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Volume 61 Supplement 4

Special Issue: Coupling Processes in the Equatorial Atmosphere (CPEA)

Validity on radar observation of middle- and upper-atmosphere dynamics

Abstract

Doppler radar observations have made a large contribution towards improving our understanding of middle- and upper-atmosphere dynamics. This radar echo is mainly due to radiowave scattering by atmospheric turbulence, which occurs almost universally throughout the atmosphere as a result of gravity wave (GW) breaking. In the strictness sense, the radar pulse is back-scattered by radio refractive index (RRI) perturbations caused by turbulence whose size along the radar beam is half of the radar wavelength. Understanding of the validity of the MST (mesosphere, stratosphere and troposphere)-radar observation requires a precise knowledge of how RRI perturbations are formed and behave. A basic property of the RRI of the atmosphere is that it has a static vertical gradient in terms of distribution and the turbulence velocity is divergence-free. The RRI depends on three atmospheric properties—humidity, air density and electron density. These three elements each have a static vertical gradient along which turbulence transports each element, hereby perturbing the density distribution of each element; that is to say, it produces the RRI irregularity for scattering the radar pulse. Since the turbulence motion and winds are divergence-free, PRI perturbation co-moves with the total air flow, i.e. turbulence motion plus winds. This can be true even in the mesosphere where the perturbation is controlled electromagnetically. Co-movement of turbulence with local winds has been shown from a comparison of observations with radars and radiosondes. In addition to tracking turbulence as wind-tracers, MST-radar observations provide important data in the study of atmosphere turbulence dynamics.

References

  • Balsley, B. B. and K. S. Gage, The MST techniques: potential for middle atmosphere studies, Pure Appl. Geophys., 118, 452–493, 1980.

    Article  Google Scholar 

  • Batchelor, G. K., The theory of homogeneous turbulence, pp. 46 and 114–132, Cambridge Monograph on Mechanics and Applied Mathematics, Cambridge Univ. Press, 1953.

    Google Scholar 

  • Hasiguchi, H., Development of an L-Band clear-air Doppler radar and its Application to planetary boundary layer observations over equatorial Indonesia, p. 10, PhD thesis, Kyoto University, January, 1995.

    Google Scholar 

  • Hocking, W. K., Measurements of turbulent energy dissipation rates in the middle atmosphere by radar techniques, A review, Radio Sci., 20, 1403–1422, 1985.

    Article  Google Scholar 

  • Holton, J. R., An introduction to dynamic meteorology (3rd edition), p. 47, Academic Press, San Diego, New York, Boston, London, Sydney, Tokyo, Toronto, 1992.

    Google Scholar 

  • Kato, S., Theory of movement of irregularities in the ionosphere, Space Sci. Rev., 4, 223–235, 1965.

    Article  Google Scholar 

  • Kato, S., Dynamics of the upper atmosphere, (a) pp. 141–150 (b) pp. 213–215, Center Acad. Publ/D. Reidel Publ, Japan/Dordrecht, Boston, London, 1980.

    Google Scholar 

  • Kato, S., Middle atmosphere research and radar observation, Proc. Jpn. Acad. Ser. B, 8, 306–320, 2005.

    Article  Google Scholar 

  • Lehmacher, G. A., C. L. Croskey, J. D. Michell, M. Friedrich, F.-J. Lueben, M. Rapp, E. Kudeki, and D. C. Fritts, Intense turbulence observed above a mesospheric temperature inversion at equatorial latitude, Geophys. Res. Lett., 33(8), L08808, 2006.

    Article  Google Scholar 

  • Luce, H., S. Fukao, M. Yamamoto, C. Sidi, and F. Dalaudier, Validation of winds measured by GPS radiosondes during the MUTSI Campaign, J. Atmos. Oceanic Tech., 18, 817–829, 2001.

    Article  Google Scholar 

  • Maekawa, Y., S. Fukao, M. Yamamoto, M. D. Yamanaka, T. Tsuda, S. Kato, and R. F. Woodman, First observation of the upper stratospheric vertical wind velocities using the Jicamarca VHF radar, Geophys. Res. Lett., 20, 2235–2238, 1993.

    Article  Google Scholar 

  • Rastogi, P. K. and S. A. Bowhill, Scattering of radio waves from the mesosphere-2, Evidence for intermittent mesospheric turbulence, J. At-mos. Terr. Phys., 38, 449–462, 1976.

    Article  Google Scholar 

  • Tatarskii, V. I., The effect of the turbulent atmosphere on wave propagation, National Technical and Information Service, pp. 74–76, Springer-field, Va, 1971.

    Google Scholar 

  • Villars, F. and V. F. Weisskopf, The scattering of electromagnetic waves by turbulent atmospheric fluctuations, Phys. Rev., 94, 232–240, 1954.

    Article  Google Scholar 

  • Woodman, R. F. and A. Guillen, Radar Observation of Winds and Turbulence of the Stratosphere and Mesosphere, J. Atmos. Sci., 31, 493–505, 1974.

    Article  Google Scholar 

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Correspondence to Susumu Kato.

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Kato, S. Validity on radar observation of middle- and upper-atmosphere dynamics. Earth Planet Sp 61, 545–549 (2009). https://doi.org/10.1186/BF03353171

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  • DOI: https://doi.org/10.1186/BF03353171

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