Low-level circulation during the 1979 Indian summer monsoon

The GARP Monsoon Experiment (MONEX) provided a unique set of observations during the months May, June, July and August 1979, to study the Indian summer monsoon. Data sets from different platforms were collected during this period. In this paper, these platforms are reviewed and their data are presented with a special emphasis on the non-conventional ones : geostationary satellite (GOES), constant-level balloons (BALSAMINE Experiment) and instrumented aircrafts. Some results on the low-level circulation over the Arabian Sea as deduced from these observations are given. In 1979, the onset of the monsoon was very late and took place around mid-June. It was characterized by the formation of a vortex off the western coast of India and its later westward displacement over the Arabian Sea.