## Sunday, February 3, 2013

### The Math behind Climate Change: Part 4Better data about El Niño and La Niña years

On Friday, I proposed a system for making fair intervals on which to measure climate data. Looking around the Internet, I found a webpage about the Oceanic Niño Index, also known as ONI, that looks to be more thorough and informative. Based on that info, I make a new list of fair intervals.

Here is the list of strong La Niña and El Niño years, written in blue and red respectively.

1955 1957 1965 1972 1973 1975 1982 1988 1991 1997 1999 2010

The list of fair years to start and end has been reduced significantly, so I am going to modify the rules as to what constitutes the fair years to be at the beginning and end of an interval.

1. The beginning and end of a fair interval have to be the same type of years, either both Strong El Niño or both Strong La Niña.

2. There has to be one year between the start and end of a fair interval that is of the opposite type from the type used for the beginning and end year.

Example #1: 1973 and 1975 are both Strong La Niña years, but there was no Strong El Niño between them, so 1973-1975 would not count as a fair interval. The earliest year that would make a fair interval starting in 1973 would be 1988.

Example #2: 1957, 1965 and 1972 are three Strong El Niño years without an intervening Strong La Niña year to break them up. That means 1957-1965, 1957-1972 and 1965-1972 would not count as fair intervals.

Here is a list of what I call the Consistent ONI.

First, the usable La Niña intervals.

Starting in 1955:
1955-1973 1955-1975 1955-1988 1955-1999 1955-2010

Starting in 1973:
1973-1988 1973-1999 1973-2010

Starting in 1975:
1975-1988 1975-1999 1975-2010

Starting in 1988:
1988-1999 1988-2010

And the fair El Niño Intervals.

Starting in 1957
1957-1982 1957-1991 1957-1997

Starting in 1965
1965-1982 1965-1991 1965-1997

Starting in 1972
1972-1982 1972-1991 1972-1997

Starting in 1982
1982-1991 1982-1997

As you can see, if we want to talk about the 21st Century, the shortest Consistent ONI is 1988 to 2010. When the next strong El Niño year is confirmed, it will make 1999 to 20xx a Consistent ONI.

As the proposer of the system, I will admit this is a weakness. Human nature wants to know what is happening now. An option would be to make Moderately Consistent ONI and Weakly Consistent ONI. For example, 2011 was a weak La Niña year and the previous weak La Niña years were 2005 and 2000. Because the weak years are more plentiful, it would make sense not to go back just one previous weak year but two, so 2000-2011 could be called a Weakly Consistent ONI.

I'm not a climate scientist, just a mathematician. I have no standing in the community to make the Consistent ONI the industry standard. El Niño and La Niña patterns have an effect over a vast region in the Indian and Pacific Oceans and the land masses that border them. I will do some research to see if the Atlantic has a similar known warming-cooling trend and if they exist, I will propose fair intervals based on them, which would be of use for regions bordering the Atlantic, including the eastern parts of North and South America, the west coast of Africa and all of Europe.

Tomorrow, we will look at a typical region and the distribution of stations.