The Relation of El Niño–Southern Oscillation (ENSO) to Winter Tornado Outbreaks

2008 ◽  
Vol 136 (8) ◽  
pp. 3121-3137 ◽  
Author(s):  
A. R. Cook ◽  
J. T. Schaefer
Keyword(s):  
United States ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
The United States ◽  
Tropical Pacific ◽  
Sea Surface ◽  
Sea Surface Temperatures ◽  
Surface Temperatures ◽  
Tornado Outbreaks

Abstract Winter tornado activity (January–March) between 1950 and 2003 was analyzed to determine the possible effect of seasonally averaged sea surface temperatures in the equatorial Pacific Ocean, the ENSO phase, on the location and strength of tornado outbreaks in the United States. Tornado activity was gauged through analyses of tornadoes occurring on tornado days (a calendar day featuring six or more tornadoes within the contiguous United States) and strong and violent tornado days (a calendar day featuring five or more tornadoes rated F2 and greater within the contiguous United States). The tornado days were then stratified according to warm (37 tornado days, 14 violent days), cold (51 tornado days, 28 violent days), and neutral (74 tornado days, 44 violent days) winter ENSO phase. It is seen that during winter periods of neutral tropical Pacific sea surface temperatures, there is a tendency for U.S. tornado outbreaks to be stronger and more frequent than they are during winter periods of anomalously warm tropical Pacific sea surface temperatures (El Niño). During winter periods with anomalously cool Pacific sea surface temperatures (La Niña), the frequency and strength of U.S. tornado activity lies between that of the neutral and El Niño phase. ENSO-related shifts in the preferred location of tornado activity are also observed. Historically, during the neutral phase, tornado outbreaks typically occurred from central Oklahoma and Kansas eastward through the Carolinas. During cold phases, tornado outbreaks have typically occurred in a zone stretching from southeastern Texas northeastward into Illinois, Indiana, and Michigan. During anomalously warm phases activity was mainly limited to the Gulf Coast states, including central Florida. The data are statistically and synoptically analyzed to show that they are not only statistically significant, but also meteorologically reasonable.

North Australian Sea Surface Temperatures and the El Niño–Southern Oscillation in the CMIP5 Models

2012 ◽  
Vol 25 (18) ◽  
pp. 6375-6382 ◽  
Author(s):  
Jennifer L. Catto ◽  
Neville Nicholls ◽  
Christian Jakob
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
La Niña ◽  
Sea Surface ◽  
Cmip5 Models ◽  
Sea Surface Temperatures ◽  
The North ◽  
La Nina ◽  
Surface Temperatures

Abstract Aspects of the climate of Australia are linked to interannual variability of the sea surface temperatures (SSTs) to the north of the country. SST anomalies in this region have been shown to exhibit strong, seasonally varying links to ENSO and tropical Pacific SSTs. Previously, the models participating in phase 3 of the Coupled Model Intercomparison Project (CMIP3) have been evaluated and found to vary in their abilities to represent both the seasonal cycle of correlations between the Niño-3.4 and north Australian SSTs and the evolution of SSTs during composite El Niño and La Niña events. In this study, the new suite of models participating in the CMIP5 is evaluated using the same method. In the multimodel mean, the representation of the links is slightly improved, but generally the models do not capture the strength of the negative correlations during the second half of the year. The models also still struggle to capture the SST evolution in the north Australian region during El Niño and La Niña events.

scholarly journals Coupled network analysis revealing global monthly scale co-variability patterns between sea-surface temperatures and precipitation in dependence on the ENSO state

2021 ◽  
Author(s):  
Nikoo Ekhtiari ◽  
Catrin Ciemer ◽  
Catrin Kirsch ◽  
Reik V. Donner
Keyword(s):  
Network Analysis ◽  
El Niño ◽  
Large Scale ◽  
El Nino ◽  
Southern Oscillation ◽  
Climate Impacts ◽  
Sea Surface ◽  
Sea Surface Temperatures ◽  
Surface Temperatures ◽  
Ocean Atmosphere

AbstractThe Earth’s climate is a complex system characterized by multi-scale nonlinear interrelationships between different subsystems like atmosphere and ocean. Among others, the mutual interdependence between sea surface temperatures (SST) and precipitation (PCP) has important implications for ecosystems and societies in vast parts of the globe but is still far from being completely understood. In this context, the globally most relevant coupled ocean–atmosphere phenomenon is the El Niño–Southern Oscillation (ENSO), which strongly affects large-scale SST variability as well as PCP patterns all around the globe. Although significant achievements have been made to foster our understanding of ENSO’s global teleconnections and climate impacts, there are many processes associated with ocean–atmosphere interactions in the tropics and extratropics, as well as remote effects of SST changes on PCP patterns that have not yet been unveiled or fully understood. In this work, we employ coupled climate network analysis for characterizing dominating global co-variability patterns between SST and PCP at monthly timescales. Our analysis uncovers characteristic seasonal patterns associated with both local and remote statistical linkages and demonstrates their dependence on the type of the current ENSO phase (El Niño, La Niña or neutral phase). Thereby, our results allow identifying local interactions as well as teleconnections between SST variations and global precipitation patterns.

scholarly journals The Impact of El Niño–Southern Oscillation (ENSO) on Winter and Early Spring U.S. Tornado Outbreaks

2017 ◽  
Vol 56 (9) ◽  
pp. 2455-2478 ◽  
Author(s):  
Ashton Robinson Cook ◽  
Lance M. Leslie ◽  
David B. Parsons ◽  
Joseph T. Schaefer
Keyword(s):  
United States ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
The United States ◽  
Early Spring ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
The Impact ◽  
Tornado Outbreaks

AbstractIn recent years, the potential of seasonal outlooks for tornadoes has attracted the attention of researchers. Previous studies on this topic have focused mainly on the influence of global circulation patterns [e.g., El Niño–Southern Oscillation (ENSO), North Atlantic Oscillation, or Pacific decadal oscillation] on spring tornadoes. However, these studies have yielded conflicting results of the roles of these climate drivers on tornado intensity and frequency. The present study seeks to establish linkages between ENSO and tornado outbreaks over the United States during winter and early spring. These linkages are established in two ways: 1) statistically, by relating raw counts of tornadoes in outbreaks (defined as six or more tornadoes in a 24-h period in the United States east of the Rocky Mountains), and their destructive potential, to sea surface temperature anomalies observed in the Niño-3.4 region, and 2) qualitatively, by relating ENSO to shifts in synoptic-scale atmospheric phenomena that contribute to tornado outbreaks. The latter approach is critical for interpreting the statistical relationships, thereby avoiding the deficiencies in a few of the previous studies that did not provide physical explanations relating ENSO to shifts in tornado activity. The results suggest that shifts in tornado occurrence are clearly related to ENSO. In particular, La Niña conditions consistently foster more frequent and intense tornado activity in comparison with El Niño, particularly at higher latitudes. Furthermore, it is found that tornado activity changes are tied not only to the location and intensity of the subtropical jet during individual outbreaks but also to the positions of surface cyclones, low-level jet streams, and instability axes.

Sign in / Sign up

Export Citation Format

Share Document