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  • Bond, N. A., 1992: Observations of planetary boundary layer structure in the eastern equatorial Pacific. J. Climate,5, 699–706.

  • ——, and M. J. McPhaden, 1995: An indirect estimate of the diurnal cycle in upper ocean turbulent heat fluxes at the equator, 140°W. J. Geophys. Res.,100, 18 369–18 378.

  • Chapman, S., and R. S. Lindzen, 1970: Atmospheric Tides. D. Reidel, 200 pp.

  • Chen, S. S., and R. A. Houze, 1997: Diurnal variation and lifecycle of deep convective systems over the tropical Pacific warm pool. Quart. J. Roy. Meteor. Soc.,123, 357–388.

  • Deser, C., 1994: Daily surface wind variations over the equatorial Pacific Ocean. J. Geophys. Res.,99, 23 071–23 078.

  • ——, and J. M. Wallace, 1990: Large-scale atmospheric circulation features of warm and cold episodes in the tropical Pacific. J. Climate,3, 1254–1281.

  • ——, and C. A. Smith, 1996: Daily cycles of SSTs and surface winds over the tropical Pacific from the TAO moored buoy array. Proc. 20th NOAA Climate Diagnostics Workshop, Seattle, WA, NOAA, 256–259.

  • Draper, N. R., and H. Smith, 1966: Applied Regression Analysis. John Wiley and Sons, 407 pp.

  • Foltz, G. S., and W. M. Gray, 1979: Diurnal variation in the troposphere’s energy balance. J. Atmos. Sci.,36, 1450–1466.

  • Freitag, H. P., M. J. McPhaden, C. H. Coho, and A. J. Shepherd, 1991: Equatorial wind, current and temperature data: 108°W to 140°W; April 1983 to October 1987. NOAA Data Rep. ERL PMEL-35, 116 pp.

  • Gage, K. S., G. G. Balsley, W. L. Ecklund, D. A. Carter, and J. R. McAfee, 1991: Wind profiler related research in the tropical Pacific. J. Geophys. Res.,96, 3209–3220.

  • Gray, W. M., and R. W. Jacobson Jr., 1977: Diurnal variation of deep cumulus convection. Mon. Wea. Rev.,105, 1171–1188.

  • Gutzler, D. S., and L. M. Hartten, 1995: Daily variability of lower tropospheric winds over the tropical western Pacific. J. Geophys. Res.,100, 22 999–23 008.

  • Hamilton, K., 1980: The geographical distribution of the solar semidiurnal surface pressure oscillation. J. Geophys. Res.,85, 1945–1949.

  • ——, 1981: Latent heat release as a possible forcing mechanism for atmospheric tides. Mon. Wea. Rev.,109, 3–17.

  • Haurwitz, B., 1956: The geographical distribution of the solar semidiurnal pressure oscillation. N.Y. University Meteor. Paper, 2(5), 36 pp.

  • ——, and A. D. Cowley, 1973: The diurnal and semidiurnal barometric pressure oscillations: Global distribution and annual variation. Pure Appl. Geophys.,102, 193–222.

  • Hayes, S. P., L. J. Mangum, J. Picaut, A. Sumi, and K. Takeuchi, 1991: TOGA–TAO: A moored array for real-time measurements in the tropical Pacific Ocean. Bull. Amer Meteor. Soc.,72, 339–347.

  • Hendon, H. H., and K. Woodberry, 1993: The diurnal cycle of tropical convection. J. Geophys. Res.,98, 16 623–16 637.

  • Janowiak, J. E., P. A. Arkin, and M. Morrissey, 1994: An examination of the diurnal cycle in oceanic tropical rainfall using satellite and in situ data. Mon. Wea. Rev.,122, 2296–2311.

  • Kalnay, E., and Coauthors, 1996: The NCEP/NCAR 40-year reanalysis project. Bull. Amer. Meteor. Soc.,77, 437–471.

  • Liebmann, B., and H. H. Hendon, 1990: Synoptic-scale disturbances near the equator. J. Atmos. Sci.,47, 1463–1479.

  • Lindzen, R. S., 1967: Thermally driven diurnal tide in the atmosphere. Quart. J. Roy. Meteor. Soc.,93, 18–42.

  • ——, 1968: The application of classical atmospheric tidal theory. Proc. Roy. Soc. London,A303, 299–316.

  • ——, and S. Nigam, 1987: On the role of sea surface temperature gradients in forcing low-level winds and convergence in the Tropics. J. Atmos. Sci.,44, 2440–2458.

  • McBride, J. L., and W. M. Gray, 1980: Mass divergence in tropical weather systems. Paper I: Diurnal variation. Quart. J. Roy. Meteor. Soc.,106, 501–516.

  • McPhaden, M. J., 1993: TOGA–TAO and the 1991–93 El Niño–Southern Oscillation event. Oceanography,6, 36–44.

  • ——, and S. P. Hayes, 1990: Variability in the eastern equatorial Pacific during 1986–88. J. Geophys. Res.,95, 13 195–13 208.

  • Morrissey, M. L., 1990: An evaluation of ship data in the equatorial western Pacific. J. Climate,3, 99–112.

  • Nitta, T., and S. Esbensen, 1974: Diurnal variations in the western Atlantic trades during BOMEX. J. Meteor. Soc. Japan,52, 254–257.

