Abstract
Long-lead forecasts of El Niño events are lacking despite their enormous societal and economic impacts. These climatic events lead to floods and droughts in many tropical regions, and damage agriculture and the economy in poor countries. Due to their impact on local climate, they can also affect human health by increasing the risk of vector-borne diseases, such as dengue fever. Physical processes at the origin of this complex coupled ocean-atmosphere phenomenon are just beginning to be better understood, with subsurface processes and stored heat as two of the main driving forces leading to the development of El Niño in a quasi-periodic manner. Taking advantage of this new knowledge, a statistical dynamic components model, using a state space approach and predictors relevant to the El Niño evolution, was specifically tailored to forecast warm events at lead times of about 2 years (well beyond the traditional spring barrier limit in El Niño predictability). This forecasting scheme provides skilful information on the amplitude of El Niño events, their duration, and the peak time of the sea surface temperature anomalies at a sufficient lead time as to efficiently serve preventive public health actions. The long-lead El Niño predictions were coupled to a statistical dengue model to estimate dengue cases during the 1998 and the 2010 epidemics in El Oro Province in Ecuador, where dengue is hyper-endemic. The dengue model correctly estimated these two largest dengue epidemics even at a 2-year simulation lead time. Thus, information is successfully passed from the El Niño forecast domain to the dengue estimation domain, and the long-lead El Niño predictions are shown to potentially anticipate the magnitude of dengue epidemics in the peak season. The results validate the sensitivity of large dengue epidemics in the region to the El Niño forecasts within the proposed model coupling set-up and imply a potential for increasing lead-time in dengue prediction. This coupled model framework and exploratory analysis, based on El Niño predictions, could be easily extended to other similarly transmitted diseases in tropical and subtropical countries, which are directly and severely affected by the large-scale temperature and precipitation teleconnections occurring before, during and after El Niño events.
Original language | English |
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Article number | 100096 |
Pages (from-to) | 1-9 |
Number of pages | 9 |
Journal | Climate Services |
Volume | 15 |
DOIs | |
Publication status | Published - Aug 2019 |
Funding
The research leading to these results was supported by the DENFREE project (FP7-HEALTH.2011.2.3.3-2; 282378) and EUPORIAS project (FP7-ENV.2012.6.1-1; 308291), funded by the European Commission’s Seventh Framework Research Programme . Many thanks to colleagues in Ecuador for providing the original data used in the analysis: Raul Mejia at the National Institute of Meteorology and Hydrology, Jhonny Real from the Ministry of Health of Ecuador, and Efrain Beltran and other colleagues from the National Vector Control Service (SNEM). RL was supported by a Royal Society Dorothy Hodgkin Fellowship . AMSI was additionally supported by NSF DEB EEID 1518681 and NSF DEB RAPID 1641145. JB gratefully acknowledges funding from the European Union’s Horizon 2020 research and innovation programme under grant agreements No 727852 (project Blue Action), 730004 (project PUCS), and 737480 (Marie Sklodowska-Curie fellowship ACCLIM). SJK acknowledges the support from CREATES (DNRF78) at Aarhus University, Denmark, funded by the Danish National Research Foundation. XR was in receipt of funds by the New Indigo project PARA-CLIM-CHANDIGARGH (Mineco, 2013). The funding sources had no direct involvement in the conduct of the research and the preparation of the article. Appendix A
Funders | Funder number |
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CREATES | DNRF78 |
DENFREE | 282378, FP7-ENV.2012.6.1-1, 308291, FP7-HEALTH.2011.2.3.3-2 |
Efrain Beltran | |
European Commission’s Seventh Framework Research Programme | |
European Union’s Horizon 2020 | Action |
Ministry of Health of Ecuador | |
NSF DEB EEID 1518681 | |
NSF DEB RAPID 1641145 | DEB RAPID 1641145 |
National Vector Control Service | |
SNEM | |
National Science Foundation | DEB EEID 1518681, 1641145 |
Aarhus Universitet | |
Horizon 2020 Framework Programme | |
H2020 Marie Skłodowska-Curie Actions | |
Royal Society | |
Danmarks Grundforskningsfond | |
Seventh Framework Programme | |
Horizon 2020 | 737480, 727852, 730004 |