JEDDAH — Intensifying El Niño conditions may bring heavy and more frequent rainfalls over the Arabian Peninsula including Saudi Arabia, UAE, Oman and Yemen during the forthcoming winter and spring seasons, according to Professor Mansour Almazroui, Director, Center of Excellence for Climate Change Research (CECCR) of King Abdulaziz University (KAU) in Jeddah. “There is a noticeable shift in the Arabian Peninsula climate since 1980s,” Prof. Almazroui said, citing CECCR's recent published scientific findings. El Niño is the warm phase of the ENSO (El Niño Southern Oscillation) phenomenon. It is measured by the sea surface temperatures (SSTs) of the band of warm ocean water that develops in the central and east-central equatorial Pacific Ocean. The cold phase of ENSO is called La Niña with below average SSTs in the east-central equatorial Pacific. The ENSO cycle (El Niño and La Niña) causes global changes of temperature and rainfall patterns. Strong El Niño events in the past have contributed to weather extremes such as heavy rainfall causes floods, deficit rainfall causes droughts, abnormal high temperature causes heat waves etc., over many parts of the world. Elaborating on the CECCR findings, Prof. Almazroui said they reveal a recent change in the ENSO-Arabian rainfall relationship. Rainfall in the region used to have a negative and weaker ENSO relationship but that has been changing since the 1980s and it has now become stronger and positive, he says. This means that stronger El Niño events may bring more rainfall over the Arabian Peninsula. El Niño events also tend to increase the western disturbances over the Arabian Peninsula, which may contribute to an increase in the frequency and intensity of rainfall during the winter and spring seasons. Currently, SSTs over the east-central Pacific are above average and expected to intensify by 2°C or more above the historical normal in the ENSO region during the 2015/16 winter season. This El Niño event since April/May 2015 may well be the most intense since 1997/98, Prof. Almazroui says. The impact of ENSO “is likely to bring above normal rainfall over the southern mountainous regions as well as the northeastern regions of the Arabian Peninsula during the forthcoming winter and spring seasons”, the professor says, not ruling out enhanced dust storm activity as well over the Peninsula. — SG
