While researchers have long focused on El Nio -- warm ocean temperatures leading to odd spells of rain and dry weather -- climate experts are not sure what caused the winter deluges that struck northern California, Oregon and Washington in the us in the past two years. Was it the handiwork of El Nio's contrary, 'wicked sister' La Nia? Also called a cold event, La Nia begins with cooler-than-normal sea-surface temperatures in the tropical eastern Pacific and warmer water in the western Pacific. The temperature difference is only a few degrees Fahrenheit, but it is enough to redirect the tropical jet stream, laden with winter snowstorms to the us. While all 'crazy weather' cannot be attributed to this phenomenon, strong La Nias were observed in 1995 and 1996. Scientists will be keeping a close watch on La Nia to help improve long-range weather forecasting models ( Popular Science , Vol 251, No 3).
We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless. You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together.
Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.