In an " unstable " atmosphere, vertical air movements ( such as in orographic lifting, where an air mass is displaced upwards as it is blown by wind up the rising slope of a mountain range ) tend to become larger, resulting in turbulent airflow and convective activity.
42.
It is generally believed that a delay in the onset of the rains caused by El Nino exacerbated the haze phenomenon, but Yong speculated that the reverse might also be true-- the haze could have blocked convective activity which causes rain to fall-- forming a kind of vicious circle.
43.
These physical types, in approximate ascending order of convective activity, include " stratiform " sheets, " cirriform " wisps and patches, " stratocumuliform " layers ( mainly structured as rolls, ripples, and patches ), " cumuliform " heaps and tufts, and very large " cumulonimbiform " heaps that often show complex structure.
44.
With maximum winds dropping below 70 mph ( 110 km / h ), Otto was reduced to a tropical storm late on October 9 . Convective activity came to a near halt due to relentless wind shear and a lack of tropical moisture, leading specialists to conclude the storm was entering an frontal banding features.
