ENSO and Global Warming

Some of you may have heard of El Nino. Some may have heard of La Nina. The number of people worldwide who are catching drift of this phenomenon is constantly growing. The formal term is defined as ENSO. El Nino Southern Oscillation (ENSO) has been recorded dating back to the 1500s when a Peruvian Fisherman named it El Nino, or, "Christ Child." ENSO has been known to cause some of the most damaging climactic effects throughout history, being responsible for droughts, floods, famine, and wind damage everywhere in the world. How can a couple of gusts of wind be so damaging? Let's first take a look at ENSO and what it really is.

ENSO is caused by temperature fluctuations in the surface waters of the Eastern Pacific Ocean. This doesn't mean that ENSO only affects North America. The climate changes that affect North America happen on such a large scale that other parts of the world are affected. Our Earth must be able to function at a balanced level. This means too much of an extreme will cause major damage to one side of the earth which will have repercussions all throughout the globe. For example, sometimes ENSO will bring large amounts of water and rain into the Americas, leaving the Eastern part of Asia and Australia extremely dry. Dry to the point of lakes being totally empty. ENSO is associated with floods, droughts, and other disturbances in a range of locations around the world. These effects, and the irregularity of the ENSO phenomenon, makes predicting it of high interest. ENSO is the most prominent known source of inter-annual variability in weather and climate around the world. ENSO has significant impact on the Pacific and Indian Oceans.

The classifications for ENSO are in two categories: Cold (La Nina) and Warm (El Nino). This causes damaging effects on the Americas, and Asia will experience the opposite. One instance is El Nino. The general wind direction of the world is to the East (Eastern Trade Winds). When El Nino gathers up, it will push the Eastern Trade Winds back over itself (since El Nino comes in from the Pacific Ocean). This will drag the water that has already gone West back east again, successfully lowering the isotherm of the Pacific Ocean. An isotherm is when pressure balances out in the Ocean. When the isotherm is lower, the upwelling of nutrients cannot reach the surface it should be at, resulting in a dying of aquatic life and huge detriments on the fishing industry.

With this being said, El Nino will now enter the Americas. As the warm winds blow in, the bottom half of the United States will experience huge rainfall and flooding. In 1982-1983 (one of the largest ENSO years ever), the Mississippi River flooded causing millions of dollars in damage. California experienced an excess of flooding and major mudslides. The Northern Part of the United States will have a much warmer winter, causing ice to melt and floods. The Colorado Rockies had record snowfall in 1982 coupled with Warm El Nino winds, causing major flooding as well.

All this is happening on the Eastern Side of the globe, while on the west dry spells are experienced everywhere. Australia had its worst year in 1982 as well, with a huge portion of its water supply being depleted, animals were dying as well as crops. An estimate was that $81.2 million in damages was caused. So these effects from ENSO have global implications.

La Nina is, you guessed it, the exact reverse of El Nino. Cold Winds blow into the Americas, causing extremely dry periods in the Midwest, affecting crops and killing off a lot of profits. Asia, meanwhile, will experience extremely warm and wet seasons, inducing the formation of hurricanes, typhoons, and cyclones.

The main trend that I wanted to point out was that in the recent years 1976-Present, we have had nothing but El Nino winds with very few La Ninas. What could be causing this? One correlation scientists have found was that global warming could be a cause, but just because there is correlation does not mean there is causation. The tracking of ENSO winds have only been really organized and recorded for not even a century, so this could just be attributed to a random fluctuation or variation in ENSO itself. Or, it could be that the increase in temperature of the Earth itself is causing only warm winds to be formed in the ENSO cycle.

Either way you put it, global warming has become a huge problem in the world of today. Both Presidential candidates find the need to address this issue, as it is causing so much damage here and abroad. For more information, you can check out these websites:

http://www.ucar.edu/communications/quarterly/winter97/connection.html

http://www.physorg.com/news117381762.html

http://www.knmi.nl/research/global_climate/enso/global_warming/