• Boutier, F. 2001. The use of profiler data at ECMWF. Z. Meteor. 10:497510.

  • Drosdowsky, W. 1996. Variability of the Australian summer monsoon at Darwin: 1957–1992. J. Climate 9:8596.

  • Gage, K. S., , J. R. McAfee, , W. G. Collins, , D. Söderman, , H. Böttger, , A. Radford, , and B. Balsley. 1988. A comparison of winds observed at Christmas Island using a wind-profiling Doppler radar with NMC and ECMWF analyses. Bull. Amer. Meteor. Soc. 69:10411046.

    • Search Google Scholar
    • Export Citation
  • Gage, K. S., , J. R. McAfee, , D. A. Carter, , W. L. Ecklund, , A. C. Riddle, , G. C. Reid, , and B. B. Balsley. 1991. Long-term mean vertical motion over the tropical Pacific: Wind-profiling Doppler radar measurements. Science 254:17711773.

    • Search Google Scholar
    • Export Citation
  • Gage, K. S., , J. R. McAfee, , and C. R. Williams. 1996. On the annual variation of tropospheric zonal winds observed above Christmas Island in the central equatorial Pacific. J. Geophys. Res. 101:1506115070.

    • Search Google Scholar
    • Export Citation
  • Jasperson, W. H. 1982. Mesoscale time and space wind variability. J. Appl. Meteor. 21:831839.

  • Kalnay, E. Coauthors,. 1996. The NCEP/NCAR 40-Year Reanalysis Project. Bull. Amer. Meteor. Soc. 77:437471.

  • Kanamitsu, M., , W. Ebisuzaki, , J. Woollen, , S. Yang, , J. J. Hnilo, , M. Fiorino, , and G. L. Potter. 2002. NCEP–DOE AMIP-II Reanalysis (R-2). Bull. Amer. Meteor. Soc. 83:16311643.

    • Search Google Scholar
    • Export Citation
  • Lietzke, C. E., , C. Deser, , and T. H. Vonder Haar. 2001. Evolutionary structure of the eastern Pacific double ITCZ based on satellite moisture retrievals. J. Climate 14:743751.

    • Search Google Scholar
    • Export Citation
  • May, P. 1993. Comparison of wind-profiler and radiosonde measurements in the Tropics. J. Atmos. Oceanic Technol. 10:122127.

  • McBride, J. L. 1987. The Australian summer monsoon. Monsoon Meteorology, C. P. Chang and T. N. Krishnamurti, Eds., Clarendon Press, 60–92.

    • Search Google Scholar
    • Export Citation
  • Parrish, D. F., and J. C. Derber. 1992. The National Meteorological Center's spectral statistical–interpolation analysis system. Mon. Wea. Rev. 120:17471763.

    • Search Google Scholar
    • Export Citation
  • Pauley, P. M., , R. L. Creasey, , W. L. Clark, , and G. D. Nastrom. 1994. Comparisons of horizontal winds measured by opposing beams with the Flatland ST radar and between Flatland measurements and NMC analyses. J. Atmos. Oceanic Technol. 11:256274.

    • Search Google Scholar
    • Export Citation
  • Strauch, R. G., , D. A. Merritt, , K. P. Moran, , K. B. Earnshaw, , and J. D. van de Kamp. 1984. The Colorado wind-profiling network. J. Atmos. Oceanic Technol. 1:3749.

    • Search Google Scholar
    • Export Citation
  • Strauch, R. G., , B. L. Weber, , A. S. Frisch, , C. G. Little, , D. A. Merritt, , K. P. Moran, , and D. C. Welsh. 1987. The precision and relative accuracy of profiler wind measurements. J. Atmos. Oceanic Technol. 4:563571.

    • Search Google Scholar
    • Export Citation
  • Trenberth, K. E., , D. P. Stepaniak, , and J. M. Caron. 2000. The global monsoon as seen through the divergent atmospheric circulation. J. Climate 13:39693993.

