Equatorial Line Observations


Part of Years of Martime Continent Project

ELO Science Topics and Objectives

Science topics and objectives to be directly addressed as part of ELO include

1. The vertical structure and variability of convective heating over the MC: to investigate the mean diurnal evolution of vertical structure of convective heating over Sumatra and Borneo and determine their changes before, during and after convective events such as CCKWs and MJO;

2. The upper ocean diurnal cycle in eastern Indian Ocean and Karimata Strait and their impact on development and evolution of convection: to investigate the evolution of upper ocean stratification, its diurnal evolution and intraseasonal-variability associated with local diurnal convection, breeze circulation and propagating convective envelopes and to assess the impact of increased heat flux from ocean to the atmosphere on convection development;

3. The coupling between diurnal cycle of convection over Sumatra and westward propagating gravity waves: to investigate the interaction between land, atmospheric and oceanic processes via convection development and off-shore propagation and to investigate the convection development over Sumatra, its daytime progression towards the coast and off-shore nighttime propagation in relation with diurnal warm layer development over eastern IO and large-scale variability (CCKWs, MJO).



Nelly Florida, Marine Meteorology Center, The Agency of Meteorology Climatology and Geophysics, BMKG, Indonesia

Erwin Makmur, Deputy Director of Meteorology Research Division, BMKG, Indonesia


Adrian Matthews, School of Environmental Sciences, University of East Anglia, Norwich, UK

Karen Heywood, School of Environmental Sciences University of East Anglia, Norwich, UK


Piotr Flatau, Scripps Institution of Oceanography, La Jolla CA, USA

Janet Sprintall, Scripps Institution of Oceanography, La Jolla CA, USA


Dariusz Baranowski and Beata Latos: Institute of Geophysics, Polish Academy of Sciences, Warsaw, Poland

Project Description :

The Maritime Continent (MC) is arguably the most important region in the global weather and climate system, in terms of forcing global atmospheric variability on sub-seasonal to decadal time scales. However, the interactions of the atmosphere, ocean and land surfaces in the MC region are sparsely observed, badly represented in our models and so there remain large gaps in our knowledge of the physical processes that contribute to the coupled variability in this region. Recent work has identified that the multi-scale interactions between the Madden-Julian Oscillation (MJO), convectively coupled Kelvin waves (CCKWs) and the diurnal cycle over the MC are important and poorly understood.

In this project, the interactions within atmospheric equatorial convectively coupled Kelvin waves (CCKWs), the leading modes of eastward moving convection on time scales between several days and three weeks, will be investigated. CCKWs and other equatorial waves form the “building blocks” of the active phase of MJO. The main effort will be to organize and execute the Equatorial Line Observations (ELO) field campaign during the winter of 2018/2019 – as a component of the International Years of the Maritime Continent (YMC) program. Based on collected in-situ data as well as other observational, remote sensing and modeling datasets, the key physical mechanisms responsible for multi-scale interactions associated with the propagating atmospheric convection over the Maritime Continent will be analyzed. To this end, a novel Lagrangian approach in the analysis of propagating events will be employed to study the interaction between tropical waves and the local atmospheric and oceanic environment, in particular over the MC region.