Principal Component Analysis of Wind Profiler Observations

Christopher R. Williams Cooperative Institute for Research in the Environmental Sciences, University of Colorado and National Oceanic and Atmospheric Administration, Aeronomy Laboratory, Boulder, Colorado

Search for other papers by Christopher R. Williams in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

Principal component analysis (PCA) is applied to wind profiler observations to study the vertical profile of the wind field and its temporal evolution. The rationale for decomposing time–height wind profiler data using PCA is twofold. The orthogonal vertical profile vectors are determined empirically from the variance of the observations, and the time evolutions of these vectors are not simple sinusoids, but are temporal varying signals that can be directly related to other measurements. As an example of its utility, PCA is used to compare the annual and interannual variation of zonal wind measured with a 50-MHz VHF wind profiler above Christmas Island, Kiribati, with the difference between surface pressures measured at Tahiti, French Polynesia, and Darwin, Australia. The high correlation coefficients relate the vertical profile of zonal wind observed in the central Pacific with the variation of convection in the western Pacific. Complex PCA (C-PCA) allows the analysis of data consisting of amplitude and phase information. It can describe the phase progression of oscillations embedded within the data. The C-PCA is applied to VHF wind profiler observations to study the seasonal behavior of the diurnal meridional wind observed above Biak, Indonesia, and the oscillatory structures of the vertical wind during a convective precipitation event observed above Darwin.

Corresponding author address: Dr. Christopher R. Williams, CIRES/NOAA/Aeronomy Laboratory, R/E/AL3, 325 Broadway, Boulder, CO 80303-3328.

Email: chris@a1.noaa.gov

Abstract

Principal component analysis (PCA) is applied to wind profiler observations to study the vertical profile of the wind field and its temporal evolution. The rationale for decomposing time–height wind profiler data using PCA is twofold. The orthogonal vertical profile vectors are determined empirically from the variance of the observations, and the time evolutions of these vectors are not simple sinusoids, but are temporal varying signals that can be directly related to other measurements. As an example of its utility, PCA is used to compare the annual and interannual variation of zonal wind measured with a 50-MHz VHF wind profiler above Christmas Island, Kiribati, with the difference between surface pressures measured at Tahiti, French Polynesia, and Darwin, Australia. The high correlation coefficients relate the vertical profile of zonal wind observed in the central Pacific with the variation of convection in the western Pacific. Complex PCA (C-PCA) allows the analysis of data consisting of amplitude and phase information. It can describe the phase progression of oscillations embedded within the data. The C-PCA is applied to VHF wind profiler observations to study the seasonal behavior of the diurnal meridional wind observed above Biak, Indonesia, and the oscillatory structures of the vertical wind during a convective precipitation event observed above Darwin.

Corresponding author address: Dr. Christopher R. Williams, CIRES/NOAA/Aeronomy Laboratory, R/E/AL3, 325 Broadway, Boulder, CO 80303-3328.

Email: chris@a1.noaa.gov

Save
  • Alexander, G. D., G. S. Young, and D. V. Ledvina, 1993: Principal component analysis of vertical profiles of Q1 and Q2 in the Tropics. Mon. Wea. Rev.,121, 535–548.

    • Crossref
    • Export Citation
  • Alexander, M. J., 1996: A simulated spectrum of convectively generated gravity waves: Propagation from the tropopause to the mesopause and effects on the middle atmosphere. J. Geophys. Res.,101, 1571–1588.

    • Crossref
    • Export Citation
  • Barnett, T. P., 1983: Interaction of the monsoon and Pacific trade wind system at interannual time scales. Part I: The equatorial band. Mon. Wea. Rev.,111, 756–773.

    • Crossref
    • Export Citation
  • Basu, S., R. M. Gairola, C. M. Kishtawal, and P. C. Pandey, 1995: Empirical orthogonal function analysis of humidity profiles over the Indian Ocean and an assessment of their retrievability using satellite microwave radiometry. J. Geophys. Res.,100, 23 009–23 017.

