Skip to main content

Volume 61 Supplement 4

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

Temporal and spatial distributions of atmospheric wave energy in the equatorial stratosphere revealed by GPS radio occultation temperature data obtained with the CHAMP satellite during 2001–2006

Abstract

Using stratospheric temperature profiles derived from GPS radio occultation (RO) measurements made by the German CHAMP satellite from June 2001 to May 2006, we studied the climatological behavior of atmospheric wave activity in the tropics. The wave potential energy, Ep, is calculated from temperature fluctuations with vertical scales shorter than 7 km in a longitude and latitude cell of 20° × 10° at 19–26 km. Ep is then averaged every 3 months (June–July–August (JJA), September–October–November (SON), December–January–February (DJF), March–April–May (MAM)), and the averages are compared with the cloud top temperature from outgoing long-wave radiation (OLR) and the convective rain rate from the TRMM precipitation radar (PR). Ep at 19–26 km in the western Pacific to Indian Ocean is found to show a clear seasonal variation, with a large Ep during DJF and MAM and a considerably enhanced Ep in SON; it becomes minimum during JJA near the equator, when the center of the enhanced Ep region appears over north India and the Indochina peninsula. Localized enhancement of Ep seems to be mainly due to atmospheric gravity waves. In addition, the longitudinally elongated portion of Ep is partially affected by Kelvin wave-like disturbances with short horizontal scales. In DJF and MAM, the convective clouds are located over the western Pacific and around Indonesia, at which time the Kelvin wavelike disturbances are effectively generated. The spatial and seasonal variations of Ep are closely related to the distribution of clouds, implying that convective wave generation is very important in the tropics. However, wave-mean flow interactions due to the wind shear of the QBO become important in the lower stratosphere, which considerably modifies our analysis of the Ep distribution at 19–26 km. Therefore, both wave generation and propagation characteristics must be taken into account in describing the climatological behavior of atmospheric wave activity in the equatorial stratosphere.

References

  • Alexander, S. P., T. Tsuda, Y. Shibagaki, and T. Koze, Seasonal Gravity Wave Activity Observed with the Equatorial Atmosphere Radar (EAR) and its relation to the Tropical Rainfall Measuring Mission (TRMM), J. Geophys. Res., 113, D02104, doi:10.1029/2007JD008777, 2008.

    Google Scholar 

  • de la Torre, A., T. Schmidt, and J. Wickert, A global analysis of wave potential energy in the lower stratosphere derived from 5 years of GPS radio occultation data with CHAMP, Geophys. Res. Lett., 33, L248009, doi:10.10292/2006GL027696, 2006.

    Google Scholar 

  • Fritts, D. C. and M. J. Alexander, Gravity wave dynamics and effects in the middle atmosphere, Rev. Geophys., 41, doi:10.1029/2001RG000106, 2003.

  • Hei, H., T. Tsuda, and T. Hirooka, Characteristics of Atmospheric Gravity Wave Activity in the Polar Regions Revealed by GPS Radio Occultation Data with CHAMP, J. Geophys. Res., 2008 (in print).

    Google Scholar 

  • Hocke, K., T. Tsuda, and A. de la Torre, A study of stratospheric gravity wave fluctuations and sporadic E at mid latitudes with focus on possible orographic effect of Andes, J. Geophys. Res. (Atmos.), 107, doi:10.1029/2001JD001330, 2002.

  • Holton, J. R., M. J. Alexander, and M. T. Boehm, Evidence for short vertical wavelength Kelvin waves in the Department of Energy-Atmospheric Radiation Measurement Nauru99 radiosonde data, J. Geophys. Res., 106(D17), 20,125–20,130, 2001.

    Article  Google Scholar 

  • Kawatani, Y., K. Tsuji, and M. Takahashi, Zonally non-uniform distribution of equatorial gravity waves in an atmospheric general circulation model, Geophys. Res. Lett., 32, L23815, doi:10.1029/2005GL024068, 2005.

