By Paul Dorian, Vencore Weather
El Nino strengthened significantly during 2015 and peaked in December as one of the strongest such episodes in the past fifty years. Even though El Nino is a phenomenon characterized by unusually warm water in the equatorial Pacific Ocean, it can have ramifications around the world. In fact, global temperatures spiked during the last half of 2015 as a result of the strong El Nino and were still at very high levels relative-to-normal as recently as last month. In addition, global sea ice appeared to be impacted by El Nino as it took a steep dive during much of 2015 and remained at well below-normal levels going into this year. In the past couple of months, however, El Nino has begun to collapse and will likely flip to a moderate or strong La Nina (colder-than-normal water) by later this year. In rather quick fashion, global temperatures have seemingly responded to the unfolding collapse of El Nino and global sea ice has actually rebounded in recent weeks to near normal levels.
Global temperatures and global sea ice
The plot above shows global temperature anomalies from the latter part of 2014 through April 11, 2016 using NOAA’s Climate Data Assimilation System (CDAS). As El Nino began to strengthen dramatically during 2015, global temperature anomalies (black line) climbed significantly and that climb lasted right into early 2016. In recent weeks, however, as the collapse of El Nino has begun, global temperature anomalies have apparently responded by dropping rather sharply (indicated on plot above with arrow).
Meanwhile, global sea ice which had hovered relatively close-to-normal from 2013 into 2015, dropped sharply during the second half of last year to well below-normal levels as El Nino strengthened and global temperatures spiked (as indicated by left arrow on above plot). The plot of daily global sea ice anomalies (red) shows that in recent weeks global sea ice has surged back to near normal as the collapse of El Nino has unfolded [right arrow on above plot].