    • Crossref
    • Export Citation
  • Berg, W., and S. K. Avery, 1995: Evaluation of monthly rainfall estimates derived from the Special Sensor Microwave/Imager (SSM/I) over the tropical Pacific. J. Geophys. Res.,100, 1295–1316.

    • Crossref
    • Export Citation
  • Bjerknes, J., 1969: Atmospheric teleconnections from the equatorial Pacific. Mon. Wea. Rev.,97, 163–172.

    • Crossref
    • Export Citation
  • Blackmon, M. L., R. A. Madden, J. M. Wallace, and D. S. Gutzler, 1979: Geophysical variations in the vertical structure of geopotential height fluctuations. J. Atmos. Sci.,36, 2450–2466.

    • Crossref
    • Export Citation
  • Carter, D. A., K. S. Gage, W. L. Ecklund, W. M. Angevine, P. E. Johnston, A. C. Riddle, J. Wilson, and C. R. Williams, 1995: Developments in lower tropospheric wind profiling at NOAA’s Aeronomy Laboratory. Radio Sci.,30, 977–1001.

    • Crossref
    • Export Citation
  • Chang, J. J.-C., and M. Mak, 1993: A dynamical empirical orthogonal function analysis of the intraseasonal disturbances. J. Atmos. Sci.,50, 613–630.

    • Crossref
    • Export Citation
  • Cifelli, R., and S. A. Rutledge, 1994: Vertical motion structure in maritime continent mesoscale convective systems: Results from a 50-MHz profiler. J. Atmos. Sci.,51, 2631–2652.

    • Crossref
    • Export Citation
  • Fraedrich, K., S. Pawson, and R. Wang, 1993: An EOF analysis of the vertical-time-delay structure of the quasi-biennial oscillation. J. Atmos. Sci.,50, 3357–3365.

    • Crossref
    • Export Citation
  • Gage, K. S., B. B. Balsley, W. L. Ecklund, R. F. Woodman, and S. K. Avery, 1990: Wind-profiling Doppler radars for tropical atmospheric research. Eos,71, 1851–1854.

    • Crossref
    • Export Citation
  • ——, ——, ——, D. A. Carter, and J. R. McAfee, 1991: Wind profiler related research in the tropical Pacific. J. Geophys. Res.,96, 3209–3220.

    • Crossref
    • Export Citation
  • ——, J. R. McAfee, W. L. Ecklund, D. A. Carter, C. R. Williams, P. E. Johnston, and A. C. Riddle, 1994: The Christmas Island wind profiler: A prototype VHF wind-profiling radar for the Tropics. J. Atmos. Oceanic Technol.,11, 22–31.

    • Crossref
    • Export Citation
  • ——, ——, and C. R. Williams, 1996a: On the annual variation of tropospheric zonal winds observed above Christmas Island in the central equatorial Pacific. J. Geophys. Res.,101, 15 061–15 070.

  • ——, ——, and ——, 1996b: Recent changes in tropospheric circulation over the central equatorial Pacific. Geophys. Res. Lett.,23, 2149–2152.

    • Crossref
    • Export Citation
  • Gamage, N., and W. Blumen, 1993: Comparative analysis of low-level coldfronts: Wavelet, Fourier, and empirical orthogonal function decompositions. Mon. Wea. Rev.,121, 2867–2878.

    • Crossref
    • Export Citation
  • Gutzler, D. S., 1990: Vertical structure and interannual variability of tropical zonal winds. J. Climate,3, 741–750.

    • Crossref
    • Export Citation
  • ——, and D. E. Harrison, 1987: The structure and evolution of seasonal wind anomalies over the near-equatorial eastern and western Pacific Oceans. Mon. Wea. Rev.,115, 169–192.

    • Crossref
    • Export Citation
  • Hansen, A. R., and A. Sutera, 1992: Structure in the phase space of a general circulation model deduced from empirical orthogonal functions. J. Atmos. Sci.,49, 320–326.

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

    • Crossref
    • Export Citation
  • Hickey, K., R. H. Khan, and J. Walsh, 1995: Parametric estimation of ocean surface currents with HF radar. IEEE J. Oceanic Eng.,20, 139–144.

