Record Details

Observational evidence of mixed rossby gravity waves at the central equatorial Indian Ocean

DRS at CSIR-National Institute of Oceanography

View Archive Info
 
 
Field Value
 
Title Observational evidence of mixed rossby gravity waves at the central equatorial Indian Ocean
 
Creator Muraleedharan, P.M.
PrasannaKumar, S.
Mohankumar, K.
Sijikumar, S.
Sivakumar, K.U.
Mathew, T.
 
Subject GEOLOGY AND GEOPHYSICS
OCEANOGRAPHY AND LIMNOLOGY
OCEANOGRAPHY AND LIMNOLOGY
OCEANOGRAPHY AND LIMNOLOGY
 
Description Six-hourly soundings (GPS sonde) were carried out at the central equatorial Indian Ocean (80º–83ºE) during 25th September–10th October 2011 under the CINDY2011 (Cooperative Indian Ocean Experiment on Intra-seasonal variability in Year 2011) field campaign. One-degree interval soundings were also taken along a meridional section at 83ºE from 5ºN to 5ºS during 12–20 October 2011 to supplement the time series data. Relative humidity (RH) and meridional wind component exhibit downward propagation of air mass in bands of high and low RH associated with northerly and southerly winds, respectively. Low (20–100 day) and high (2–10 day) frequency band pass filtered OLR data (NOAA-interpolated OLR) revealed the presence of Madden and Julian Oscillation (MJO) with 20- to 40-day periodicity, and weak Mixed Rossby Gravity (MRG) waves with 4- to 5-day periodicity. Eastward (westward) propagating MJO (MRG wave) with wave numbers 3–4 (4–5), amplitudes of anomaly 1.1–1.2 Wm-2 (1.8 Wm-2) were observed. The asymmetric bifurcation of warm surface water by the subsurface cold water off Sumatra generate asymmetric convective regimes in the vicinity of the equator probably triggered convection with periodicity similar to MRG waves. The intermittent surface convection associated is believed to be responsible for the ascending moisture to the middle troposphere prior to the initiation of MJO. The moisture pumped to the middle troposphere makes the layer convectively more unstable leading to the state of deep convection, a situation conducive for the MJO initiation processes
 
Date 2015-10-26T08:39:11Z
2015-10-26T08:39:11Z
2015
 
Type Journal Article
 
Identifier Meteorology and Atmospheric Physics, vol.127(4); 2015; 407-417
http://drs.nio.org/drs/handle/2264/4807
 
Language en
 
Rights An edited version of this paper was published by Springer. This paper is for R & D purpose and Copyright [2015] Springer.
 
Publisher Springer