    Article  Google Scholar 

  • Kozu, T., T. Kawanishi, H. Kuroiwa, M. Kojima, K. Oikawa, H. Kumagai, K. Okamoto, M. Okumura, H. Nakatsuka, and K. Nichikawa, Development of precipitation radar onboard the Tropical Rainfall Measuring Mission (TRMM) satellite, IEEE Trans. Geosci. Remote Sens., 39(1), 102–116, 2001.

    Article  Google Scholar 

  • Randel, W. J. and F. Wu, Kelvin wave variability near the equatorial tropopause observed in GPS radio occultation measurements, J. Geophys. Res., 110, doi:10.1029/2004JD005006, 2005.

  • Ratnam, M. V., G. Tetzlaff, and C. Jacobi, Global and Seasonal Variations of Stratospheric Gravity Wave Activity Deduced from the CHAMP/GPS Satellite, J. Atmos. Sci., 61, 1610–1620, 2004.

    Article  Google Scholar 

  • Ratnam, M. V., T. Tsuda, T. Kozu, and S. Mori, Long-term behavior of the Kelvin waves revealed by CHAMP/GPS RO measurements and their effects on the tropopause structure, Ann. Geophys., 24, 1355–1366, 2006a.

    Article  Google Scholar 

  • Ratnam, M. V., T. Tsuda, Y. Shibagaki, T. Kozu, and S. Mori, Gravity Wave Characteristics over the Equator Observed During the CPEA Campaign using Simultaneous Data from Multiple Stations, J. Meteor. Soc. Jpn., 84A, 239–257, 2006b.

    Article  Google Scholar 

  • Sato, K. and T. J. Dunkerton, Estimation of momentum flux associated with equatorial Kelvin and gravity waves, J. Geophys. Res., 102, 26,247–26,261, 1997.

    Article  Google Scholar 

  • Tsai, H.-F., T. Tsuda, Y. Aoyama, G. A. Hajj, and J. Wickert, Equatorial Kelvin Waves Observed with GPS Occultation Measurements (CHAMP and SAC-C), J. Meteor. Soc. Jpn., 82(1B), 397–406, 2004.

    Article  Google Scholar 

  • Tsuda, T., Y. Murayama, H. Wiryosumarto, S. W. B. Harijono, and S. Kato, Radiosonde observations of equatorial atmosphere dynamics over Indonesia, Part II: Characteristics of gravity waves, J. Geophys. Res., 99, 10507–10516, 1994.

    Article  Google Scholar 

  • Tsuda, T., M. Nishida, C. Rocken, and R. H. Ware, A global morphology of gravity wave activity in the stratosphere revealed by the GPS occultation data (GPS/MET), J. Geophys. Res. (Atmos.), 105, 7257–7273, 2000.

    Article  Google Scholar 

  • Tsuda, T., M. V. Ratnam, T. Kozu, and S. Mori, Characteristics of 10-day Kelvin Wave Observed with Radiosondes and CHAMP/GPS Occultation during the CPEA Campaign (April–May, 2004), J. Meteor. Soc. Jpn., 84A, 277–293, 2006.

    Article  Google Scholar 

  • Wickert, J., Ch. Reigber, G. Beyerle, R. Koig, C. Marquardt, T. Schmidt, L. Grunwaldt, R. Galas, T. Meehan, W. Melbourne, and K. Hocke, Atmospheric soundings by GPS radio occultation: First results from CHAMP, Geophys. Res. Lett., 28, 3263–3266, 2001.

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Toshitaka Tsuda.

Rights and permissions

Open Access  This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made.

The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/.

Reprints and permissions

About this article

Cite this article

Tsuda, T., Venkat Ratnam, M., Alexander, S.P. et al. Temporal and spatial distributions of atmospheric wave energy in the equatorial stratosphere revealed by GPS radio occultation temperature data obtained with the CHAMP satellite during 2001–2006. Earth Planet Sp 61, 525–533 (2009). https://doi.org/10.1186/BF03353169

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1186/BF03353169

Key words