Record Details
Buoy and satellite observation of wind induced surface heat exchange in the intraseasonal oscillation over West Pacific and Indian Ocean
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Buoy and satellite observation of wind induced surface heat exchange in the intraseasonal oscillation over West Pacific and Indian Ocean |
| Names |
Araligidad, Nilesh
(creator) Maloney, Eric (advisor) |
| Date Issued | 2007-09-20T23:13:05Z (iso8601) |
| Internet Media Type | application/pdf |
| Note | Graduation date: 2008 |
| Abstract | The importance of wind-driven latent heat fluxes for supporting tropical intraseasonal precipitation variability is analyzed. Tropical intraseasonal variability in the west pacific and Indian ocean is analyzed for northern and southern hemisphere summer during 1999-2005 using satellite and buoy observations. A composite analysis of QuikSCAT ocean vector winds and TRMM precipitation for the intraseasonal oscillation (ISO) indicate that enhanced precipitation is associated with anomalous surface westerly flow over the west Pacific and the Indian oceans. Anomalous westerly flow associated with the ISO is also accompanied by enhanced wind speed over the west Pacific and Indian ocean. Enhanced wind speed during westerly phases in the west Pacific and Indian oceans suggests an increase in the wind-driven component of latent heat flux. An analysis using TAO buoys and TRMM precipitation shows a significant correlation between intraseasonal (30-100 day) latent heat flux and TRMM precipitation in the region where enhanced precipitation occurs during the ISO westerly phase. Latent heat flux anomalies are about 20% of precipitation anomalies, a magnitude approximately sufficient as suggested by previous studies to support a flux-driven convective instability. The correlation of QuikSCAT wind speed and TRMM precipitation was analyzed over the west Pacific and it also showed a correlation of similar magnitude as the correlation of latent heat flux and precipitation. As a sensitivity test to determine how much of the latent heat flux anomalies were wind-driven, latent heat flux anomalies were recalculated at the location of strong correlation by fixing SST, boundary layer relative humidity, and boundary layer temperature to their sixty days running averages. This sensitivity analysis shows that most of the latent heat flux anomaly is wind-driven, indicating that intraseasonal precipitation may be supported by a wind-evaporation feedback mechanism. Wind speed and precipitation anomalies also show a significant correlation in the Indian ocean. This result suggests that if latent heat flux anomalies in the Indian ocean are primarily wind-driven, then a wind-evaporation feedback mechanism may also be supported there. |
| Genre | Thesis |
| Topic | Intraseasonal Oscillation |
| Identifier | http://hdl.handle.net/1957/6546 |