  • Pedder, M. A., 1978: Diurnal and semidiurnal variations in the A/B Scale-averaged wind fields during phase III of GATE. Mon. Wea. Rev.,106, 782–788.

  • Randall, D. A., Harshvardhan, and D. A. Dazlich, 1991: Diurnal variability of the hydrologic cycle in a general circulation model. J. Atmos. Sci.,48, 40–62.

  • Reynolds, R. W., and T. M. Smith, 1994: Improved global sea surface temperature analyses using optimum interpolation. J. Climate,7, 929–948.

  • Ruprecht, E., and W. M. Gray, 1976: Analysis of satellite-observed cloud clusters, Paper I and II. Tellus,28, 391–425.

  • Wallace, J. M., T. P. Mitchell, and C. Deser, 1989: The influence of sea surface temperature variability upon surface wind in the eastern equatorial Pacific: Seasonal and interannual variability. J. Climate,2, 1492–1499.

  • Webster, P. J., C. A. Clayson, and J. A. Curry, 1996: Clouds, radiation, and the diurnal cycle of sea surface temperature in the tropical western Pacific. J. Climate,9, 1712–1730.

  • Williams, C. R., and S. K. Avery, 1996: Diurnal winds observed in the tropical troposphere using 50 MHz wind profilers. J. Geophys. Res.,101, 15 051–15 060.

  • ——, ——, J. R. McAfee, and K. S. Gage, 1992: Comparison of observed diurnal and semidiurnal tropospheric winds at Christmas Island with tidal theory. Geophys. Res. Lett.,19, 1471–1474.

  • Xu, K., and D. A. Randall, 1995: Impact of interactive radiative transfer on the macroscopic behavior of cumulus ensembles. Part II: Mechanisms for cloud-radiative interactions. J. Atmos. Sci.,52, 800–817.

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Diurnal and Semidiurnal Variations of the Surface Wind Field over the Tropical Pacific Ocean

Clara DeserCIRES, University of Colorado, Boulder, Colorado

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Catherine A. SmithCIRES, University of Colorado, Boulder, Colorado

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Print Publication:
01 Jul 1998
DOI:
https://doi.org/10.1175/1520-0442(1998)011<1730:DASVOT>2.0.CO;2
Page(s):
1730–1748
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Abstract

The climatological large-scale patterns of diurnal and semidiurnal near-surface wind variations over the tropical Pacific Ocean are documented using 3 yr of hourly measurements from the Tropical Atmosphere–Ocean moored buoy array. Semidiurnal variations account for 68% of the mean daily variance of the zonal wind component, while diurnal variations account for 82% of the mean daily variance of the meridional wind component. The spatially uniform amplitude (0.15 m s−1) and phase (0300 LT) of the semidiurnal zonal wind variations are shown to be consistent with atmospheric thermal tidal theory.

The diurnal meridional wind variations on either side of the equator are approximately out of phase. This pattern results in a diurnal variation of wind divergence along the equator, with maximum divergence in the early morning (∼0800 LT). The average amplitude of the diurnal cycle in zonal mean divergence is 0.45 × 10−6 s−1, which corresponds to a day–night change of 45% relative to the daily mean. The relative day–night changes in near-surface equatorial wind divergence are larger in the western Pacific (78%) than in the eastern Pacific (31%) due mainly to differences in the daily mean divergence. The diurnal amplitude of equatorial wind divergence changes seasonally and interannually in proportion to the strength of the mean divergence.

It is suggested that diurnal heating of the sea surface may contribute to the zonally symmetric diurnal cycle of equatorial wind divergence.

Corresponding author address: Dr. Clara Deser, Climate and Global Dynamics Division, NCAR, P.O. Box 3000, Boulder, CO 80307-3000.

Email: cdeser@ucar.edu

* Current affiliation: National Center for Atmospheric Research, Boulder, Colorado.

Abstract

The climatological large-scale patterns of diurnal and semidiurnal near-surface wind variations over the tropical Pacific Ocean are documented using 3 yr of hourly measurements from the Tropical Atmosphere–Ocean moored buoy array. Semidiurnal variations account for 68% of the mean daily variance of the zonal wind component, while diurnal variations account for 82% of the mean daily variance of the meridional wind component. The spatially uniform amplitude (0.15 m s−1) and phase (0300 LT) of the semidiurnal zonal wind variations are shown to be consistent with atmospheric thermal tidal theory.

The diurnal meridional wind variations on either side of the equator are approximately out of phase. This pattern results in a diurnal variation of wind divergence along the equator, with maximum divergence in the early morning (∼0800 LT). The average amplitude of the diurnal cycle in zonal mean divergence is 0.45 × 10−6 s−1, which corresponds to a day–night change of 45% relative to the daily mean. The relative day–night changes in near-surface equatorial wind divergence are larger in the western Pacific (78%) than in the eastern Pacific (31%) due mainly to differences in the daily mean divergence. The diurnal amplitude of equatorial wind divergence changes seasonally and interannually in proportion to the strength of the mean divergence.

It is suggested that diurnal heating of the sea surface may contribute to the zonally symmetric diurnal cycle of equatorial wind divergence.

Corresponding author address: Dr. Clara Deser, Climate and Global Dynamics Division, NCAR, P.O. Box 3000, Boulder, CO 80307-3000.

Email: cdeser@ucar.edu

* Current affiliation: National Center for Atmospheric Research, Boulder, Colorado.

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