December, why are you so warm? This unusually warm start to winter can be attributed to a global event known as “El Niño.” Generally speaking, El Niño can be defined as a prolonged increase in average sea surface temperatures across the Pacific Ocean. A cyclic event, El Niño typically occurs every 2-7 years, every five on average. This ocean warming means different things to different places. Here in the Northeast, it brings warmer, drier winter months. El Niño’s rush of warm ocean water, heated as it travels eastward in the Equatorial Current, replaces the cold waters of the Humboldt current, that travels north along the western coast of South America. This warmer ocean water is nutrient poor, compared to the usual colder water. If prolonged, this leads to decreases in many important fish populations worldwide. In addition, El Niño can also cause serious droughts which affect global agriculture. This phenomenon has increased in frequency over the past decade, and though more time and data collection is needed to make any significant conclusions, many have attributed this increase to global climate change.