The September, 2002 eruption of Ruang was the largest in Indonesia for many years. The eruption cloud reached a height of approximately 20 km, and was well observed by satellites sensors.

Ash dispersed towards Singapore (cloud 'B' on the animation below) and Jakarta (cloud 'C'), with a higher level cloud 'D' nearly stationary near the tropopause (the top of the troposphere, where most of the Earth's weather occurs), and the highest cloud 'E' moving eastwards in the stratosphere. The colours in the GMS-5 animation reflect the strength of the ash signal detected.

This eruption was very valuable for testing satellite techniques, and producing experimental images such as the one below, using NOAA/AVHRR data to highlight cold thunderstorm tops in yellow, and the ash cloud in pink.