Wednesday, 17 January 2007: 1:45 PM
Roles of the MJO in the development of Oceanic Kelvin waves and ENSO
214C (Henry B. Gonzalez Convention Center)
Intraseasonal Kelvin waves in the equatorial Pacific link weather events such as the Madden-Julian Oscillation (MJO) to climate variability associated with the El Niņo/Southern Oscillation (ENSO). These oceanic Kelvin waves may be responsible for much of the observed warming of the East Pacific during some periods of adjustment toward El Niņo. The MJO interacts with Kelvin waves in the equatorial Pacific in a manner that changes with the phase of ENSO. The details of the relationships of these waves to the MJO and to El Niņo are still being debated. Data obtained from the Tropical Atmosphere Ocean (TAO) array of buoys moored in the tropical Pacific have been applied to study these relationships, but since these data are sparse prior to 1990, their application to the study of relationships between Kelvin waves and ENSO is difficult. However, Kelvin wave signals are also found in daily sea level data from island and coastal sites. Sea level data are available from some sites since before 1970. This presentation will describe the reconstruction of an Oceanic Kelvin wave dataset based on regression relationships between the TAO dynamic height data and the sea level data. This reconstruction will then be applied to show how the patterns of wind stress associated with Kelvin waves differ between periods of strong trends toward and away from El Niņo conditions.