, 18, 50665085, https://doi.org/10.1175/JCLI3596.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Perigaud, C. M., and C. Cassou, 2000: Importance of oceanic decadal trends and westerly wind bursts for forecasting El Niño. Geophys. Res. Lett., 27, 389392, https://doi.org/10.1029/1999GL010781.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Puy, M., J. Vialard, M. Lengaigne, and E. Guilyardi, 2016: Modulation of equatorial Pacific westerly/easterly wind events by the Madden–Julian oscillation and convectively-coupled Rossby waves. Climate Dyn., 46, 21552178, https://doi.org/10.1007/s00382-015-2695-x.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Randall, D., M. Khairoutdinov, A. Arakawa, and W. Grabowski, 2003: Breaking the cloud parameterization deadlock. Bull. Amer. Meteor. Soc., 84, 15471564, https://doi.org/10.1175/BAMS-84-11-1547.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Seiki, A., and Y. N. Takayabu, 2007a: Westerly wind bursts and their relationship with intraseasonal variations and ENSO. Part I: Statistics. Mon. Wea. Rev., 135, 33253345, https://doi.org/10.1175/MWR3477.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Seiki, A., and Y. N. Takayabu, 2007b: Westerly wind bursts and their relationship with intraseasonal variations and ENSO. Part II: Energetics over the western and central Pacific. Mon. Wea. Rev., 135, 33463361, https://doi.org/10.1175/MWR3503.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Slingo, J., D. Rowell, K. Sperber, and E. Nortley, 1999: On the predictability of the interannual behaviour of the Madden–Julian oscillation and its relationship with El Niño. Quart. J. Roy. Meteor. Soc., 125, 583609, https://doi.org/10.1002/qj.49712555411.

    • Search Google Scholar
    • Export Citation
  • Sobel, A. H., E. D. Maloney, G. Bellon, and D. M. Frierson, 2010: Surface fluxes and tropical intraseasonal variability: A reassessment. J. Adv. Model. Earth Syst., 2 (2), https://doi.org/10.3894/JAMES.2010.2.2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Straub, K. H., and G. N. Kiladis, 2003: The observed structure of convectively coupled Kelvin waves: Comparison with simple models of coupled wave instability. J. Atmos. Sci., 60, 16551668, https://doi.org/10.1175/1520-0469(2003)060<1655:TOSOCC>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Sura, P., and P. D. Sardeshmukh, 2008: A global view of non-Gaussian SST variability. J. Phys. Oceanogr., 38, 639647, https://doi.org/10.1175/2007JPO3761.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Tziperman, E., and L. Yu, 2007: Quantifying the dependence of westerly wind bursts on the large scale equatorial Pacific SST. J. Climate, 20, 27602768, https://doi.org/10.1175/JCLI4138a.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Vecchi, G. A., and D. E. Harrison, 1997: Westerly wind events in the tropical Pacific, 1986 1995: An atlas from the ECMWF operational surface wind fields. NOAA/Pacific Marine Environmental Laboratory Tech. Memo. ERL PMEL-109 (PB97-188213), 222 pp.

  • Yu, L., R. A. Weller, and T. W. Liu, 2003: Case analysis of a role of ENSO in regulating the generation of westerly wind bursts in the western equatorial Pacific. J. Geophys. Res., 108, 3128, https://doi.org/10.1029/2002JC001498.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Zavala-Garay, J., C. Zhang, A. Moore, and R. Kleeman, 2005: The linear response of ENSO to the Madden–Julian oscillation. J. Climate, 18, 24412459, https://doi.org/10.1175/JCLI3408.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Zebiak, S. E., 1982: A simple atmospheric model of relevance to El Niño. J. Atmos. Sci., 39, 20172027, https://doi.org/10.1175/1520-0469(1982)039<2017:ASAMOR>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Zhang, C., 1996: Atmospheric intraseasonal variability at the surface in the tropical western Pacific Ocean. J. Atmos. Sci., 53, 739758, https://doi.org/10.1175/1520-0469(1996)053<0739:AIVATS>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Zhang, C. D., 2005: Madden-Julian oscillation. Rev. Geophys., 43, RG2003, https://doi.org/10.1029/2004RG000158.

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