25th Conference on Hurricanes and Tropical Meteorology

Friday, 3 May 2002: 9:30 AM
Surface heat fluxes during the MJO and their effects on the oceanic mixed layer in the Tropical Eastern Hemisphere.
Crispian P. Batstone, Univ. of East Anglia, Norwich, United Kingdom; and A. J. Matthews and D. P. Stevens
Poster PDF (639.1 kB)
Intraseasonally varying surface heat fluxes associated with the Madden-Julian Oscillation (MJO) during boreal winter and their spatial and temporal relationships with concomitant Sea Surface Temperature (SST) anomalies are investigated over a larger domain than has previously been examined. Due to the air-sea interaction nature of these processes the MJO is defined by the combined principal component analysis of surface fields, namely zonal and meridional wind and SST. Throughout the propagation path of the MJO, increased shortwave radiation (SWR) is largely in quadrature with increased SST, which in turn is in quadrature with enhanced convection, indicating the possibility of a two-way self sustaining mechanism for the MJO. The structure of the MJO in surface latent heat flux is dependent on the climatological surface winds. These reverse direction in the Eastern Indian Ocean, so that large scale surface wind anomalies superimposed lead to a dipole structure in the heat flux. This structure, when considered with the accompanying SWR anomaly, may lead to the apparent standing oscillation observed in the MJO SST composite in this region. A 1D ocean model was forced at each grid point with the composite heat fluxes. The results will be compared with the results of the analysis.

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