Australia: The Land Where Time Began

A biography of the Australian continent 

Wyrtki jets in the Autumn - Impact of Tropical Cyclones on Intensity and Phase Propagation

This paper reports the study of the impacts of tropical cyclones on the autumn Wyrtki jets by the use of observations and model simulation. Peaking in November, these strong, narrow equatorial currents haven a vital role in the transport of energy and mass in the tropical Indian Ocean (TIO). During November the maximum number of tropical cyclones are observed with life spans that are longer than usual, 8-15 days. The equatorial surface westerly winds are enhanced by these tropical cyclones and the monthly mean Wyrtki jets are enhanced, both surface and subsurface, by 0.4 ms^-1, during tropical cyclones anomalies exceed 0.7 ms-¹, about half the climatological amplitude. The heat continent of the eastern tropical Indian Ocean is increased by the intensity of the Wyrtki jets and they modulate air-sea interaction. It is also shown that the westwards phase propagation of the Wyrtki jets, which is a previously unexplored mechanism, are mainly caused by the movement of tropical cyclones.  These features have also present in the ECCO2 simulation.

Sources & Further reading

Sreenivas, P., J. S. Chowdary, and C. Gnanaseelan. "Impact of Tropical Cyclones on the Intensity and Phase Propagation of Fall Wyrtki Jets." Geophysical Research Letters 39, no. 22 (2012): L22603.