Abstract
Longitudinal dependences of stratospheric GW (gravity wave) fluctuations and lower ionospheric irregularities (sporadic E) at mid latitudes are studied by means of radio occultation data of the GPS/MET satellite mission. The zonal average of temperature variance of GW fluctuations with vertical scales less than 7 km at northern mid latitudes is observed to be similar to that at southern mid latitudes, but there is a significant interhemispheric difference in the longitudinal dependence of GW fluctuations. The GPS/MET data at northern mid latitudes show a rapid change of the gravity wave distribution from 25 to 35 km height, resulting in a broad maximum of temperature variance located over Atlantic and Eurasia. We only find in the wave distribution at h=25 km some weak traces of possible orographic effects. On the other hand, the distribution of GW fluctuations at southern mid latitudes has a strong and sharp maximum over Andes which is obviously due to orographic wave generation by interaction of surface wind with the Andean mountain ridge. This observation of the new GPS radio occultation technique is in agreement with previous measurements of spaceborne microwave and infrared limb sounders. The amplitude of the average wave field increases with height over Andes, while the amplitude maximum moves westward, against the prevailing wind. The temperature fluctuations have an apparent, dominant vertical wave length of around 6 km. In situ measurements by a balloon-borne rawinsonde at Ushuaia, Argentina (54.7°S, 68.1°W) are compared to a simultaneous GPS/MET temperature profile. The balloon observations of temperature and horizontal wind are interpreted by a large amplitude mountain wave propagating to the upper stratosphere. Finally, the GPS/MET experiment indicates enhanced sporadic E in the lower ionosphere over Southern Andes. We assume that these plasma irregularities are generated by enhanced, upward wave flux due to the possible orographic effect of Andes.
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References
de la Torre A, Alexander P (1995) The interpretation of wavelengths and periods as measured from atmospheric balloons. Journal of Applied Meteorology 34: 2747–2756
de la Torre A, Teitelbaum H, Vial F (1996) Stratospheric and tropospheric wave measurements near the Andes mountains. J Atmos Terr Phys 58: 521–530
Eckermann SD, Preusse P (1999) Global measurements of stratospheric mountain waves from space. Science 286: 1534–1537
Fritts DC, Nastrom GD (1992) Sources of mesoscale variability of gravity waves, II, Frontal, convective, and jet stream excitation. J Atmos Sci 49: 111–127
Gill AE (1982) Atmosphere-ocean dynamics. Academic Press, New York
Gossard EE, Hooke WH (1975) Waves in the atmosphere. pp. 457, Elsevier, Amsterdam
Hines CO (1960) Internal gravity waves at ionospheric heights. Can J Phys 38: 1441–1481
Hocke K, Tsuda T (2001) Gravity waves and ionospheric irregularities over tropical convection zones observed by GPS/MET radio occultation. Geophys Res Lett 28: 2815–2818
Hocke K, Igarashi K, Nakamura M, Wilkinson P, Wu J, Wickert J (2001) Global sounding of sporadic E layers by the GPS/MET experiment. J Atmos Solar-Terr Phys 63: 1973–1980
McLandress C, Alexander MJ, Wu DL (2000) Microwave limb sounder observations of gravity waves in the stratosphere: a climatology and interpretation. J Geophys Res 105: 11947–11962
Meriwether JW, Biondi MA, Herrero FA, Fesen CG, Hallenback DC (1997) Optical interferometric studies of the nighttime equatorial thermosphere: Enhanced temperatures and zonal wind gradients. J Geophys Res 102: 20041–20058
Nastrom GD, Fritts DC (1992) Sources of mesoscale variability of gravity waves, I, Topographic excitation. J Atmos Sci 49: 101–110
Preusse P, Eckermann SD, Offermann D (2000) Comparison of global distributions of zonal-mean gravity wave variance inferred from different satellite instruments. Geophys Res Lett 27: 3877–3880
Preusse P, Eidmann G, Eckermann SD, Schaeler B, Spang R, Offermann D (2001) Indications of convectively generated gravity waves in Crista temperatures. Adv Space Res 27: 1653–1658
Sato K (1993) Small-scale wind disturbances observed by the MU radar during the passage of Typhoon Kelly. J Atmos Sci 50: 518–537
Satomura T, Sato K (1999) Secondary generation of gravity waves associated with the breaking of mountain waves. J Atmos Sci 56: 3847–3858
Tan K-A, Eckermann SD (2000) Numerical simulation of mountain waves in the middle atmosphere over South Andes, Atmospheric science across the stratopause. AGU monograph 123: 311–318
Tsuda T, Nishida M, Rocken C, Ware RH (2000) A global morphology of gravity wave activity in the stratosphere revealed by the GPS occultation data (GPS/MET). J Geophys Res 105: 7257–7273
Whitehead JD (1960) Formation of the sporadic E layer in the temperate zones. Nature 188: 567
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de la Torre, A., Tsuda, T., Hocke, K., Giraldez, A. (2004). Stratospheric Gravity Wave Fluctuations and Sporadic E at Mid-latitudes with Focus on Possible Effects of the Andes. In: Kirchengast, G., Foelsche, U., Steiner, A.K. (eds) Occultations for Probing Atmosphere and Climate. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-662-09041-1_31
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DOI: https://doi.org/10.1007/978-3-662-09041-1_31
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