    • Crossref
    • Export Citation
  • Horel, J. D., 1984: Complex principal component analysis: Theory and examples. J. Climate Appl. Meteor.,23, 1660–1672.

    • Crossref
    • Export Citation
  • 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.

    • Crossref
    • Export Citation
  • Kayano, M. T., V. E. Kousky, and J. E. Janowiak, 1995: Outgoing longwave radiation bias and their impacts on EOF modes of interannual variability in the Tropics. J. Geophys. Res.,100, 3173–3195.

    • Crossref
    • Export Citation
  • Keenan, T. D., and S. A. Rutledge, 1993: Mesoscale characteristics of monsoonal convection and associated stratiform precipitation. Mon. Wea. Rev.,121, 352–374.

    • Crossref
    • Export Citation
  • Legler, D. M., 1983: Empirical orthogonal function analysis of wind vectors over the tropical Pacific region. Bull. Amer. Meteor. Soc.,64, 234–241.

    • Crossref
    • Export Citation
  • Mapes, B. E., and R. A. Houze Jr., 1995: Diabatic divergence profiles in western Pacific mesoscale convective systems. J. Atmos. Sci.,52, 1807–1828.

    • Crossref
    • Export Citation
  • May, P. T., and D. K. Rajopadhyaya, 1996: Wind profiler observations of vertical motion and precipitation microphysics of a tropical squall line. Mon. Wea. Rev.,124, 807–815.

    • Crossref
    • Export Citation
  • North, G. R., 1984: Empirical orthogonal functions and normal modes. J. Atmos. Sci.,41, 879–886.

    • Crossref
    • Export Citation
  • ——, T. L. Bell, R. F. Cahalan, and F. J. Moeng, 1982: Sampling errors in the estimation of empirical orthogonal functions. Mon. Wea. Rev.,110, 699–706.

    • Crossref
    • Export Citation
  • Palo, S. E., and S. K. Avery, 1993: Mean winds and the semiannual oscillation in the mesosphere and lower thermosphere at Christmas Island. J. Geophys. Res.,98, 20 385–20 400.

    • Crossref
    • Export Citation
  • Poon, M. W. Y., R. H. Khan, and S. Le-Ngoc, 1993: A singular value decomposition (SVD) based method for suppressing ocean clutter in high frequency radar. IEEE Trans. Signal Processing,41, 1421–1425.

    • Crossref
    • Export Citation
  • Preisendorfer, R. W., 1988: Principal Component Analysis in Meteorology and Oceanography. Elsevier Science, 425 pp.

  • Richman, M., 1986: Rotation of principal components. J. Climatol.,6, 293–335.

    • Crossref
    • Export Citation
  • Trenberth, K. E., and T. J Hoar, 1996: The 1990–95 El Niño–Southern Oscillation event: Longest on record. Geophys. Res. Lett.,23, 57–60.

    • Crossref
    • Export Citation
  • Waliser, D. E., and C. Gautier, 1993: A satellite-derived climatology of the ITCZ. J. Climate,6, 2162–2174.

    • Crossref
    • Export Citation
  • Webster, P. J., 1972: Response of the tropical atmosphere to local steady forcing. Mon. Wea. Rev.,100, 518–540.

    • Crossref
    • Export Citation
  • Williams, C. R., and S. K. Avery, 1996a: Diurnal nonmigrating tidal oscillations forced by deep convective clouds. J. Geophys. Res.,101, 4079–4091.

    • Crossref
    • Export Citation
  • ——, and ——, 1996b: Diurnal winds observed in the tropical troposphere using 50 MHz wind profilers. J. Geophys. Res.,101, 15 051–15 060.

    • Crossref
    • Export Citation
  • ——, W. L. Ecklund, and K. S. Gage, 1995: Classification of precipitating clouds in the Tropics using 915-MHz wind profilers. J. Atmos. Oceanic Technol.,12, 996–1012.

    • Crossref
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 293 145 12
PDF Downloads 179 122 13