The Blob (Pacific Ocean) the surface waters of the mid-latitude Pacific Ocean flipping from a cold phase to a warm phase in a cycle known as the Pacific decadal oscillation (PDO). This poorly-understood change happens at irregular intervals of years or decades. During a warm phase, the west Pacific becomes cooler and part of the eastern ocean warms; during the cool phase, these changes reverse. Scientists believe a cold phase started in the late 1990s and the arrival of the Blob may be the start of the next warm phase. The PDO phases may also be related to the likelihood of El Nino events.
The Blob (Pacific Ocean) of Queensland observed the first ever mass bleaching event for Hawaiian coral reefs in 2014, and attributed it to the blob. Research from the University of Washington found positive temperature anomalies in the NE Pacific Ocean (upper ~100 m, greater than 2.5 °C, with temperatures at the coast below normal) for the winter period of 2013–2014. Heat loss from the ocean during the winter time was suppressed. During spring and summer 2014 the warmer sea surface temperature anomalies reached coastal waters. The anomaly may have had a significant effect on the unusually warm summer of 2014, with record high temperatures