May 27, 2013
Weather And Climate: El Nino Phases And Locations
Now is the time to move on from the sun’s solar impact on our climate. In this post we will look at the process known as ENSO. We will look at the El Niño phase with this blog and some of the documented impacts that can occur and have occurred in past El Niño events. El Niño is an important topic to understand as we talk about climate due to the large impacts that it can have on any given place on Earth.
First, it is important to know that the actual ENSO process takes place and occurs in the Pacific Ocean, however it has global impacts. We look at the tropical waters off the coast of Peru and along the tropical belt that extends all the way across the Pacific Ocean. Did you know that we have multiple El Niño phases and regions that can take place? In this post we are going to look at the El Niño (East base) and also the El Niño (West base).
El Niño (East base) takes place when the waters off the coast of Peru warm well above their average temperatures, which can impact fishing operations along the coast of Peru. The El Niño (West base) takes place further out in the Pacific, but still has global impact.
I am also going to evaluate both of these El Niños for one location on the globe: Biloxi, MS.
Let’s start with the East-based El Niño, the event that takes place off the coast of Peru. Here are some impacts that have taken place for Biloxi MS. This type of El Niño has been more common on the way towards Solar Minimums. Temperatures with this type of El Niño have given the Biloxi, MS region an average of 0.5-1.0F below normal temps. The second thing that is important with El Niño is its strength. The average strength of this type of East-based El Niño has been 1.4. While the highest observed was 2.0, this occurred in 1973, which was near the Solar Minimum. This gave Biloxi an average November temperature that year of 79F, while the average for the region is 79.5, so just slightly cooler than average for the month. However, in 1977, another East-based El Niño took place. This time the results were much different. The strength of this El Niño was around 0.5, which is low, and caused the temperatures in Biloxi, MS to be an average of 75F, which is 4.5 degrees below normal. The weakness of the El Niño could be possibly blamed for the colder temperatures. So, to summarize an East-based El Niño will bring colder temperatures to Biloxi, MS.
Now, let’s look at a West-Based El Niño. This would be an El Niño that sets up further west in the Pacific. These types of El Niños were popular when we were heading into Solar Maximum. The impacts for Biloxi during this type of El Niño brought the average temperatures down to around 2.0-2.5 degrees below normal. The highest El Niño for this region during this time occurred in the year of 2009. The value of that El Niño was 1.5, the results for Biloxi was the temperatures were about 2.5 degrees below normal during that period. While a weaker, 1.0 El Niño occurred in 1969, this caused Biloxi to see an average temperature for the month at 78F, which is 1.5 degrees below normal. So, a stronger West-based El Niño kept Biloxi cooler than a weaker West-based El Niño.
Both of these findings are huge in that now I can observe the El Niño patterns and better create long range forecast for this region.
Here are a few other key findings in this research.
First, if an El Niño occurs near a Solar Maximum and has a strength of 0.5-1.0, this will likely take place in regions that are experiencing droughts. During an El Niño period, these regions will have larger chances of seeing the drought worsen or expand in coverage.
Second, during a 1.0-2.2 El Niño and entering a Solar Minimum, it would likely occur in places that flood and are cold. During an El Niño, these areas could see both of those conditions worsen.
Third, with an El Niño between 1.0-2.2 and near a Solar Minimum, the places that are dry and warm will see smaller impacts, such as drought conditions not getting much stronger. Lastly, during a 0.5-1.0 El Niño and near a Solar Maximum, impacts will be smaller on the cold and wet locations, such as lesser extreme weather.
Now this gives us a little more understanding on how the West versus East-based El Niño, the strength of El Niño and where it occurs in regards to the solar cycle can impact our weather.
Image Credit: Thinkstock.com