Twenty-one-year hindcasts of sea surface temperature (SST) anomalies in the tropical Pacific were performed to validate the influence of ocean subsurface entrainment on SST prediction.A new hybrid coupled model was us...Twenty-one-year hindcasts of sea surface temperature (SST) anomalies in the tropical Pacific were performed to validate the influence of ocean subsurface entrainment on SST prediction.A new hybrid coupled model was used that considered the entrainment of subsurface temperature anomalies into the sea surface.The results showed that predictions were improved significantly in the new coupled model.The predictive correlation skill increased by about 0.2 at a lead time of 9 months,and the root-mean-square (RMS) errors were decreased by nearly 0.2°C in general.A detailed analysis of the 1997-98 El Nio hindcast showed that the new model was able to predict the onset,peak (both time and amplitude),and decay of the 1997-98 strong El Nio event up to a lead time of one year,factors that are not represented well by many other forecast systems.This implies,in terms of prediction,that subsurface anomalies and their impact on the SST are one of the controlling factors in ENSO cycles.Improving the presentation of such effects in models would increase the forecast skill.展开更多
This preliminary study examines the definition problem and challenges of climate forecasting and disaster responses associated with the El Nio costero(coastal) of2017, which developed rapidly with no warning and had...This preliminary study examines the definition problem and challenges of climate forecasting and disaster responses associated with the El Nio costero(coastal) of2017, which developed rapidly with no warning and had catastrophic effects in Peru. Such a localized El Nio was not documented since 1925. An initial review suggests that in addition to the characteristics of the event(surprise),government responses may have been inadequate(as media reported) because of conflicting forecast reports(U.S. and Peru), which provoked a hydrometeorological debate and stifled decision making. Partly to blame was the El Nio definition problem, which can cause uncertainty and affect perception of risk, depending on which region of the equatorial Pacific one uses to identify an event. Responses were further complicated by the fact that some regions within Peru were experiencing drought prior to the El Nio costero's onset and impacts from the El Nio 2015–2016 were less than expected. Furthermore, a new government was in place, which may have hindered action. Thus, El Nio costero provides lessons to heed, not only with respect to the forecast information, but also with reference to the context of the forecast and disaster setting, which can influence disaster responses to hydrometeorological threats.展开更多
The troubled forecast of El Nio’s onset in2014 requires an explanation as well as an open dialogue with the user community that depends on such an important forecast. A review of the forecasts on the Internet refle...The troubled forecast of El Nio’s onset in2014 requires an explanation as well as an open dialogue with the user community that depends on such an important forecast. A review of the forecasts on the Internet reflects two different perceptions about what transpired. The forecast community suggests they got it right, while the popular media suggests forecasters got it wrong. Why such a gap? The major El Nio that was alluded to by several organizations did not materialize when or even as expected. A science-fed media frenzy took place about an event considered in retrospect to have been an unusual borderline(weak) El Nio event, 'trickiest ever to forecast.'That is understandable, as the science of El Nio is still on a learning curve. But it suggests that the forecasting of El Nio’s onset is still in an experimental phase and not yet operational. Forecasting its onset(as a specific event)should be separated from forecasting its behavior and impacts(as a process) once the onset has been assured.Whenever a forecast is made, someone is responding to it.Therefore, such a distinction is necessary for the benefit of those societies and economic sectors affected by El Nio.展开更多
The aim of this pilot study conducted by the consortium for capacity building was to develop a prototype concept and methodology for the classification and visualization of the geographic impacts of El Nio on annual...The aim of this pilot study conducted by the consortium for capacity building was to develop a prototype concept and methodology for the classification and visualization of the geographic impacts of El Nio on annual climates and seasonality. Our study is based on the Kppen–Geiger climate classification scheme for a set of selected countries affected by strong El Nios in Latin America. By identifying and visualizing the annual and seasonal changes in regional, national, or subnational climate regimes that generally accompany an El Nio event,this research proposes an efficient way to detect and describe climate shifts and variability across time and space. Such knowledge provides a support tool for risk analysis and can potentially enhance government efforts of climate risk management, including disaster risk reduction activities that prevent, mitigate, and improve coping responses to El Nio-related hydrometeorological threats.Details of the conceptual approach and methodology to classifying and mapping El Nio's impacts are described and explained using the Central American and circumCaribbean region as a case study. The potential applications for disaster risk reduction as well as its limitations and future work are also discussed.展开更多
基金supported by the Key Program of the Chinese Academy of Sciences (KZCX2-YW-218)the National Basic Research Program of China (2006CB403606)the National Natural Science Foundation of China (40821092)
文摘Twenty-one-year hindcasts of sea surface temperature (SST) anomalies in the tropical Pacific were performed to validate the influence of ocean subsurface entrainment on SST prediction.A new hybrid coupled model was used that considered the entrainment of subsurface temperature anomalies into the sea surface.The results showed that predictions were improved significantly in the new coupled model.The predictive correlation skill increased by about 0.2 at a lead time of 9 months,and the root-mean-square (RMS) errors were decreased by nearly 0.2°C in general.A detailed analysis of the 1997-98 El Nio hindcast showed that the new model was able to predict the onset,peak (both time and amplitude),and decay of the 1997-98 strong El Nio event up to a lead time of one year,factors that are not represented well by many other forecast systems.This implies,in terms of prediction,that subsurface anomalies and their impact on the SST are one of the controlling factors in ENSO cycles.Improving the presentation of such effects in models would increase the forecast skill.
