Geoscience Reference
In-Depth Information
Fig. 3.6
Typical surface pressure pattern and vertical structure of a convective system. The top shows the case
of weak and the bottom the case of sharp pressure gradients, in association with rear-inflow jets that
proceed forward toward the leading convective line or are blocked, respectively. (From Johnson, 2001.)
accompanied by brief and sudden wind storms or “squalls,” and tend to occur along sharp
cold fronts. Mesoscale convective complexes are a major mechanism for the production
of heavy precipitation at the midlatitudes during the warmer seasons of the year (Maddox,
1980; Fritsch
et al.
, 1986; Houze
et al.
, 1989).
3.2.3
Seasonal tropical systems
These systems occur in the zone of convergence of the northerly and southerly trade
winds and as wave-like structures in the zone between the subtropical high-pressure
belts and the Equator; they are mostly responsible for the well-known tropical rainfall
and the abundant natural vegetation in those regions. They typically produce deep cloud
clusters and, intermittent with fair weather, heavy precipitation of the convective type.
These systems tend to have a seasonal character, as they follow the sun between the two
tropics.
