US CLIVAR ENSO Diversity Workshop Agenda

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ENSO Diversity Workshop Information

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Boulder, CO

The final workshop report for the ENSO Diversity Workshop is now available to download (see link below).  Links to individual abstract and presentation files are included in the agenda below on this page.


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Wednesday, February 6         Thursday, February 7         Friday, February 8


Wednesday, February 6

8:00 - 8:30 am: Breakfast

Wednesday Morning Session:

8:30 am - 12:30 pm: “Statistical Characterization of ENSO diversity in models and observations”


  1. What are the major uncertainties in the observational record and reanalysis products that limit our ability to characterize ENSO diversity?  How can these uncertainties be reduced?
  2. How well do climate models reproduce the “observed” characteristics of ENSO diversity?
  3. Do discrete classes of ENSO events emerge from observations and models, or is ENSO diversity better described as a continuum with some interesting extremes?
  4. Are oceanic indices sufficient to characterize ENSO diversity, or indices/metrics accounting for the atmospheric state are necessary?

8:30 - 8:40 am: Welcome

8:40 - 9:00 am: Alexey Kaplan “Indices of El Niño-Southern Oscillation from historical data sets, based on SST measurements: Estimates and their uncertainty” (View PowerPoint presentation)

9:00 - 9:20 am: Benjamin Giese ”Are there really different types of ENSO? What can be learnt from reanalyses, reconstructions, and the CMIP5 historical runs?” (View PowerPoint presentation)

9:20 - 9:40 am: Matt Newman “Modelling an ENSO continuum using multivariate red noise (View PowerPoint presentation)

9:40 -10:00 am: Chunzai Wang  "El Niño Modoki I and II Classified by Different Impacts on Rainfall in Southern China, Typhoon Landfall Activity and the Indian Ocean Dipole" (View PowerPoint presentation)

10:00 - 10:10 am: Poster presentations

10:10 - 10:40 am: Break with poster viewing


10:40 - 11:00 am: Kris Karnauskas “El Niño typology and trends: Insights from three decades of weekly SST observations” (View PowerPoint presentation)

11:00 - 11:20 am: Andrew Chiodi “OLR-based El Niño and La Niña indices for impacts on global seasonal weather anomalies” (View PowerPoint presentation)

11:20 - 11:40 am: Kao Hsun-Ying “Zonal surface currents and the evolution of the two types of El Niño” (View PowerPoint presentation)

11:40 am - 12:00 pm: Gil Compo “Removing ENSO-related variations from the climate record” (View PowerPoint presentation)

12:00 - 12:30 pm: Discussion



Autumn Kidwell “Examining El Niño diversity in recent warm-pool migration events

Benjamin Hamlington “Improving sea level reconstructions using non-sea level measurements

Jin-Yi Yu “Indices for the two types of ENSO


12:30 - 1:30 pm: Lunch


Wednesday Afternoon Session:

1:30 - 5:30 pm: “Dynamical processes associated with the different flavors (relative role of the different oceanic feedbacks and surface atmospheric forcing”


  1. Are different ENSO flavors/extremes characterized by different leading dynamical processes? What is the relative importance of the various oceanic feedbacks and surface fluxes, and what is the role of nonlinear processes?
  2. Do climate models (CMIP3/CMIP5) capture the differences in dynamics suggested by observations, and do they agree among themselves?  How can the models be improved?
  3. Are simple models (either statistical, or dynamical conceptual and intermediate models) able to capture the full diversity of obs and GCMs?  If so, how can these be used to improve the more complex models? Can they help us understand whether ENSO characteristics may vary as a continuum or be characterized by “discrete modes”?
  4. How does understanding of the dynamics of ENSO diversity inform assessments of the influence of climate change on ENSO?

