Geoscience Reference
In-Depth Information
Figure 9.11
(A) Cross-sectional
model of a depression with ana-fronts,
where the air is rising relative to each
frontal surface. Note that an ana-
warm front may occur with a kata-cold
front and vice versa. J
U
and J
L
show the
locations of the upper and lower jet
streams, respectively. (B) Model of
a depression with kata-fronts, where
the air is sinking relative to each frontal
surface.
Sources
: After Pedgley (1962), and
Bennetts
et al
. (1988). Crown copyright
©, reproduced by permission of the
Controller of Her Majesty's Stationery
Office.
Figure 9.12
Model of the large-scale flow and mesoscale
precipitation structure of a partially occluded depression typical of
those affecting the British Isles. It shows the 'conveyor belt' (A)
rising from 900 mb ahead of the cold front over the warm front.
This is overlaid by a mid-tropospheric flow (B) of potentially colder
air from behind the cold front. (C) indicates air subsiding ahead
of the occluded front. Most of the precipitation occurs in the
well-defined region shown, within which it exhibits a cellular and
banded structure.
Source
: After Harrold (1973), by permission of the Royal
Meteorological Society.
