The Twins (IMAGE) DOE/Pacific Northwest National Laboratory Caption On the left, La Nina cools off the ocean surface (greens and blues) in the winter of 1988. On the right, El Nino warms up it up (oranges and reds) in the winter of 1997. Credit Jin-Ho Yoon/PNNL Usage Restrictions Please credit Jin-Ho Yoon/PNNL License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.