1:30 - 1:50 pm: Fei-Fei Jin “El Niño multiplicity and sensitivity” (View PowerPoint presentation)

1:50 - 2:10 pm: Jin-Yi Yu “Central-Pacific El Niño: Dynamics, climate impacts, and the cause of its recent emergence” (View PowerPoint presentation)

2:10 - 2:30 pm: Boris Dewitte “The thermocline feedback in the western-central equatorial Pacific: A key player for explaining ENSO diversity

2:30 - 2:50 pm: Mike McPhaden “A 21st Century shift in ENSO Properties” (View PowerPoint presentation)

2:50 - 3:20 pm: Break and poster viewing


3:20 - 3:40 pm: Andrew Wittenberg “ENSO diversity in the GFDL CM2.1 coupled GCM” (View PowerPoint presentation)

3:40 - 4:00 pm: Ken Takahashi “Strong and moderate El Niño regimes in the GFDL-CM2.1 model” (View PowerPoint Presentation)

4:00 - 4:20 pm: Antonietta Capotondi “Dynamics of El Niño flavors in the NCAR CCSM4” (View PowerPoint presentation)

4:20 - 4:40 pm: Maria Gehne “On the relation between the ENSO cycle, its irregularity and decadal variation (View PowerPoint presentation)

4:40 - 5:00 pm: Jyothi Nattala “El Niño and the Southern Oscillation in parameterized and super-parameterized coupled general circulation models

5:00 - 5:30 pm: Discussion



Maria Gehne “On the relation between the ENSO cycle, its irregularity and decadal variation


5:30 pm: Reception


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Thursday, February 7

8:00 - 8:30 am: Breakfast

Thursday Morning Session:

8:30 am - 12:30 pm: “Predictability and Prediction" (including precursors)


  1. Are there specific precursors associated with different ENSO types? If so, are they associated with extra-tropical or inter-basin influences, or do they originate within the tropical Pacific?  What are the relative roles of the Northern and Southern Hemispheres?
  2. Are existing ENSO forecast systems able to realistically simulate these precursors?  How can the forecasts be improved?
  3. Do certain ENSO flavors/extremes offer significantly enhanced or degraded predictability?  If so, are these predictability variations evident within existing forecast systems, e.g. via retrospective forecast skill over the instrumental epoch?

8:30 - 8:50 am: Emanuele Di Lorenzo “ENSO and the Meridional Mode: a null hypothesis for Pacific decadal climate” (View PowerPoint presentation)

8:50 - 9:10 am: Bruce Anderson “Influence of extra-tropical sea-level pressure variations on the longitudinal location of ENSO events” (View PowerPoint presentation)

9:10 - 9:30 am: Sang-Wook Yeh “Changes in the ENSO spatial structure in relation to the PDO in the CMIP5 (View PowerPoint presentation)

9:30 - 9:50 am: Kathy Pegion “The seasonal footprinting mechanism in CFSv2: Simulation and impacts on ENSO predictions (View PowerPoint presentation)

9:50 - 10:10 am: Honghai Zhang “The South Pacific Meridional Mode: A mechanism for ENSO-like variability (View PowerPoint presentation)

10:10 - 10:15 am: Poster presentation

10:15 - 10:30 am: Break and poster viewing


10:30 - 10:50 am: Alexey Fedorov “Westerly wind bursts revisited: Implications for Central Pacific, eastern Pacific, and extreme El Niño events” (View PowerPoint presentation)

10:50 - 11:10 am: Takeshi Izumo “Influence of Indian Ocean Dipole and Pacific recharge on following year’s El Niño: Interdecadal robustness (View PowerPoint presentation)

11:10 - 11:30 am: Ben Kirtman “ENSO diversity in the US National Multi-Model Ensemble (NMME) Prediction System” (View PowerPoint presentation)

11:30 - 11:50 am: Yan Xue “Prediction skill and predictability of two flavors of ENSO in the NCEP Climate Forecast System Version 2 (View PowerPoint presentation)

11:50 - 12:10 am: Ernesto Munoz “Tropical Atlantic Variability leading tropical Pacific sea level pressure anomalies in CCSM4 (View PowerPoint presentation)

12:10 - 12:30 pm: Discussion


12:30 - 1:30 pm: Lunch



Shineng Hu “The effect of westerly wind bursts on ENSO: Why each El Niño event is unique?

