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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Observations of the intraseasonal oscillations over two Brazilian low latitude stations: A comparative study

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Author(s):
Guharay, A. [1] ; Batista, P. P. [1] ; Clemesha, B. R. [1] ; Buriti, R. A. [2]
Total Authors: 4
Affiliation:
[1] INPE, Natl Inst Space Res, Sao Jose Dos Campos, SP - Brazil
[2] Univ Fed Campina Grande, Campina Grande, PB - Brazil
Total Affiliations: 2
Document type: Journal article
Source: JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS; v. 120, p. 62-69, DEC 2014.
Web of Science Citations: 4
Abstract

A comparative study of intraseasonal oscillations (ISO) in the period range 20-110 days is carried out in the mesosphere and lower thermosphere (MLT) zonal wind at two low latitude stations, Cariri (7.4 degrees S, 36.5 degrees W) and Cachoeira Paulista (22.7 degrees S, 45 degrees W) located far from the convective anomaly region. Considerable seasonal and interannual variability is observed. The ISO in the MLT and lower atmosphere are found to be well correlated during winter and spring indicating a coupling of the atmospheric regions through the ISO. On the other hand, relatively less correlation during summer and fall may suggest a dominance of the in situ excitation of the ISO in the MLT relative to the lower atmospheric contribution. The correlation between the MLT and lower atmosphere is found to be a little higher at Cachoeira Paulista than Cariri. The ISO in the MLT shows good correlation between the two stations, but correlation is insignificant in the case of lower atmosphere. The ISO is most prominent in the upper troposphere, upper stratosphere and MLT. The waves responsible for communicating the ISO signature from the troposphere to the middle atmosphere in the tropics are believed to refract through mid-latitudes in course of their propagation. An evident height variation of the high amplitude ISO in the upper troposphere is observed with a clear annual oscillation at Cariri. The observed behaviors of the ISO at the present sites are discussed in the light of plausible physical mechanisms. (C) 2014 Elsevier Ltd. All rights reserved. (AU)

FAPESP's process: 10/18645-0 - Investigation of middle atmospheric dynamics with the help of lidar, radar and airglow measurements over low latitude stations of Brazil
Grantee:Amitava Guharay
Support Opportunities: Scholarships in Brazil - Post-Doctoral