Observed Intraseasonal and Interannual Variability of Arabian Sea Warm Pool along the Gulf of Aden to Strait of Malacca shipping Lane during 1951–2010

Abstract

All the available historic surface marine meteorological data collected from Voluntary Observing Ships (VOS) in the tropical Indian Ocean during the period 1951–2010, archived by National Centre for Atmospheric Research, Boulder, Colorado, USA are assembled, quality controlled, processed and analyzed. Data for all the meteorological parameters stratified into 4° latitude by 1° longitude boxes, over five day durations, for all the 60 years are quality controlled, averaged and analyzed to portray the observed spatio-temporal evolution of all these parameters as Hovmoller diagrams for the Gulf of Aden to Strait of Malacca shipping lane. Two dimensional machine contouring is carried out with appropriate colour shading intensities to highlight the maxima and minima in the analyzed fields. The observed intraseasonal and interannual variability of these parameters is characterized along this shipping lane. These analyzed distributions amply highlight the observed variability of the surface meteorological parameters both on intraseasonal and interannual time scales during 1951–2010. Composites of SST and other marine meteorological parameters for strong and weak ASWP regimes, for strong and weak monsoon years, for El Nino (+1Y) and La Nina (+1Y) years and for Positive and Negative IOD (+1Y) years are presented.