Climate Program Office News

Different Control of Tropical Cyclone Activity in the Eastern Pacific for Two Types of El Niño

  • 1 March 2016
  • Number of views: 1691

As the current El Niño event winds down, we can reflect on its influence over tropical cyclone activity in 2015.

El Niño somewhat suppressed Atlantic tropical cyclone activity (though perhaps not as much as was expected) and enhancing Pacific tropical cyclone activity to make 2015 the second most active Pacific hurricane season on record. This was likely due, in part, to the "flavor" of El Niño that we experienced--a canonical, Eastern Pacific El Niño rather than a Modoki, Central Pacific El Niño.

Newly published research in Geophysical Research Letters by Boucharel et al.--and supported by CPO's Climate Variability and Predictability program--seeks to understand these modes of expression, or "flavors," of El Niño, and their influence on tropical cyclones.

From the abstract:

We find that the oceanic control, through meridional redistribution of subsurface heat, is the main driver of tropical cyclone activity during the hurricane season following Eastern Pacific events. In contrast, atmospheric conditions tend to be destructive to tropical cyclone intensification after those events. The altered atmospheric circulation, in particular the reduction of vertical wind shear and the increase in relative humidity, tends to be more influential in controlling tropical cyclone activity post Central Pacific events. However, unlike for subsurface heat, these changes in atmospheric conditions are not statistically distinct between these two ENSO flavors—although they are consistent across all atmospheric data sets tested. Overall, unlike after Eastern Pacific El Niño events, the hurricane season activity following a Central Pacific event is not significantly different from neutral or even La Niña years.

Access the paper, at:



About the Climate Program Office

The Climate Program Office (CPO) manages competitive research programs in which NOAA funds high-priority climate science, assessments, decision support research, outreach, education, and capacity-building activities designed to advance our understanding of Earth’s climate system, and to foster the application of this knowledge in risk management and adaptation efforts.  CPO-supported research is conducted in regions across the United States, at national and international scales, and globally.  Learn more...

«May 2018»


Americans’ health, security and economic wellbeing are tied to climate and weather. Every day, we see communities grappling with environmental challenges due to unusual or extreme events related to climate and weather. In 2017, the United States experienced a record-tying 16 climate- and weather-related disasters where overall costs reached or exceeded $1 billion. Combined, these events claimed 362 lives, and had significant economic effects on the areas impacted, costing more than $306 billion. Businesses, policy leaders, resource managers and citizens are increasingly asking for information to help them address such challenges.


Climate Program Office
1315 East-West Hwy, Suite 1100
Silver Spring, MD 20910