MarkoBoquete Posted February 20, 2016 Share Posted February 20, 2016 (edited) The large el Niño that has vexed Panama (and delighted California) for the last two years is dissipating very rapidly. NOAA is out with a prediction that it will be replaced by a rather strong la Niña as this year progresses. What does it mean for Panama? Just to review, el Niño and la Niña together are called ENSO for short (El Nino Southern Oscillation). Somewhat simplified, the Westerly equatorial winds blow surface water toward the Pacific Warm Pool, stretching from Australia to about Korea. As it travels almost halfway around the world, it is heated by the sun. In fact, the sea level in Indonesia is about 1 meter higher than in Panama, due to the piling up of windblown water. When the winds stop or reverse for a moment, it triggers a massive ¨sloshing¨ of warm water back across the equator, an el Niño. The warm water heats the atmosphere and creates measurable global warming. When the big slosh is over, el Niño is generally followed by the opposite, la Niña. The Westerly equatorial winds increase, blowing surface water from Latin America back toward Indonesia. In the process, cold water is pulled up from the deep ocean along the west coast of South and Central America. This cold water cools the atmosphere. The massive ENSO oscillation is the largest and most influential single weather phenomenon on the earth. It creates measurable and sometimes dramatic shifts in temperature and rainfall around the world and is a major driver of short to medium term climate change. No one knows or can predict the timing or severity of the cycles, although they appear to fall into periods of one, then the other. On the chart below, notice the predominance of la Niña events during the 70s until about 1990, compared with more recent prevalence of el Niño, including the giant one in 97/98 and the one we are just coming out of now. Zooming in, we can look to see if there is a correlation with what we have seen right here in Panama. The 97/98 el Niño was recorded by the water authorities in Panama as a drought. During 2015-2016 we have experienced another drought coincident with the current large el Niño. The big flood of 2008 happened right in the middle of a large la Niña. So, looking forward, we can expect more rain in the next couple of years. The cold, nutrient-rich water being pulled up from the deep is heaven for fish, which should return to Panama once again. For Panama, there is no such thing a "normal" weather. The fascinating thing is that while rain and wind swirl unpredictably around us, the temperature remains absolutely constant, day and night, year by year. It's almost as if we are living in the Earth's thermostat. Maybe we are. Edited February 20, 2016 by MarkoBoquete 2 Quote Link to comment Share on other sites More sharing options...
TwoSailors Posted February 20, 2016 Share Posted February 20, 2016 Let's hope this pans out and it is a medium la Nina and not a major one. Great report Marko! Quote Link to comment Share on other sites More sharing options...
JohnF13 Posted February 21, 2016 Share Posted February 21, 2016 Thanks for the explanation, Mark. Made it easy for me to understand. Quote Link to comment Share on other sites More sharing options...
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