Predicting monthly precipitation along coastal Ecuador: ENSO and transfer function models.
- Authors
- Bustamante P?rez, Lelys Isaura
- Format
- Article
- Status
- publishedVersion
- Description
It is well known that El Ni?o-Southern Oscillation (ENSO) modifies precipitation patterns in several parts of the world. One of the most impacted areas is the western coast of South America, where Ecuador is located. El Ni?o events that occurred in 1982?1983, 1987?1988, 1991?1992, and 1997?1998 produced important positive rainfall anomalies in the coastal zone of Ecuador, bringing considerable damage to livelihoods, agriculture, and infrastructure. Operational climate forecasts in the region provide only seasonal scale (e.g., 3-month averages) information, but during ENSO events it is key for decision-makers to use reliable sub-seasonal scale forecasts, which at the present time are still non-existent in most parts of the world. This study analyzes the potential predictability of coastal Ecuador rainfall at monthly scale. Instead of the discrete approach that considers training models using only particular seasons, continuous (i.e., all available months are used) transfer function models are built using standard ENSO indices to explore rainfall forecast skill along the Ecuadorian coast and Gal?pagos Islands. The modeling approach considers a large-scale contribution, represented by the role of a sea-surface temperature index, and a local-scale contribution represented here via the use of previous precipitation observed in the same station. The study found that the Ni?o3 index is the best ENSO predictor of monthly coastal rainfall, with a lagged response varying from 0 months (simultaneous) for Gal?pagos up to 3 months for the continental locations considered. Model validation indicates that the skill is similar to the one obtained using principal component regression models for the same kind of experiments. It is suggested that the proposed approach could provide skillful rainfall forecasts at monthly scale for up to a few months in advance.
Escuela Superior Polit?cnica del Litoral
http://link.springer.com/article/10.1007/s00704-016-1828-4
- Publication Year
- 2016
- Language
- eng
- Topic
- PREDICTING
PRECIPITATION
COASTAL ECUADOR
FUNCTION MODELS
- Repository
- Repositorio SENESCYT
- Rights
- openAccess
- License
- openAccess