Convective Wakes in the Equatorial Western Pacific during TOGA

Abstract

The evolution of convective wakes was studied using composite time series calculated from data collected in the western Pacific warm pool during a pilot cruise and intensive observation period (IOP) of the Tropical Ocean Global Atmosphere (TOGA) Coupled Ocean-Atmosphere Response Experiment (COARE). Hourly averaged observations from 42 convective wakes were used to compute wake-relative composite time series of the bulk meteorological variables, as well as sensible and latent heat fluxes. These analyses show great similarities between the convective wake characteristics of the pilot cruise and the IOP, despite differences in season and location. This result, combined with a strong correlation between individual wakes and the composite time series, demonstrates the representativeness of the composites.TOGA convective wakes were found to cause a significant decrease in air temperature, a significant increase in wind speed, and thus significant increases in sensible and latent heat fluxes, which is similar to GATE results. Decreases in sea surface temperature mixing ratio in the atmospheric surface layer, and sea surface saturation mixing ratio were also observed to accompany the convective wakes; the bulk transfer coefficients, in contrast, were found to remain nearly constant.