Articles | Volume 34, issue 4
Ann. Geophys., 34, 411–419, 2016
https://doi.org/10.5194/angeo-34-411-2016
Ann. Geophys., 34, 411–419, 2016
https://doi.org/10.5194/angeo-34-411-2016

Regular paper 12 Apr 2016

Regular paper | 12 Apr 2016

Latitudinal variability of the quasi-16-day wave in the middle atmosphere over Brazilian stations

Amitava Guharay1, Paulo Prado Batista2, Barclay Robert Clemesha2, Ricardo Arlen Buriti3, and Nelson Jorge Schuch4 Amitava Guharay et al.
  • 1Space and Atmospheric Sciences Division, Physical Research Laboratory, Ahmedabad, GJ, India
  • 2Aeronomy Division, National Institute for Space Research, INPE, São José dos Campos, SP, Brazil
  • 3Federal University of Campina Grande, Campina Grande, PB, Brazil
  • 4Southern Regional Space Research Center, Santa Maria, RS, Brazil

Abstract. A comparative study of the quasi-16-day wave (QSDW) in the middle atmosphere using meteor radar observations and reanalysis data from three Brazilian stations, Sao Joao do Cariri (7.4° S, 36.5° W) (CA), Cachoeira Paulista (22.7° S, 45° W) (CP), and Santa Maria (29.7° S, 53.7° W) (SM) has been carried out in the year 2005 to delineate its latitudinal variability characteristics. The broad spectral behavior around 16-day periodicity may indicate multiple modes of the concerned wave component. The wave amplitude shows a number of peaks over the year with the largest one in summer and winter in the case of mesosphere–lower thermosphere (MLT) and stratosphere, respectively. A potential coupling of the concerned wave with other short period planetary waves, especially at CA and CP is evinced. Although zonal propagation exhibits both eastward as well as westward waves there is a general preference of eastward waves at mid-latitude and westward waves at tropical latitudes. The prevailing westerly background wind in the middle atmosphere is conceived to favor the wave filtering of westward propagating Rossby waves at lower latitude.

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Short summary
A comparative study of the quasi-16-day wave in the middle from three Brazilian stations, indicates multiple modes of the concerned wave component. The wave amplitude shows maxima in summer and winter. A potential coupling of the concerned wave with other short period planetary waves is found. The dominant wave components vary from the westward to eastward from the tropical to mid-latitude in the stratosphere. The prevailing westerly wind may favor the wave filtering of westward waves.