    • Search Google Scholar
    • Export Citation
  • Vincent, R. A., and I. M. Reid. 1983. HF Doppler measurements of mesospheric gravity wave momentum fluxes. J. Atmos. Sci. 40:13211333.

    • Search Google Scholar
    • Export Citation
  • Weber, B. L., and D. B. Wuertz. 1990. Comparison of rawinsonde and wind profiler radar measurements. J. Atmos. Oceanic Technol. 7:157174.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 155 155 4
PDF Downloads 30 30 0

A Comparison of VHF Wind Profiler Observations and the NCEP–NCAR Reanalysis over the Tropical Pacific

View More View Less
  • a Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado
  • | b Aeronomy Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado
© Get Permissions Rent on DeepDyve
Restricted access

Abstract

VHF wind profiler measurements of zonal and meridional winds are compared with the NCEP–NCAR reanalysis at sites in the tropical Pacific. By December 1999 the profilers at Darwin, Australia, and Biak, Indonesia, in the western Pacific; Christmas Island, Kiribati, in the central Pacific; and Piura Peru, in the eastern Pacific had collected between 8 and 13 yr of nearly continuous data. While these profilers routinely observe winds up to about 20 km, only winds at Christmas Island are assimilated into the reanalysis. The long period of profiler operation provides an opportunity to study differences between the profiler and reanalysis winds in the equatorial Pacific, a region with geographically sparse observations. Mean and seasonal mean zonal and meridional winds are used to identify differences in the profiler and reanalysis winds. Two potential causes for the discrepancy between profiler and reanalysis winds are identified. The first of these is related to different spatial and temporal characteristics of the reanalysis and profiler data. The second cause is the geographical sparseness of rawinsonde data, and not assimilating wind profiler observations. The closest agreement between the mean and seasonal mean zonal winds was found at Christmas Island, a site at which profiler winds are assimilated. A good agreement between reanalysis and profiler meridional and zonal winds is also shown at Darwin, where nearby rawinsonde observations are available. The poorest agreement was found at Piura (where profiler winds are not assimilated), the closest rawinsonde is almost 2000 km from the profiler site, and topography is not adequately resolved in the reanalysis.

Corresponding author address: Robert Schafer, University of Colorado, CIRES Building, Room 318, Boulder, CO 80309-0216. robert.schafer@colorado.edu

Abstract

VHF wind profiler measurements of zonal and meridional winds are compared with the NCEP–NCAR reanalysis at sites in the tropical Pacific. By December 1999 the profilers at Darwin, Australia, and Biak, Indonesia, in the western Pacific; Christmas Island, Kiribati, in the central Pacific; and Piura Peru, in the eastern Pacific had collected between 8 and 13 yr of nearly continuous data. While these profilers routinely observe winds up to about 20 km, only winds at Christmas Island are assimilated into the reanalysis. The long period of profiler operation provides an opportunity to study differences between the profiler and reanalysis winds in the equatorial Pacific, a region with geographically sparse observations. Mean and seasonal mean zonal and meridional winds are used to identify differences in the profiler and reanalysis winds. Two potential causes for the discrepancy between profiler and reanalysis winds are identified. The first of these is related to different spatial and temporal characteristics of the reanalysis and profiler data. The second cause is the geographical sparseness of rawinsonde data, and not assimilating wind profiler observations. The closest agreement between the mean and seasonal mean zonal winds was found at Christmas Island, a site at which profiler winds are assimilated. A good agreement between reanalysis and profiler meridional and zonal winds is also shown at Darwin, where nearby rawinsonde observations are available. The poorest agreement was found at Piura (where profiler winds are not assimilated), the closest rawinsonde is almost 2000 km from the profiler site, and topography is not adequately resolved in the reanalysis.

Corresponding author address: Robert Schafer, University of Colorado, CIRES Building, Room 318, Boulder, CO 80309-0216. robert.schafer@colorado.edu

Save