Why were some La Niñas followed by another La Niña?
- Zeng-Zhen HuAffiliated withNCEP/NWS/NOAA, Climate Prediction Center Email author
- , Arun KumarAffiliated withNCEP/NWS/NOAA, Climate Prediction Center
- , Yan XueAffiliated withNCEP/NWS/NOAA, Climate Prediction Center
- , Bhaskar JhaAffiliated withNCEP/NWS/NOAA, Climate Prediction CenterWYLE Science, Technology and Engineering Group
Rent the article at a discountRent now
* Final gross prices may vary according to local VAT.Get Access
This paper investigates why some La Niña events are followed by another La Niña and some others are not. We propose two preconditions that result in continuation of a La Niña. The first one is that La Niña must be a strong event (a major La Niña). This ensures that the reflected Rossby wave signal at the eastern boundary of the Pacific has a strong westward propagating cold ocean temperature anomaly over the off-equatorial region. The off-equator cold anomaly may not be conducive to the equatorial recharge process, and as a result, may favor the persistence of cold ocean subsurface temperature anomaly and prevent the transition from La Niña to El Niño. The second precondition is whether there are eastward propagating downwelling Kelvin waves during the decay phase of a major La Niña. Eastward propagating downwelling Kelvin waves could lead to demise for a tendency for a follow-up La Niña. The equatorial Kelvin wave activities are associated with fluctuations of surface wind in the equatorial far-western Pacific. The analysis suggests that both the surface wind in the equatorial far-western Pacific and the recharge/discharge of the equatorial Pacific are indicators for occurrence or no occurrence of a follow-up La Niña event.
KeywordsMulti-year La Nina Oceanic Kelwin wave Surface wind stress divergence in far-western Pacific Recharge and discharge processes
- Why were some La Niñas followed by another La Niña?
Volume 42, Issue 3-4 , pp 1029-1042
- Cover Date
- Print ISSN
- Online ISSN
- Springer Berlin Heidelberg
- Additional Links
- Multi-year La Nina
- Oceanic Kelwin wave
- Surface wind stress divergence in far-western Pacific
- Recharge and discharge processes
- Industry Sectors