Somali Jet in the Arabian Sea, El Nino, and India rainfall

Interannual variations of the Somali Jet in the Arabian Sea during 1988-99 were linked to El Nino and La Nina episodes and to India west coast rainfal l. Onset dates and monthly mean strengths of the Somali Jet were described with Special Sensor Microwave Imager surface wind speeds. Each year the Som ali Jet formed in a similar area in the western Arabian Sea, and always bef ore the onset of monsoon rainfall in Goa. The average date of Somali Jet on set was two days later in El Nino events in comparison with La Nina conditi ons. Monthly mean strength of the Somali Jet was 0.4 m s(-1) weaker during El Nino episodes than during La Nina intervals. When the monthly mean inten sity of the Somali Jet was above (below) normal, there was an excess (defic it) of rainfall along the Indian west coast.