文摘This preliminary study examines the definition problem and challenges of climate forecasting and disaster responses associated with the El Nio costero(coastal) of2017, which developed rapidly with no warning and had catastrophic effects in Peru. Such a localized El Nio was not documented since 1925. An initial review suggests that in addition to the characteristics of the event(surprise),government responses may have been inadequate(as media reported) because of conflicting forecast reports(U.S. and Peru), which provoked a hydrometeorological debate and stifled decision making. Partly to blame was the El Nio definition problem, which can cause uncertainty and affect perception of risk, depending on which region of the equatorial Pacific one uses to identify an event. Responses were further complicated by the fact that some regions within Peru were experiencing drought prior to the El Nio costero's onset and impacts from the El Nio 2015–2016 were less than expected. Furthermore, a new government was in place, which may have hindered action. Thus, El Nio costero provides lessons to heed, not only with respect to the forecast information, but also with reference to the context of the forecast and disaster setting, which can influence disaster responses to hydrometeorological threats.
文摘The troubled forecast of El Nio’s onset in2014 requires an explanation as well as an open dialogue with the user community that depends on such an important forecast. A review of the forecasts on the Internet reflects two different perceptions about what transpired. The forecast community suggests they got it right, while the popular media suggests forecasters got it wrong. Why such a gap? The major El Nio that was alluded to by several organizations did not materialize when or even as expected. A science-fed media frenzy took place about an event considered in retrospect to have been an unusual borderline(weak) El Nio event, 'trickiest ever to forecast.'That is understandable, as the science of El Nio is still on a learning curve. But it suggests that the forecasting of El Nio’s onset is still in an experimental phase and not yet operational. Forecasting its onset(as a specific event)should be separated from forecasting its behavior and impacts(as a process) once the onset has been assured.Whenever a forecast is made, someone is responding to it.Therefore, such a distinction is necessary for the benefit of those societies and economic sectors affected by El Nio.
基金the support provided by the Office of US Foreign Disaster Assistance,Bureau for Democracy,Conflict and Humanitarian Assistance,US Agency for International Development
文摘The aim of this pilot study conducted by the consortium for capacity building was to develop a prototype concept and methodology for the classification and visualization of the geographic impacts of El Nio on annual climates and seasonality. Our study is based on the Kppen–Geiger climate classification scheme for a set of selected countries affected by strong El Nios in Latin America. By identifying and visualizing the annual and seasonal changes in regional, national, or subnational climate regimes that generally accompany an El Nio event,this research proposes an efficient way to detect and describe climate shifts and variability across time and space. Such knowledge provides a support tool for risk analysis and can potentially enhance government efforts of climate risk management, including disaster risk reduction activities that prevent, mitigate, and improve coping responses to El Nio-related hydrometeorological threats.Details of the conceptual approach and methodology to classifying and mapping El Nio's impacts are described and explained using the Central American and circumCaribbean region as a case study. The potential applications for disaster risk reduction as well as its limitations and future work are also discussed.
