Variation characteristics of the extreme sea surface temperature events in the Northwest Pacific and its relationship with ENSO over the past 33 Years

Utilizing The NOAA Optimum Interpolation 1/4 Degree Daily Sea Surface Temperature Analysis data for the period 1982~2014.Variation characteristics of the extreme SST events and its relationship with ENSO in the Northwest Pacific are analyzed.The results indicate that:The frequency of extreme high temperature eventshas increased significantly, In the 1980s it was 2 to 5 years, and in the 1990s it was 1 to 4 years, since the 21st century, except for 2004 and 2011, other years have occurred.The number of days with extreme high temperature increased linearly with an increase rate of 30 d/10 a.The duration of a single extreme high temperature event gradually increased with an increase rate of 0.56 d/time, and the average temperature and maximum temperature also showed an upward trend, with the rate of increase being 0.032℃/time and 0.049℃/time, respectively.On the contrary, the frequency of extreme cold events has decreased significantly, from 1982 to 2000 once in 1~2 years, and since the 21st century, the frequency of occurrence has decreased significantly.The duration of the days of extreme cold temperature occurrence and the duration of single event both decreased significantly, with the reduction rate of -27 d/10 a and -1.6 d/time respectively.The average temperature and the minimum temperature of a single extreme cold temperature event showed a linear upward trend with a growth rate of 0.0087℃/time and 0.017℃/time.The extreme high temperature events show high and low frequency oscillations in the 1~4 year and 4~7 year cycles.The cold events show a multi-scale periodic variation with a main period scale of 3~4 years.In the second half of Nino 3.4, the ENSO index was significantly negatively correlated with the extreme high temperature in the western North Pacific, and was significantly positively correlated with extreme cold events.This means that in the La Niña years extreme heat events are more likely to occur.On the contrary, in the El Niño years, extreme cold events are prone to occur.