Summary: One of the mysteries of the public climate change debate (now encompassing extreme weather) is the reliance of journalists and interested people on fringe sources when NOAA and the other climate agencies produce clear and timely articles. Such as NOAA’s about this El Niño, including this new one that tells us about this important weather event — and debunks much of what you’ve been told.
By Emily Becker, climate scientist at NOAA, 11 February 2016
Despite getting a little boost from some strong winds across the tropical Pacific Ocean in January, the warmer-than-average ocean temperatures that drive El Niño have likely peaked. Now that we’re looking out from the other side of the mountain, let’s answer some questions.
Is this the strongest El Niño on record?
This is definitely one of the strongest three going back to 1950. It’s hard to say definitively what single El Niño is the strongest, because there are many different ways to measure strength.
The Oceanic Niño Index, the three-month-average sea surface temperature departure from the long-term normal in one region of the Pacific Ocean, is the primary number we use to measure the ocean part of El Niño, and that value for November – January is 2.3°C, tied with the same period in 1997-98. There are other areas of the ocean that we watch, though, including the eastern Pacific (warmer in 1997/98) and the western Pacific (warmer in 2015/16).
Also, don’t forget the “SO” part of the El Niño/Southern Oscillation (ENSO), which is the all-important atmospheric response. All that extra heat in the tropical Pacific Ocean warms up the atmosphere above it, leading to more rising air, which changes the circulation all around the globe. By one measure (the EQSOI), the El Niño-related changes in the atmospheric circulation in 1997/98 and 2015/16 are tied; by another (the SOI), 1997/98 was stronger.