Tropical easterly jet located using TOMS data

The formative stages of the onset of the 1979 southwest monsoon was marked by a WNW-ESE oriented band of marine convection over the South Arabian Sea. This convection was first observed on June 10, 1979 using satellite cloud imagery. The marine convection appeared during a major acceleration of the upper troposphere easterly wind field. A composite vertical meridional cross-section of upper level winds for June 11, revealed the core of the Tropical Easterly Jet (TEJ) at 115 mb, 9.5 deg N. Time analysis of the upper level wind field over the Tropical Wind Observing Ship (TWOS) polygon show a lowering of both the pressure level of maximum wind and tropopause level with acceleration of the upper level easterlies. The tropopause was as much as 20 mb lower on the equatorial side of the TEJ. Streamline analysis of the maximum observed easterly winds over India did not reveal the horizontal position of the TEJ. Careful analysis of Total Ozone Mapping Spectrometer (TOMS) data for June 11, 1979 showed relatively high values of ozone south of India. It was observed that the latitudinal position of the TEJ on June 11, at approximately 70 deg E coincided with the northern edge of relatively high ozone values. Using this as a reference, the TEJ core was identified as far as NE Bay of Bengal (the limits of the available TOMS data)

A simple calculation of the sea level trajectories over the Indian Ocean

Quasi-horizontal, 48-hr air trajectories are constructed over the Indian Ocean utilizing a mean sea level map for July and a series of daily maps in June 1970. The purpose of this calculation is to provide a field of trajectories based on the broad scale pressure gradient. Special emphasis is placed on those trajectories associated with the East African jet, the southern equatorial trough and the monsoon trough.&#x0D; Results included in this article showed that reasonably representative trajectories were calculated. Furthermore, the derived vorticity and divergence fields (not shown here) showed fair association with the significant synoptic features.</jats:p