INDOEX: Indian Ocean Experiment

Summary

The Indian Ocean Experiment (INDOEX) is a focused field experiment in the Indian Ocean with international participation from the United States, Europe, and the Indian Ocean Region. INDOEX addresses questions of climate change that are of high priority and of great value to the US and the international community. The project's goal is to study natual and anthropogenic climate forcing by aerosols and feedbacks on regional and global climate. The three month Intensive Field Phase (IFP) operated from 1 January through March 1999 with research aircraft flights and ship cruises conducted during various times within the IFP. The Operations Center was located in Male, Maldives. More information on the INDOEX Project can be found at the World Wide Web (WWW) "Home Page" from INDOEX (http://www-indoex.ucsd.edu/).

Objectives:

INDOEX has three interrelated scientific objectives: (1) Assess the significance of sulfates and other continental aerosols for global radiative forcing; (2) Assess the magnitude of the solar absorption at the surface and in the troposphere including the Intertropical Convergence Zone (ITCZ) cloud systems; and (3) Assess the role of the ITCZ in the transport of trace species and pollutants and their resulting radiative forcing. The first objective will contribute to a better understanding of the decadal and longer time scale forcing; the second will lead to improved coupled ocean-atmosphere models; and the third will aid in the development of tropospheric chemistry models. The equatorial Indian Ocean during the northeast monsoon season is a unique natural laboratory for addressing these objectives. The selected experiment area is probably the only place in the world where an intense source of continental aerosols, anthropogenic trace species and their reaction products (e.g., sulfates and ozone) from the northern hemisphere is directly connected to the pristine air of the southern hemisphere by a cross equatorial monsoonal flow into the ITCZ. Furthermore, the deep convection within the ITCZ gives rise to extensive mid- and upper-level cloud systems.