Geoscience Reference
In-Depth Information
130
o
120
o
140
o
150
o
0
o
0
500
1000
km
10
o
20
o
30
o
limited rainfall (>50 mm)
winter rainfall (>250 mm)
40
o
summer rainfall (>400 mm)
uniform rainfall (>250 mm)
cold sub-surface current
warm ocean current
cold current with
ephemeral upwelling
rainfall > 3500mm in New Guinea
rainfall < 1000mm in New Guinea
Figure 22.3. Present-day precipitation zones of Australia and surrounding region and
major ocean currents. (After Williams et al.,
2009b
.)
summer and a warm, dry winter. The Intertropical Convergence Zone (ITCZ) lies just
north of Australia in January and moves south over tropical Australia in February,
which is the peak of the northern Australian wet season (
Chapter 2
;
Figure 2.2
). In
the far north of Australia, the wet season lasts from November to April and the dry
season lasts from May to October, when the land is effectively a desert. In north-east
Australia, the summer rains are associated with the southward passage of the ITCZ
and with humid easterlies (Gentilli,
1971
; Gentilli,
1977
; Linacre and Hobbs,
1977
;
Sturman and Tapper,
1996
; Wang,
2006
). Rainfall is increased by tropical summer
