Interannual El Niño/Southern Oscillation (ENSO) and decadal ENSO-like climate variations of the Pacific Ocean basin are important contributors to the year-to-year (and longer) variations of the climate of North and South America. Analysis of historical observations of global sea-surface temperatures, global 500 mb pressure surfaces, and western hemisphere hydroclimatic variations that are linea...

The changes in model ENSO behavior due to an increase in greenhouse gases (according to the IPCC Business-As-Usual scenario) are investigated using a 62 member ensemble 140-year simulation (1940–2080) with the National Center for Atmospheric Research Community Climate System Model (CCSM, version 1.4). Although the global mean surface temperature increases by about 1.2 K over the period 2000–208...

A four-dimensional variational (4D-Var) data assimilation method is implemented in an improved intermediate coupled model (ICM) of the tropical Pacific. A twin experiment is designed to evaluate the impact of the 4D-Var data assimilation algorithm on ENSO analysis and prediction based on the ICM. The model error is assumed to arise only from the parameter uncertainty. The “observation” of the S...

We examine the use of El Niño-Southern Oscillation (ENSO) forecasts for flood planning in the Pacific Northwest. Using theories of resource mobilization as a conceptual foundation, the paper relies on: 1) case studies of three communities vulnerable to flooding that have had access to long-term forecasts of ENSO conditions; and 2) analysis of data collected from a survey of nearly 60 local emer...

[1] Visibility was used as a long-term indicator of atmospheric haze caused by peat fires on the peat land area of the island of Sumatra, Indonesia. Visibility and the anomalies of sea surface temperature in the Niño 3.4 region from 1973 to 2003 were analyzed. A significant linear relationship existed between the visibility and time, and the two signals shared two periodic components of 45 mont...

Singular vector analysis and Floquet analysis are carried out on a linearized variant of the Zebiak–Cane atmosphere–ocean model of El Niño–Southern Oscillation (ENSO), hereinafter called the nominal model. The Floquet analysis shows that the system has a single unstable mode. This mode has a shape and frequency similar to ENSO and is well described by delayed oscillator physics. Singular vector...

In many parts of the world, climate projections for the next century depend on potential changes in the properties of the El Niño – Southern Oscillation (ENSO). The current staus of these projections is assessed by examining a large set of climate model experiments prepared for the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Firstly, the patterns and time series o...

Streamflow responses to the El Niño/Southern Oscillation (ENSO) phenomenon in the tropical Pacific are detectable in many regions. During warm-tropical El Niño and cool-tropical La Niña episodes, streamflows are affected throughout the Americas and Australia, in northern Europe, and in parts of Africa and Asia. In North and South America, correlations between peakflow season streamflows and sea...

Meningococcal meningitis is a major public health problem that kills thousands annually in Africa, Europe, North, and South America. Occurrence is, however, highest during the dry seasons in Sahel Africa. Interannual changes in precipitation correlate with interannual changes in El Niño-Southern Oscillation (ENSO), while interdecadal changes in precipitation correlate with Pacific Decadal Oscil...