WASHINGTON DC (13 Jan 2002) -- Recent patterns of warming surface waters in the eastern Pacific are heralding early warnings of a developing El Nino - a periodic weather anomaly that could have far-reaching effects on weather throughout the Pacific and Indian Oceans. NOAA's Climate Prediction Center officially announced this week that increased sea surface temperatures observed over the Tropical Pacific could lead to an El Nino by early spring. Enhanced cloudiness and precipitation are now occurring over the equatorial central Pacific for the first time since the 1997-98 El Nino episode. Indications for a warm episode, or El Nino, in the Tropical Pacific were first noted in August 2001. Global sea surface temperatures NOAA experts say that it is too early to predict the magnitude of the developing 2002 El Nino, or how long it would last. "The magnitude of an El Nino determines the severity of its impacts," said Vernon Kousky, NOAA climate specialist. "At this point, it is too early to predict if this El Nino might develop along the same lines as the 1997-98 episode, or be weaker," said Kousky. In normal years, the winds tend to blow from east to west across the waters of the tropical Pacific. The easterly winds push the surface waters westward across the ocean. In turn, this causes deeper, colder waters to rise to the surface. This "upwelling" of deep ocean waters brings with it the nutrients that otherwise would remain near the bottom. All marine life dwelling in surface waters - including fish populations - are ultimately dependent on the food chain supported by such nutrients for survival. | | During El Nino years, the winds weaken, causing the upwelling of deep water to cease. The consequent warming of the ocean surface further weakens the winds and strengthens El Nino. As the ocean warms, the warmer water shifts eastward and so do the clouds and thunderstorms that produce heavy rainfall along the equator. This results in changes in jet streams (winds aloft), which lead to dry conditions in Indonesia and Australia, and floods in Peru and Ecuador. El Nino events occur on average every 3 to 5 years. "The first region on the globe to experience El Nino's impacts (in 2002) would be in the tropical Pacific," said Kousky. "Indonesia is likely to realize some relief from torrential rains. The last El Nino took place in 1997-1998 and was extremely severe. In the U.S. it was marked by such conditions as flooding rains in California and along the Gulf Coast. Historically, El Nino episodes have occurred every two to seven years and can last up to 12 months. NOAA will continue to carefully monitor its evolution and provide monthly updates to the public. The next update is scheduled for early February 2002. © CDNN - CYBER DIVER NEWS NETWORKSCUBA FORUMDISCUSS THIS TOPIC - Dive in and have your say at Scuba Forum |