Andrew Chiodi “Pre- and Post-1997/1998 Westerly Wind Events and Equatorial Pacific Cold Tongue Warming 


Thursday Afternoon Session:

1:30 - 5:30 pm: “Teleconnections of the different flavors and impacts”


  1. Do atmospheric teleconnections significantly differ among various ENSO flavors/extremes?  If so, what dynamical processes are responsible?
  2. What ENSO flavors/extremes have the greatest impacts on various stakeholders?
  3. How are these ENSO teleconnections and impacts influenced by changing radiative forcings, natural or anthropogenic?

1:30 - 1:50 pm:  Prashant Sardeshmukh "Does “ENSO diversity” remotely matter?" (View PowerPoint presentation)

1:50 - 2:10 pm:  Sang-Ik Shin "ENSO flavors and their global impacts" (View PowerPoint presentation)

2:10 - 2:30 pm: Martin Hoerling  "Teleconnection sensitivity to El Niño diversity" (View PowerPoint presentation)

2:30 - 2:50 pm:  Margaret Hurwitz "Extra-tropical atmospheric response to two types of El Niño events"

2:50 - 3:10 pm: Eriko Nishimoto  "Intraseasonal to interannual variability in the tropical tropopause temperature and its relationship with convective activity" (View PowerPoint presentation)

3:10 - 3:30 pm: Break


3:30 - 3:50 pm: Sang-Ki Lee "Trans-Niño and Springtime Tornado Outbreaks in the U.S" (View PowerPoint presentation)

3:50 - 4:10 pm: Speaker TBD

4:10 - 4:30 pm: Simon Grainger "Assessment and Projected Changes of ENSO-related Interannual Variability of Southern Hemisphere Atmospheric Circulation in CMIP5 Models" (View PowerPoint presentation)

4:30 - 4:50 pm: Aaron Wilson "Evaluating the Impacts of ENSO Flavors on the ENSO-SAM Teleconnection to Antarctica Using CAM 4" (View PowerPoint presentation)

4:50 - 5:10 pm: Michelle Gierach "Biophysical response to the 1997-98 and 2009-10 El Niño events in the equatorial Pacific Ocean" (View PowerPoint presentation)

5:10 - 5:30 pm: Mark Ohman "Biological evidence for an anomalous California Nino of 2009/10"

5:30 - 6:00 pm: Discussion



Andrew Wittenberg "Variation of ENSO teleconnections"


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Friday, February 8

8:00 - 8:30 am: Breakfast

Friday Morning Session:

8:30 am - 12:30 pm:  “Insight from paleoclimates”


  1. What are the major sources of uncertainty in the paleo proxies and reconstructions that limit our ability to characterize past ENSO diversity?
  2. How can paleo proxies inform reconstructions of ENSO diversity during the instrumental epoch?
  3. Do discrete classes of ENSO events emerge from paleo reconstructions and paleo simulations?

8:30 - 9:00 am: Continuing discussion from previous day

9:00 - 9:30 am: Julien Emile-Geay "Paleoclimate constraints on ENSO statistics" (View PowerPoint presentation)

9:30 - 9:50 am: Emanuele Di Lorenzo (for Kim Cobb) "New estimates of ENSO variability over the last 7,000 years:  data-model comparisons" (View PowerPoint presentation)

9:50 - 10:10 am: Diane Thompson "Reconciling coral-based reconstructions of tropical Pacific SST and salinity" (View PowerPoint presentation)

10:10 - 10:30 am: Break


10:30 - 10:50 am: Christina Karamperidou "The response of ENSO ‘flavors’ to orbital forcing: Implications for interpreting proxies"

10:50 - 11:10 am: Jinbao Li "El Niño Dynamics During the Past Seven Centuries"

11:10 - 11:30 am: Toby Ault "Characterizing decadal to centennial variability of the last millennium" (View PowerPoint presentation)

11:30 am - 12:30 pm: Discussion



Diane Thompson: “Tropical climate trends inferred from coral pseudoproxy modeling


12:30 - 1:30 pm: Lunch


1:30 - 3:30 pm: Working Group meeting  (working group members only)

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