Climatological study of atmospheric stability over Saudi Arabia

Abstract EN

The atmospheric stability in midseason months (January, April, July and October) over the Kingdom of Saudi Arabia (KSA) has been studied using the average global data for the period 1960-2002.

Generally, it was found that the areas of low static stability are situated in the areas of cyclones or troughs and in the area of largest frequency of disturbances occurrence.

In the transitional seasons (springs and autumns), the area of Arabian Peninsula and south west Red Sea shows significant low static stability throughout the troposphere up to 500 hPa.

In the lowest layer (surface–850 hPa).

It is associated with large baroclinicity with maximum heating, what seems to be a favorable condition for cyclonic disturbances and development in the western Arabian Gulf.

The appearance of very low static stability over central and south west Red Sea at the same periods (April–October) in the lower layers, seems to be a cause of the simultaneous amplification of the easterly Sudan monsoon wave.

This leads to the conclusion that the development over the Arabian Peninsula and Gulf area is due to the interaction between the tropical and extratropical disturbances.

The low static stability is a very essential factor especially for development of the small scale systems, such as the desert depressions and the formation of convective clouds.