Uncovering the Extratropical Pacemaker Effect on El Nino

Dillon Amaya

Graduate Researcher at Scripps Institution of Oceanography
djamaya@ucsd.edu

Schedule of Visit here

Research Interests

  • Tropical climate variability on seasonal, interannual, and decadal timescales and its impact on higher latitudes.
  • El Niño and its teleconnections.
  • Climate mode extremes and their predictability.

Degrees

  • B.S., Meteorology, Texas A&M University
  • M.S., Oceanography, Scripps Institution of Oceanography
  • Ph.D., Oceanography, Scripps Institution of Oceanography (In Progress)

 

Will present a seminar entitled:

Uncovering the Extratropical Pacemaker Effect on ENSO

 

Abstract

The Pacific Meridional Mode (PMM) is a coupled mode of climate variability found in the subtropical North and South Pacific that integrates extratropical surface wind variability into a propagating pattern of SST/wind anomalies that stretches into the deep tropics. In recent years, many studies have indicated that the PMM can act as a precursor and predictor of the El Niño-Southern Oscillation (ENSO) due to this propagation; however, there has been little effort to put these extratropical-tropical interactions into the context of ENSO events in the historical record. To quantify the role of the extratropics in pacing the timing and magnitude of historical ENSO events, we use a fully-coupled climate model to produce an ensemble of North Pacific Ocean-Global Atmosphere (nPOGA) pacemaker simulations, which are forced by the observed trajectory of North Pacific (>15˚N) SST anomalies in addition to historical radiative forcing. We are then able to utilize the ensemble mean of nPOGA to analyze the relationship between extratropical atmospheric variability, the PMM, and ENSO. We find that North Pacific SST variability accounts for approximately 16% of total ENSO variance, but can be a much larger contributor on an event-by-event basis. For example, nPOGA reproduces the complicated 2014-2016 ENSO cycle remarkably well. Our results illustrate the significant role of extratropical noise in pacing the initiation and magnitude of ENSO events and may improve the predictability of ENSO on seasonal timescales.

Event Details

Date/Time:

  • Tuesday, October 16, 2018
    11:00 am - 12:00 pm
Location: Ford Environmental, Science & Technology (ES&T) Building, Rm. L1255
Fee(s): Free

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  • Dillon Amaya

For More Information Contact

Daniela Estrada
Program Coordinator for Ocean Science and Engineering
daniela.estrada@eas.gatech.edu