|Why the NOI?
The SOI is a good indicator of tropical variations related to El Niño and
La Niña, but it may not be the best way to represent global interannual to
decadal variability, particularly at extratropical latitudes. Here are two main
It is more straightforward and intuitive to use an index that complements the SOI, but also has a physical connection to the
extratropics. Alternatives and supplements to the SOI should be considered,
both for extratropical diagnosis of interannual/decadal variability and to
better understand the processes responsible for global-scale shifts in
atmospheric and oceanic conditions.
- The extratropical impacts of El Niño/La Niña are
poorly understood and more correlative than mechanistically linked
- The SOI does not have a direct physical link to the northeast Pacific region.
The NOI ia a reliable indicator for monitoring and predicting climate fluctuations, and their
physical and biological consequences in the Northeast Pacific.