The Influence of ENSO Diversity on Future Atlantic Tropical Cyclone Activity

Teryn J. Mueller aDepartment of Geological and Atmospheric Sciences, Iowa State University, Ames, Iowa.

Search for other papers by Teryn J. Mueller in
Current site
Google Scholar
PubMed
Close
,
Christina M. Patricola aDepartment of Geological and Atmospheric Sciences, Iowa State University, Ames, Iowa.
bClimate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California.

Search for other papers by Christina M. Patricola in
Current site
Google Scholar
PubMed
Close
, and
Emily Bercos-Hickey bClimate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California.

Search for other papers by Emily Bercos-Hickey in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

The El Niño–Southern Oscillation (ENSO) influences seasonal Atlantic tropical cyclone (TC) activity by impacting environmental conditions important for TC genesis. However, the influence of future climate change on the teleconnection between ENSO and Atlantic TCs is uncertain, as climate change is expected to impact both ENSO and the mean climate state. We used the Weather Research and Forecasting model on a tropical channel domain to simulate 5-member ensembles of Atlantic TC seasons in historical and future climates under different ENSO conditions. Experiments were forced with idealized sea-surface temperature configurations based on the Community Earth System Model (CESM) Large Ensemble representing: a monthly-varying climatology, Eastern Pacific El Niño, Central Pacific El Niño, and La Niña. The historical simulations produced fewer Atlantic TCs during Eastern Pacific El Niño compared to Central Pacific El Niño, consistent with observations and other modeling studies. For each ENSO state, the future simulations produced a similar teleconnection with Atlantic TCs as in the historical simulations. Specifically, La Niña continues to enhance Atlantic TC activity, and El Niño continues to suppress Atlantic TCs, with greater suppression during Eastern Pacific El Niño compared to Central Pacific El Niño. In addition, we found a decrease in Atlantic TC frequency in the future relative to historical regardless of ENSO state, which was associated with a future increase in northern tropical Atlantic vertical wind shear and a future decrease in the zonal tropical Pacific SST gradient, corresponding to a more El Niño-like mean climate state. Our results indicate that ENSO will remain useful for seasonal Atlantic TC prediction in the future.

© 2024 American Meteorological Society. This is an Author Accepted Manuscript distributed under the terms of the default AMS reuse license. For information regarding reuse and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Christina M. Patricola, cmp28@iastate.edu

Abstract

The El Niño–Southern Oscillation (ENSO) influences seasonal Atlantic tropical cyclone (TC) activity by impacting environmental conditions important for TC genesis. However, the influence of future climate change on the teleconnection between ENSO and Atlantic TCs is uncertain, as climate change is expected to impact both ENSO and the mean climate state. We used the Weather Research and Forecasting model on a tropical channel domain to simulate 5-member ensembles of Atlantic TC seasons in historical and future climates under different ENSO conditions. Experiments were forced with idealized sea-surface temperature configurations based on the Community Earth System Model (CESM) Large Ensemble representing: a monthly-varying climatology, Eastern Pacific El Niño, Central Pacific El Niño, and La Niña. The historical simulations produced fewer Atlantic TCs during Eastern Pacific El Niño compared to Central Pacific El Niño, consistent with observations and other modeling studies. For each ENSO state, the future simulations produced a similar teleconnection with Atlantic TCs as in the historical simulations. Specifically, La Niña continues to enhance Atlantic TC activity, and El Niño continues to suppress Atlantic TCs, with greater suppression during Eastern Pacific El Niño compared to Central Pacific El Niño. In addition, we found a decrease in Atlantic TC frequency in the future relative to historical regardless of ENSO state, which was associated with a future increase in northern tropical Atlantic vertical wind shear and a future decrease in the zonal tropical Pacific SST gradient, corresponding to a more El Niño-like mean climate state. Our results indicate that ENSO will remain useful for seasonal Atlantic TC prediction in the future.

© 2024 American Meteorological Society. This is an Author Accepted Manuscript distributed under the terms of the default AMS reuse license. For information regarding reuse and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Christina M. Patricola, cmp28@iastate.edu
Save